阅读说明：本技术 高散热手机3d后盖保护材料及其制备方法 (High-heat-dissipation mobile phone 3D rear cover protection material and preparation method thereof ) 是由 张福军 周卫卫 于 2020-03-26 设计创作，主要内容包括：高散热手机3D后盖保护材料,按重量百分比其组分为5-10％MgAl<Sub>2</Sub>O<Sub>4</Sub>,28-30％MgO·Al<Sub>2</Sub>O<Sub>3</Sub>·SiO<Sub>2</Sub>,5-8％SiO<Sub>2</Sub>·MgO·B<Sub>2</Sub>O<Sub>3</Sub>,7-8％SnO·P<Sub>2</Sub>O<Sub>5</Sub>,6-7.5％SiO<Sub>2</Sub>·B<Sub>2</Sub>O<Sub>3</Sub>·ZnO,19-21％SiO<Sub>2</Sub>·R<Sub>2</Sub>O·TiO<Sub>2</Sub>,2-3％2Li<Sub>2</Sub>O·SiO<Sub>2</Sub>,14-15％Na<Sub>2</Sub>O·2SiO<Sub>2</Sub>,1-2％Bi<Sub>2</Sub>O<Sub>3</Sub>·B<Sub>2</Sub>O<Sub>3</Sub>,2.5-4.5％SiC,0.8-2％石墨；采用低温热压烧结,引入大量的陶瓷晶体,阻挡摔落时微裂纹的扩展,低温烧结体中引入碱金属离子,进行化学强化,结合高强玻璃本体,有效增加材料的抗摔性能；同时引入部分高导热系数陶瓷晶体与石墨形成导热路径和导热网联,整体散热性能获得较大提高。(The high-heat-dissipation mobile phone 3D rear cover protective material comprises 5-10% of MgAl in percentage by weight 2 O 4 ，28‑30％MgO·Al 2 O 3 ·SiO 2 ，5‑8％SiO 2 ·MgO·B 2 O 3 ，7‑8％SnO·P 2 O 5 ，6‑7.5％SiO 2 ·B 2 O 3 ·ZnO，19‑21％SiO 2 ·R 2 O·TiO 2 ，2‑3％2Li 2 O·SiO 2 ，14‑15％Na 2 O·2SiO 2 ，1‑2％Bi 2 O 3 ·B 2 O 3 2.5-4.5% of SiC and 0.8-2% of graphite; the low-temperature hot-pressing sintering is adopted, a large amount of ceramic crystals are introduced to block the expansion of microcracks during falling, alkali metal ions are introduced into a low-temperature sintering body to carry out chemical strengthening, and the anti-falling performance of the material is effectively improved by combining a high-strength glass body; meanwhile, a part of high-thermal conductivity ceramic crystals and graphite are introduced to form a heat conduction path and a heat conduction network connection, so that the overall heat dissipation performance is greatly improved.)

1. Lid protective material behind high heat dissipation cell-phone 3D, its characterized in that: comprises the following components in percentage by mass: 5-10% of MgAl₂O₄，28-30％MgO·Al₂O₃·SiO₂，5-8％SiO₂·MgO·B₂O₃，7-8％SnO·P₂O₅，6-7.5％SiO₂·B₂O₃·ZnO，19-21％SiO₂·R₂O·TiO₂，2-3％2Li₂O·SiO₂，14-15％Na₂O·2SiO₂，1-2％Bi₂O₃·B₂O₃2.5-4.5% of SiC and 0.8-2% of graphite.

2. The high-heat-dissipation mobile phone 3D rear cover protection material as claimed in claim 1, wherein MgAl is added₂O₄The mass percentage of the components is 8-10%; the particle size distribution is that D50 is more than 0.5um and less than 1um, and D95 is less than 2.5 um.

3. The high heat dissipation mobile phone 3D rear cover protection material as claimed in claim 1 or 2, wherein MgO-Al is used as the material₂O₃-SiO₂The particle size distribution is 2um < D50 < 3um, D95 < 4 um.

4. The high heat dissipation mobile phone 3D rear cover protective material according to claim 1 or 2, characterized in that MgO-Al₂O₃-SiO₂SiO with the specific mass percent of 65%₂25% of Al₂O₃10% of MgO.

5. The high-heat-dissipation mobile phone 3D rear cover protection material as claimed in claim 1 or 2, wherein SiO is₂·MgO·B₂O₃The particle size distribution is 2um < D50 < 3um, D95 < 2.5 um.

6. The high-heat-dissipation mobile phone 3D rear cover protection material as claimed in claim 1 or 2, wherein SnO & P₂O₅The particle size distribution is 2um < D50 < 3um, D95 < 4 um.

7. The high-heat-dissipation mobile phone 3D rear cover protection material as claimed in claim 1 or 2, wherein SiO is₂·B₂O₃The grain size distribution of ZnO is 2um < D50 < 3um, D95 < 4 um.

8. High heat dissipation cell-phone 3D back lid is protected according to claim 1 or 2A protective material, characterized in that SiO₂·R₂O·TiO₂The particle size distribution is 1um < D50 < 2um, D95 < 3 um.

9. The high-heat-dissipation mobile phone 3D rear cover protection material as claimed in claim 1 or 2, wherein SiO is₂·R₂O·TiO₂Characterized by being SiO₂·R₂O·TiO₂Is SiO₂·Li₂O·TiO₂、SiO₂·Na₂O·TiO₂、SiO₂·K₂O·TiO₂One or more of; when the number of the components is more than one, the mass percentage of the components satisfies SiO₂·Li₂O·TiO₂+SiO₂·K₂O·TiO₂≤SiO₂·Na₂O·TiO₂。

10. The high heat dissipation mobile phone 3D rear cover protection material as claimed in claim 9, wherein the mass percentage of 2Li₂O·SiO₂:Na₂O·2SiO₂﹤1:5。

11. The high heat dissipation mobile phone 3D rear cover protection material as claimed in claim 9, wherein the Bi is₂O₃·B₂O₃The particle size distribution is that D50 is more than 0.5um and less than 1.5um, and D95 is less than 2.5 um.

12. The high heat dissipation mobile phone 3D rear cover protection material as claimed in claim 9, wherein the SiC particle size distribution is 1.5um < D50 < 2um, D95 < 4 um.

13. The high heat dissipation mobile phone 3D rear cover protection material as claimed in claim 9, wherein the graphite particle size distribution is 1.5um < D50 < 2.5um, D95 < 4 um.

14. The preparation method of the high-heat-dissipation mobile phone 3D rear cover protection material comprises the following steps:

s1, weighing the raw materials of claims 1-13, mixing the raw materials with water according to the proportion of 92:8 to 84:16, and premixing and stirring the mixture by using a stirrer to form slurry;

s2, grinding the premixed slurry by using a grinder;

s3, mixing and stirring the ground slurry by a stirrer;

s4, adding the slurry into a die for pressing, demolding and drying in a mesh belt furnace;

s5, hot-pressing and sintering the dried slurry by using a silicon carbide mould;

s6, carrying out chemical strengthening on the hot-pressed and sintered material, wherein the specific chemical strengthening process comprises the following steps: carrying out ion exchange treatment in potassium nitrate molten salt at the temperature of 430-450 ℃ for 2-5h to obtain the high-heat-dissipation mobile phone 3D rear cover protective material;

and step S1, the premixing and stirring of the stirrer is gradient stirring, the gradient stirring procedure comprises the steps of sequentially adopting, stirring at the rotating speed of 8-12rpm for 25-35min in the first stage, stirring at the rotating speed of 23-27rpm for 50-70min in the second stage, stirring at the rotating speed of 43-47rpm for 30-40min in the third stage, stirring at the rotating speed of 53-57rpm for 20-30min in the fourth stage, and adopting at least three gradient stirring stages in the four gradient stirring stages.

15. The method for preparing the 3D rear cover protective material of the mobile phone with high heat dissipation performance according to claim 14, wherein the gradient stirring procedure comprises sequentially adopting a first stage of stirring at a rotation speed of 10rpm for 25-35min, a second stage of stirring at a rotation speed of 25rpm for 50-70min, a third stage of stirring at a rotation speed of 45rpm for 30-40min, a fourth stage of stirring at a rotation speed of 55rpm for 20-30min, and at least three gradient stirring stages are adopted in the four gradient stirring stages;

step S2, the grinding procedure is adopted in sequence, the first grinding gap is 20-30um, the pressure of the discharging blade is 7-8bar, the rotating speed of the discharging roller is 50-100rpm, the second grinding gap is 18-26um, the pressure of the discharging blade is 7-8bar, the rotating speed of the discharging roller is 50-100rpm, the third grinding gap is 14-17um, the pressure of the discharging blade is 9-10bar, the rotating speed of the discharging roller is 50-100rpm, the fourth grinding gap is 8-12um, the pressure of the discharging blade is 9-10bar, the rotating speed of the discharging roller is 150-200rpm, the fifth grinding gap is 8-12um, the pressure of the discharging blade is 9-10bar, the rotating speed of the discharging roller is 150-200rpm, the sixth grinding gap is 8-12um, the pressure of the discharging blade is 11-12bar, and the rotating speed of the discharging roller is 150-200rpm, the seventh grinding clearance is 6-8um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 150-200rpm, the eighth grinding clearance is 6-8um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 300-400rpm, the ninth grinding clearance is 4-6um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 300-400rpm, the tenth grinding clearance is 4-6um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 450-550rpm, and the ten gradient grinding programs adopt at least seven grinding programs.

16. The method for preparing the 3D rear cover protective material of the mobile phone with high heat dissipation performance according to claim 14, wherein the grinding procedure is sequentially performed, the first grinding gap is 25um, the discharging blade pressure is 7-8bar, the discharging roller rotation speed is 50-100rpm, the second grinding gap is 20um, the discharging blade pressure is 7-8bar, the discharging roller rotation speed is 50-100rpm, the third grinding gap is 15um, the discharging blade pressure is 9-10bar, the discharging roller rotation speed is 50-100rpm, the fourth grinding gap is 10um, the discharging blade pressure is 9-10bar, the discharging roller rotation speed is 150-200rpm, the fifth grinding gap is 10um, the discharging blade pressure is 9-10bar, the discharging roller rotation speed is 150-200rpm, the sixth grinding gap is 10um, and the discharging blade pressure is 11-12bar, the rotating speed of a discharging roller is 150-200rpm, the grinding gap for the seventh time is 7um, the pressure of a discharging blade is 11-12bar, the rotating speed of the discharging roller is 150-200rpm, the grinding gap for the eighth time is 7um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 300-400rpm, the grinding gap for the ninth time is 5um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 300-400rpm, the grinding gap for the tenth time is 5um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 450-550rpm, and at least seven grinding programs are adopted in the ten gradient grinding;

and step S3, the mixing and stirring of the double-planetary stirrer is gradient stirring, the gradient stirring procedure comprises the steps of stirring for 10-15min at the rotating speed of 10-20rpm in the first stage, stirring for 25-30min at the rotating speed of 20-30rpm in the second stage, stirring for 25-30min at the rotating speed of 35-45rpm in the third stage, and at least one of the three gradient stirring steps is adopted.

17. The method for preparing a 3D rear cover protective material for a mobile phone according to claim 14, wherein the gradient stirring procedure comprises sequentially performing a first stage of stirring at 15rpm for 10-15min, a second stage of stirring at 25rpm for 25-30min, a third stage of stirring at 40rpm for 25-30min, wherein at least one of the three gradient stirring stages is performed;

step S4, the mesh belt furnace drying is gradient drying, the gradient drying procedure mainly comprises two stages, the first stage is 20-80 ℃, 4-7 sections of temperature zones are set, one temperature zone is set at intervals of 10-20 ℃ from 20 ℃ to 90 ℃, the residence time of each temperature zone is 2-5min, the second stage is 3-5 sections of temperature zones, one temperature zone is set at intervals of 5-10 ℃ from 90 ℃ to 110 ℃, and the residence time of each temperature zone is 10-50 min;

s5, the silicon carbide mould is hot-pressed and sintered by gradient, the gradient procedure mainly comprises the steps of sequentially adopting a first stage, heating the mould at 20 ℃, 1-5Mpa and keeping the temperature for 10min, a second stage, heating the mould from 20 ℃ to 380 ℃, heating the mould at a rate of 5-10 ℃/min and a pressure of 0-2Mpa, a third stage, heating the mould from 380 ℃, heating the mould at a rate of 2-5 ℃/min and heating the mould to 510-560 ℃, at a pressure of 0-5Mpa, a fourth stage, keeping the temperature constant, keeping the pressure at 8-10Mpa for 5-10min, a fifth stage, keeping the temperature constant, keeping the pressure at 15-20Mpa for 10-20min, a sixth stage, cooling the mould to 380 ℃, cooling the mould at a rate of 2-5 ℃/min and keeping the pressure constant, a seventh stage, cooling the mould from 380 ℃ to 20 ℃, and cooling the mould at a rate of 10-20 ℃/min, the pressure is 0-5Mpa, and at least five stages of procedures are adopted in the seven gradient hot pressing.

18. The method for preparing the 3D rear cover protection material of the high-heat-dissipation mobile phone according to claim 14, wherein the gradient hot-pressing sintering comprises a first stage of heating to 380 ℃ at a hot-pressing temperature of 20 ℃ and a pressure of 5MPa for 10min, a second stage of heating to 5 ℃ from 20 ℃ and a temperature rate of 5-10 ℃/min and a pressure of 0MPa, a third stage of heating to 380 ℃ at a temperature rate of 2-5 ℃/min and a temperature of 510-560 ℃ and a pressure of 5MPa, a fourth stage of keeping the temperature constant, a pressure of 8-10MPa for 5-10min, a fifth stage of keeping the temperature constant, a pressure of 15-20MPa for 10-20min, a sixth stage of cooling to 380 ℃ and a temperature rate of 2-5 ℃/min and a pressure of 0, a seventh stage of cooling to 20 ℃ from 380 ℃, the cooling rate is 10-20 ℃/min, the pressure is 0Mpa, and at least five stages of procedures are adopted in the seven gradient hot pressing.

Technical Field

The application belongs to the field of mobile phone cover materials, and particularly relates to a high-heat-dissipation mobile phone 3D rear cover protection material and a preparation field thereof.

Background

The mobile phone rear cover plate adopts a 3D structure, so that the holding feeling of a mobile phone of a consumer can be improved, and the mobile phone rear cover plate becomes a standard matching option of a flagship type at present. With the increased pace of commercialization of 5G, the demand for 3D back cover materials for 5G cellular phones continues to increase.

The original material for the 3D mobile phone rear cover mainly comprises 4 types of metal, glass, ceramic, special plastic and the like, but the metal rear cover material can generate obvious absorption and shielding effects on 5G high-frequency signals, so that mobile phone signals are weakened, and therefore the metal material cannot be applied to the rear cover plate of the 5G mobile phone.

Among three materials of the existing glass, ceramic and special plastic, plastic is easy for 3D-shaped injection molding processing, but is low in hardness, easy to scratch and easy to harden, and affects the experience of consumers, so that a small amount of low-end non-smart phones can be selected and adopted. Although the ceramic material is used as the rear cover plate, the hardness is high, the ceramic material is not easy to scratch, and the inherent artistic aesthetic feeling of the ceramic can improve the user experience of consumers, the ceramic material is not easy to process into a 3D shape due to the inherent ceramic crystal structure, in addition, only a small number of flagship models are selectively used due to the high production cost of the ceramic cover plate at the present stage, and the ceramic material is easy to fragment when the impact force is trapped, so that the falling resistance is poor.

The most practical applications of the protective materials for the 5G mobile phone rear cover plate on the market are mainly glass materials. The glass material is lower on the one hand, and is less to 5G communication frequency's absorption and shielding influence, can satisfy the requirement, and on the other hand, glass texture itself can satisfy consumer's user experience. However, the glass material has a low thermal conductivity, and is easily overheated when the 5G mobile phone is used for a long time, which affects the user experience of consumers.

Disclosure of Invention

In order to solve the problem that the mobile phone 3D rear cover protective material is difficult to dissipate heat, the invention provides a high-heat-dissipation mobile phone 3D rear cover protective material and a preparation method thereof, wherein the preparation method comprises the following steps:

lid protective material behind high heat dissipation cell-phone 3D, its characterized in that: comprises the following components in percentage by mass: consists of MgAl 5-10 wt%₂O₄，28-30％MgO·Al₂O₃·SiO₂，5-8％SiO₂·MgO·B₂O₃，7-8％SnO·P₂O₅，6-7.5％SiO₂·B₂O₃·ZnO，19-21％SiO₂·R₂O·TiO₂，2-3％2Li₂O·SiO₂，14-15％Na₂O·2SiO₂， 1-2％Bi₂O₃·B₂O₃2.5-4.5% of SiC and 0.8-2% of graphite.

Preferably: the MgAl₂O₄The mass percentage of the components is 8-10%.

Preferably: the MgAl₂O₄The particle size distribution is 0.5um < D50 < 1um, D95 < 2.5 um.

Preferably: the MgO-Al₂O₃-SiO₂The particle size distribution is 2um < D50 < 3um, D95 < 4 um.

Preferably: the MgO-Al₂O₃-SiO₂SiO with the specific mass percent of 65%₂25% of Al₂O₃10% of MgO.

Preferably: the SiO₂·MgO·B₂O₃The particle size distribution is 2um < D50 < 3um, D95 < 2.5 um.

Preferably: the SnO. P₂O₅The particle size distribution is 2um < D50 < 3um, D95 < 4 um.

Preferably: the SiO₂·B₂O₃The grain size distribution of ZnO is 2um < D50 < 3um, D95 < 4 um.

Preferably: the SiO₂·R₂O·TiO₂The particle size distribution is 1um < D50 < 2um, D95 < 3 um.

Preferably: the SiO₂·R₂O·TiO₂Is SiO₂·Li₂O·TiO₂、SiO₂·Na₂O·TiO₂、SiO₂·K₂O·TiO₂At least one of (1).

Preferably: the SiO₂·R₂O·TiO₂In the component mass percent of SiO₂·Li₂O·TiO₂+SiO₂·K₂O·TiO₂≤SiO₂·Na₂O·TiO₂。

Preferably: the 2Li₂O·SiO₂The mass percent of the components is equal to Na₂O·2SiO₂The mass percentage of the components satisfies the ratio of less than 1: 5.

Preferably: the Bi₂O₃·B₂O₃The particle size distribution is that D50 is more than 0.5um and less than 1.5um, and D95 is less than 2.5 um.

Preferably: the SiC grain size distribution is 1.5um < D50 < 2um, D95 < 4 um.

Preferably: the particle size distribution of the graphite is that D50 is more than 1.5um and less than 2.5um, and D95 is less than 4 um.

The preparation method of the high-heat-dissipation mobile phone 3D rear cover protection material comprises the following steps:

s1, weighing the raw materials, mixing the raw materials with water according to the proportion of 92: 8-84: 16, and premixing and stirring the raw materials by using a double-planet stirrer to form slurry.

S2 the premixed slurry is ground with a three-roll mill.

S3, the ground slurry is mixed and stirred by a double-planet stirrer.

S4, adding the slurry into a die for pressing, demoulding and drying in a mesh belt furnace.

S5, hot-pressing and sintering the dried slurry by using a silicon carbide mould.

S6, carrying out chemical strengthening on the hot-pressed and sintered material, wherein the specific chemical strengthening process comprises the following steps: and carrying out ion exchange treatment in potassium nitrate molten salt at the temperature of 430-450 ℃ for 2-5h to obtain the 3D mobile phone rear cover protective material.

And step S1, the premixing and stirring of the double planetary stirrer is gradient stirring, the gradient stirring procedure comprises the steps of stirring for 25-35min at the rotating speed of 8-12rpm in the first stage, stirring for 50-70min at the rotating speed of 23-27rpm in the second stage, stirring for 30-40min at the rotating speed of 43-47rpm in the third stage, and stirring for 20-30min at the rotating speed of 53-57rpm in the fourth stage, wherein at least three gradient stirring stages are adopted in the gradient.

The further procedure of the gradient stirring comprises the steps of sequentially adopting a first stage of stirring at the rotating speed of 10rpm for 25-35min, a second stage of stirring at the rotating speed of 25rpm for 50-70min, a third stage of stirring at the rotating speed of 45rpm for 30-40min, and a fourth stage of stirring at the rotating speed of 55rpm for 20-30min, wherein at least three stages of gradient stirring are adopted in the above gradient.

Step S2, the three-roll grinder grinds to be a gradient grinder, the gradient grinder adopts a three-roll gap mode, the grinding program is adopted in sequence, the first grinding gap is 20-30um, the pressure of a discharging blade is 7-8bar, the rotating speed of the discharging roller is 50-100rpm, the second grinding gap is 18-26um, the pressure of the discharging blade is 7-8bar, the rotating speed of the discharging roller is 50-100rpm, the third grinding gap is 14-17um, the pressure of the discharging blade is 9-10bar, the rotating speed of the discharging roller is 50-100rpm, the fourth grinding gap is 8-12um, the pressure of the discharging blade is 9-10bar, the rotating speed of the discharging roller is 150-200rpm, the fifth grinding gap is 8-12um, the pressure of the discharging blade is 9-10bar, the rotating speed of the discharging roller is 150-200rpm, and the sixth grinding gap is 8-12um, the pressure of a discharging blade is 11-12bar, the rotating speed of a discharging roller is 150-200rpm, the grinding gap for the seventh time is 6-8um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 150-200rpm, the grinding gap for the eighth time is 6-8um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 300-400rpm, the grinding gap for the ninth time is 4-6um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 300-400rpm, the grinding gap for the tenth time is 4-6um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 450-550rpm, and at least seven grinding programs in the gradient are adopted.

Further, the grinding procedure is adopted in sequence, the first grinding gap is 25um, the pressure of the discharging blade is 7-8bar, the rotating speed of the discharging roller is 50-100rpm, the second grinding gap is 20um, the pressure of the discharging blade is 7-8bar, the rotating speed of the discharging roller is 50-100rpm, the third grinding gap is 15um, the pressure of the discharging blade is 9-10bar, the rotating speed of the discharging roller is 50-100rpm, the fourth grinding gap is 10um, the pressure of the discharging blade is 9-10bar, the rotating speed of the discharging roller is 150-200rpm, the fifth grinding gap is 10um, the pressure of the discharging blade is 9-10, the rotating speed of the discharging roller is 150-200rpm, the sixth grinding gap is 10um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 150-200rpm, the seventh grinding gap is 7um, and the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 150-200rpm, the grinding gap for the eighth time is 7um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 300-400rpm, the grinding gap for the ninth time is 5um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 300-400rpm, the grinding gap for the tenth time is 5um, the pressure of the discharging blade is 11-12bar, the rotating speed of the discharging roller is 450-550rpm, and at least seven grinding programs are arranged in the gradient.

And step S3, the mixing and stirring of the double-planetary stirrer is gradient stirring, the gradient stirring procedure comprises the steps of stirring for 10-15min at the rotating speed of 10-20rpm in the first stage, stirring for 25-30min at the rotating speed of 20-30rpm in the second stage, and stirring for 25-30min at the rotating speed of 35-45rpm in the third stage, wherein at least one stage in the gradient is adopted.

Further, the procedure of the gradient stirring comprises the steps of sequentially adopting a first stage of stirring at a rotating speed of 15rpm for 10-15min, a second stage of stirring at a rotating speed of 25rpm for 25-30min, and a third stage of stirring at a rotating speed of 40rpm for 25-30min, wherein at least one stage is selected from the gradients.

Step S4, the mesh belt oven drying is gradient drying, the gradient drying procedure mainly comprises two stages, the first stage is 20-80 ℃, 4-7 sections of temperature zones are set, one temperature zone is set at intervals of 10-20 ℃ from 20 ℃ to 90 ℃, the residence time of each temperature zone is 2-5min, the second stage is 3-5 sections of temperature zones, one temperature zone is set at intervals of 5-10 ℃ from 90 ℃ to 110 ℃, and the residence time of each temperature zone is 10-50 min.

S5, the hot-pressing sintering of the silicon carbide mould is gradient hot-pressing sintering, the gradient program mainly comprises the steps of sequentially adopting a first stage of heating to a temperature of 20 ℃, a pressure of 1-5MPa and keeping for 10min, a second stage of heating to a temperature of 380 ℃, a heating rate of 5-10 ℃/min and a pressure of 0-2MPa, a third stage of heating to a temperature of 380 ℃, a heating rate of 2-5 ℃/min and heating to a temperature of 510-560 ℃, a pressure of 0-5MPa, a fourth stage of keeping the temperature unchanged, a pressure of 8-10MPa and keeping for 5-10min, a fifth stage of keeping the temperature unchanged, a pressure of 15-20MPa and keeping for 10-20min, a sixth stage of cooling to a temperature of 380 ℃, a cooling rate of 2-5 ℃/min and keeping the pressure unchanged, a seventh stage of cooling to a temperature of 380 ℃, cooling at a rate of 10-20 deg.C/min and under a pressure of 0-5MPa, and performing at least five steps in the gradient.

Further, the gradient hot-pressing sintering comprises a first stage of sequentially adopting a hot-pressing temperature of 20 ℃, a pressure of 5MPa and a holding time of 10min, a second stage of heating from 20 ℃ to 380 ℃, a heating rate of 5-10 ℃/min, a pressure of 0MPa, a third stage of heating from 380 ℃, a heating rate of 2-5 ℃/min and heating to 510-560 ℃, a pressure of 5MPa, a fourth stage of keeping the temperature unchanged, a pressure of 8-10MPa and holding time of 5-10min, a fifth stage of keeping the temperature unchanged, a pressure of 15-20MPa and holding time of 10-20min, a sixth stage of cooling to 380 ℃, a cooling rate of 2-5 ℃/min and holding time of pressure unchanged, and a seventh stage of cooling from 380 ℃ to 20 ℃, a cooling rate of 10-20 ℃/min and a pressure of 0MPa, wherein at least five stages of the above gradient procedures are adopted.

The technical principle of the invention is as follows: the low-temperature sintering agent is used for bonding the high-strength glass and the high-thermal conductivity ceramic crystal composition to realize the one-step forming of 3D hot-pressing sintering

The beneficial technical effects of the invention are as follows: according to the glass ceramic sintered body, a large number of ceramic crystals are introduced to block the expansion of microcracks during falling, alkali metal ions are introduced into the low-temperature sintered body to perform chemical strengthening, and the high-strength glass body is combined to further increase the falling resistance of the material. Meanwhile, the introduced high-heat-conductivity component can improve the heat dissipation effect, and the situation of overheating of the mobile phone cannot occur after long-time use.

Detailed Description

In order to clearly understand the technical spirit and the advantages of the present invention, the following detailed description is given by way of examples, but the description of the examples is not intended to limit the scope of the present invention, and any equivalent changes made according to the present inventive concept, which are merely in form and not in substance, should be considered as the scope of the present invention.

The high-heat-dissipation mobile phone 3D mobile phone rear cover protection material is characterized in that: comprises the following components in percentage by weight: consists of MgAl 5-10 wt%₂O₄，28-30％MgO·Al₂O₃·SiO₂，5-8％SiO₂·MgO·B₂O₃， 7-8％SnO·P₂O₅，6-7.5％SiO₂·B₂O₃·ZnO，19-21％SiO₂·R₂O·TiO₂，2-3％2Li₂O·SiO₂， 14-15％Na₂O·2SiO₂，1-2％Bi₂O₃·B₂O₃2.5-4.5% of SiC and 0.8-2% of graphite.

The principle of the high heat dissipation mobile phone 3D rear cover protective material for limiting the components and the content thereof is explained below.

MgAl₂O₄In the magnesium aluminate spinel, oxygen atoms are equivalent and are arranged in cubic packing in the magnesium aluminate spinel, and because the oxygen atoms are much larger than magnesium and aluminum ions, metal ions of aluminum and magnesium metal are respectively inserted into octahedral and tetrahedral gaps formed by the oxygen atoms according to packing density according to a certain rule and keep electric neutrality. MgAl₂O₄High temperature resistance, corrosion resistance, abrasion resistance, high impact resistance, high hardness and good strength. In the formula system, MgAl₂O₄The introduction of the formula mainly uses the high-hardness high-impact-resistance high-.

MgO·Al₂O₃·SiO₂Has similar performance to that of magnesium-aluminum-silicon high-strength glass fiber, especially has higher elastic modulus, higher strength and better impact resistance, and MgO-Al in the formula system₂O₃·SiO₂The introduction of the compound mainly uses the compound to improve the anti-falling performance, the compound is used as a basic component, the content of the component is 28-30 percent, and when the content is less than 28 percent, MgO & Al₂O₃·SiO₂The base structure is incomplete after sintering, the shock resistance of the sintered body is reduced, and when the content is more than 30 percent, excessive MgO & Al₂O₃·SiO₂Can block the subsequent chemical strengthening channel, influence the uniformity and depth of chemical strengthening and ensure the falling resistanceCan be reduced.

SiO₂·MgO·B₂O₃、SnO·P₂O₅、SiO₂·B₂O₃·ZnO、SiO₂·R₂O·TiO₂All are sintering aids, the sintering temperature and time can be effectively controlled by adjusting the proportion and the particle size distribution, and SiO₂·R₂O·TiO₂The introduction of Li, Na and K provides a part of ions for exchange for subsequent chemical strengthening, and the content satisfies SiO₂·Li₂O·TiO₂+SiO₂·K₂O·TiO₂≤SiO₂·Na₂The O & TiO2 is beneficial to controlling the concentration difference between K ions in the molten salt and K ions in the glass and the concentration difference between Na ions in the molten salt and Na ions in the glass to be large enough during K, Na ion exchange, thereby ensuring that the ion exchange can be controlled sufficiently.

2Li₂O·SiO₂，Na₂O·2SiO₂The three-roller grinding dispersion device is mainly used for reacting with added water when slurry is prepared to form jelly, is used for adjusting the overall viscosity of the slurry, and is convenient for better realizing three-roller grinding dispersion and pressing of a 3D shape. Meanwhile, the introduced Li and Na ions are the ion concentration difference required by chemically enhanced ion exchange, so that sufficient exchange is ensured.

SiC mainly improves the thermal radiation performance of the material, graphite mainly improves the thermal conductivity of the material, and the SiC and the graphite are matched to form a heat conduction network and a heat conduction network, so that the excellent and efficient heat dissipation effect of the material is realized. Meanwhile, the hardness of the whole material can be improved by SiC.

The high-heat-dissipation mobile phone 3D rear cover protection material and the preparation method thereof in the embodiments 1-5 (Table 1) of the invention comprise the following components in percentage by weight: 5-10% of MgAl₂O₄，28-30％MgO·Al₂O₃·SiO₂，5-8％SiO₂·MgO·B₂O₃，7-8％SnO·P₂O₅， 6-7.5％SiO₂·B₂O₃·ZnO，19-21％SiO₂·R₂O·TiO₂，2-3％2Li₂O·SiO₂，14-15％Na₂O·2SiO₂， 1-2％Bi₂O₃·B₂O₃2.5-4.5% of SiC and 0.8-2% of graphite. The specific implementation steps are as follows:

s1, the raw materials are weighed, mixed with water according to the proportion of 92:8 to 84:16, and premixed and stirred by a double-planet stirrer to form slurry.

S2 the premixed slurry is ground with a three-roll mill.

S3, the ground slurry is mixed and stirred by a double-planet stirrer.

S4, adding the slurry into a die for pressing, demoulding and drying in a mesh belt furnace.

S5, hot-pressing and sintering the dried slurry by using a silicon carbide mould.

S6, carrying out chemical strengthening on the hot-pressed and sintered material, wherein the specific chemical strengthening process comprises the following steps: and carrying out ion exchange treatment in potassium nitrate molten salt at the temperature of 430-450 ℃ for 2-5h to obtain the 3D mobile phone rear cover protective material.

The fineness test is referred to GB/T17473.2-2008.

The acid resistance test is referred to GB/T7962.14-2010.

The Vickers hardness test is referred to GB/T4340.1.

The ball drop test is referred to GB/T2130-2012.

The bending strength test is referred to GB/T36259-2018.

The fracture toughness test is referred to GB/T23806-2009.

Comparative example 1 is an actual measurement value of a commercially available glass material.

TABLE 1