PA10T molded composite material, its manufacturing method and use

Abstract

The present invention is mainly concerned with the crystal peak half-width ΔT 1 / 2 The present invention provides a PA10T molding composite material that has the advantages of reducing blue light, high contrast, and high gradation, and can meet the needs of packaging process and long-term reliability by adjusting the temperature to 3-10°C, adjusting the whiteness to less than 26, and adjusting the light source reflectance at 460 nm to less than 6.5%, and can be used to produce a light source reflecting bracket of an LED display. The packaging product made of the PA10T molding composite material of the present invention can be used to manufacture a light source reflecting bracket of a high-contrast LED display for multi-scenario applications.

Description

[Technical Field]

[0001] This invention relates to the technical field of polymer materials, and more particularly to PA10T molded composite materials, methods for producing the same, and uses thereof. [Background technology]

[0002] An LED light source is primarily composed of a semiconductor chip, an LED light source reflective bracket, gold wire, and package adhesive. The LED light source reflective bracket is the "skeleton" of the LED light source and also a functional component. The LED packaging process requires die attachment, wire bonding, and curing of the package adhesive, and all other materials and components are integrated into the reflective bracket. The LED reflective bracket needs to reflect the light emitted by the LED chip at a specific angle to reduce light loss, transmit light through the package material such as epoxy resin or silicone, and form the light source for LED lighting and displays. The LED reflective bracket material is the core material of LED lighting and is directly related to the performance and lifespan of the LED light source.

[0003] Currently, the following points need to be considered when selecting materials for LED reflective brackets.

[0004] Firstly, throughout the packaging process, the LED reflective bracket is exposed to temperatures of 150-200°C for 6-10 hours. Furthermore, if the lamp beads are to be used in a display after packaging, SMT (Surface Mount Manufacturing) is required. The LED bracket and lamp beads must not deform or break under load during packaging and SMT, and there are high requirements for the adhesion of the LED bracket material.

[0005] Secondly, in recent years, LED display light sources have been gradually developed for narrow-pitch displays with a point pitch of P2.5 or less. As a result, the research and development and manufacturing of LED displays continue to face significant challenges in this process. The manufacturing of brackets for small-pitch displays is gradually progressing towards thinner walls, multi-cavity designs, and miniaturization, requiring stricter requirements for the fluidity of LED reflective bracket materials, the moldability of ultra-multi-cavity designs, and mechanical strength.

[0006] Thirdly, LED lighting fixtures and displays are often affected by adverse weather conditions such as high temperatures, typhoons, heavy rain, and lightning during use, depending on the environment. Therefore, there are high requirements for the dimensional stability and other performance characteristics of the materials used to protect lighting fixtures and displays from adverse weather conditions.

[0007] Fourthly, in the application fields of LED displays, brightness and contrast are crucial indicators for displaying clear image quality. Currently, the form mainly used on the market is an LED bracket made of pure white LED reflective material, which requires silk-screen printing of black ink onto the surface. This process is complicated, negatively impacts efficiency, and is costly. However, the sides and surface of the reflective cup remain white, reducing the contrast and gradation of the LED display.

[0008] Fifth, regarding light sources, the wavelengths that the average person's eye can perceive are 780-400nm. Of these, short-wave blue light with a wavelength of 400-450nm causes the most damage to the retina. This wavelength of blue light increases the amount of toxins in the macular region of the eye, seriously threatening people's eye health. On the other hand, LED full-color display light sources are packaged with three types of chips: red (R), green (G), and blue (B). Of these, the blue chip emits the lowest brightness of light, meaning it has the highest contrast. Therefore, the reflectivity of the blue light of the chip used in the LED light source bracket directly affects the overall contrast of the LED display. Blue light prevention using LED screens is widespread in various mobile phones and televisions, and the common measure is to coat the screen surface with a blue light prevention film, but each of these thin films has the drawback of being fragile and expensive.

[0009] Those skilled in the art have primarily focused on improving LED reflective bracket materials in the first and second points mentioned above. Little attention has been paid to the package stability of polyamide molded composite materials, and the contrast and gradation of LED display brackets have not been improved by improving the contrast and gradation of the material itself. [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The objective of the present invention is to solve the above-mentioned technical defects and provide a polyamide molded composite material that has high contrast and high gradation and can meet the needs of packaging processes and long-term reliability. Another object of the present invention is to provide the use of the above-described polyamide molded composite material. [Means for solving the problem]

[0011] This invention is achieved through the following technical solutions.

[0012] PA10T molded composite material, The ingredients include 40-70 parts by weight of PA10T resin, 30-60 parts by weight of wollastonite, and 0.4-5 parts by weight of toner. In the resin matrix of PA10T molded composite materials, wollastonite has an average diameter of 4-20 μm and an average length of 10-250 μm. The crystal peak width at half maximum (ΔT) was measured by differential scanning calorimetry at a temperature of 20°C / min after heating to 345°C. 1 / 2 The temperature is 3-10℃. The whiteness is less than 26, and the reflectance of the 460nm light source is less than 6.5%.

[0013] Preferably, the PA10T molded composite material is measured by differential scanning calorimetry, with the crystal peak width at half maximum ΔT measured at a temperature of 20°C / min after heating to 345°C. 1 / 2 The temperature range is 4.5 to 7°C.

[0014] The PA10T resin of the present invention may be a commercially available product or may be synthesized by the following method. For more accurate experiments, the PA10T used in the examples and comparative examples of the present invention was a self-made sample, while the raw materials such as monomers and capping agents were commercially available.

[0015] (1) Prepolymerization: Terephthalic acid, 1,10-sebadian, benzoic acid as a capping agent, and deionized water were added to a stainless steel high-pressure reaction vessel equipped with mechanical stirring. After vacuum suction and N2 substitution three times, heating and stirring were started, and the temperature was raised to 180°C at a rate of 5°C / min. After holding the temperature for 60 minutes, the temperature was raised to 270°C at a rate of 2°C / min, with slow stirring, and the temperature was held for 4 hours to allow the prepolymerization reaction to proceed sufficiently. After the holding period, the temperature was slowly raised to 280°C, and drainage was started to reduce the temperature to atmospheric pressure. Once atmospheric pressure was reached, the drain valve was closed to terminate the reaction, the temperature was reduced to room temperature, and the material was discharged.

[0016] (2) Solid-phase thickening: The material produced in the prepolymerization process is placed in a vacuum rotating drum, with the rotation speed of the drum set to 10 r / min and the vacuum level to 30 Pa. The temperature is increased at a rate of 20°C / min, and when the temperature reaches 265°C, a sample is taken and the viscosity is measured. The endpoint of the material is determined by the viscosity (or number-average molecular weight) result.

[0017] In this invention, the number-average molecular weight range of the PA10T resin is not particularly limited, and the objectives of the invention can be achieved if it is between 1500 and 26000. The method for measuring the number-average molecular weight is a conventional method, specifically, the number-average molecular weight (Mn) of the PA10T resin sample is measured by gel permeation chromatography (GPC). The Agilent HPLC-1260 high-performance liquid chromatograph configuration is: Eppendorf column oven, Shodex KF-801, 802, 802.5 and 803 gel permeation chromatography columns, differential detector, and G7129A autosampler. Hexafluoroisopropanol is used as the mobile phase, and the molecular weight of the resin is measured under conditions of a column temperature of 40°C. This data is processed with the Cirrus chromatography workstation software to obtain the number-average molecular weight distribution Mn.

[0018] Preferably, the wollastonite in the resin matrix of the PA10T molded composite material has an average diameter of 6 to 13 μm and an average length of 80 to 120 μm. Wollastonite is a powder with a constant aspect ratio, and its microstructure is fibrous, so its length and diameter hardly change during melt shearing in a screw. Experiments showed that when two materials, PA10T and wollastonite (average diameter 17 μm, average length 180 μm), were melt-sheared and blended through the production process, and the resin was further dissolved using a solvent, the average diameter and average length of the wollastonite were measured, it was found that the diameter of the wollastonite did not change during shearing by the screw, but the average length changed by about 0.5%.

[0019] The toner is a mixed toner of at least one or more colors selected from carbon black, black masterbatch, and amorphous carbon toner. It is mainly black, and a small amount of other color toners such as purple, blue, and red may be added for color adjustment.

[0020] Preferably, the toner is selected from amorphous carbon toners.

[0021] Preferably, the reflectance of the PA10T molded composite material to a 460 nm light source is less than 5%, and more preferably, the reflectance of the PA10T molded composite material to a 460 nm light source is 2.5 - 4%.

[0022] It further contains 0 - 3 parts by weight of an antioxidant, and the antioxidant is at least one selected from hindered phenol antioxidants, hindered amine antioxidants, phosphite antioxidants, thiol antioxidants, and thiodipropionate antioxidants.

[0023] The use of the PA10T molded composite material of the present invention is used for manufacturing a light source reflection bracket of an LED display.

[0024] The manufacturing method of the PA10T molded composite material of the present invention is to add each component to a mixer and mix uniformly, and then extrude and pelletize by a twin-screw extruder with a screw temperature range of 280 - 330°C and a rotation speed of 450 r / min to obtain a PA10T molded composite material.

Advantages of the Invention

[0025] The present invention has the following beneficial effects.

[0026] The reflectivity of a 460nm light source correlates primarily with the surface roughness of the material (the higher the value of the surface roughness within a certain range, the more the light emitted from the light source is diffusely reflected by the surface of the object, resulting in less light energy received at the light-receiving end) and the whiteness of the material (the lower the whiteness, the lower the reflectivity). The influence of the light source reflective bracket of an LED display on the gradation and contrast of the LED display is mainly due to the whiteness and reflectivity of the light source reflective bracket. According to this principle, the PA10T molded composite material of the present invention exhibits the following properties: 4 In two respects, it has the advantage of controlling the whiteness to less than 26 and the reflectance of the 460nm light source to less than 6.5% (improving gradation and contrast), long-term package stability (adhesion), and thus low blue light emission from the packaged LED screen.

[0027] Firstly, compared to other inorganic fillers, wollastonite can bring the surface roughness of PA10T molded composite parts to a reasonable range that reduces light reflection and lowers the reflectivity of a 460nm light source. The preferred distribution dimensions of wollastonite in the resin matrix can further reduce the reflectivity of a 460nm light source (reducing blue light from LED displays).

[0028] Secondly, by adjusting the color of the material with toner, a black color with good light absorption effect can be obtained. Preferably, amorphous carbon toner further reduces whiteness, improves light absorption, and reduces the reflectance of a 460nm light source.

[0029] Thirdly, the crystal peak full width at half maximum (FWHM) of the PA10T molded composite material also clearly affects the reflectance of the composite material under a 460nm light source, and the crystal peak FWHM ΔT of the composite material. 1 / 2 Experiments have shown that the surface roughness of products manufactured at temperatures of 3.5 to 10°C better meets the need to reduce the reflectivity of a 460 nm light source. In the technical solution of the present invention, the crystalline peak full width at half maximum of the PA10T molded composite material is adjusted mainly by adjusting the amount and specifications of toner and wollastonite added, and the number-average molecular weight of PA10T.

[0030] Fourthly, by adjusting the crystal peak full width at half maximum of the PA10T molded composite material, the specifications of the wollastonite, and the surface roughness, excellent adhesion can be obtained.

[0031] The PA10T molded composite material of the present invention does not require additional spraying or matting of light-absorbing paint, thereby reducing the cost of light source brackets for LED displays. [Modes for carrying out the invention]

[0032] The present invention will be described in detail below with reference to specific examples. The following examples will facilitate a further understanding of the present invention by those skilled in the art, but will not limit the present invention in any form. Those skilled in the art may make some modifications and improvements without departing from the concept of the present invention. All of these will fall within the scope of protection of the present invention.

[0033] The raw materials used in the examples and comparative examples are as follows:

[0034] The following monomers for polyamide polymerization are commercially available, polymerization-grade, and pure. PA10T-A: Number-average molecular weight is 3000, crystal peak full width at half maximum ΔT 1 / 2 The temperature was 8.5℃, and it was made by the user by referring to the method described in the summary of the invention. PA10T-B: Number-average molecular weight is 3400, crystal peak full width at half maximum ΔT 1 / 2 The temperature was 5.6℃, and it was manufactured by the user by referring to the method described in the summary of the invention. PA10T-C: Number-average molecular weight is 5500, crystal peak full width at half maximum ΔT 1 / 2 The temperature was 5.9℃, and it was made by the user by referring to the method described in the summary of the invention. PA10T-D: Number-average molecular weight is 6500, crystal peak full width at half maximum ΔT 1 / 2 The temperature is 6.5℃, and it was made by the user by referring to the method described in the summary of the invention. PA10T-E: Number-average molecular weight is 10,000, crystal peak full width at half maximum ΔT 1 / 2is 11.2 °C and was made by oneself referring to the method described in the summary of the invention. PA10T-F: The number average molecular weight is 12,000, and the crystallization peak half-width ΔT 1 / 2 is 12.4 °C and was made by oneself referring to the method described in the summary of the invention. PA10T-G: The number average molecular weight is 25,000, and the crystallization peak half-width ΔT 1 / 2 is 15.3 °C and was made by oneself referring to the method described in the summary of the invention. Wollastonite A: The average diameter is 4 μm and the average length is 60 μm; Wollastonite B: The average diameter is 6 μm and the average length is 120 μm; Wollastonite C: The average diameter is 13 μm and the average length is 80 μm; Wollastonite D: The average diameter is 17 μm and the average length is 180 μm. The wollastonite used in the present invention is obtained by screening commercially available products to be within the desired ranges of average diameter and average length. Talc powder: AH-1250, Guangxi Longsheng Huamei Talc Development Co., Ltd. Toner A: Amorphous carbon toner N774, Tianjin Tianyang Qiushi Chemical Technology Co., Ltd.; Toner B: Carbon black M570, Cabot Chemical Co., Ltd.; Toner C: Black masterbatch UN2014, Cabot Chemical Co., Ltd.; Toner D: Mazcol Blue 153K, Shenzhen Dingtai Chemical Co., Ltd. Antioxidant: Irganox1098, a hindered phenol-based antioxidant. Method for manufacturing the polyamide molding composite material in the examples and comparative examples: Add PA10T, wollastonite, toner, and antioxidant to a mixer and mix uniformly. Next, extrude and granulate using a twin-screw extruder with a screw temperature range of 280 - 330 °C and a rotational speed of 450 r / min to obtain a PA10T molding composite material.

[0035] Test method: (1) Adhesion: For samples of PA10T molded composite material, the adhesion between the bracket plastic and metal is expressed through a red ink test. An LED reflective cup, formed by in-mold injection molding of the light source bracket material of an LED display and plated metal strip material, is immersed in red ink. The pins are positioned so that they are immersed in the red ink, and it is observed whether the red ink penetrates into the interior of the reflective cup. If the red ink does not penetrate the reflective cup within 5 minutes, the adhesion grade is judged to be A. If the red ink does not penetrate the reflective cup within 3 minutes, but does penetrate within 5 minutes, the adhesion grade is judged to be B. If the red ink does not penetrate the reflective cup within 1 minute, but does penetrate within 3 minutes, the adhesion grade is judged to be Class C. If the red ink penetrates the reflective cup within 1 minute, the adhesion grade is judged to be Class D. A D-grade adhesion rating indicates poor adhesion between the plastic and metal components, posing a risk of lamp bead failure. Conversely, an A, B, or C-grade adhesion rating indicates excellent airtightness and reliability of the packaged lamp beads.

[0036] (2) Whiteness: The contrast of the material is evaluated using the whiteness of the material as an indicator. For a test specimen of PA10T molded composite material measuring 60 mm in length, 60 mm in width, and 1 mm in thickness, the L, a, and b values ​​are measured using a Color Eye 7000A colorimeter, and the whiteness is calculated. W H =100-[(100-L) 2 +a 2 +b 2 ] 1 / 2 .

[0037] (3) Reflectance: A test specimen measuring 60 mm in length, 60 mm in width, and 1 mm in thickness, made by injection molding PA10T molded composite material, is used to measure the reflectance of the specimen to light with a wavelength of 460 nm using a Color Eye 7000A colorimeter.

[0038] (4) Crystal peak width at half maximum ΔT of PA10T molded composite material1 / 2 Using a differential scanning calorimetry analyzer manufactured by NETZSCH, the temperature was increased from 30°C to 345°C at a rate of 20°C / min under a nitrogen atmosphere, maintained for 2 minutes, and then cooled at a rate of 20°C / min. The crystal peak temperature observed at this time was defined as the crystallization temperature Tc (°C), and the crystal peak width at half maximum (FMAX) ΔT was defined as half the measured peak width. 1 / 2 Let's assume that.

[0039] [Table 1]

[0040] Examples 1-6 showed that when the amount of wollastonite added was increased to control the crystal peak full width at half maximum within a desirable range, the adhesion grade improved, while both whiteness and reflectance remained low.

[0041] [Table 2]

[0042] Examples 4, 7, 8, 9, and 10 showed that adjusting the amount of toner used reduced both whiteness and reflectivity.

[0043] [Table 3]

[0044] From Examples 4, 11-15, it was found that the wollastonite preferably has an average diameter of 6-13 μm and an average length of 80-120 μm, and the toner is preferably an amorphous carbon toner.

[0045] [Table 4]

[0046] [Table 5]

[0047] Examples 4 and 16-24 showed that adjusting the crystal peak half-width of PA10T by adding wollastonite and toner affected the adhesion, whiteness, and reflectivity of the molded composite material. Specifically, Examples 16-21 showed that the crystal peak half-widths of Examples 18 and 19 were excellent in both adhesion grade and reflectivity within a favorable range.

[0048] [Table 6]

[0049] Comparative Example 1 showed that if the wollastonite content is too high, the crystal peak full width at half maximum is too low, resulting in poor adhesion grade, and the surface structure of the PA10T molded composite material is also destroyed, leading to poor reflectivity. Comparative Example 2 showed that if the wollastonite content is too low, the crystal peak full width at half maximum cannot be reduced to within 10°C, resulting not only in poor adhesion grade but also high reflectivity.

[0050] Comparative Example 3 showed that PA10T molded composite materials with an excess of wollastonite failed to achieve the desired high adhesion grade and low reflectivity, even when the crystal peak full width at half maximum was in the range of 3 to 10°C. This was found to be because the excess wollastonite destroyed the surface structure of the composite material, and because wollastonite is a white powder, an excess amount increased its whiteness.

[0051] Comparative Example 4 showed that talc powder cannot be used as a substitute for wollastonite.

[0052] Comparative Example 5 showed that if the wollastonite content is too low, the objective of high adhesion grade and low reflectivity cannot be achieved, even if the crystal peak full width at half maximum is in the range of 3-10°C.

[0053] Comparative Example 6 showed that if the amount of toner added is too low, the whiteness becomes too high, resulting in a high reflectivity.

[0054] Comparative Example 7 showed that if too much toner is added, the toner becomes excessively concentrated on the surface, affecting adhesion and reflectivity.

Claims

1. PA10T molded composite material, As ingredients, For a total of 100 parts by weight of PA10T resin and wollastonite, 50 to 70 parts by weight of PA10T resin and 30 to 50 parts by weight of wollastonite are used. The toner is present in an amount of 0.4 to 5% by weight relative to the total amount of PA10T resin and wollastonite. In the resin matrix of PA10T molded composite materials, wollastonite has an average diameter of 4 to 20 μm and an average length of 10 to 250 μm. The crystal peak width at half maximum (ΔT) was measured by differential scanning calorimetry at a temperature of 20°C / min after heating to 345°C. １／２ The temperature is between 3 and 10°C. The whiteness is less than 26, and the 460nm light source reflectance is less than 6.5%. The PA10T molded composite material is characterized in that the toner is a mixed toner of at least one or more colors selected from a black masterbatch and an amorphous carbon toner.

2. The crystal peak width at half maximum (ΔT) was measured by differential scanning calorimetry at a temperature of 20°C / min after heating to 345°C. １／２ The PA10T molded composite material according to claim 1, characterized in that the temperature is 4.5 to 7°C.

3. The PA10T molded composite material according to claim 1, characterized in that the number average molecular weight of the PA10T resin is 1,500 to 26,000.

4. The PA10T molded composite material according to claim 1, characterized in that the wollastonite in the resin matrix of the PA10T molded composite material has an average diameter of 6 to 13 μm and an average length of 80 to 120 μm.

5. The PA10T molded composite material according to claim 1, characterized in that the toner is selected from amorphous carbon toners.

6. The PA10T molded composite material according to claim 1, characterized in that the reflectance of a 460 nm light source is less than 5%.

7. The PA10T molded composite material according to claim 6, characterized in that the reflectance of a 460 nm light source is 2.5 to 4%.

8. The PA10T molded composite material according to claim 1, further comprising more than 0 parts by weight and 3 parts by weight or less of an antioxidant.

9. A method for producing a PA10T molded composite material according to any one of claims 1 to 8, characterized by comprising the steps of adding each component to a mixer and mixing them uniformly, and then extruding and granulating the mixture using a twin-screw extruder with a screw temperature range of 280 to 330°C and a rotation speed of 400 to 500 r / min to obtain a PA10T molded composite material.

10. The use of the PA10T molded composite material according to any one of claims 1 to 8, characterized in that it is used in the manufacture of a light source reflective bracket for an LED display.

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