CN116218296A - High-weather-resistance coating composition for black backboard of photovoltaic cell assembly - Google Patents

Abstract

The invention provides a high weather-resistant coating composition for a black backboard of a photovoltaic cell assembly; the coating composition consists of a main agent and a curing agent, wherein the main agent comprises: 20-30 parts of fluorocarbon resin, 15-35 parts of acrylic resin, 10-30 parts of polyester resin, 10-20 parts of black pigment, 10-20 parts of inorganic filler, 1-5 parts of auxiliary agent and 90-130 parts of anhydrous diluent. According to the invention, the hydroxyl acrylic resin and the polyester resin with a special structure are mixed in the fluorocarbon resin, so that the adhesion force and the ultraviolet resistance of the black coating to the EVA are improved, and meanwhile, the adhesion force and the ultraviolet resistance of the black coating to PET are also improved, and the defect that the traditional fluorocarbon coating system is applied to black photovoltaic backboard coating is overcome.

Description

A kind of high weather resistance coating composition for black backboard of photovoltaic cell module

technical field

The invention belongs to the technical field of coatings, and relates to a high-weather-resistant coating composition for black backboards of photovoltaic cell components.

Background technique

Photovoltaic modules are the smallest indivisible photovoltaic cell combination devices that are based on battery integration, have packaging and internal connections, and can provide direct current output alone. Photovoltaic cells, the core component of photovoltaic modules, have a limited amount of power generated by a single piece, so they need to be connected in series and packaged into modules before they can be used as power sources. Usually, the core component of a photovoltaic module, the photovoltaic cell, is encapsulated between the front glass on the incident side of the sun and the photovoltaic backplane placed on the back, and passed through the encapsulation material (usually ethylene-vinyl acetate copolymer (EVA) resin) Make a seal. In order to ensure the service life of photovoltaic modules, it is necessary for the backsheet to have good weather resistance and high sealing performance with the EVA adhesive layer.

In recent years, with the vigorous development of distributed photovoltaics and building-integrated photovoltaics, new requirements have been put forward for the design of modules, especially the appearance needs to be consistent in color. Nowadays, integrated black modules are more and more popular. Black photovoltaic back The application of boards is also becoming more and more extensive. The black solar battery backplane is mainly used in distributed power stations, and can achieve the same color as the black crystal silicon battery and the black frame. The color of the backsheet is beautiful and can be coordinated with the building. At the same time, it also ensures the mechanical strength of the solar panel and prevents water vapor from penetrating into the sealing layer, which will affect the life of the battery and the power generation efficiency. Due to the heat absorption effect of black components, stricter requirements are put forward for the weather resistance of black backplanes in actual use. High temperature, ability to resist ultraviolet radiation.

According to the adhesive layer type, black backsheets are mainly divided into composite type and coated type. Among them, the composite backplane has high manufacturing cost due to the use of fluorine film as the bonding layer, and the adhesion between the fluorine film and EVA is poor. In addition, the fluorine film and the polyester base film need to be bonded by glue in a high-humidity environment. It is prone to aging and peeling problems. Coated backsheets are formed by compounding or coating materials such as weather-resistant fluorine-containing resins on the polyester base film and drying and curing. According to most existing technical patents (CN201410411372, CN20161053161, CN103805043, etc.), although it meets the requirements of moisture-heat aging resistance and ultraviolet resistance of conventional white backplanes, in the black backplane system, not only the product cost is high, but also the use of In the process, there are still problems such as backplane delamination, poor adhesion, poor weather resistance and UV resistance.

Contents of the invention

In view of the defects in the prior art, the present invention provides a high-weather-resistant coating composition for a black back sheet of a photovoltaic cell assembly, which satisfies performance requirements such as high adhesion, ultraviolet resistance, heat and humidity resistance, and weather resistance. At the same time, it can also reduce costs and increase efficiency.

The purpose of the present invention is achieved through the following technical solutions:

The invention provides a high weather resistance coating composition for a black photovoltaic backplane, comprising a main agent and a curing agent, the main agent comprising:

Fluorocarbon resin 20-30 parts,

Acrylic resin 15-35 parts,

10-30 parts of polyester resin,

10-20 parts of black pigment,

10-20 parts of inorganic filler,

1-5 parts of auxiliary agent,

90-130 parts of anhydrous diluent;

The curing agent is 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), isophorone diisocyanate (IPDI) trimer, 1,6-hexamethylene One or more of diisocyanate (HDI) trimer and 1,6-hexamethylene diisocyanate (HDI) biuret;

The mass ratio of the main agent and the curing agent is 100:10-100:15.

Wherein the curing agent is preferably 1,6-hexamethylene diisocyanate (HDI) trimer with a solid content of 100%. Preferably it is Covestro N3300.

As an embodiment, the fluorocarbon resin is selected from fluorocarbon resins (FEVE) obtained by copolymerizing solvent-soluble fluoroolefins and alkyl vinyl ethers or alkyl vinyl esters. FEVE resin includes one or two kinds of chlorotrifluoroethylene type and tetrafluorochloroethylene type fluorocarbon resins mixed according to any ratio. The fluorocarbon resin used preferably has a hydroxyl value of 50-70 mgKOH/g, an acid value of ≤10 mgKOH/g, a solid content of ≥55%, and a fluorine content of about 20-35 wt%. It is preferably JF-2XA of Changshu Sanai Fuzhonghao Material Co., Ltd., L101 of Wanbo Paint Chemical Co., Ltd., ZHM-2 of chlorotrifluoroethylene of Dongfu Chemical Co., Ltd. or GK570 of tetrafluoroethylene of Dajin Fluor Chemical Co., Ltd.

As an embodiment, the acrylic resin is a (meth)hydroxyl acrylic resin containing a long alkyl chain of 12-50 carbons; It is obtained by copolymerization of one or more of meth)acrylic monomers, short-chain (meth)acrylic monomers, and hydroxyl-containing (meth)acrylic monomers.

As an embodiment, the acrylic resin comprises (meth)acrylate-hydroxyethyl acrylate, propyl ester copolymer, (meth)acrylate-propyl acrylate-hydroxyethyl acrylate, propyl ester copolymer, (meth)acrylate Acrylates-butyl acrylate-hydroxyethyl acrylate, propyl ester copolymer, (meth)acrylate-vinyl acrylate-hydroxyethyl acrylate, propyl ester copolymer, (meth)acrylate-(meth)acrylate dodeca One or more of alkyl esters-hydroxyethyl acrylate, propyl ester copolymer, (meth)acrylate-hexadecyl (meth)acrylate-hydroxyethyl acrylate, propyl ester copolymer according to any ratio Mix composition.

As an embodiment, the polyester resin includes saturated and unsaturated aliphatic polyester resins containing terminal hydroxyl functional groups. The polyester resin composition used in the present invention is aliphatic saturated and unsaturated polyester with special non-aromatic ring structure and terminal hydroxyl group. The acid value and hydroxyl value requirements of the polyester resin used in the resin composition are: the hydroxyl value is 20-30 mgKOH/g; the acid value is ≤4 mgKOH/g.

As an embodiment, the black pigment is composed of one or more of silicon rubber carbon black, iron oxide black, iron chrome black, copper chrome black, iron manganese black, nickel chrome black, titanium iron black, black pearl powder, organic black dye It is composed by mixing in any proportion. Carbon black is preferred.

As an embodiment, the inorganic filler is composed of one or more of titanium dioxide, calcium carbonate, silicon dioxide, talcum powder, kaolin, barium sulfate, talc powder, montmorillonite, mica powder, white carbon black, and aluminum oxide. It can be mixed in any proportion.

As an embodiment, the auxiliary agent is composed of one or more of a wetting and dispersing agent, a catalyst, a leveling agent, a defoamer, and an antihydrolysis agent mixed in any proportion.

The wetting and dispersing agent is composed of one or more of acidic group-containing copolymer solutions, acrylic block copolymers, hydroxyl functional carboxylate esters, highly branched polyesters, and polyamine block copolymer solutions. A variety of compositions are mixed in any proportion.

The catalyst is a metal compound catalyst, and the metal compound catalyst includes one or more of stannous octoate, dibutyltin dilaurate, dioctyltin dilaurate, monobutyl triisooctoate tin, and zinc isooctanoate according to any formulation. Than mixed composition. Dibutyltin dilaurate is preferred.

The anti-hydrolysis agent is carbodiimide or polycarbodiimide compound.

As an embodiment, the auxiliary agent includes 0.8-2.5 parts of wetting and dispersing agent, 0.5-1 part of catalyst, and 0-2 parts of anti-hydrolysis agent.

As an embodiment, the anhydrous diluent is a mixture of one or more than two of the following solvents in any proportion: toluene, xylene, n-butyl acetate, ethyl acetate, butanone, cyclohexanone, methyl ethyl ketone, cyclohexanone, Hexane, propylene glycol methyl ether acetate.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention provides a coating with high weather resistance to be used as the bonding layer of the black photovoltaic backplane, and the side chain of the acrylic resin blended with the fluorocarbon resin contains a longer carbon chain, which can strengthen the bonding layer with the EVA resin. The entanglement between the molecular chains of the acrylic resin improves the adhesion. In addition, there are more ester bond groups in the main chain of the acrylic resin, which is conducive to improving its adhesion on the polyester base film;

(2) By replacing saturated and unsaturated aliphatic polyester resins containing terminal hydroxyl functional groups in the black paint at the same time, the overall flexibility of the coating is improved and the brittleness is reduced. Under the condition of ensuring better adhesion with EVA, Further improve the adhesion to the substrate and improve the UV aging resistance of the finished backsheet;

(3) The coating prepared in the present invention can take into account the adhesion between itself and the polyester base film and packaging material, high peel strength, excellent weather resistance and durability, and at the same time, in addition to the introduction of conventional acrylic resin, it is combined with a special structure While improving the overall performance, the advanced polyester resin further significantly reduces the application cost of the coating.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

The main agent in the present invention can be prepared by the following method: Weigh the anhydrous diluent, add fluorocarbon resin, acrylic resin, polyester resin, black pigment, inorganic filler and wetting and dispersing agent in sequence, and after high-speed dispersion is uniform, pour Put it into a sand mill and grind until the particle fineness is ≤2μm; then add catalyst and other additives, add anhydrous diluent to a solid content of 50%, disperse and mix evenly at high speed, filter, and seal and fill in a dry container.

The specific use of the high weather resistance coating composition for black photovoltaic backboard of the present invention on solar modules is: after the main agent of the bonding coating is mixed with a curing agent and a diluent in a prescribed ratio for 30 minutes evenly (the amount of the diluent depends on Predetermined coating thickness), coated on the polyester base film, and dried to prepare a high-adhesive back sheet; then the prepared high-adhesive back sheet is laminated with the battery assembly through the packaging material. The average thickness of the polyester base film is 150-300 μm, and the material used is mainly polyethylene terephthalate (PET); the packaging material is mainly ethylene-vinyl acetate copolymer (EVA).

Described polyester base film needs to carry out surface treatment before coating adhesive coating, optional flame treatment, atmospheric pressure plasma treatment, corona treatment, low-pressure plasma treatment, ultraviolet treatment etc.; In addition preferably corona treatment, time is 1 -10s; Coating method can be roller coating, spray coating, dip coating and brush coating; coating dry weight thickness 6-30μm, curing temperature 150-180 ℃, curing time 10-30min.

Examples 1-9

This example provides a high-weather-resistant coating composition for a black photovoltaic backplane, including a main agent and a curing agent; the specific formulation is shown in Table 1.

Comparative example 1-7

This comparative example provides a coating composition for a black photovoltaic backplane, including a main agent and a curing agent; the specific formulation is shown in Table 1.

Table 1 embodiment and comparative example formula table

固化剂为科思创Desmodur N 3300，溶剂为乙酸丁酯。Among them, the fluorocarbon resin is GK570 from Daikin Fluorochemical Co., Ltd., the acrylic resin 1 is Gaoming Tongde Chemical ACR6730, the acrylic resin 2 is Bollier BM51, the polyester resin 1 is Eastman polyester resin IC3020, and the polyester resin 2 is Toyobo GK680, Grace Syloid_ED30 silica as the inorganic filler, Degussa carbon black HIBLACK 50L, BYK-163 as the wetting and dispersing agent, dibutyltin dilaurate as the catalyst, and Langil as the anti-hydrolysis agent

The curing agent is Covestro Desmodur N 3300, and the solvent is butyl acetate.

Performance Testing

The test method is as follows:

1. Peel strength between backplane and EVA film

Measure according to the national standard GB/T2790-1995, and record the peel strength value.

2. Moisture resistance and UV resistance:

According to the performance test of the photovoltaic cell backsheet, the test is carried out according to the GB/T2423.3 test method and the GB/T 31034-2014 insulating backsheet standard for crystalline silicon solar cell modules. The adhesion of the sample sheet was tested according to the ISO-2409-2007 standard before and after the experiment; the yellowing index (△YI) of the sample sheet was measured according to the national standard GB2409-80.

The performance detection result of each embodiment of table 2 and comparative example

Comparing the data in Table 1, the coating-type black photovoltaic backsheet prepared by the high-adhesive weather-resistant coating provided by the present invention has high peel strength from the packaging material, and can still maintain a relatively high temperature and humidity after aging for 2000 hours compared with the comparative example. High adhesion. After UV180KWH irradiation, the adhesion is good, and the yellowing index is less than 2.

In summary, the present invention improves the adhesion between the black coating and EVA and the heat and humidity resistance by mixing the hydroxyacrylic resin and the polyester resin of a special structure simultaneously in the fluorocarbon resin, and also improves the resistance to PET. Adhesion and UV resistance can solve the defects of existing fluorocarbon coating systems applied to black photovoltaic backplane coatings. In addition, the invention not only improves the comprehensive anti-aging performance of the coating, but also ensures better blackness and covering rate, and solves the defects of poor moisture and heat resistance and ultraviolet resistance of the existing black coating.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims (10)

1. a kind of high weather resistance paint composition for black photovoltaic backboard, comprises main agent and curing agent, it is characterized in that, described main agent comprises: Fluorocarbon resin 20-30 parts, Acrylic resin 15-35 parts, 10-30 parts of polyester resin, 10-20 parts of black pigment, 10-20 parts of inorganic filler, 1-5 parts of auxiliary agent, 90-130 parts of anhydrous diluent; The curing agent is 1,6-hexamethylene diisocyanate, isophorone diisocyanate, isophorone diisocyanate trimer, 1,6-hexamethylene diisocyanate trimer, 1,6 - one or more of hexamethylene diisocyanate biuret; The mass ratio of the main agent and the curing agent is 100:10-100:15. 2. the black photovoltaic backboard according to claim 1 is characterized in that, described fluorocarbon resin is selected from the FEVE resin of solvent-soluble type; One or two of fluorochloroethylene type fluorocarbon resins. 3. the high weather resistance coating composition for black photovoltaic backboard according to claim 1, is characterized in that, described acrylic resin is the (methyl) hydroxyl acrylic resin that contains long alkyl chain 12-50 carbon; The (meth) hydroxy acrylic resin with 12-50 carbons in the alkyl chain consists of one of long-chain (meth) acrylic monomers, short-chain (meth) acrylic monomers, and hydroxyl-containing (meth) acrylic monomers or A variety of copolymers can be obtained. 4. the black photovoltaic backboard according to claim 1 is characterized in that, described polyester resin is the saturated or unsaturated aliphatic polyester resin that contains terminal hydroxyl functional group; Described polyester resin The hydroxyl value of the polyester resin is 20-30 mgKOH/g, and the acid value of the polyester resin is 0-4 mgKOH/g. 5. the black photovoltaic backboard according to claim 1 is characterized in that, described black pigment is silicone rubber carbon black, iron oxide black, iron chromium black, copper chromium black, iron manganese black, One or more of nickel-chrome black, titanium-iron black, black pearl powder, and organic black dye. 6. the high weather resistance coating composition for black photovoltaic backboard according to claim 1, is characterized in that, described inorganic filler is titanium dioxide, calcium carbonate, silicon dioxide, talcum powder, kaolin, barium sulfate, talcum powder, smectite One or more of desoiling, mica powder, white carbon black, and alumina. 7. The high weather-resistant coating composition for black photovoltaic backplane according to claim 1, wherein the auxiliary agent is one of a wetting and dispersing agent, a catalyst, a leveling agent, a defoamer, and an anti-hydrolysis agent one or more species. 8. The high weather resistance coating composition for black photovoltaic backplane according to claim 1, characterized in that, the additives include 0.8-2.5 parts of wetting and dispersing agent, 0.5-1 part of catalyst, 0-2 parts of anti-hydrolysis agent share. 9. according to claim 7 or 8 described high weather resistance coating composition for black photovoltaic backplane, it is characterized in that, described wetting and dispersing agent is the interpolymer solution containing acidic group, acrylic acid block copolymer, hydroxyl functional group One or more of carboxylic acid esters, highly branched polyesters, polyamine block copolymer solutions; the catalyst is a metal compound catalyst, including stannous octoate, dibutyltin dilaurate, dibutyltin dilaurate, One or more of dioctyltin laurate, tin monobutyl triisooctoate, and zinc isooctanoate; the anti-hydrolysis agent is carbodiimide or polycarbodiimide compounds. 10. the high weather resistance coating composition for black photovoltaic backboard according to claim 1, is characterized in that, described anhydrous diluent is toluene, xylene, n-butyl acetate, ethyl acetate, butanone, cyclohexane One or more of ketone, methyl ethyl ketone, cyclohexane, propylene glycol methyl ether acetate.