阅读说明：本技术 一种包含聚四氟乙烯树脂的原料及混合工艺 (Raw material containing polytetrafluoroethylene resin and mixing process ) 是由 韩伏龙 李宝珠 武聪 张立欣 冯春明 乔韵豪 刘正 李攀 靳绍贤 于 2020-11-17 设计创作，主要内容包括：本发明涉及一种包含聚四氟乙烯树脂的原料及混合工艺,由以下质量百分比的原料组成：无机填料：40-75wt%；玻璃纤维：1-5wt%；聚四氟乙烯乳液：22-58wt%；硅烷偶联剂：0.5-1.5wt%；表面活性剂：0.1-0.4wt%；絮凝剂：0.02-0.08wt%。本发明制备的微波复合介质基板具有极高的介电常数均匀性,原料组份偏差小于0.4%。本发明原料混合工艺方法便捷,使复合原料与水分离,显著提高生产效率,单次原料混合量可达100kg以上,易于工业生产。(The invention relates to a raw material containing polytetrafluoroethylene resin and a mixing process, which consists of the following raw materials in percentage by mass: inorganic filler: 40-75 wt%; glass fiber: 1-5 wt%; polytetrafluoroethylene emulsion: 22-58 wt%; silane coupling agent: 0.5-1.5 wt%; surfactant (b): 0.1-0.4 wt%; flocculating agent: 0.02-0.08 wt%. The microwave composite dielectric substrate prepared by the invention has extremely high dielectric constant uniformity, and the component deviation of the raw material is less than 0.4%. The raw material mixing process method is convenient, the composite raw material is separated from water, the production efficiency is obviously improved, the mixing amount of the raw material for one time can reach more than 100kg, and the industrial production is easy to realize.)

1. A feedstock comprising polytetrafluoroethylene resin, characterized by: the composite material consists of the following raw materials in percentage by mass:

inorganic filler: 40-75 wt%;

glass fiber: 1-5 wt%;

polytetrafluoroethylene emulsion: 22-58 wt%;

silane coupling agent: 0.5-1.5 wt%;

surfactant (b): 0.1-0.4 wt%;

flocculating agent: 0.02-0.08 wt%.

2. A feedstock comprising polytetrafluoroethylene resin according to claim 1, wherein:

the inorganic filler is selected from one or more of alumina powder, aluminum nitride powder, silicon dioxide powder, titanium dioxide powder, strontium titanate powder, boron nitride powder and calcium sulfate powder.

3. A feedstock comprising polytetrafluoroethylene resin according to claim 1, wherein:

the glass fiber is selected from one or more of E-CR glass fiber and E glass fiber.

4. A feedstock comprising polytetrafluoroethylene resin according to claim 1, wherein:

the solid content of the polytetrafluoroethylene emulsion is selected from 21-61wt%, the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is selected from 0.25-0.35 mu m, the dynamic viscosity of the polytetrafluoroethylene emulsion is selected from 4-10mPa & s, and the surfactant content of the polytetrafluoroethylene emulsion is selected from 1-10 wt%.

5. A feedstock comprising polytetrafluoroethylene resin according to claim 1, wherein:

the silane coupling agent is selected from one or more of vinyl trichlorosilane, vinyl trimethoxy silane, phenyl trimethoxy silane, anilinomethyl triethoxy silane, 3-aminopropyl triethoxy silane, 3- (2-aminoethylamino) propyl trimethoxy silane and N-aminoethyl-Y-aminopropyl triethoxy silane.

6. A feedstock comprising polytetrafluoroethylene resin according to claim 1, wherein:

the surfactant is selected from one or more of polyethylene glycol octyl phenyl ether, polyethylene glycol trimethyl nonyl ether, nonylphenol polyoxyethylene ether and N-sodium lauroyl sarcosine.

7. A feedstock comprising polytetrafluoroethylene resin according to claim 1, wherein:

the flocculating agent is selected from: one or more of ammonium carbonate, polyacrylamide, polyethylene oxide, polyethyleneimine, ammonium bicarbonate, aluminum sulfate and polyaluminium chloride.

8. A process for mixing raw materials containing polytetrafluoroethylene resin according to claim 1, characterized in that: the method comprises the following steps:

firstly, chopping glass fiber, wherein the length of the glass fiber after treatment is 6-200 mu m;

secondly, adding a silane coupling agent and a surfactant into water, wherein the pH value of the water is less than or equal to 4.6, and the mass of the water is 900 times of the mass sum of the silane coupling agent and the surfactant;

adding inorganic filler powder into the water, starting stirring at the rotation speed of 100 plus materials for 150 r/min;

fourthly, adding the glass fiber treated in the step three, adding polytetrafluoroethylene emulsion, and adjusting the rotating speed to 160-220 r/min;

adding a flocculating aid into the composite slurry, continuously stirring, keeping the stirring speed at 50-300r/min for 2-12min until the raw material is completely flocculated in water, and completely separating the composite raw material from the water to form flocculated particles with the diameter of more than or equal to 6 mm;

sixthly, transferring the flocculated raw materials into a filtering device, and filtering excessive water;

and seventhly, transferring the composite raw material into a drying oven, drying at 70-180 ℃, and removing water and a flocculating agent to obtain the composite raw material.

Technical Field

The invention relates to the technical field of composite raw material mixing, in particular to a raw material containing polytetrafluoroethylene resin and a mixing process, wherein the composite raw material has high component uniformity and can be used in the fields of manufacturing high-frequency copper-clad plates and the like.

Background

The 5G technology and the electronic military field require that the electronic material medium is uniform and the dielectric constant is stable. The microwave composite dielectric substrate taking the polytetrafluoroethylene resin as the matrix has excellent performance, and particularly the electrical performance of the microwave composite dielectric substrate in an ultrahigh frequency band (more than 30 GHz) is obviously superior to that of other materials. Inorganic filler powder and glass fiber are usually added to a polytetrafluoroethylene resin substrate to adjust the properties of the substrate, such as dielectric constant, linear thermal expansion coefficient, and the like. Because the difference of the dielectric constants of the polytetrafluoroethylene and the added inorganic filler powder and other raw materials is large, the microwave composite dielectric substrate can be ensured to have a stable dielectric constant only if the mixed composite raw materials have extremely high uniformity. The existing composite raw material mixing process containing polytetrafluoroethylene resin, such as a dry mixing means such as a V-shaped mixer described in Chinese patent CN201910316897.1, has poor mixing uniformity, and the polytetrafluoroethylene resin is easy to be oriented in the mixing process to influence the performance of the material; the existing wet mixing method, such as the ball milling method described in chinese patent CN201711456721.3, is inefficient and cannot be produced in large scale.

The mixing technology described by the method is simple and convenient, can be used for preparing the composite raw material containing the polytetrafluoroethylene resin in a large scale, has extremely high uniformity, and can be used for industrial production in the fields of high-frequency copper clad plates and the like.

Disclosure of Invention

In view of the state and the defects of the prior art, the invention provides a raw material containing polytetrafluoroethylene resin and a mixing process, and the mixed composite raw material has extremely high uniformity and can be used in the fields of microwave composite medium substrate manufacturing and the like.

The technical scheme adopted by the invention is as follows: a raw material containing polytetrafluoroethylene resin comprises the following raw materials in percentage by mass:

inorganic filler: 40-75 wt%; glass fiber: 1-5 wt%; polytetrafluoroethylene emulsion: 22-58 wt%;

silane coupling agent: 0.5-1.5 wt%; surfactant (b): 0.1-0.4 wt%; flocculating agent: 0.02-0.08 wt%.

A raw material mixing process containing polytetrafluoroethylene resin comprises the following steps:

firstly, chopping glass fiber, wherein the length of the glass fiber after treatment is 6-200 mu m;

secondly, adding a silane coupling agent and a surfactant into water, wherein the pH value of the water is less than or equal to 4.6, and the mass of the water is 900 times of the mass sum of the silane coupling agent and the surfactant;

adding inorganic filler powder into the water, starting stirring at the rotation speed of 100 plus materials for 150 r/min;

fourthly, adding the glass fiber treated in the step three, adding polytetrafluoroethylene emulsion, and adjusting the rotating speed to 160-220 r/min; adding a flocculating aid into the composite slurry, continuously stirring, keeping the stirring speed at 50-300r/min for 2-12min until the raw material is completely flocculated in water, and completely separating the composite raw material from the water to form flocculated particles with the diameter of more than or equal to 6 mm;

sixthly, transferring the flocculated raw materials into a filtering device, and filtering excessive water;

and seventhly, transferring the composite raw material into a drying oven, drying at 70-180 ℃, and removing water and a flocculating agent to obtain the composite raw material.

Preferably, the inorganic filler is one or more selected from alumina powder, aluminum nitride powder, silica powder, titanium dioxide powder, strontium titanate powder, boron nitride powder and calcium sulfate powder.

Preferably, the glass fiber is selected from one or more of E-CR glass fiber and E glass fiber.

Preferably, the solid content of the polytetrafluoroethylene emulsion is selected from 21-61wt%, the average particle size of polytetrafluoroethylene in the polytetrafluoroethylene emulsion is selected from 0.25-0.35 μm, the average particle size of polytetrafluoroethylene is selected from 0.25-0.35 μm, the dynamic viscosity of the polytetrafluoroethylene emulsion is selected from 4-10mPa & s, and the surfactant content of the polytetrafluoroethylene emulsion is selected from 1-10 wt%.

Preferably, the silane coupling agent is selected from one or more of vinyltrichlorosilane, vinyltrimethoxysilane, phenyltrimethoxysilane, anilinomethyltrimethoxysilane, anilinomethyltriethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane and N-aminoethyl-Y-aminopropyltriethoxysilane.

Preferably, the surfactant is selected from one or more of polyethylene glycol octyl phenyl ether, polyethylene glycol trimethyl nonyl ether, nonylphenol polyoxyethylene ether and N-lauroyl sarcosine sodium.

Preferably, the flocculating agent is selected from: one or more of ammonium carbonate, polyacrylamide, polyethylene oxide, polyethyleneimine, ammonium bicarbonate, aluminum sulfate and polyaluminium chloride.

The invention has the following beneficial effects: the existing composite raw material mixing process containing polytetrafluoroethylene resin has poor component uniformity of composite raw materials and low single mixing amount, and the relative dielectric constant range of 24 points of the prepared microwave composite dielectric substrate is 0.04-0.08, so that the requirement of the microwave composite dielectric substrate is difficult to meet. The microwave composite dielectric substrate prepared by the invention has extremely high dielectric constant uniformity, and the component deviation of the raw material is less than 0.4%. The copper-clad plate prepared by the raw material mixing process has the dielectric constant covering of 2.45-3.05, the relative dielectric constant very difference of 24 points in a 457X 609mm substrate is less than 0.04, the X/Y/Z triaxial thermal expansion coefficient of the substrate is less than 12/12/24 ppm/DEG C, the water absorption is less than 0.05 percent, the relative dielectric constant temperature coefficient is between-10 ppm/DEG C and 10 ppm/DEG C, and the copper-clad plate has very stable dielectric property.

The raw material mixing process method is convenient, the composite raw material is separated from water, the production efficiency is obviously improved, the mixing amount of the raw material for one time can reach more than 100kg, and the industrial production is easy to realize.

Detailed Description

Example 1;

a raw material containing polytetrafluoroethylene resin comprises the following raw materials in percentage by mass:

1wt% of glass fiber, 63wt% of silicon dioxide powder, 35wt% of polytetrafluoroethylene emulsion, 0.7wt% of anilinomethyltrimethoxysilane, 0.24wt% of polyethylene glycol trimethylnonyl ether and 0.06wt% of ammonium carbonate.

The preparation method comprises the following steps: firstly, processing glass fibers, wherein the average length of the processed glass fibers is 15-30 mu m; dissolving polyethylene glycol trimethyl nonyl ether and anilinomethyl trimethoxy silane in water with pH =4, and mixing for 1 h; thirdly, adding silicon dioxide powder, starting stirring, rotating at the speed of 120r/min, and mixing for more than 0.5 h; adding the treated glass fiber into the prepared slurry, mixing, adding polytetrafluoroethylene emulsion with the solid content of 35%, rotating at 180r/min, and mixing for 0.5 h; fifthly, adding ammonium carbonate solid, and mixing for 10min at the speed of 180 r/min; sixthly, transferring the flocculated raw materials into a filtering device, and filtering excessive water;and transferring the composite raw material into an oven, drying at 150 ℃/10h, and removing water and a flocculating agent to obtain the composite raw material.

Through detection, the relative dielectric constant of the microwave composite dielectric substrate prepared by the raw material mixing process is 2.98, the relative dielectric constant range of 24 points in the 457X 609mm substrate is less than 0.03, and the dielectric loss factor is 1.2X 10^-3The water absorption rate is 0.02%, the temperature coefficient of the relative dielectric constant is 6 ppm/DEG C, the three-axis thermal expansion coefficient of X/Y/Z is 12/11/23 ppm/DEG C, and the uniformity is extremely high.

Example 2;

a raw material containing polytetrafluoroethylene resin comprises the following raw materials in percentage by mass:

5wt% of E glass fiber, 40.4wt% of silicon dioxide powder, 54wt% of polytetrafluoroethylene emulsion, 0.4wt% of 3-aminopropyltriethoxysilane, 0.17wt% of polyethylene glycol trimethylnonyl ether and 0.03wt% of ammonium carbonate.

The preparation method comprises the following steps: firstly, processing glass fiber, wherein the length of the processed glass fiber is 6-15 mu m; dissolving polyethylene glycol trimethyl nonyl ether and 3-aminopropyltriethoxysilane in water with pH =4.3, and mixing for 45 min; thirdly, adding silicon dioxide powder, starting stirring, rotating at the speed of 110r/min, and mixing for more than 0.5 h; adding the treated glass fiber into the prepared slurry, mixing, adding polytetrafluoroethylene emulsion with the solid content of 32%, and rotating at 160 r/min; mixing for 0.5 h; fifthly, adding ammonium carbonate solid, and mixing for 10min at a speed of 160 r/min; sixthly, transferring the flocculated raw materials into a filtering device, and filtering excessive water;and transferring the composite raw material into an oven, drying at the temperature of 120 ℃/15h, and removing water and a flocculating agent to obtain the composite raw material.

Through detection, the relative dielectric constant of the microwave composite dielectric substrate prepared by the raw material mixing process is 2.55, the relative dielectric constant range of 24 points in the 457X 609mm substrate is less than 0.02, and the dielectric loss factor is 0.8X 10^-4The water absorption rate is 0.01%, the temperature coefficient of the relative dielectric constant is 5 ppm/DEG C, the three-axis thermal expansion coefficient of X/Y/Z is 12/12/24 ppm/DEG C, and the uniformity is extremely high.