High-weather-resistance bonding coating for transparent back plate for solar cell module

文档序号：336174 发布日期：2021-12-03 浏览：12次中文

阅读说明：本技术 一种用于太阳能电池组件用透明背板的高耐候粘结涂料 (High-weather-resistance bonding coating for transparent back plate for solar cell module ) 是由虞明东李登峰王世哲丁万强吴小娟于 2020-05-28 设计创作，主要内容包括：本发明提供了一种用于太阳能电池组件用透明背板的高耐候粘结涂料；由主剂和固化剂组成,其中,所述主剂包括如下组分：氟碳树脂、丙烯酸树脂、无机填料、分散剂、催化剂、溶剂；所述固化剂包括如下组分：异氰酸酯聚合体。本发明添加了低细度的纳米填料,在提高涂层耐紫外老化性能的同时也保证了较好的透明度,解决现有透明涂层耐紫外性较差的缺陷。(The invention provides a high weather-resistant bonding coating for a transparent back plate for a solar cell module; the curing agent consists of a main agent and a curing agent, wherein the main agent comprises the following components: fluorocarbon resin, acrylic resin, inorganic filler, dispersant, catalyst and solvent; the curing agent comprises the following components: an isocyanate polymer. The invention adds the low-fineness nano filler, improves the ultraviolet aging resistance of the coating, ensures better transparency, and solves the defect of poor ultraviolet resistance of the existing transparent coating.)

1. The high-weather-resistance bonding coating composition for the transparent back plate for the solar cell module is characterized by consisting of a main agent and a curing agent, wherein the main agent comprises the following components: 10-30 parts of fluorocarbon resin, 10-30 parts of acrylic resin, 2-15 parts of inorganic filler, 0.2-1 part of catalyst, 0.2-2 parts of wetting dispersant and 20-50 parts of anhydrous diluent; the curing agent comprises 50-70 parts by weight of isocyanate curing agent and 30-50 parts by weight of anhydrous diluent.

2. The highly weather-resistant primer composition for transparent back sheets for solar cell modules according to claim 1, wherein the fluorocarbon resin is one or two of solvent-soluble vinylidene chloride type, trifluorochloroethylene type, and tetrafluorochloroethylene type fluorocarbon resins mixed at an arbitrary ratio.

3. The highly weather-resistant adhesive coating composition for a transparent back sheet for a solar cell module according to claim 1, wherein the acrylic resin comprises one or more of (meth) acrylate-hydroxyethyl acrylate copolymer, (meth) acrylate-butyl acrylate-hydroxyethyl acrylate copolymer, (meth) acrylate-n-octyl acrylate-hydroxyethyl acrylate copolymer, (meth) acrylate-2-ethylhexyl acrylate-hydroxyethyl acrylate, and (meth) acrylate- (stearyl (meth) acrylate-hydroxyethyl acrylate copolymer, mixed in an arbitrary ratio.

4. The highly weather-resistant adhesive coating composition for a transparent back sheet for a solar cell module as claimed in claim 1, wherein the inorganic filler is composed of one or more of calcium carbonate, zinc oxide, silica, magnesium carbonate, wax powder, kaolin, barium sulfate, carbon black, talc, ceramic fine powder, white corundum, and alumina, which are mixed in an arbitrary ratio.

5. The highly weather-resistant bond coating composition for a transparent back sheet for a solar cell module according to claim 4, wherein the inorganic filler is treated with a functional coupling agent comprising one or more of an aluminate coupling agent, a zirconate coupling agent, a titanate coupling agent, an aluminum-zirconate coupling agent, and an aluminum-titanate coupling agent, which are mixed in an arbitrary ratio.

6. The highly weather-resistant adhesive coating composition for a transparent back sheet for a solar cell module according to claim 1, wherein the inorganic filler has a particle size of 100 to 1000 nm.

7. The highly weatherable tie-coat composition for a transparent back sheet for a solar cell module according to claim 1, wherein the catalyst is a metal compound catalyst; the metal compound catalyst comprises one or more of stannous octoate, dibutyltin dilaurate, dioctyltin dilaurate, monobutyl triisotin octoate and zinc isooctoate which are mixed according to any proportion.

8. The highly weather-resistant adhesive coating composition for a transparent back sheet for a solar cell module as claimed in claim 1, wherein the wetting dispersant is composed of one or more of a copolymer solution containing an acidic group, an acrylic block copolymer, a hydroxyl functional carboxylate, a highly branched structure polyester, and a block copolymer solution of a polyamine, which are mixed in an arbitrary ratio.

9. The highly weatherable bond coating composition for a transparent back sheet for a solar cell module according to claim 1, wherein the non-aqueous diluent of the main agent and the curing agent is one or more of the following solvents, respectively, and the solvents are mixed in any ratio: toluene, xylene, n-butyl acetate, ethyl acetate, butanone, cyclohexanone, methyl ethyl ketone, propylene glycol methyl ether acetate.

10. The highly weather-resistant adhesive coating composition for a transparent back sheet for a solar cell module as claimed in claim 1, wherein the highly weather-resistant adhesive coating composition is obtained by premixing the two components in such an amount that the ratio of the amount of the isocyanate group in the curing agent to the amount of the hydroxyl group in the main agent is 0.8 to 1.4:1 before use.

Technical Field

The invention belongs to the technical field of bonding coatings, and particularly relates to a high-weather-resistance bonding coating for a transparent back plate for a solar cell module.

Background

The battery cell in the conventional solar battery module is sandwiched between a front glass on the sunlight incident side and a solar back sheet disposed on the back side, and is sealed by an encapsulating material, typically an ethylene-vinyl acetate copolymer (EVA) resin. In order to ensure the service life of the solar cell module, the back sheet is required to have good weather resistance and high sealing property with the EVA adhesive layer.

In view of the development requirement of integration of a double-sided photovoltaic power generation assembly and a photovoltaic building, the application of the transparent solar cell back plate is more extensive, and higher strictness is provided for the performance of the transparent solar cell back plate. The back plate not only needs to meet the electrical insulation, moisture resistance and weather resistance of the conventional product, but also needs to have high light transmission and ultraviolet resistance. The transparent back sheet product in the market at present is mainly a transparent PET type back sheet, and is selected as a supporting base film of the back sheet due to its excellent heat resistance, chemical resistance and mechanical properties, and low price. However, since the polyester material and the EVA resin have a large polarity difference, and it is difficult to directly bond them, it is necessary to bond them together through an intermediate adhesive layer. The adhesion between the packaging material and the back plate includes the interface between the polyester base film and the adhesive layer and the interface between the packaging material and the adhesive layer, so that the sealing performance of the assembly can be ensured by simultaneously improving the performance between the two interfaces. The transparent back sheet is mainly classified into a composite type (common KPK and TPT) and a coating type according to the type of the adhesive layer. The composite back plate has high manufacturing cost due to the fact that the fluorine film is used as the bonding layer, the bonding property between the fluorine film and EVA is poor, and the problem of aging and peeling easily occurs when the fluorine film and the polyester base film are bonded through glue in a high-humidity and high-heat environment. The coating type back plate is formed by compounding or coating a fluorine-containing resin material with weather resistance on a polyester base film and drying and curing. Although the adhesive layers mentioned in most prior art patents (CN201410411372, CN201610531615, etc.) satisfy weather resistance and light transmittance, the product cost is high, and in addition, the risk of delamination of the back plate still exists during the use process, and the ultraviolet resistance is poor.

Disclosure of Invention

The invention provides a high-weather-resistance bonding coating for a transparent back plate for a solar cell module, which meets performance requirements such as adhesion, ultraviolet resistance, light transmittance and weather resistance and is low in cost.

The purpose of the invention is realized by the following technical scheme:

the invention provides a high weather-resistant bonding coating composition for a transparent back plate for a solar cell module, which consists of a main agent and a curing agent, wherein the main agent comprises the following components: 10-30 parts of fluorocarbon resin, 10-30 parts of acrylic resin, 2-15 parts of inorganic filler, 0.2-1 part of catalyst, 0.2-2 parts of wetting dispersant and 20-50 parts of anhydrous diluent; the curing agent comprises 50-70 parts by weight of isocyanate curing agent and 30-50 parts by weight of anhydrous diluent. Before use, the two components are premixed according to the ratio of the isocyanate group in the curing agent to the hydroxyl group in the main agent of 0.8-1.4:1 to obtain the high weather resistant adhesive coating.

Further, the fluorocarbon resin is prepared by mixing one or two of solvent-soluble vinylidene chloride type, trifluorochloroethylene type and tetrafluorochloroethylene type fluorocarbon resins according to any proportion. The hydroxyl value of the fluorocarbon resin is 50-70mgKOH/g, the acid value is less than or equal to 10mgKOH/g, the solid content is more than or equal to 55 percent, and the fluorine content is about 15-35 percent by weight.

Further, the acrylic resin comprises one or more of (meth) acrylate-hydroxyethyl acrylate copolymer, methyl (meth) acrylate-butyl acrylate-hydroxyethyl acrylate copolymer, methyl (meth) acrylate-n-octyl acrylate-hydroxyethyl acrylate copolymer, methyl (meth) acrylate-2-ethylhexyl acrylate-hydroxyethyl acrylate, and (meth) acrylate- (stearyl (meth) acrylate-hydroxyethyl acrylate copolymer, which are mixed according to any proportion. Of these, 2-ethylhexyl acrylate (meth) acrylate is most preferred.

Further, the inorganic filler is formed by mixing one or more of calcium carbonate, zinc oxide, silicon dioxide, magnesium carbonate, wax powder, kaolin, barium sulfate, carbon black, talcum powder, ceramic micro powder, white corundum and alumina according to any proportion.

Further, the inorganic filler is treated by a functional coupling agent, and the functional coupling agent comprises one or more of an aluminate coupling agent, a zirconate coupling agent, a titanate coupling agent, an aluminum-zirconate coupling agent and an aluminum-titanate coupling agent which are mixed according to any proportion. Among them, rutile type titanium dioxide treated with an aluminum-zirconate coupling agent is most preferable.

Furthermore, the particle size of the inorganic filler is 100-1000 nm. The nano-grade filler has small particle size, can reflect or diffuse ultraviolet rays, can absorb part of the ultraviolet rays, and also ensures the dispersion stability in the coating.

Further, the catalyst is a metal compound catalyst; the metal compound catalyst comprises one or more of stannous octoate, dibutyltin dilaurate, dioctyltin dilaurate, monobutyl triisotin octoate and zinc isooctoate which are mixed according to any proportion.

Furthermore, the wetting dispersant is prepared by mixing one or more of copolymer solution containing acid groups, acrylic block copolymer, hydroxyl functional group carboxylic ester, hyperbranched structure polyester and block copolymer solution of polyamine according to any proportion. Among them, most preferred is an acid group-containing copolymer solution such as BYK chemical BYK 111.

Furthermore, the anhydrous diluents in the main agent and the curing agent are respectively one or more than two of the following solvents which are mixed according to any proportion: toluene, xylene, n-butyl acetate, ethyl acetate, butanone, cyclohexanone, methyl ethyl ketone, propylene glycol methyl ether acetate. More preferably one or a mixture of two or more of the following: toluene, xylene, butyl acetate, butanone, propylene glycol methyl ether acetate.

Further, the isocyanate curing agent is an aliphatic isocyanate oligomer. The aliphatic isocyanate oligomer comprises one or more than two of 1, 6-Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI) tripolymer, 1, 6-Hexamethylene Diisocyanate (HDI) tripolymer and 1, 6-Hexamethylene Diisocyanate (HDI) biuret which are mixed according to any ratio. The isocyanate curing agent is diluted with a non-aqueous diluent and used. Of these, 1, 6-Hexamethylene Diisocyanate (HDI) trimer is most preferable.

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

1) according to the invention, the nano filler with low particle size (100-1000nm) and subjected to surface treatment is added into the bonding coating, so that the ultraviolet shielding rate is obviously improved and the ultraviolet aging resistance of the finished backboard is improved under the condition of ensuring better transmittance;

2) the invention provides a high-weatherability coating used as a bonding layer of a transparent solar cell back plate, the side chain of the used acrylic resin contains a longer carbon chain, which can enhance the winding with the molecular chain of EVA resin, and in addition, the main chain of the acrylic resin contains more ester bond groups, which is beneficial to improving the adhesive force of the acrylic resin on a polyester base film; meanwhile, after the polyester basal membrane is subjected to corona treatment, the surface of the polyester basal membrane contains a large number of hydroxyl and carboxyl active collective groups, and the isocyanate curing agent in the component B can form chemical bonding with the bonding layer, so that the adhesion of the bonding layer and the polyester basal membrane is further enhanced;

3) the coating prepared by the invention can give consideration to the cohesiveness with the polyester base film and the packaging material, has high peel strength, excellent weather resistance and durability, and simultaneously greatly reduces the manufacturing cost of the coating due to the introduction of the acrylate.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.

The main agent in the invention can be prepared by the following method: weighing anhydrous diluent, sequentially adding fluorocarbon resin, modified acrylic resin, inorganic filler and wetting dispersant, uniformly dispersing at a high speed, pouring into a sand mill, and milling until the particle fineness is less than or equal to 2 mu m; adding catalyst, adding anhydrous diluent until the solid content reaches 50%, mechanically mixing uniformly, filtering, sealing and filling in a drying container.

The specific application of the high weather-resistant bonding coating on the solar module is as follows: coating the bonding coating on a polyester base film to prepare a high-bonding back plate; and laminating the prepared high-adhesion back plate with the battery component through a packaging material. The average thickness of the polyester-based film is 100-300 mu m, and the used material is mainly polyethylene terephthalate (PET); the encapsulating material is mainly ethylene-vinyl acetate copolymer (EVA).

The polyester basal membrane is required to be subjected to surface treatment before being coated with the bonding coating, and flame treatment, atmospheric pressure plasma treatment, corona treatment, low-pressure plasma treatment, ultraviolet treatment and the like can be selected; corona treatment is furthermore preferred, for a time of 1 to 10 s; the coating mode can be selected from roll coating, spray coating, dip coating and brush coating; the coating thickness is 5-30 μm, the curing temperature is 150-200 ℃, and the curing time is 5-15 min.

Example 1

The embodiment provides a high weather-resistant bonding coating for a transparent back plate for a solar cell module, which consists of a main agent and a curing agent; the main agent comprises the following components (in parts by weight):

fluorocarbon resin (Shanghai Shengwei trade Co., Ltd SW-5570)	30
		Acrylic resin (Mitsubishi chemical 7765)	17.3
Nano TiO2 (Beijing Germany island gold science and technology Co., Ltd DK-TiO2-T30Q)	2
		Wetting dispersant (bike chemical BYK111)	0.2
Dibutyltin dilaurate (Jinan Haiyuan chemical industry Co., Ltd. T12)	0.5
		Acetic acid butyl ester	50