High-temperature-resistant self-adhesive modified polycarbonate material and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant self-adhesive modified polycarbonate material which is prepared from the following components: polycarbonate resin, a silane coupling agent, liquid silicone rubber, methyl silicone oil, hydroxyl silicone oil, a filling agent, an antioxidant and a lubricating agent. The invention also provides a preparation method of the high-temperature-resistant self-adhesive modified polycarbonate material. Through the mode, the high-temperature-resistant self-adhesive modified polycarbonate material provided by the invention has higher viscosity with common silica gel, is suitable for integrated molding processes such as double-color injection and the like, greatly shortens the molding time, greatly reduces the production cost, and has a very good popularization value in the fields of medical instruments, automobile parts and the like.

Description

Technical Field

[0001] The invention relates to the technical field of polymer material modification, in particular to a high-temperature resistant self-adhesive modified polycarbonate material and a preparation method thereof. Background Art

[0002] Polycarbonate (PC) has a wide range of uses in automobile transportation, curtain wall construction, medical equipment, military equipment, aerospace and other fields due to its excellent impact resistance, high mechanical strength, high heat resistance, high light transmittance, creep resistance, weather resistance and good product stability.

[0003] In the above applications, polycarbonate usually needs to be used in combination with other soft plastics, such as elastomers, silicone, etc. However, the adhesion between ordinary polycarbonate and silicone is poor, so in most cases, adhesives are needed to increase the adhesion between the two. This method, on the one hand, adds a process, increases the difficulty of the integrated molding process, prolongs the molding cycle time, and reduces production efficiency, and on the other hand, increases time and product manufacturing costs.

[0004] In view of the above situation, the existing technology is to modify the silicone to make it self-adhesive and without the need for an additional adhesive layer, so that it has good adhesion with polycarbonate. However, the price of self-adhesive silicone on the market is expensive, more than twice that of non-self-adhesive silicone, which seriously limits its application and promotion. Summary of the invention

[0005] The main technical problem solved by the present invention is to take a different approach and develop a high-temperature resistant self-adhesive modified polycarbonate material, which greatly reduces the cost of raw materials, has strong bonding strength, can use a two-color injection molding process, and greatly shortens the product molding cycle. It can be promoted for use in the fields of medical devices, automotive parts, etc.

[0006] To solve the above technical problems, a technical solution adopted by the present invention is: to provide a high temperature resistant self-adhesive modified polycarbonate material, which is composed of the following components: polycarbonate resin, silane coupling agent, liquid silicone rubber, methyl silicone oil, hydroxy silicone oil, filler, antioxidant and lubricant.

[0007] Preferably, the mass percentages of the above components are as follows: 80% to 90% polycarbonate resin, 1% to 5% silane coupling agent, 1% to 5% liquid silicone rubber, 1% to 5% methyl silicone oil, 0.2% to 1% hydroxy silicone oil, 5% to 15% filler, 0.5% to 1% antioxidant and 0.5% to 2% lubricant.

[0008] Preferably, the polycarbonate resin is a high temperature resistant polycarbonate resin having an aromatic ring or aromatic heterocyclic structure and a weight average molecular weight Mw of 15000 g.mol-1 ~100000g.mol -1 The polycarbonate polymer between.

[0009] Preferably, the silane coupling agent is selected from one or more of vinyltriethoxysilane, vinyltrimethoxysilane and vinylmethoxyethoxysilane.

[0010] Preferably, the liquid silicone rubber is selected as a single-component or two-component liquid silicone rubber.

[0011] Preferably, the hydroxy silicone oil is selected as low-polymerization-degree terminal hydroxyl polydimethylsiloxane.

[0012] Preferably, the filler is selected to be precipitated silica or fumed silica.

[0013] In order to solve the above technical problems, another technical solution adopted by the present invention is: to provide a method for preparing a high temperature resistant self-adhesive modified polycarbonate material, the preparation method comprising the following steps:

[0014] (1) Weighing the components and mass fractions, putting the weighed liquid silicone rubber, silane coupling agent and hydroxy silicone oil into a vacuum kneader for kneading, and repeatedly kneading until the mixture is uniform and has no variegated color, and the surface of the material is fine and uniform without obvious granular or striped protrusions;

[0015] (2) Add the weighed filler into a vacuum kneader, knead and mix repeatedly until the raw materials are evenly mixed into a mass;

[0016] (3) After the raw materials are mixed into a mass, they are heat treated by steam at a certain temperature, and methyl silicone oil is added during the cooling process. After cooling, they are crushed and sheared into uniform small particles to obtain silica gel particles;

[0017] (4) mixing the silica gel particles obtained in step (3) above, the weighed polycarbonate resin, the antioxidant and the lubricant uniformly in a mixer;

[0018] (5) adding the mixed materials into a co-rotating twin-screw extruder, and melt-extrude and blend the components in the formula in proportion in the screw extruder, the screw temperature is 280° C. to 350° C., and the extruded material strips are pulled through water for cooling and then pelletized by a pelletizer to obtain high-temperature resistant self-adhesive modified polycarbonate pellets.

[0019] Preferably, the filler in the above step (2) is added twice, specifically, the weighed filler is evenly divided into two parts, one of which is put into a vacuum kneader, and kneaded and mixed repeatedly until the surface of the material is fine and uniform without obvious granular or stripe-like protrusions; the raw materials are mixed into a mass, and then white carbon black is added for the second time and mixed evenly, and the surface of the material is fine and uniform without obvious granular or stripe-like protrusions.

[0020] Preferably, the heat treatment process in step (3) is as follows: turn on nitrogen protection, heat to a temperature of 160°C to 170°C by steam, and keep the temperature constant for 1.5 to 2.5 hours; then turn off the steam heating, cool down, add methyl silicone oil in proportion during the cooling process, stir for about 1 hour, discharge the material when the temperature drops to 60°C to 80°C, filter with a rubber filter press, and wait for the rubber material to cool to room temperature.

[0021] The beneficial effects of the present invention are:

[0022] The present invention aims at the technical drawbacks existing in the prior art, and finally obtains a polycarbonate material with good comprehensive performance, high temperature resistance and self-adhesiveness through in-depth research and development of formula components, component selection, component content, preparation process and other solutions. The self-adhesive polycarbonate provided by the present invention gives the material self-adhesiveness, which, on the one hand, enables it to be closely attached to other materials without the need for additional adhesives, greatly improving production efficiency and product performance; on the other hand, the self-adhesive polycarbonate of the present invention retains the high transparency and high strength characteristics of the polycarbonate itself, ensuring the clarity of the display effect, and is suitable for certain application scenarios requiring high transparency; and the self-adhesive polycarbonate of the present invention has high heat resistance, can maintain stable performance in a high temperature environment, and is suitable for application scenarios requiring high temperature resistance;

[0023] Based on the above characteristics, the high-temperature resistant self-adhesive polycarbonate provided by the present invention is widely used in multiple fields, including electronic products, automobile industry, etc.; in the field of electronic products: such as protective films of touch panels such as mobile phone screens and tablet computers, self-adhesive polycarbonate can ensure the clarity of the display effect, and achieve close fit with the touch panel, thereby improving user experience; in the field of automobile industry: self-adhesive polycarbonate is used to manufacture vehicle body films, window glass and other components, which can effectively protect the vehicle body from scratches and impact damage, while improving the explosion-proof performance of window glass; therefore, the high-temperature resistant self-adhesive polycarbonate material and the preparation method thereof provided by the present invention have very good technical promotion value and market promotion value. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0025] Embodiment 1:

[0026] The components and mass percentages are as follows:

[0027] High temperature resistant polycarbonate resin 90%; vinyl triethoxysilane 1%; two-component liquid silicone rubber 1%; methyl silicone oil 1%; terminal hydroxyl polydimethylsiloxane 0.2%; fumed silica 5%; antioxidant 0.8%; lubricant 1%.

[0028] The preparation method is as follows:

[0029] (1) Weighing the components and mass fractions, putting the weighed two-component liquid silicone rubber, vinyl triethoxysilane and terminal hydroxyl polydimethylsiloxane into a vacuum kneader for kneading, and repeatedly kneading until the mixture is uniform and has no variegated color, and the surface of the material is fine and uniform without obvious granular or striped protrusions;

[0030] (2) Divide the weighed fumed silica into two equal parts, put one part into a vacuum kneader, and knead and mix repeatedly until the surface of the material is fine and uniform without obvious granular or stripe-like protrusions; mix the raw materials into a mass, and then add the fumed silica for the second time, mix evenly, and likewise until the surface of the material is fine and uniform without obvious granular or stripe-like protrusions;

[0031] (3) After the raw materials are mixed into a mass, nitrogen is turned on for protection, and the temperature is heated to 160° C. by steam, and the temperature is kept constant for 2.0 hours; then the steam heating is turned off, and the temperature is lowered. During the cooling process, methyl silicone oil is added in proportion, and stirred for about 1 hour. When the temperature drops to 70° C., the material is discharged, filtered with a rubber filter press, and the rubber material is cooled to room temperature. After cooling, it is crushed and sheared into uniform small particles to obtain silica gel particles;

[0032] (4) mixing the silica gel particles obtained in step (3) above, the weighed high temperature resistant polycarbonate resin, the antioxidant and the lubricant uniformly in a mixer;

[0033] (5) The mixed materials are added into a co-rotating twin-screw extruder, and the components in the formula are melt-extruded and blended in the screw extruder according to the proportion. The screw temperature is 310° C. The extruded material strips are pulled through water for cooling and then pelletized by a pelletizer to obtain high-temperature resistant self-adhesive modified polycarbonate pellets.

[0034] Embodiment 2:

[0035] The components and mass percentages are as follows:

[0036] High temperature resistant polycarbonate resin 80%; vinyl trimethoxy silane 5%; one-component liquid silicone rubber 4%; methyl silicone oil 4%; terminal hydroxyl polydimethylsiloxane 1%; precipitated silica 5%; antioxidant 0.5%; lubricant 0.5%.

[0037] The preparation method is as follows:

[0038] (1) Weighing the components and mass fractions, putting the weighed single-component liquid silicone rubber, vinyl trimethoxysilane and terminal hydroxyl polydimethylsiloxane into a vacuum kneader for kneading, and repeatedly kneading until the mixture is uniform and has no variegated color, and the surface of the material is fine and uniform without obvious granular or striped protrusions;

[0039] (2) The weighed precipitated silica is divided into two parts, one of which is put into a vacuum kneader, and kneaded and mixed repeatedly until the surface of the material is fine and uniform without obvious granular or stripe-like protrusions; the raw materials are mixed into a mass, and then the fumed silica is added for the second time and mixed evenly, and the surface of the material is fine and uniform without obvious granular or stripe-like protrusions;

[0040] (3) After the raw materials are mixed into a mass, nitrogen is turned on for protection, and the temperature is heated to 170° C. by steam, and the temperature is kept constant for 2.0 hours; then the steam heating is turned off, and the temperature is lowered. During the cooling process, methyl silicone oil is added in proportion, and stirred for about 1 hour. When the temperature drops to 80° C., the material is discharged, filtered with a rubber filter press, and the rubber material is cooled to room temperature. After cooling, it is crushed and sheared into uniform small particles to obtain silica gel particles;

[0041] (4) mixing the silica gel particles obtained in step (3) above, the weighed high temperature resistant polycarbonate resin, the antioxidant and the lubricant uniformly in a mixer;

[0042] (5) The mixed materials are added into a co-rotating twin-screw extruder, and the components in the formula are melt-extruded and blended in the screw extruder according to the proportion. The screw temperature is 290° C. The extruded material strips are pulled through water for cooling and then pelletized by a pelletizer to obtain high-temperature resistant self-adhesive modified polycarbonate pellets.

[0043] Embodiment 3:

[0044] The components and mass percentages are as follows:

[0045] High temperature resistant polycarbonate resin 85%; vinyl methoxyethoxy silane 2.5%; one-component liquid silicone rubber 2.5%; methyl silicone oil 1%; terminal hydroxyl polydimethylsiloxane 0.5%; precipitated silica 7.5%; antioxidant 0.5%; lubricant 0.5%.

[0046] The preparation method is as follows:

[0047] (1) Weighing the components and mass fractions, putting the weighed single-component liquid silicone rubber, vinyl trimethoxysilane and terminal hydroxyl polydimethylsiloxane into a vacuum kneader for kneading, and repeatedly kneading until the mixture is uniform and has no variegated color, and the surface of the material is fine and uniform without obvious granular or striped protrusions;

[0048] (2) The weighed precipitated silica is divided into two parts, one of which is put into a vacuum kneader, and kneaded and mixed repeatedly until the surface of the material is fine and uniform without obvious granular or stripe-like protrusions; the raw materials are mixed into a mass, and then the fumed silica is added for the second time and mixed evenly, and the surface of the material is fine and uniform without obvious granular or stripe-like protrusions;

[0049] (3) After the raw materials are mixed into a mass, nitrogen is turned on for protection, and the temperature is heated to 165° C. by steam, and the temperature is kept constant for 1.5 hours; then the steam heating is turned off, and the temperature is lowered. During the cooling process, methyl silicone oil is added in proportion, and stirred for about 1 hour. When the temperature drops to 70° C., the material is discharged, filtered with a rubber filter press, and the rubber material is cooled to room temperature. After cooling, it is crushed and sheared into uniform small particles to obtain silica gel particles;

[0050] (4) mixing the silica gel particles obtained in step (3) above, the weighed high temperature resistant polycarbonate resin, the antioxidant and the lubricant uniformly in a mixer;

[0051] (5) The mixed materials are added into a co-rotating twin-screw extruder, and the components in the formula are melt-extruded and blended in the screw extruder according to the proportion. The screw temperature is 300° C. The extruded material strips are pulled through water for cooling and then pelletized by a pelletizer to obtain high-temperature resistant self-adhesive modified polycarbonate pellets.

[0052] The high temperature resistant self-adhesive modified polycarbonate pellets obtained in the above Examples 1, 2 and 3, and two non-self-adhesive ordinary PCs were randomly selected as Comparative Examples 1 and 2, and the bonding failure of polycarbonate and silicone was measured according to GB / T 7760-2003. The failure is generally material failure or interface failure; interface failure indicates weak bonding, and material failure (cohesive failure) indicates strong bonding; in addition, the Vicat softening temperature was tested under the same conditions, and the test results are as follows:

[0053] Table 1 Bond failure of polycarbonate and silicone

[0054] PC Type Silicone Type Bond failure Vicat softening temperature Example 1 High temperature resistant self-adhesive PC Ordinary silicone 80% cohesive failure 176℃ Example 2 High temperature resistant self-adhesive PC Ordinary silicone 100% cohesive failure 168℃ Example 3 High temperature resistant self-adhesive PC Ordinary silicone 90% cohesive failure 173℃ Comparative Example 1 Ordinary PC Ordinary silicone Interface damage 180℃ Comparative Example 2 Ordinary PC Self-adhesive silicone 100% cohesive failure 180℃

[0055] From the above Table 1 we can see that:

[0056] 1. The bonding failure of Examples 1, 2, and 3 of the present invention all reached more than 80% of the cohesive failure, indicating that the bonding performance with ordinary silicone is good;

[0057] 2. Comparative Example 1 shows that the bonding failure between ordinary PC and ordinary silicone is interface failure, indicating that the bonding force between the two is very poor;

[0058] 3. Comparative Example 2 shows that the bonding failure between ordinary PC and self-adhesive silicone is 100% cohesive failure, indicating that the bonding between the two is very good, but as described in the background technology, the cost of self-adhesive silicone is relatively high;

[0059] 4. The thermal stability and heat resistance of the high temperature resistant self-adhesive modified polycarbonate pellets prepared according to the present invention are comparable to those of ordinary PC, without significant reduction.

[0060] Therefore, according to the needs of the final product, the present invention can use the high-temperature resistant self-adhesive polycarbonate resin of the present invention and ordinary silicone to obtain the final product through a two-color injection integrated molding process; the high-temperature resistant self-adhesive polycarbonate material developed by the present invention is firmly bonded to ordinary silicone, and the cost of raw materials is greatly reduced, which overcomes the high cost disadvantage of modifying silicone to have self-adhesiveness in the prior art, and the idea is innovative.

[0061] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A high temperature resistant self-adhesive modified polycarbonate material, characterized in that: The invention is composed of the following components: polycarbonate resin, silane coupling agent, liquid silicone rubber, methyl silicone oil, hydroxy silicone oil, filler, antioxidant and lubricant.

2. The high temperature resistant self-adhesive modified polycarbonate material according to claim 1, characterized in that: The mass percentages of the above components are as follows: 80% to 90% polycarbonate resin, 1% to 5% silane coupling agent, 1% to 5% liquid silicone rubber, 1% to 5% methyl silicone oil, 0.2% to 1% hydroxy silicone oil, 5% to 15% filler, 0.5% to 1% antioxidant and 0.5% to 2% lubricant.

3. The high temperature resistant self-adhesive modified polycarbonate material according to claim 1, characterized in that: The polycarbonate resin is a high temperature resistant polycarbonate resin having an aromatic ring or aromatic heterocyclic structure and a weight average molecular weight Mw of 15000 g.mol -1 ~100000g.mol -1 The polycarbonate polymer between.

4. The high temperature resistant self-adhesive modified polycarbonate material according to claim 1, characterized in that: The silane coupling agent is selected from one or more of vinyl triethoxy silane, vinyl trimethoxy silane and vinyl methoxyethoxy silane.

5. The high temperature resistant self-adhesive modified polycarbonate material according to claim 1, characterized in that: The liquid silicone rubber is selected to be a single-component or two-component liquid silicone rubber.

6. The high temperature resistant self-adhesive modified polycarbonate material according to claim 1, characterized in that: The hydroxy silicone oil is selected to be low-polymerization-degree terminal hydroxyl polydimethylsiloxane.

7. The high temperature resistant self-adhesive modified polycarbonate material according to claim 1, characterized in that: The filler is selected from precipitated silica or fumed silica.

8. A method for preparing a high temperature resistant self-adhesive modified polycarbonate material according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: (1) Weighing the components and mass fractions, putting the weighed liquid silicone rubber, silane coupling agent and hydroxy silicone oil into a vacuum kneader for kneading, and repeatedly kneading until the mixture is uniform and has no variegated color, and the surface of the material is fine and uniform without obvious granular or striped protrusions; (2) Add the weighed filler into a vacuum kneader, knead and mix repeatedly until the raw materials are evenly mixed into a mass; (3) After the raw materials are mixed into a mass, they are heat treated by steam at a certain temperature, and methyl silicone oil is added during the cooling process. After cooling, they are crushed and sheared into uniform small particles to obtain silica gel particles; (4) mixing the silica gel particles obtained in step (3) above, the weighed polycarbonate resin, the antioxidant and the lubricant uniformly in a mixer; (5) adding the mixed materials into a co-rotating twin-screw extruder, and melt-extrude and blend the components in the formula in proportion in the screw extruder, the screw temperature is 280° C. to 350° C., and the extruded material strips are pulled through water for cooling and then pelletized by a pelletizer to obtain high-temperature resistant self-adhesive modified polycarbonate pellets.

9. The method for preparing a high temperature resistant self-adhesive modified polycarbonate material according to claim 8, characterized in that: In the above step (2), the filler is added twice. Specifically, the weighed filler is evenly divided into two parts, one of which is put into a vacuum kneading machine, and kneaded and mixed repeatedly until the surface of the material is fine and uniform without obvious granular or stripe-like protrusions; the raw materials are mixed into a mass, and then white carbon black is added for the second time and mixed evenly, and the surface of the material is fine and uniform without obvious granular or stripe-like protrusions.

10. The method for preparing a high temperature resistant self-adhesive modified polycarbonate material according to claim 8, characterized in that: The heat treatment process of step (3) above is selected as follows: turn on nitrogen protection, heat to a temperature of 160°C to 170°C by steam, and keep the temperature constant for 1.5 to 2.5 hours; then turn off the steam heating, cool down, add methyl silicone oil in proportion during the cooling process, stir for about 1 hour, discharge the material when the temperature drops to 60°C to 80°C, filter it with a rubber filter press, and wait for the rubber material to cool to room temperature.