CN113831716A

CN113831716A - Flame-retardant polycarbonate material with high metal texture and preparation method thereof

Info

Publication number: CN113831716A
Application number: CN202111174708.5A
Authority: CN
Inventors: 缪正坤; 刘朋; 缪策; 田国华; 林丽娟; 王东
Original assignee: Jiangsu Institute of Architectural Technology
Current assignee: Jiangsu Institute of Architectural Technology
Priority date: 2021-10-09
Filing date: 2021-10-09
Publication date: 2021-12-24

Abstract

The application provides a flame-retardant polycarbonate PC material with high metal texture and a preparation method thereof. Relates to the technical field of high polymer materials. The transparent halogen-containing flame retardant can be used, and the pc material with high metal texture can be prepared by mixing the metal pigment, the pc and the auxiliary agent. During the preparation process, the metal pigment is modified and is melted with the polycarbonate, the transparent halogen-containing flame retardant and the mixture of the additives in stages, so that the PC material with high metal texture and good stability is prepared.

Description

Flame-retardant polycarbonate material with high metal texture and preparation method thereof

Technical Field

The application relates to the technical field of high polymer materials, in particular to a flame-retardant polycarbonate material with high metal texture and a preparation method thereof.

Background

With the increasing importance of people on environmental protection, spraying-free plastics are produced at the same time, and the spraying technology of plastics is gradually replaced in limited fields. At present, conventional engineering plastics, such as polypropylene (PP), Polycarbonate (PC), Acrylonitrile Butadiene Styrene (ABS), etc., have been used in the fields of home appliances, automobiles, etc. for coating-free projects.

Although PC resin as a common engineering plastic has a certain flame retardant property, the PC resin still cannot meet the project requirements, and in a common flame retardant scheme, except for the addition of a flame retardant, an anti-dripping agent needs to be added to meet the higher flame retardant requirement. The principle of the anti-dripping agent is that the anti-dripping agent is fiberized in a screw to form a net structure, so that the haze of the PC material is increased, and when the flame-retardant PC resin is used as a base material to be compounded with pearl powder, aluminum powder and the like to prepare a spraying-free material with high gloss and high metal texture, the surface of the material is often fogged, so that the final product is influenced. Therefore, in a spraying-free PC project with high flame retardant requirements, how to avoid the fogging of the PC material caused by the flame retardant function so as to fail to realize high metal texture, and how to subsequently improve the stability of the material and widen the window of injection molding processing is a difficult point of the spraying-free PC technology.

Disclosure of Invention

The application aims to overcome the difficulties that when the existing flame-retardant PC reaches the flame-retardant level of 1.0mm V0, a high-metal-texture material cannot be prepared by adding a metal pigment, the material stability is not increased, the injection molding process window is narrow, and the requirement on the structure of a workpiece is high, and provides a spraying-free flame-retardant PC material which can reach the flame-retardant level of 1.0mm V0, has high gloss, high metal texture and high processability, and a preparation method thereof.

Therefore, the invention aims to provide a flame-retardant polycarbonate PC material with high metal texture and a preparation method thereof, and the preparation of the PC material with high metal texture and good stability can be realized.

In order to achieve the above objects, in a first aspect, the present application provides a flame retardant polycarbonate PC material with high metallic texture, which mainly comprises polycarbonate, a transparent halogen-containing flame retardant, an auxiliary agent, and a metallic pigment.

Optionally or preferably, the polycarbonate, the transparent halogen-containing flame retardant, the auxiliary agent and the metallic pigment are contained in the following contents by mass percent: the polycarbonate: the transparent halogen-containing flame retardant: the auxiliary agent is as follows: the metal pigment accounts for 81-98.3%: 0.5-5%: 1-10%: 0.2 to 4 percent.

Alternatively or preferably, the halogen containing flame retardant in the transparent state is a bromotriazine.

Alternatively or preferably, the polycarbonate is compounded from two or three polycarbonates of different viscosities.

In a second aspect, the present application provides a method for preparing the flame retardant polycarbonate PC material with high metallic quality as provided in the first aspect, the method comprising:

carrying out surface hydroxylation treatment on the metal pigment with preset mass in a constant temperature and humidity box at 70-90 ℃ and 60-80 RH% for a first preset time;

adding a silane coupling agent aqueous solution with the concentration of 3% -7% into the treated metal pigment; stirring and reacting at the temperature of 60-90 ℃ for a second preset time;

grinding the stirred material containing the metal pigment into powder, treating the powder in a vacuum environment at 95 ℃ for a third preset time, and performing ball milling on the treated material containing the metal pigment to obtain a modified metal pigment;

mixing the modified metal pigment with a lubricant, uniformly mixing in a mixing bin, and treating in an oven at 80 ℃ for a fourth preset time;

mixing polycarbonate, a transparent halogen-containing flame retardant and an auxiliary agent according to a preset mass ratio to obtain a mixture;

feeding the mixture from a first feeding port of a double-screw extruder, melting the mixture, feeding the modified metal pigment from at least one second feeding port of the double-screw extruder, mixing the mixture with the mixture, and extruding and granulating the mixture.

Optionally or preferably, the method further comprises: in the stirring process of the treated metal pigment and the silane coupling agent, the pH value in the reaction process is controlled to be 8-10 by using an aqueous solution of ammonia, and the stirring speed is gradually increased from 50-100rpm to 300-500 rpm.

Alternatively or preferably, the modified metal pigment and the lubricant are in a mass ratio of: the modified metal pigment: the lubricant is 100: (0.5-5).

Alternatively or preferably, the polycarbonate, the halogen-containing flame retardant in a transparent state, the antioxidant and the metallic pigment consist of, in mass percent:

the polycarbonate: the transparent halogen-containing flame retardant: the auxiliary agent is as follows: the metal pigment accounts for 81-98.3%: 0.5-5%: 1-10%: 0.2 to 4 percent.

Optionally or preferably, the twin-screw extruder comprises ten sections of cylinders, the ten sections of cylinders are sequentially connected, the first feeding port is connected with a first section of cylinder in the ten sections of cylinders, the number of the second feeding ports is multiple, and each of a sixth section of cylinder to a ninth section of cylinder in the ten sections of cylinders is connected with one second feeding port.

Alternatively or preferably, the feeding of the modified metallic pigment from at least one second feeding port of the twin-screw extruder specifically comprises:

feeding the modified metal pigment with a first particle size into the sixth barrel from a second feeding port connected with the sixth barrel, feeding the modified metal pigment with a second particle size into the seventh barrel from a second feeding port connected with the seventh barrel, feeding the modified metal pigment with a third particle size into the eighth barrel from a second feeding port connected with the eighth barrel, and feeding the modified metal pigment with a fourth particle size into the ninth barrel from a second feeding port connected with the ninth barrel, wherein the first particle size is smaller than the second particle size, the second particle size is smaller than the third particle size, and the third particle size is smaller than the fourth particle size.

According to the flame-retardant polycarbonate PC material with high metal texture and the preparation method thereof, the transparent halogen-containing flame retardant, the metal pigment, the PC and the auxiliary agent are mixed to prepare the PC material with high metal texture. During the preparation process, the metal pigment is modified and is melted with the polycarbonate, the transparent halogen-containing flame retardant and the mixture of the additives in stages, so that the PC material with high metal texture and good stability is prepared.

Drawings

FIG. 1 is a schematic flow chart of a method for preparing a flame-retardant polycarbonate PC material with high metallic texture provided by an embodiment of the present application.

Detailed Description

In order to better understand the scheme of the application, the following detailed description is provided for the application with the accompanying drawings and the detailed description.

The terminology used in the following examples is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of this application and the appended claims, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, such as "one or more", unless the context clearly indicates otherwise. It should also be understood that in the following embodiments of the present application, "at least one", "one or more" means one or more than two (including two). The term "and/or" is used to describe an association relationship that associates objects, meaning that three relationships may exist; for example, a and/or B, may represent: a alone, both A and B, and B alone, where A, B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise. The term "coupled" includes both direct and indirect connections, unless otherwise noted.

In the following, the terms "first", "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as examples, illustrations or descriptions. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

The flame-retardant polycarbonate PC material with high metal texture provided by the application mainly comprises polycarbonate, a flame retardant, an auxiliary agent and a modified metal pigment. Of course, other materials may be included in the PC material. As shown in Table 1, the polycarbonate, the transparent halogen-containing flame retardant, the auxiliary agent and the metallic pigment comprise the following components in percentage by mass:

TABLE 1

The polycarbonate can be obtained by compounding one or more bisphenol A type polycarbonates. In order to ensure the physical properties (such as tensile property, impact resistance and the like) and processability of the flame-retardant PC material, the polycarbonate can be compounded by high-viscosity polycarbonate and low-viscosity polycarbonate or high-viscosity polycarbonate, medium-viscosity polycarbonate and low-viscosity polycarbonate. Wherein the melt index of the high-viscosity polycarbonate at 300 ℃ and 1.2kg is 1.2-5 g/10min, the melt index of the medium-viscosity polycarbonate at 300 ℃ and 1.2kg is 12-25 g/10min, and the melt index of the low-viscosity polycarbonate at 300 ℃ and 1.2kg is 50-80 g/10 min. In one example, in a compounding system of a high viscosity PC and a low viscosity PC, the ratio by mass of the high viscosity PC: low viscosity PC ═ 60 to 90: (40-10). In one example, in a compounding system of high-viscosity PC, medium-viscosity PC, and low-viscosity PC, the ratio by mass of high-viscosity PC: medium viscosity PC: low viscosity PC ═ 50-85: (30-10): (20-5).

The transparent halogen-containing flame retardant can be brominated triazine, and preferably, the bromine content is 60-70%. It can be understood that experiments show that the flame retardant PC material with high metal texture prepared by using the brominated triazine as the flame retardant has better transparency, gloss, haze and the like than other materials (such as phosphorus-containing materials and the like), so the brominated triazine is used as the flame retardant in the scheme. In addition, the halogen-containing flame retardant in a transparent state is utilized, so that the transparency of the PC material is not influenced in the using process, and a good basis is provided for the subsequent preparation of the PC material. In one example, the use of bromotriazine eliminates the need for the addition of an anti-drip agent, thereby avoiding the problem of the addition of an anti-drip agent that increases the haze of the polycarbonate. It can be understood that the flame-retardant scheme adopted by the scheme can be free of adding the anti-dripping agent, so that the defects of other flame retardant and anti-dripping agent schemes are avoided, and the spraying-free material with high metal texture can be prepared.

The auxiliary agent can be one or more of a toughening agent, a lubricant and an antioxidant. In one example, the toughening agent may be one or more of a methyl methacrylate-acrylate copolymer, an acrylate copolymer, a methyl methacrylate-butadiene-styrene copolymer, a methyl methacrylate-acrylate-silicone copolymer. In one example, the lubricant may be one or more of stearate, stearic acid, polyethylene wax, calcium stearate, zinc stearate, silicone powder. In one example, the antioxidant can be prepared by compounding a primary antioxidant and a secondary antioxidant (i.e., a secondary antioxidant), i.e., the antioxidant is a compound system of the primary antioxidant and the secondary antioxidant. Illustratively, the primary antioxidant may be one or more of hindered phenol antioxidants and aromatic amine antioxidants, and the secondary antioxidant may be one or more of phosphite antioxidants and thioester antioxidants.

The metallic pigment may be made of a metallic powder. In one example, the metal powder may be one or more of aluminum powder and copper powder. Illustratively, the aluminum element content in the aluminum powder is not less than 55 mass%, the shape of the aluminum powder may be one or more of flake, sphere, petal or silver, and the particle size of the aluminum powder may be 2-200 μm. Illustratively, the copper powder contains copper element not less than 65 wt%, and may be in the form of one or more of flake and ellipsoid, and may have a particle size of 10 to 300 μm.

In one example, the surface of the metallic pigment may be subjected to a modification treatment. For example, the surface modifier used to surface modify the metallic pigment may be a silane coupling agent. Wherein, the silane coupling agent can comprise one of gamma-glycidoxypropyltrimethoxysilane, isobutyl triethoxysilane coupling agent, vinyl triethoxysilane and vinyl trimethoxysilane, and preferably, the silane coupling agent is gamma-glycidoxypropyltrimethoxysilane.

Next, based on the flame retardant polycarbonate PC material with high metallic quality described above, a method for preparing the flame retardant polycarbonate PC material with high metallic quality provided in the examples of the present application will be described.

Exemplarily, fig. 1 shows a schematic flow chart of a method for preparing a flame retardant polycarbonate PC material with a high metallic texture. As shown in fig. 1, the method may include: firstly, in step 1, the metal pigment with preset mass can be subjected to surface hydroxylation treatment for 24 hours in a constant temperature and humidity chamber with the temperature of 70-90 ℃ and the RH percent of 60-80, so that the number of hydroxyl groups on the surface of the metal pigment is increased, and the grafting rate of the surface of the subsequent metal pigment is further increased.

Then, in step 2, 3-7% aqueous solution of silane coupling agent can be added into the treated metal pigment; and stirring and reacting for 6h at the temperature of 60-90 ℃ so as to ensure that the silane coupling agent and the hydroxyl on the surface of the metal pigment are fully reacted. Wherein the mass ratio of the metal pigment to the silane coupling agent is that the metal pigment: silane coupling agent ═ 1: (0.03-0.1).

Wherein, the PH value of the reaction system can be controlled to be 8-10 by using the aqueous solution of ammonia water during the stirring process, and the stirring speed is gradually increased from 50-100rpm to 300-500rpm, so as to promote the more sufficient reaction of the silane coupling agent and the hydroxyl on the surface of the metal pigment and improve the reaction efficiency.

Next, in step 3, the material obtained after stirring may be ground into powder, and subjected to a heating and vacuum-pumping treatment at 95 ℃ for a predetermined period of time (for example, 20 hours, etc.) to remove the silane physically adsorbed on the surface of the metal pigment. And then, ball milling can be carried out on the material obtained after treatment to obtain a submicron metal material, and the obtained metal material is the required modified metal pigment, so that the subsequent modified metal pigment can be well dispersed, and the metal texture of the PC material is improved. In one example, the surface graft ratio was (0.1 to 8)%, as measured by thermogravimetry, depending on the kinds of the metallic pigment and the silane coupling agent. In one example, other grinding methods than ball milling may be used, and the method is not limited herein. In one example, the metal pigments may be ball milled to different particle sizes to facilitate subsequent enhancement of the dispersion of the metal pigments.

Next, in step 4, the modified metal pigment may be mixed with a lubricant, and treated in an oven at 80 ℃ for 2-6 hours after being uniformly mixed in a mixing bin, so as to facilitate subsequent metal material dispersion, thereby improving the impact force of PC. Wherein the modified metal pigment and the lubricant are calculated according to the mass ratio as follows: lubricant 100: (0.5-5).

Next, in step 5, the polycarbonate, the transparent halogen-containing flame retardant, and the auxiliary agent may be mixed in a predetermined mass ratio to obtain a mixture. Wherein, the components can be weighed according to the mass percentage in the table 1, and the weighed polycarbonate, the transparent halogen-containing flame retardant and the auxiliary agent are mixed in a mixer for 5-10 minutes so as to be fully mixed.

Finally, in step 6, the mixture can be added into a double-screw extruder and melted, the treated modified metal pigment is fed from six to nine areas of the double-screw extruder in a side feeding mode and mixed with the mixture, and the mixture is extruded, pulled, cooled by a water tank and cut into particles, so that the high-metal-texture thin-wall flame-retardant PC material is obtained. Wherein, the double screw extruder has ten sections of barrels, and the temperature setting is respectively: the first section of the cylinder body is 220 ℃ and 240 ℃; the second section of the cylinder 240-265 ℃; the third section of the cylinder body 265-280 ℃; the fourth section of the cylinder 265 and 280 ℃; the fifth section of the cylinder 265 and 280 ℃ and the sixth section of the cylinder 265 and 280 ℃; the seventh section of the cylinder 265-280 ℃; the eighth section of the cylinder 265 plus 280 ℃; 280 ℃ for the ninth cylinder 265, 280 ℃ for the tenth cylinder 265, 295 ℃ for the head temperature 265, and 295 ℃ for the screw speed of the extruder, and the vacuum degree is not less than 0.09 MPa.

In one example, after being pelletized by the twin-screw extruder, the pelletized particles may be subjected to a heating and vacuum-pumping treatment at 80 ℃ in a vacuum environment for a predetermined time (e.g., 10 hours, etc.) to remove moisture from the particles. Thereafter, the particles obtained after the heating and vacuum-pumping treatment may be vacuum-packed. Thereby reducing the risk of silver wire and water splash in the subsequent injection molding process.

In one example, the twin screw extruder may include a plurality of feeding ports, one of which may be connected to the first barrel and used to feed the mixture, and each of the sixth through ninth barrels may be connected to one of the feeding ports and used to feed the modified metallic pigment.

In one example, a modified metal pigment of a first particle size can be fed to the sixth barrel, a modified metal pigment of a second particle size can be fed to the seventh barrel, a modified metal pigment of a third particle size can be fed to the eighth barrel, and a modified metal pigment of a fourth particle size can be fed to the ninth barrel, wherein the first particle size is less than the second particle size, the second particle size is less than the third particle size, and the third particle size is less than the fourth particle size. Therefore, the modified metal pigment with small particle size is fed firstly, and then the modified metal pigment with large particle size is fed, so that the dispersion degree of the modified metal pigment can be effectively improved, and the metal texture of the PC material can be improved. Illustratively, after obtaining the modified metallic pigment, screens of different mesh sizes may be used to obtain modified metallic pigments of different particle sizes. It is understood that the small-sized particles are easy to maintain the particle size during blending, but are prone to the problem of dispersion unevenness, and therefore need to be fed from the front to improve the dispersibility. Particles with large particle size are easy to disperse, but the shape is difficult to maintain after blending, so the particles are fed from the back to keep the original appearance as much as possible.

It can be understood that the modified metal pigment is fed from six to ten zones of the twin-screw extruder, so that the shape of the modified metal pigment can be kept as much as possible, the metal texture of the PC material is improved, and the phenomenon that the modified metal pigment is sheared too much to cause poor metal texture of the PC material due to early feeding is avoided.

In summary, the flame retardant polycarbonate PC material with high metallic quality and the preparation method thereof provided by the embodiment of the application use the transparent halogen-containing flame retardant, and mix the metal pigment with the PC and the auxiliary agent to prepare the PC material with high metallic quality. During the preparation process, the metal pigment is modified and is melted with the polycarbonate, the transparent halogen-containing flame retardant and the mixture of the additives in stages, so that the PC material with high metal texture and good stability is prepared.

The flame retardant polycarbonate material with high metallic texture and the preparation method thereof provided by the application are described in detail above. The principles and embodiments of the present application are explained herein using specific examples, which are merely set forth to aid in understanding the core concepts of the present application. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present application without departing from the principle of the present application, and such improvements and modifications also fall within the scope of the claims of the present application.

Claims

1. The flame-retardant polycarbonate PC material with high metal texture is characterized by mainly comprising polycarbonate, a transparent halogen-containing flame retardant, an auxiliary agent and a metal pigment.

2. The flame-retardant polycarbonate PC material with high metallic texture as claimed in claim 1, wherein the polycarbonate, the transparent halogen-containing flame retardant, the antioxidant and the metallic pigment are contained in the following contents by mass percent: the polycarbonate: the transparent halogen-containing flame retardant: the auxiliary agent is as follows: the metal pigment accounts for 81-98.3%: 0.5-5%: 1-10%: 0.2 to 4 percent.

3. The flame retardant polycarbonate PC material with high metallic feeling of claim 1 or 2, wherein the transparent halogen-containing flame retardant is bromotriazine.

4. The flame-retardant polycarbonate PC material with high metallic feeling as claimed in claim 1 or 2, wherein the polycarbonate is obtained by compounding two or three kinds of polycarbonates with different viscosities.

5. A method for preparing the flame retardant polycarbonate PC material with high metallic feeling as claimed in any one of claims 1 to 4, wherein the method comprises:

6. The method of claim 5, further comprising:

in the stirring process of the treated metal pigment and the silane coupling agent, the pH value in the reaction process is controlled to be 8-10 by using an aqueous solution of ammonia, and the stirring speed is gradually increased from 50-100rpm to 300-500 rpm.

7. The method according to claim 5 or 6, characterized in that the modified metal pigment and the lubricant are in a mass ratio of: the modified metal pigment: the lubricant is 100: (0.5-5).

8. The method according to claim 5 or 6, wherein the polycarbonate, the halogen-containing flame retardant in a transparent state, the auxiliary agent and the metallic pigment consist of, in mass percent:

9. The method of claim 5 or 6, wherein the twin screw extruder comprises ten barrels, the ten barrels are connected in series, and the first feeding port is connected with a first barrel of the ten barrels;

the second feeding openings are multiple, and each section of the cylinder body from the sixth section of the cylinder body to the ninth section of the cylinder body is connected with one second feeding opening.

10. The method according to claim 9, wherein the feeding of the modified metallic pigment from at least one second feeding port of the twin-screw extruder comprises: