CN106010414A - High-cohesiveness fluorocarbon coating and application - Google Patents

Abstract

The invention discloses a high-bonding fluorocarbon paint, which is used as a bonding layer of a solar cell backboard. The fluorocarbon coating is composed of components A and B, wherein component A contains an isocyanate curing agent as a crosslinking agent; component B includes fluorocarbon resin, modified polyolefin, modified by functional coupling agent Inorganic filler A. In the present invention, the inorganic filler treated with the functional coupling agent acts as a "bridge" at the interface between the bonding layer and EVA, effectively improving the bonding force between the coating and EVA; while the modification introduced by the bonding layer Polyolefins exhibit excellent adhesion to corona-treated polyester supports containing polar groups on the surface. The fluorocarbon coating adhesive layer prepared by the present invention can simultaneously take into account the adhesion with the packaging material and the polyester support, has high peel strength with the packaging material, good adhesion, and has durable adhesion under humid heat and light environments and excellent weather resistance, and can be prepared at low cost.

Description

A kind of high adhesion fluorocarbon coating and its application

technical field

The invention relates to a coating, in particular to a fluorocarbon coating suitable for preparing a coated solar battery back plate and improving the adhesion between packaging materials and the back plate.

Background technique

The application of solar energy is mainly to convert it into electrical energy through solar cell modules and utilize it. It does not emit carbon dioxide during power generation and has a small environmental burden. It is a representative of green energy. At present, in a conventional solar cell module, the solar cell unit is sandwiched between the front glass on the sunlight incident side and the so-called back sheet placed on the opposite side (back side), wherein, between the front glass and the solar cell unit and the sun The battery cells and the back plate are respectively sealed with packaging materials (usually ethylene-vinyl acetate copolymer (EVA) resin). In order to achieve a 25-year service life of the solar cell module, it is important to protect the solar cell unit and the sealing material from wind, rain, moisture, high temperature, sand and dust, etc. of tightness.

Because of its excellent heat resistance, mechanical properties and chemical resistance, and cost advantages, polyester film is usually selected as the support of the backplane. However, due to the different components of the polyester support and the packaging material EVA , so it is difficult to directly bond the two, and it is necessary to bond the two through an intermediate adhesive layer. The adhesion between the encapsulant and the backsheet includes both the interface between the polyester support and the adhesive layer and the interface between the adhesive layer and the encapsulant, so ensuring the hermeticity of the module requires improving both. interface performance. At present, the mainstream products of backsheets include composite type (TPT, KPK) and coated type. Due to the high manufacturing cost of composite type backsheets, and the fluorine film as the adhesive layer has poor adhesion to EVA, and there is also a combination of glue and polyester. The ester support is easily aged and peeled off after being bonded by heat and humidity treatment.

Patent CN105097971 A makes the fluorocarbon resin and the EVA in the packaging material have good adhesion through the addition of a functional coupling agent. The fluorocarbon coating described in this patent only has a fluorocarbon resin and a curing agent other than the functional coupling agent. It can ensure the reflectivity of the inner coating, and after high-temperature and high-humidity aging treatment, the yellowing is relatively large and the adhesion is poor. At the same time, the curing agent contains aromatic isocyanate, which further increases the yellowing and affects the weather resistance and appearance of the backplane. . The techniques described in JP-A No. 2006-152013 and JP-A No. 2003-060218 can improve the initial adhesion between the sealing material and the backsheet, but have poor durability in a relatively high-temperature and high-humidity environment. Patent CN 102792462 A uses polyolefins, polyesters, acrylic polymers and polyurethanes as adhesives, and adds inorganic fine particles to form an adhesive layer coated on the surface of polyester supports, which improves the performance of backplanes and sealing materials in hot and humid environments. Durability, but the adhesive described in it has poor weather resistance and serious yellowing after aging, which cannot meet the 25-year service life of the backsheet outdoors. Patent CN 105102228 A sets a laminated film on a polyester support. The laminated film has a two-layer structure. The first layer is a modified polyolefin resin of a copolymer of ethylene, (meth)acrylate and acid anhydride, and the second layer is a modified polyolefin resin. The layer is an olefin resin, which effectively has both the adhesion to EVA and the adhesion to the polyester support, but its manufacturing process is complicated and the requirements are high. The thickness of the laminated film is as low as 0.05 μm, and industrial production has certain challenge.

In view of the above circumstances, it is important to provide an adhesive layer that has excellent adhesion to the packaging material and also has excellent adhesion to the polyester support. In particular, the adhesive layer is not only durable under normal temperature and pressure. It is excellent, has bonding durability and excellent weather resistance in humid heat and light environment, and can be prepared at low cost, which is particularly important for the protection of solar cell components.

Contents of the invention

The object of the present invention is to provide a high-adhesive fluorocarbon coating aiming at the deficiencies of the prior art.

The purpose of the present invention is achieved through the following technical solutions: a high-adhesive fluorocarbon coating, which is composed of two components A and B; the component A is a crosslinking agent, including 40 to 65 parts by weight of Isocyanate curing agent and 35-60 parts by weight of anhydrous diluent A; said component B contains 35-50 parts by weight of fluorocarbon resin, 2-15 parts by weight of modified polyolefin, 5-25 parts by weight of Inorganic filler A modified by coupling agent, 15-35 parts by weight of anhydrous diluent B; The ratio of the amount of mixing is 0.4 to 1.5, that is, high-adhesive fluorocarbon coatings.

Further, the B component can also include 0-15 parts by weight of fluorocarbon resin, 0.1-2 parts by weight of catalyst, 0-20 parts by weight of inorganic filler B, 0-0.5 parts by weight of leveling agent and 0.2-2 parts by weight of wetting One or more dispersants;

The catalyst is a metal compound catalyst;

The inorganic filler B is rutile titanium dioxide;

The wetting and dispersing agent is composed of a copolymer solution containing acidic groups, a block copolymer solution of polyamines, acrylic block copolymers, highly branched polyesters, and hydroxyl functional carboxylates. or a variety of mixtures in any proportion;

The anhydrous diluent A and anhydrous diluent B are each independently a mixture of one or more of the following in any proportion: C7-C10 aromatic hydrocarbons, C3-C8 ester compounds, C1-C5 alcohols Compounds, C2 ~ C6 ketone compounds.

Further, the B component is prepared by the following method: Weigh the anhydrous diluent B and pour it into a sand mill, add fluorocarbon resin to the diluent B sequentially under stirring at a speed of 1500-3500 rpm, and modify the polyolefin , Inorganic filler A, after pre-dispersion, milled to particle size ≤ 5 microns; then add one or more of polyester resin, wetting and dispersing agent, catalyst, leveling agent, inorganic filler B, mechanically mix evenly , add anhydrous diluent B to adjust the viscosity to 500-2000mPa·S, filter, and store in a dry sealed container for later use.

Further, the ratio of the amount of isocyanate groups (NCO) in component A to hydroxyl groups (OH) in component B is preferably 0.5-1.2, more preferably 0.8-1.0.

Further, the isocyanate curing agent is aliphatic isocyanate; the fluorocarbon resin is composed of one or two solvent-soluble vinylidene fluoride-type, chlorotrifluoroethylene-type, tetrafluoroethylene-type fluorocarbon resins according to any Proportional mixing composition, the hydroxyl value of the fluorocarbon resin is 45-60 mgKOH/g, the acid value is 2-12 mgKOH/g, the solid content is ≥ 50%, and the fluorine content is 20wt%-30wt%;

Further, the content of the modified polyolefin is preferably 5% to 30% of the fluorocarbon resin, more preferably 10% to 25%, which can be grafted polyolefin, ester modified polyolefin, hydroxyl-terminated polyolefin Olefins, including low-density polyethylene with terpolymers of acrylates and maleic anhydride, ethylene-(meth)acrylate-maleic anhydride copolymers, ethylene-propylene-(meth)acrylate-maleic anhydride Alkenedic anhydride copolymer, hydroxyl terminated polybutadiene, hydrogenated hydroxyl terminated polybutadiene, maleic anhydride grafted polybutadiene, maleic anhydride grafted polypropylene, ethylene-propylene-butene-(methyl) Acrylate-maleic anhydride copolymers, among which ethylene-(meth)acrylate-maleic anhydride copolymers are most preferred.

Further, the inorganic filler A is treated with a functional coupling agent, and the inorganic filler A is composed of silica, calcium carbonate, magnesium carbonate, zinc oxide, aluminum oxide, talcum powder, wax powder, kaolin, white corundum, barium sulfate, ceramic One or more of fine powder and carbon black are mixed in any proportion; the functional coupling agent is composed of titanate coupling agent, aluminate coupling agent, fluorosilane modified coupling agent, zirconic acid One or more of ester coupling agent, aluminum-zirconate coupling agent and aluminum-titanium composite coupling agent are mixed in any proportion;

Further, the specific treatment of the functional coupling agent is as follows: first, 100 parts by weight of inorganic filler A is added to 30 to 80 parts by weight of anhydrous diluent A or B, and ultrasonically dispersed at a temperature of 30°C to 50°C for 0.5 h ~ 3h, after uniform dispersion, then add 0.1 ~ 10 parts by weight of functional coupling agent, and then ultrasonically treat at 50°C ~ 60°C for 1h ~ 3h, to obtain inorganic filler A treated with coupling agent; The amount used is preferably 0.3 to 5 parts by weight.

A use of the above-mentioned high-adhesive fluorocarbon coating on solar modules, the application is specifically: coating the fluorocarbon coating on a polyester support to prepare a high-adhesive back sheet; and then applying the high-adhesive back sheet The board and the packaging material are laminated; the average thickness of the polyester support is 50-300 μm, and the carboxyl content is 0.5 equivalent/t to 35 equivalent/t, which is polyethylene terephthalate (PET), polyethylene A single-layer or multi-layer film made of ethylene naphthalate (PEN), polybutylene terephthalate (PBT), and polytrimethylene terephthalate (PTT); the packaging material is ethylene- Copolymer vinyl acetate (EVA).

Further, the polyester support is surface-treated before coating the fluorocarbon coating, and the surface treatment is selected from corona treatment, flame treatment, low-pressure plasma treatment, atmospheric pressure plasma treatment, ultraviolet treatment, etc.; preferably corona treatment treatment, the corona treatment time is 0.5s ~ 100s; the coating method is selected from brush coating, dip coating, roller coating, spray coating; the coating thickness is 3 ~ 30 μm, the curing temperature is 150 ° C ~ 200 ° C, the curing time 1min to 15min.

The beneficial effect of the present invention is: the present invention provides a kind of high cohesive fluorocarbon coating, as the adhesive layer of solar cell panel, the surface of the inorganic filler treated with the functional coupling agent in the adhesive layer contains the active functional group in the fluorocarbon resin The groups that undergo chemical reactions can also react with the free radicals generated by EVA during the lamination process to form chemical bonds, and act as a "bridge" at the interface, effectively improving the adhesion between the coating and EVA. On the performance of high peel strength. At the same time, after the PET is treated, the surface contains a large number of hydroxyl groups and carboxyl groups. During the curing process, it reacts with the crosslinking agent in the first component to form a chemical bond to improve the adhesion between the adhesive layer and the polyester support. At the same time, the corona The treated polyester support with polar groups on the surface exhibits excellent adhesion to the modified polyolefin, and shows good adhesion macroscopically. The fluorocarbon coating adhesive layer prepared by the present invention can take into account the adhesion with the packaging material and the polyester support at the same time, has high peel strength with the packaging material, high adhesion, and has durable adhesion in humid heat and light environments and excellent weather resistance, and can be prepared at low cost.

detailed description

The present invention will be described in detail below, wherein, the numerical range represented by "～" in this specification refers to the range including the numerical value described before and after "～" as the lower limit value and the upper limit value, and unless otherwise specified, the range Appearing "parts" and "%" are based on mass.

The high-adhesive fluorocarbon coating of the present invention consists of two components, A and B; the component A is a crosslinking agent for the bonding layer, which consists of 40-65 parts by weight of isocyanate curing agent and 35-60 parts by weight of Anhydrous diluent A is prepared by mixing evenly, and stored in a dry airtight container for use; said component B contains at least 35-50 parts by weight of fluorocarbon resin, 2-15 parts by weight of modified polyolefin, 5-5 parts by weight 25 parts by weight of inorganic filler A modified by functional coupling agent, and 15-35 parts by weight of anhydrous diluent B.

In order to further improve the bonding performance of the bonding layer, increase the reaction rate of the two components, increase the hiding power of the coating and improve the overall performance of the coating, the B component can also include 0 to 15 fluorocarbon resins, 0.1-2 parts by weight of catalyst, 0-20 parts by weight of inorganic filler B, 0-0.5 parts by weight of leveling agent, 0.2-2 parts by weight of wetting and dispersing agent, especially preferably at least containing catalyst and wetting and dispersing agent.

The preparation steps of the B component are as follows: Weigh 15-35 parts by weight of anhydrous diluent B and pour it into a sand mill, and add 35-50 parts by weight of fluorocarbon resin to the diluent B under low-speed stirring. 15 parts by weight of modified polyolefin, 0.2 to 2 parts by weight of wetting and dispersing agent, 5 to 25 parts by weight of inorganic filler A, after pre-dispersion, milled to a particle size of ≤5 microns, as required in the coating composition Use optional additives, although not necessary, such additives include 0.1 to 2 parts by weight of catalyst, 0 to 0.5 parts by weight of leveling agent, 0 to 15 parts by weight of polyester resin, 0 to 20 parts by weight of inorganic filler B, mechanically mixed uniformly , add an appropriate amount of anhydrous diluent A as needed to adjust the viscosity to 500-2000mPa·S, filter to obtain component A, and store it in a dry and sealed container for later use.

The high-bonding fluorocarbon coating is based on the ratio of the amount of the isocyanate group (NCO) in the first component and the hydroxyl group (OH) in the second component to be 0.4 to 1.5 (preferably 0.5 to 1.2, more preferably 0.8 ~1.0), mix the components A and B, and mix them uniformly mechanically to prepare the mixed coating, which is evenly coated on the polyester support by automatic continuous molding or batch process, and the high-viscosity coating can be obtained after curing. Conjunctive backplate.

The amount of isocyanate group (NCO) in the said component A can be calculated according to the amount of isocyanate curing agent used, and the solid content of isocyanate curing agent is generally marked on the commodity packaging, or can be detected by itself.

The amount of hydroxyl (OH) in the component B can be calculated according to the hydroxyl value in the fluorocarbon resin contained in the component B. The hydroxyl value of the fluorocarbon resin is also a parameter of the product label, or can be detected by itself.

Described isocyanate solidifying agent is the aliphatic isocyanate of non-yellowing, gloss retention, preferably isophorone diisocyanate (IPDI) trimer, isophorone diisocyanate (IPDI) adduct, hexamethylene diisocyanate One or more mixtures of (HDI) biuret and hexamethylene diisocyanate (HDI) adducts.

The fluorocarbon resin is fluorocarbon resin (FEVE) formed by copolymerization of fluoroolefin and alkyl vinyl ether or alkyl vinyl ester. The fluorocarbon resin applicable to the present invention is a mixture of one or two of solvent-soluble vinylidene fluoride type, chlorotrifluoroethylene type, and tetrafluoroethylene type fluorocarbon resin, and the preferred fluorocarbon resin has a hydroxyl value of 45-45. 60mgKOH/g, acid value 2-12mgKOH/g, solid content ≥ 50%, fluorine content 20%-30%.

The modified polyolefins can be grafted polyolefins, ester modified polyolefins, hydroxyl-terminated polyolefins, including terpolymers of low-density polyethylene, acrylate and maleic anhydride, ethylene-( Meth)acrylate-maleic anhydride copolymer, ethylene-propylene-(meth)acrylate-maleic anhydride copolymer, hydroxyl-terminated polybutadiene, hydrogenated hydroxyl-terminated polybutadiene, maleic Anhydride-grafted polybutadiene, maleic anhydride-grafted polypropylene, ethylene-propylene-butene-(meth)acrylate-maleic anhydride copolymer, among which ethylene-(meth)acrylate is the most preferred -maleic anhydride copolymer, the form of the copolymer can be any one of trackless copolymer, block copolymer, graft copolymer etc., in terms of easy to obtain, it is preferably random copolymer, graft copolymer, etc. branch copolymers.

The content of the modified polyolefin is preferably 5% to 30% of the fluorocarbon resin, more preferably 10% to 25%. The content greater than 5% can ensure the adhesion of the adhesive layer to EVA. If the content is less than 30% %, the effect of improving the target weather resistance can be obtained.

The cross-linking agent catalyst is further used in combination with component B. The catalyst containing the cross-linking agent can promote the reaction between the main resin and the curing agent, and realize the improvement of solvent resistance. Moreover, the cross-linking progresses well and can be further improved. The strength and dimensional stability of the adhesive layer can improve the adhesion of the adhesive layer.

The catalyst is a metal compound catalyst, specifically one or a mixture of two or more of the following: zinc isooctanoate, stannous octoate, dioctyltin dilaurate, monobutyltin oxide, monobutyltin triisooctoate, Dibutyltin dilaurate, etc.

The thinner A or thinner B can improve coating adhesion and final coating performance, and the thinner A or thinner B suitable for the present invention are each independently the following one or a mixture of two or more: C7～C10 aromatic Hydrocarbons, C3-C8 ester compounds, C1-C5 alcohol compounds, C2-C6 ketone compounds. Further, the diluent A or diluent B are each independently one or a mixture of two or more of the following: toluene, xylene, n-butyl acetate, propylene glycol methyl ether acetate, ethyl acetate, butyl acetate, ethylene glycol Alcohol, methanol, n-butanol, butanone, methyl ethyl ketone, cyclohexanone; more preferably the following one or a mixture of two or more: toluene, xylene, ethyl acetate, butyl acetate, propylene glycol methyl ether acetate, butyl ketone.

The wetting and dispersing agent is one of copolymer solutions containing acidic groups, block copolymer solutions of polyamines, acrylic block copolymers, polyesters with highly branched structures, and carboxylates with hydroxyl functional groups or a mixture of two or more.

The leveling agent is one or a mixture of polyether siloxane copolymers, reactive polyether modified fluorosiloxanes, polyether modified polyorganosiloxanes, and polyacrylates .

Further, the bonding layer contains at least one inorganic filler A modified by a functional coupling agent.

The inorganic filler A includes silicon dioxide, calcium carbonate, magnesium carbonate, zinc oxide, aluminum oxide, talcum powder, wax powder, kaolin, white corundum, barium sulfate, ceramic micropowder, carbon black, and carbon black is selected as the inorganic filler here , which can make the solar backsheet have concealment, wherein, from the viewpoint of reducing the adhesion when exposed to heat and humid atmosphere, talcum powder and wax powder are preferred; the particle size of the inorganic filler A is 0.1-5 μm, It is preferably 0.5-3 μm. When the particle size is within this range, more satisfactory easy adhesion can be obtained.

The inorganic filler A is treated with a functional coupling agent.

The functional coupling agent is titanate coupling agent, aluminate coupling agent, fluorosilane modified coupling agent, zirconate coupling agent, aluminum-zirconate coupling agent and aluminum-titanium composite One or more of the coupling agents.

The method for treating the inorganic filler A with the functional coupling agent is as follows: first, 100 parts by weight of the inorganic filler A is added to 30 to 80 parts by weight of anhydrous diluent A or B, and ultrasonically dispersed at a temperature of 30°C to 50°C After 0.5h to 3h of uniform dispersion, slowly add 0.1 to 10 parts by weight of a functional coupling agent, and then ultrasonically treat at 50°C to 60°C for 1 to 3h to obtain the inorganic filler A treated with the coupling agent.

The functional coupling agent accounts for 0.1% to 10% by weight of the inorganic filler, preferably 0.3% to 5%. If the amount added is less than 0.1%, it cannot ensure that the inorganic filler is completely treated and cannot achieve good bonding. Function, if the addition amount is greater than 10%, the residual functional coupling agent will reduce the adhesion between the bonding coating and the substrate, which is manifested in the fact that the bonding coating remains on the EVA packaging film when the EVA packaging film is peeled off. , the amount of coupling agent within the above range can significantly improve the peeling force between the fluorocarbon resin and the EVA packaging film, without the need for subsequent treatment of the cured adhesive layer. Under the premise of ensuring high adhesion, The preparation process is simplified.

Based on the content of the adhesive layer B component, the content of the inorganic filler A is in the range of 15 to 50%, and if the content of the inorganic filler is less than 15%, satisfactory adhesion cannot be maintained when exposed to heat and humidity. If the content is greater than 50%, the surface state of the adhesive layer will be deteriorated, preferably in the range of 20-40%.

The inorganic filler B is titanium dioxide, and the crystal system of titanium dioxide includes rutile type, anatase type, and brookite type. Based on the reflectivity of the bonding layer, the requirements for weather resistance under long-term high-temperature and high-humidity experiments and UV aging experiments, Rutile titanium dioxide is preferred, and at the same time it can increase the hiding power of the coating on the polyester support and further improve the adhesion with other critical layers.

The molar ratio of isocyanate groups in component A to hydroxyl groups in component B is 0.4 to 1.5, preferably 0.5 to 1.2, and most preferably 0.8 to 1.0. If the molar ratio of isocyanate groups to hydroxyl groups is lower than 0.4, the fluorocarbon resin The hydroxyl group in the reaction is not complete, resulting in low cross-linking density of the bonding coating, poor film-forming performance of the bonding coating, and reducing the humidity and heat aging resistance of the backsheet; if the molar ratio of isocyanate groups to hydroxyl groups is higher than 1.5 , the unreacted isocyanate will react with the moisture in the air, resulting in a high curing crosslink density of the bond coat and a hard bond coat, resulting in a decrease in the adhesion of the bond coat on the polyester support.

The invention also relates to the application of the fluorocarbon coating on the photovoltaic module backplane, specifically, the fluorocarbon coating can be coated on the polyester support.

The polyester support can be polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polyethylene terephthalate Single-layer or multi-layer films composed of propylene glycol formate (PTT), etc., from the evaluation of thermal stability, cost, etc., polyethylene terephthalate (PET) is preferred, and different thicknesses and different colors of polyethylene terephthalate (PET) can be selected according to different uses. Ester support body; the surface tension of the polyester support body is greater than 10 dyn/cm, and the carboxyl group content is 0.5 equivalent/t to 35 equivalent/t.

The average thickness of the polyester support is 50-300 μm, and the thickness is greater than 50 μm, which is beneficial to the mechanical strength, insulation and high-voltage resistance of the backplane. Considering the cost, the thickness should be less than 300 μm, especially the polyester support The substrate has hydrolysis resistance deteriorates as the thickness increases, and thus durability decreases during long-term use, so the average film thickness of the polyester substrate is preferably 300 μm or less.

The polyester support is subjected to surface treatments such as corona treatment, flame treatment, low-pressure plasma treatment, atmospheric pressure plasma treatment or ultraviolet treatment before coating to increase surface polarity, and corona treatment increases surface functional groups (-OH , -COOH) content, after coating, it reacts with the crosslinking agent in component A during the curing process to form a chemical bond to improve the adhesion between the adhesive layer and the polyester support, and at the same time the corona treated The polyester support with polar groups on the surface exhibits excellent adhesion to the modified polyolefin.

The corona treatment time is preferably 0.5s to 100s, more preferably 1 to 50s. If the treatment time is less than 0.5s, the effect of improving the adhesion may not be sufficient. Membrane deformation or coloring problems.

The coating method adopts known coating methods, including brush coating, dip coating, roll coating, spray coating and the like. When applied and cured, the thickness of the typical coating composition of the present invention is 3-30 μ m, when the thickness of the bonding layer is greater than 3 μ m, the bonding coating can fully obtain the improvement of durability and weather resistance, ensuring that the coating Reflectivity, and adhesion between the adhesive layer and the polyester support and EVA. When the thickness of the adhesive layer is less than 30 μm, the increase in cost can be controlled, the deterioration of the surface shape can be suppressed, and the adhesion can be guaranteed. The preferred film thickness is In the range of 5 μm to 25 μm.

The curing conditions of the adhesive layer are as follows: the curing temperature is adjustable, generally 150°C-200°C, and preferably 160°C-190°C; the curing time is variable, typically 1 min to 15 min, and preferably 2 min to 10 min.

The present invention also includes the application of the high-adhesive back sheet on solar modules, which is formed by laminating with encapsulation materials.

The packaging material is ethylene-vinyl acetate copolymer (EVA) resin.

The present invention will be further described below in conjunction with specific examples, but the scope of protection of the present invention is not limited to the content of these specific embodiments and examples, and the substrate is not limited to polyethylene terephthalate.

Example 1:

Preparation of component A: 55g (155.81mmol NCO group) isophorone diisocyanate (IPDI) trimer Z4470BA (37.5% NCO content, Bayer, Germany) and 20g anhydrous xylene (Hangzhou Chemical Reagent Co., Ltd.) Mix evenly with 25g of anhydrous butyl acetate (Hangzhou Chemical Reagent Co., Ltd.), filter to make component A, and store in a dry sealed tank for use.

Preparation of component B: Put 15g of methyl ethyl ketone (Hangzhou Chemical Reagent Co., Ltd.) in a container, and add 50g (49.1mmol OH group) of fluorocarbon resin ZHM-2 (Dongfu Chemical Industry Co., Ltd.) and 2g of modified poly Olefin CHEMIPEARLS (trade name, manufactured by Mitsui Chemicals, Inc.), 0.65g wetting and dispersing agent BYK-163 (Germany BAK Chemical Co., Ltd.), 15g titanium dioxide (Shanghai Hongyunyuan Chemical Co., Ltd.) and 5g titanate couple Calcium carbonate (Shanghai Hongyunyuan Chemical Co., Ltd.) treated by the joint agent is pre-dispersed and then ground with a sand mill until the particle size is ≤5 microns. Add 0.2g leveling agent BYK310 (Germany BAK Chemical Co., Ltd.), 0.1 g Catalyst Zinc isooctanoate (Taixing Shengling Co., Ltd.), after mixing evenly, adjust the viscosity, filter to obtain component B pigment slurry, store it in a dry airtight tank for later use.

A preparation of fluorocarbon coating for solar cell backsheet: mix components A and B according to the molar ratio of NCO/OH of 1.2:1.0, and uniformly coat the cleaned corona by automatic continuous molding or batch process On a PET polyester support, cured at 170°C for 5 minutes to obtain a backsheet for solar modules with a 20 μm thick adhesive layer, denoted as S1.

Example 2:

Preparation of component A: 50g (233.5mmol NCO group) hexamethylene diisocyanate trimer curing agent HT-90BS (NCO content is 19.6%, Wanhua Chemical Group Co., Ltd.) and 20g anhydrous toluene (Hangzhou Chemical Reagent Co., Ltd.) and 30g of anhydrous ethyl acetate (Hangzhou Chemical Reagent Co., Ltd.) were mixed evenly, filtered to make component A, and stored in a dry sealed tank for use.

Preparation of component B: Put 10g of ethyl acetate (Hangzhou Chemical Reagent Co., Ltd.) and 25g of propylene glycol methyl ether acetate (PMA) (Kunshan Chengxin Chemical) into a container, and add 35g (37.49mmolOH group) of fluorine successively under low-speed stirring Carbon resin GK570 (Dakin in Japan), 15g modified polyolefin S-75N (manufactured by Mitsui Chemicals, Inc.), 3g fluorocarbon resin DESMOPHEN1652 (Bayer, Germany), 1.2g wetting and dispersing agent BYK-9010 (Germany than Gram Chemical Co., Ltd.), 25g of BHS8860 talcum powder treated with fluorosilane coupling agent (Quanzhou Xufeng Powder Raw Materials Co., Ltd.), after pre-dispersion, grind it with a sand mill until the particle size is ≤5 microns, add 0.2g Leveling agent BYK310 (Germany BAK Chemical Co., Ltd.), 0.48g dioctyltin dilaurate catalyst (Jintian Raw Materials Co., Ltd.), after mixing evenly, adjust the viscosity, filter, and prepare component B pigment paste, store in a dry sealed Serve in a jar.

A preparation of fluorocarbon coating for solar cell backsheet: mix components A and B according to the NCO/OH molar ratio of 0.4:1.0, and uniformly coat the cleaned corona by automatic continuous molding or batch process The PET polyester support was cured at 145°C for 10 minutes to obtain a backsheet for solar modules with a 10 μm thick adhesive layer, denoted as S2.

Example 3:

Preparation of component A: 40g (206.56mmol NCO group) hexamethylene diisocyanate trimer curing agent TKA100 (Asahi Kasei Chemical Co., Ltd.) and 20g anhydrous dibutyl ketone (Hangzhou Chemical Reagent Co., Ltd.) and 30g anhydrous Butyl acetate (Hangzhou Chemical Reagent Co., Ltd.) was mixed evenly, filtered to make component A, and stored in a dry sealed tank for use.

Preparation of component B: Put 23g xylene (Hangzhou Chemical Reagent Co., Ltd.) Olefin Hitech (Hitech) S3121 (manufactured by Toho Chemical), 15g fluorocarbon resin DESMOPHEN2200B (Germany Bayer), 2g wetting and dispersing agent BYK-9010 (Germany BAK Chemical Co., Ltd.), 18g zirconate coupling agent Treated wax powder PTFE0101 (Nanjing Tianshi wax powder), after pre-dispersion, grind it with a sand mill until the particle size is ≤5 microns, add 0.22g polyether modified polyorganosiloxane leveling agent 505 ( Shenzhen Weibo Chemical Co., Ltd.), 0.82g stannous octoate catalyst (Nantong Youer Chemical Co., Ltd.), after mixing evenly, adjust the viscosity, filter, and prepare the B component pigment slurry, which is stored in a dry sealed tank for use.

A preparation of fluorocarbon coating for solar cell backsheet: mix components A and B according to the molar ratio of NCO/OH of 0.9:1.0, and uniformly coat the cleaned corona by automatic continuous molding or batch process On the PET polyester support body, cured at 155 ° C for 8 minutes to obtain a 15 μm thick adhesive layer backsheet for solar modules, denoted as S3.

Example 4:

Preparation of component A: mix 60g (228.6mmol NCO group) hexamethylene diisocyanate adduct curing agent HXT (Japan Polyurethane Industry Co., Ltd.) with 15g anhydrous xylene (Hangzhou Chemical Reagent Co., Ltd.) and 25g anhydrous Butanone (Hangzhou Chemical Reagent Co., Ltd.) was mixed evenly, filtered to make component A, and stored in a dry sealed tank for use.

Preparation of component B: Put 20g of propylene glycol methyl ether acetate (Hangzhou Chemical Reagent Co., Ltd.) in a container, and add 45g (48.15mmolOH group)) of fluorocarbon resin SW-5570 (Shanghai Shengwei Trading Co., Ltd. ), 12g hydroxyl-terminated polybutadiene (Hangzhou Tianyuan Chemical Research Institute), 5g fluorocarbon resin DESMOPHEN1652 (Germany Bayer), 0.2g wetting and dispersing agent BYK-163 (Germany BAK Chemical Co., Ltd.), 5g aluminum-zirconium Carbon black treated with ester coupling agent (Dongguan Jutai Chemical Co., Ltd.), after pre-dispersion, grind it with a sand mill until the particle size is ≤5 microns, add 0.3g leveling agent BYK310 (Germany BAK Chemical Co., Ltd. Co., Ltd.), 0.82g stannous octoate catalyst (Nantong Youer Chemical Co., Ltd.), after mixing evenly, adjust the viscosity, filter, and prepare the B component pigment slurry, which is stored in a dry sealed tank for use.

A preparation of fluorocarbon coating for solar cell backsheet: mix components A and B according to the molar ratio of NCO/OH of 1.0:1.0, and uniformly coat the cleaned corona by automatic continuous molding or batch process On the PET polyester support body, cured at 175 ° C for 3.5 min to obtain a 12 μm thick adhesive layer back sheet for solar modules, denoted as S4.

Example 5:

Preparation of component A: 50g (141.65mmol NCO group) isophorone diisocyanate (IPDI) trimer Z4470BA (37.5% NCO content, Bayer, Germany) and 30g anhydrous xylene (Hangzhou Chemical Reagent Co., Ltd.) Mix evenly with 20g of anhydrous butyl acetate (Hangzhou Chemical Reagent Co., Ltd.), filter to make component A, store in a dry sealed tank for use.

Preparation of component B: Put 20g of ethyl acetate (Hangzhou Chemical Reagent Co., Ltd.) in a container, and add 40g (42.8mmolOH group)) of fluorocarbon resin SW-5570 (Shanghai Shengwei Trading Co., Ltd.) in sequence under low-speed stirring, 8g modified polyolefin Arrowbase (Arrowbase) SE-1013N (manufactured by Unijika), 4g fluorocarbon resin DESMOPHEN1652 (Germany Bayer), 0.59g wetting and dispersing agent BYK-163 (Germany BAK Chemical Co., Ltd.) , 9g of aluminum-titanium composite coupling agent-treated ceramic powder (Henan Xingyu Ceramic Powder Co., Ltd.), 6g of titanium dioxide R790 (DuPont), after pre-dispersion, grind with a sand mill until particle size≤5 microns, Add 0.2g leveling agent BYK310 (Germany BAK Chemical Co., Ltd.), 1.22g monobutyl triisooctanoate tin catalyst (Nantong Suner Chemical Co., Ltd.), mix well, adjust the viscosity, filter, and prepare the B component pigment The slurry is stored in a dry airtight container for later use.

A preparation of fluorocarbon coating for solar battery backplane: Mix A and B components according to the NCO/OH molar ratio of 1.5:1.0, and uniformly coat the cleaned corona by automatic continuous molding or batch process On the PET polyester support, it was cured at 165°C for 4 minutes to obtain a backsheet for solar modules with a 15 μm thick adhesive layer, denoted as S5.

Embodiment 6:

Preparation of component A: mix 65g (247.65mmol NCO group) hexamethylene diisocyanate adduct curing agent HXT (Japan Polyurethane Industry Co., Ltd.) with 15g anhydrous xylene (Hangzhou Chemical Reagent Co., Ltd.) and 20g anhydrous Butanone (Hangzhou Chemical Reagent Co., Ltd.) was mixed evenly, filtered to make component A, and stored in a dry sealed tank for use.

Preparation of component B: Put 16 ethyl acetate (Hangzhou Chemical Reagent Co., Ltd.) and 8 g toluene (Hangzhou Chemical Reagent Co., Ltd.) Daikin), 8g modified polyolefin Arrowbase (Arrowbase) SE-1013N (manufactured by Unijika), 12g fluorocarbon resin DESMOPHEN2200B (Germany Bayer), 1.68g acidic group copolymer-based dispersant BYK9076 (Germany Byk Chemical Company), 9g aluminum-titanium composite coupling agent-treated silica (Dongguan Jutai Chemical Co., Ltd.), 9g titanium dioxide R793 (Luohe Xingmao Titanium Industry Co., Ltd.), pre-dispersed and sand milled Grinding machine until the particle fineness is ≤5 microns, add 0.22g leveling agent BYK310 (Germany BAK Chemical Co., Ltd.), 0.1g dioctyltin dilaurate catalyst (Jintian Raw Materials Co., Ltd.), mix well, and adjust the viscosity , and filtered to obtain component B pigment slurry, which was stored in a dry sealed tank for later use.

A preparation of fluorocarbon coating for solar cell backsheet: mix components A and B according to the molar ratio of NCO/OH of 0.9:1.0, and uniformly coat the cleaned corona by automatic continuous molding or batch process On the PET polyester support body, cured at 180 ° C for 2.5 min to obtain a 25 μm thick adhesive layer back sheet for solar modules, denoted as S6.

Comparative example 1:

Preparation of Component A: same as Example 1;

Preparation of component B: the same preparation method as in Example 1, except that calcium carbonate treated with titanate coupling agent is not added to the raw material;

A solar cell backsheet prepared with fluorocarbon coating: same as in Example 1, denoted as B1.

Comparative example 2:

Preparation of Component A: same as Example 4;

Preparation of component B: the same method as in Example 4, except that hydroxyl-terminated polybutadiene is not added to the raw materials;

Preparation of a solar cell back sheet with fluorocarbon coating: same as in Example 4, denoted as B2.

Comparative example 3:

Preparation of Component A: same as Example 5;

Preparation of component B: the same preparation method as in Example 5, the production raw materials do not add modified polyolefin Arrowbase (Arrowbase) SE-1013N, and do not add ceramic powder treated with aluminum-titanium composite coupling agent;

A solar cell backsheet prepared with fluorocarbon coating: same as in Example 5, denoted as B3.

Performance tests were performed on the high-adhesion coated backsheets prepared in Examples 1-6 and the coated backsheets prepared in Comparative Examples 1-3, and the evaluation results are listed in Table 1. Among them, in addition to the high-adhesive coating type backplane provided by the present invention, the components used for the peel strength test also need to use other materials, including ultra-clear embossed glass (CSG Group), EVA film F406, F806 ( Hangzhou Foster Photovoltaic) for composite lamination.

Available lamination conditions are: lamination temperature 140°C-165°C, vacuuming 2min-8min, lamination time 8min-20min, to make components; wherein, for the convenience of comparison test, the present invention uses the same preparation conditions, specifically The lamination temperature is 150°C, the vacuum is pumped for 3.5 minutes, and the lamination time is 10 minutes.

It should be noted that the paints and coating-type backsheets obtained through the above examples are evaluated by the following test methods.

1. Coating hardness

Test the hardness of the coating according to GB/T6739 "Pencil Test Method for Coating Hardness": move the pencil horizontally on the sample for 3mm at a speed of 0.5mm/s to measure the hardness, and record the hardness value according to the scratches.

2. Humidity and heat aging resistance

According to the test method of GB/T2423.3, the damp heat aging test is carried out.

Experimental conditions: +85°C, relative humidity 85%.

Before and after the experiment, the adhesion of the sample was tested according to the ISO-2409-2007 standard; the yellowing index (△YI) of the sample was measured according to the national standard GB2409-80 "Plastics Yellowness Index Test Method".

3. Peel strength between backplane and EVA film

The test method is tested according to the national standard GB/T2790-1995 "Adhesive 180° Peel Strength Test Method Flexible Material Versus Rigid Material", and the peel strength value is recorded.

Table 1: Performance testing results of each embodiment and comparative example

Comparing the data in the table, it can be seen that the coated solar cell back sheet prepared by the high-adhesive fluorocarbon coating of the present invention has high coating hardness and high peel strength from the packaging material. After 2500 hours of aging treatment at high temperature and high humidity It still maintains more than 80% of the peel strength, the adhesion is 90% and above, and the yellowing index (ΔYI) is within 3. The fluorocarbon coating bonding layer prepared by the invention can simultaneously take into account the bonding properties with the encapsulation material and the polyester support, has bonding durability and excellent weather resistance under humid heat and light environments, and can be prepared at low cost.

Claims (10)

1. A highly cohesive fluorocarbon coating is characterized in that it consists of two components, A and B; The component A is a crosslinking agent, including 40-65 parts by weight of isocyanate curing agent and 35-60 parts by weight of anhydrous diluent A; The B component contains 35-50 parts by weight of fluorocarbon resin, 2-15 parts by weight of modified polyolefin, 5-25 parts by weight of inorganic filler A modified by functional coupling agent, 15-35 parts by weight of Anhydrous diluent B; When in use, mix component A and component B according to the ratio of the isocyanate group in component A to the hydroxyl group in component B at a ratio of 0.4 to 1.5 to obtain a high-adhesive fluorocarbon coating. 2. A high-adhesive fluorocarbon coating as claimed in claim 1, characterized in that, said component B may also include 0-15 parts by weight of fluorocarbon resin, 0.1-2 parts by weight of catalyst, 0-20 parts by weight One or more of inorganic filler B, 0-0.5 parts by weight of leveling agent and 0.2-2 parts by weight of wetting and dispersing agent; The catalyst is a metal compound catalyst; The inorganic filler B is rutile titanium dioxide; The wetting and dispersing agent is composed of a copolymer solution containing acidic groups, a block copolymer solution of polyamines, acrylic block copolymers, highly branched polyesters, and hydroxyl functional carboxylates. or a variety of mixtures in any proportion; The anhydrous diluent A and anhydrous diluent B are each independently a mixture of one or more of the following in any proportion: C7-C10 aromatic hydrocarbons, C3-C8 ester compounds, C1-C5 alcohols Compounds, C2 ~ C6 ketone compounds. 3. A kind of high cohesion fluorocarbon coating as claimed in claim 2, is characterized in that, described B component is prepared by the following method: Weigh anhydrous diluent B and pour in sand mill, 1500- Stir at 3500rpm and add fluorocarbon resin, modified polyolefin, and inorganic filler A to diluent B in sequence. After pre-dispersion, grind until the particle size is ≤5 microns; One or more of catalyst, leveling agent, and inorganic filler B, mechanically mix evenly, add anhydrous diluent B to adjust the viscosity to 500-2000mPa·S, filter, and store in a dry and sealed container for later use. 4. A kind of high binding property fluorocarbon paint as claimed in claim 1, is characterized in that, the amount of the isocyanate group (NCO) in the described first component and the hydroxyl group (OH) in the second component The ratio is preferably 0.5 to 1.2, more preferably 0.8 to 1.0. 5. A kind of high cohesion fluorocarbon coating as claimed in claim 1, is characterized in that, described isocyanate solidifying agent is aliphatic isocyanate; Described fluorocarbon resin is made of solvent-soluble vinylidene fluoride type, three One or two kinds of fluorocarbon resins of chlorofluoroethylene type and tetrafluoroethylene type are mixed in any proportion. The hydroxyl value of the fluorocarbon resin is 45-60 mgKOH/g, the acid value is 2-12 mgKOH/g, and the solid content is ≥ 50%, and the fluorine content is 20wt%-30wt%. 6. A high-adhesive fluorocarbon coating as claimed in claims 1-3, characterized in that the content of the modified polyolefin is preferably 5%-30% of the fluorocarbon resin, more preferably 10% ~25%, can be grafted polyolefin, ester modified polyolefin, hydroxyl terminated polyolefin, including low density polyethylene and terpolymer of acrylate and maleic anhydride, ethylene-(meth)acrylate -maleic anhydride copolymer, ethylene-propylene-(meth)acrylate-maleic anhydride copolymer, hydroxyl-terminated polybutadiene, hydrogenated hydroxyl-terminated polybutadiene, maleic anhydride grafted polybutylene Diene, maleic anhydride grafted polypropylene, ethylene-propylene-butene-(meth)acrylate-maleic anhydride copolymer, among which ethylene-(meth)acrylate-maleic anhydride copolymer is most preferred anhydride copolymer. 7. A kind of high cohesion fluorocarbon coating as claimed in claim 1～3, it is characterized in that described inorganic filler A is treated with functional coupling agent, and described inorganic filler A is made of silicon dioxide, calcium carbonate, carbonic acid One or more of magnesium, zinc oxide, aluminum oxide, talcum powder, wax powder, kaolin, white corundum, barium sulfate, ceramic micropowder, and carbon black are mixed in any proportion; The functional coupling agent consists of titanate coupling agent, aluminate coupling agent, fluorosilane modified coupling agent, zirconate coupling agent, aluminum-zirconate coupling agent and aluminum-titanium composite One or more of the coupling agents are mixed in any proportion. 8. A kind of high cohesion fluorocarbon coating as claimed in claim 7, is characterized in that, described functional coupling agent treatment specifically is: firstly add 100 parts by weight of inorganic filler A to 30-80 parts by weight In anhydrous diluent A or B, ultrasonically disperse at a temperature of 30°C to 50°C for 0.5h to 3h, after the dispersion is uniform, then add 0.1 to 10 parts by weight of a functional coupling agent, and then ultrasonically at a temperature of 50°C to 60°C After treatment for 1h-3h, the inorganic filler A treated with the coupling agent is obtained; the dosage of the functional coupling agent is preferably 0.3-5 parts by weight. 9. A use of the high-adhesive fluorocarbon coating of claim 1 on a solar module, characterized in that the application is specifically: coating the fluorocarbon coating on a polyester support to prepare a high-adhesive coating Backsheet; then laminate the high-adhesion backsheet with encapsulation material; The average thickness of the polyester support is 50-300 μm, and the carboxyl group content is 0.5 equivalent/t to 35 equivalent/t, which is polyethylene terephthalate (PET), polyethylene naphthalate ( PEN), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT) single-layer or multi-layer film; The packaging material is ethylene-vinyl acetate copolymer (EVA). 10. A high-adhesive fluorocarbon coating as claimed in claims 1 to 9, wherein the polyester support is subjected to surface treatment before coating the fluorocarbon coating, and the surface treatment is selected from corona Treatment, flame treatment, low-pressure plasma treatment, atmospheric pressure plasma treatment, ultraviolet treatment, etc.; corona treatment is preferred, and the corona treatment time is 0.5s to 100s; The coating method is selected from brush coating, dip coating, roller coating and spray coating; the coating thickness is 3-30 μm, the curing temperature is 150°C-200°C, and the curing time is 1min-15min.