CN101260196B - White polyester solar energy battery back film and preparation method thereof - Google Patents

Abstract

The invention relates to a white polyester solar cell back film and a preparation method thereof, belonging to the polyester film field. The white polyester solar cell back film consists of a polyester chip and a white polyester master batch, wherein the weight percent ratio of the polyester chip and the white polyester master batch is between 1.0:1 and 9.0:1; the white polyester master batch comprises the following components in weight percent: 35 to 89.4 percent of polyester chip, 0.5 to 10 percent of silicon dioxide, 10 to 50 percent of titanium dioxide and 0.1 to 5 percent of ultraviolet light absorbent; moreover, the silicon dioxide undergoes organic surface treatment with the particle diameter ranging between 10 and 100 nm, and the titanium dioxide also undergoes organic surface treatment with the particle diameter ranging between 100 and 1,000 nm. The white polyester solar cell back film has the characteristics of excellent light tight performance, insulativity, aging resistance and barrier property.

Description

White polyester solar cell back film and preparation method thereof

technical field

The invention relates to a white polyester solar battery back film and a preparation method thereof, belonging to the field of polyester films.

Background technique

Polyester film is usually colorless, transparent, glossy, with good strength, toughness and elasticity. Compared with other plastic films, it has high relative density, high tensile strength, moderate elongation, high impact strength and low air permeability. Good heat resistance and high transparency, and non-toxic and harmless, and widely used in packaging materials. With the rapid development of science and technology, polyester film has been applied in capacitors, photosensitive materials, audio and video, and solar cells. As disclosed in CN101065849A, "Easy Adhesive Polyester Film and Solar Cell Back Protective Film Using It" consists of a polyester film and a resin film coated on one side of the polyester film, and the crystallographic orientation of the polyester film ends Previously, the resin film coating solution was coated on the polyester film, and then dried, stretched, and heat-treated to form an easy-adhesive polyester film. Due to the two-layer structure of this solar cell holding film, the manufacturing process is complicated, and special equipment is required for thermal processing. Not only the manufacturing cost is high, but also when the surface coating layer is processed, the surface coating layer is easily scraped off and the performance is damaged. decline. In addition, because the resin film is composed of resin and cross-linking agent, the resin is composed of polyester resin, acrylic resin and polyvinyl alcohol, etc., and the cross-linking agent contains oxazoline-based polymers or melamine, urea resin or ring Oxygen resin, because solvents must be used in the preparation process of film coating liquid, and conventional solvents contain volatile organic compounds, so during the production and use of polyester films, volatile organic compounds cause certain harm to the environment. And CN1286911C discloses "a kind of black opaque polyester film and its preparation method", which is composed of polyester chip, carbon black type black polyester masterbatch and carbon black organic dye compound type black polyester masterbatch. Opaque polyester film can achieve uniform blackness, bright surface, good thermal stability, etc., but it is not resistant to aging and has poor barrier performance. It can only be used for decoration, packaging, etc., but not for solar cells. protective film.

Contents of the invention

The purpose of the present invention is to provide a white polyester solar cell back film with good light-shielding property, good aging resistance and barrier property and its preparation method.

The technical scheme of the present invention to achieve the above object is: a white polyester solar cell back film, characterized in that: it is composed of polyester chips and white polyester masterbatch, and the ratio of polyester chips and white polyester The masterbatch ratio is 1.0-9.0:1, and the white polyester masterbatch contains the following components, by weight percentage, 35%-89.4% of polyester chips, 0.5%-10% of silicon dioxide, 10%- 50% of titanium dioxide and 0.1-5% of ultraviolet light absorber, the silicon dioxide undergoes organic surface treatment with a particle size of 10-100nm, and the titanium dioxide undergoes organic surface treatment with a particle size of 100-1000nm.

The preparation method of the white polyester solar cell back film of the present invention is characterized in that:

(1) According to weight percentage, 0.5%-10% of silicon dioxide and 10%-20% of polyester chips are surface-treated in a twin-screw extruder in a molten state and extruded to make masterbatches, ground Stand-by, similarly 10%-50% titanium dioxide and 25%-69.4% polyester chips are surface-treated in a twin-screw extruder in a molten state and extruded to make masterbatches, ground for use, and the aforementioned two The masterbatch and 0.1-5% of ultraviolet light absorber are fully mixed in a high-speed mixer, and then extruded with a twin-screw extruder to obtain a white polyester masterbatch;

(2) Put polyester chips and white polyester masterbatch in a ratio of 1.0-9.0:1 into a high-speed mixer and fully mix, then pre-crystallize in a vacuum drum at a temperature of 60-100°C for 3-6 hours;

(3) Dry the pre-crystallized mixture at a temperature of 120-170° C. for 2-6 hours;

(4) Feed the dried mixture into an extruder to melt, extrude, and cast into sheets at a temperature of 270-300°C to make thick sheets;

(5) The thick sheet is preheated at a temperature of 50-85°C, enters the far-infrared heating zone of 110°C-50°C, and stretches longitudinally at a line speed of 3m/min-5m/min, and the longitudinal stretching ratio is 1.5- 3.5;

(6) After preheating the longitudinally stretched film at a temperature of 90-135° C., and then stretching it transversely at a temperature of 100-150° C., the stretching ratio of the transverse stretching is 1.5-3.8;

(7) After setting the film at a temperature of 200-240°C, it is wound up.

The white polyester solar cell back film of the present invention is made up of polyester chip and white polyester masterbatch, and white polyester masterbatch adopts silicon dioxide, titanium dioxide and ultraviolet light absorber, owing to adding nano-scale silicon dioxide, Not only the crystallinity of the solar cell back film is significantly improved, but also because of the organic surface treatment of the silicon dioxide, carboxyl groups are introduced on the surface of the silicon dioxide, so that the silicon dioxide and the polyester matrix are chemically bonded, thereby improving the The combination of the two makes the solar cell back film have good barrier properties and low water absorption, effectively preventing the solar cell from being corroded by water, oxygen, corrosive gas and liquid, etc. The present invention adds surface-treated titanium dioxide to improve the properties of titanium dioxide activated by light, so that titanium dioxide has better dispersibility and light-shielding properties in the back film of solar cells, and after white titanium dioxide is mixed with an ultraviolet light absorber, the While maintaining the excellent physical properties of the original polyester film, the solar cell back film has better light-shielding properties and aging resistance, which improves the service life of the solar cell. In the present invention, the white polyester masterbatch is prepared first, and then blended with polyester slices to form a back film, which can ensure sufficient mixing of materials, especially the surfaces of titanium dioxide and silicon dioxide have been organically treated, so they are used in the back film of solar cells It has good dispersibility. In addition, the mixture of polyester chips and white polyester masterbatch is pre-crystallized at low temperature first, and then dried, which eliminates the problem of agglomeration of the mixture caused by direct high-temperature drying. The white color of the film is more uniform and the performance is stable. The present invention has stable industrialized production and good production processability, and the white polyester solar cell back film of the present invention can be prepared by using existing processing equipment, which can reduce the manufacturing cost.

Detailed ways

The white polyester solar battery back film of the present invention is composed of polyester chips and white polyester masterbatch components. Slicing adopts bottle grade or film grade, and the specific weight parts are as shown in Table 1,

Table 1

Component name Example 1 Example 2 Example 3 Implementation column 4 Example 5 Example 6 Polyester chips 1 3 5 6 8 9 White polyester masterbatch 1 1 1 1 1 1

Percentage by weight, the white polyester masterbatch of the present invention has the following components: 35%-89.4% polyester chips, 0.5%-10% silicon dioxide, 10%-50% titanium dioxide and 0.1-5% As for the ultraviolet light absorber, silicon dioxide is treated with an organic surface and has a particle size of 10-100nm, and titanium dioxide is treated with an organic surface and has a particle size of 100-1000nm. The white polyester masterbatch is preferably 50%-75% polyester chip, 1%-7% silicon dioxide, 23%-40% titanium dioxide and 1-3% ultraviolet absorber. The polyester chips used for the white polyester masterbatch are selected from high-viscosity polyester chips, and the ultraviolet light absorbers are selected from benzotriazoles or benzophenones, and the specific weight percentages are shown in Table 2.

Table 2

White polyester masterbatch components Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Polyester chips 35 50 55 65 75 89.4 Silica 10 7 5 3 1 0.5 Titanium dioxide 50 40 38 30 twenty three 10 UV absorber 5 3 2 2 1 0.1

The preparation method of white polyester solar cell back film of the present invention is as follows:

(1) According to weight percentage, 0.5%-10% of silicon dioxide and 10%-20% of polyester chips are surface-treated in a twin-screw extruder in a molten state and extruded to make masterbatches, ground Stand-by, similarly surface treat 10%-50% titanium dioxide and 25%-69.4% polyester chips in a twin-screw extruder in a molten state and extrude them into masterbatches, grind them for use, and mix the above two After fully mixing the seed masterbatch and 0.1-5% ultraviolet light absorber in a mixer, the speed of the mixer is more than 300r/min, extruding with a twin-screw extruder to obtain a white polyester masterbatch. The specific weight percentage of the white polyester masterbatch can be shown in Table 2.

(2) Put the polyester chips and white polyester masterbatch into the blender in a weight ratio of 1.0-9.0:1 and fully mix them. The speed of the blender is ≥300r/min. Polyester chips and white polyester The specific weight and part ratio of the masterbatch can be shown in Table 1, and then pre-crystallized in a vacuum drum at a temperature of 60-100° C. for 3-6 hours.

(3) Dry the pre-crystallized mixture at a temperature of 120-170° C. for 2-6 hours, and control the moisture content below 30 ppm.

(4) Feed the dried mixture into an extruder to melt, extrude, and cast into sheets at a temperature of 270-300°C to make thick sheets;

(5) The thick sheet is first preheated at 50-85°C, and then enters the far-infrared heating zone of 110°C-50°C, stretched longitudinally at a line speed of 3m/min-5m/min, and the longitudinal stretching ratio is controlled In 1.5-3.5.

(6) Preheating the longitudinally stretched film at a temperature of 90-135° C., and then stretching it transversely at a temperature of 100-150° C., the stretching ratio of the transverse stretching is controlled at 1.5-3.8.

(7) The diaphragm is shaped at a temperature of 200-240° C., and finally wound to obtain a white polyester solar battery back film.

Each embodiment of the present invention was tested respectively, and the test results are shown in Table 3.

table 3

It can be seen from Table 3 that the white polyester solar cell back film of the present invention has good light-shielding properties, insulating properties, and good aging resistance and barrier properties.

Claims (4)

1. white polyester solar energy battery back film, it is characterized in that: form by polyester slice and white polyester masterbatch, by ratio of weight and the number of copies, polyester slice is 1.0-9.0 with white polyester masterbatch ratio: 1, wherein, described white polyester masterbatch contains following component, by weight percentage, the polyester slice of 35%-89.4%, the silicon-dioxide of 0.5%-10%, the titanium dioxide of 10%-50% and the ultraviolet absorbers of 0.1-5%, silicon-dioxide is through organising surface treatment, and particle diameter is at 10-100nm, and titanium dioxide is through organising surface treatment, and particle diameter is at 100-1000nm.

2. white polyester solar energy battery back film according to claim 1 is characterized in that: the polyester slice that described white polyester masterbatch is 50%-75%, the silicon-dioxide of 1%-7%, the titanium dioxide of 23%-40% and the ultraviolet absorbers of 1-3%.

3. white polyester solar energy battery back film according to claim 1 is characterized in that: described ultraviolet absorbers is selected benzotriazole category or benzophenone for use.

4. the preparation method of a white polyester solar energy battery back film is characterized in that:

(1), by weight percentage, the polyester slice of the silicon-dioxide of 0.5%-10% and 10%-20% carried out surface treatment under the molten state in twin screw extruder and extrude make master batch, grind stand-by, equally the polyester slice of the titanium dioxide of 10%-50% and 25%-69.4% is carried out surface treatment under the molten state in twin screw extruder and extrude make master batch, grinding is stand-by, the ultraviolet absorbers of aforementioned two kinds of master batches and 0.1-5% in mixer behind the thorough mixing, is extruded with twin screw extruder and to be made the white polyester masterbatch;

(2), by ratio of weight and the number of copies, with polyester slice and white polyester masterbatch by 1.0-9.0: 1 put into the mixer thorough mixing after, in vacuum drum under 60-100 ℃ of temperature pre-crystallization 3-6 hour;

(3), with the dry 2-6h under 120-170 ℃ of temperature of the batch mixing after the pre-crystallization;

(4), dried batch mixing is sent into fusion under 270-300 ℃ of temperature in the forcing machine, extruded, casts sheet, make sheet;

(5), sheet preheating under 50-85 ℃ of temperature, enter 110 ℃-50 ℃ far-infrared heating district, with the linear velocity longitudinal stretching of 3m/min-5m/min, the longitudinal stretching multiplying power is at 1.5-3.5;

(6), will be after preheating under the 90-135 ℃ of temperature through the diaphragm of longitudinal stretching, cross directional stretch under 100-150 ℃ of temperature again, the stretching ratio of cross directional stretch is at 1.5-3.8;

(7), diaphragm is finalized the design under 200-240 ℃ of temperature condition the back rolling.