JP6499490B2 - Hot melt seal composition - Google Patents

Description

  The present invention relates to a sealing composition that can be used for a frameless solar cell module, and in particular, a hot-melt seal that seals the ends in four directions formed when two glass plates are stacked with a certain gap therebetween. Relates to the composition.

  Conventionally, a hot-melt sealing composition that can be used as a sealing material for frameless solar cell modules, has an appropriate flowability at the melting temperature of the sealing composition, and has excellent insulating properties, waterproof properties, water vapor barrier properties, and durability. Has been proposed (Patent Document 1). The hot melt seal composition disclosed in Patent Document 1 includes polyisobutylene having a weight average molecular weight of 1 to 250,000, polyisobutylene having a weight average molecular weight of 35 to 450,000, and a polyisobutylene having a weight average molecular weight of 80 to 100,000. It is composed of isobutylene, a hygroscopic agent composed of at least quick lime or zeolite, a silane-modified polyolefin, and a filler, characterized in that the number average molecular weight obtained from the weight average molecular weight of each polyisobutylene is 190,000 to 300,000. To do.

JP 2014-19837 A

  However, the hot-melt seal composition disclosed in Patent Document 1 is an end portion in four directions formed when two glass plates such as a frameless solar cell module are stacked with a certain gap therebetween. When used for sealing, the solar cell module has a moderate flowability at the melting temperature of the sealing composition and is excellent in insulation, waterproofness, water vapor barrier property, and durability, but at a temperature of about 150 ° C. When cured for about 80 hours, very fine entrained bubbles that are contained in the composition and difficult to remove during production expand as the curing time elapses, resulting in pores that can be visually confirmed in the sealing composition. There exists a subject that an external appearance may become bad.

  The problem to be solved by the present invention is that it can be used as a sealing material for a frameless solar cell module, and the end of the four directions formed when two glass plates are stacked with a certain gap therebetween. An object of the present invention is to provide a hot melt seal composition in which no voids are generated in the seal composition when it is cured for about 80 hours at a temperature of about 150 ° C. when used for sealing.

The invention described in claim 1 includes polyisobutylene, quicklime as a moisture absorbent, an amorphous poly-α-olefin polymer silylated as a silane-modified polyolefin , a filler selected from talc, kaolin clay, and carbon black , It consists of hydrophobic fumed silica as a thixotropic agent , and has a complex viscosity η ^* in a dynamic viscoelasticity measurement at a measurement frequency of 1.0 Hz and 150 ° C. in a range of 16000 to 27000 Pa · s, and a measurement frequency of 0 Provided is a hot-melt seal composition for a solar cell module , wherein the energy loss tan δ at 0.01 Hz and 150 ° C. is in the range of 0.4 to 0.9.

The invention according to claim 2 is characterized in that the polyisobutylene comprises polyisobutylene having a weight average molecular weight of 150,000 to 250,000 and polyisobutylene having a weight average molecular weight of 80,000 to 100,000. The hot-melt seal composition for solar cell modules is provided.

The invention of claim 3 wherein the hygroscopic agent is a hot melt sealing composition for a solar cell module according to claim 1 or claim 2, characterized in that it comprises 20 to 60 parts by weight per 100 parts by weight of polyisobutylene Offer things.

The invention according to claim 4 is the solar cell module according to any one of claims 1 to 3, wherein the silane-modified polyolefin contains 15 to 45 parts by weight with respect to 100 parts by weight of polyisobutylene . A hot melt seal composition is provided.

The invention according to claim 5 is the solar cell module according to any one of claims 1 to 4, wherein the filler contains 50 to 200 parts by weight with respect to 100 parts by weight of polyisobutylene . A hot melt seal composition is provided.

  Since the hot melt seal composition according to the present invention has suitable dynamic viscoelastic properties at a melting temperature of about 150 ° C. and has a low viscosity, the two glass plates such as a frameless solar cell module are used. Even when it is used for sealing at the end portions in the four directions formed when they are overlapped while maintaining a certain gap, there is no effect that pores that can be visually confirmed are not generated in the sealing composition There is.

  The present invention will be described in detail below.

The hot melt seal composition of the present invention comprises polyisobutylene, a hygroscopic agent comprising at least quick lime or zeolite, a silane-modified polyolefin, a filler, and a thixotropic agent, and has a measurement frequency of 1.0 Hz and 150 ° C. In which the complex viscosity η ^* in the dynamic viscoelasticity measurement is 16000 to 27000 Pa · s, and the energy loss tan δ at a measurement frequency of 0.01 Hz and 150 ° C. is in the range of 0.4 to 0.9. It is a melt seal composition and contains a diluent, a tackifier, a heat-resistant auxiliary, a flame retardant, an antioxidant and the like.

Polyisobutylene The polyisobutylene used in the present invention can suitably use a polymer of isobutylene having a weight average molecular weight of 5 to 300,000, has an excellent water vapor barrier effect, and has a relatively low molecular weight. , Good flowability when melted at high temperature. If the weight average molecular weight is less than 50,000, the water vapor barrier property is insufficient, and if it exceeds 300,000, the flowability at high temperature melting is insufficient. If it is less than 80,000, the water vapor barrier property tends to be insufficient, and if it exceeds 250,000, the flow property at high temperature melting tends to be insufficient. A commercially available polyisobutylene having a weight average molecular weight of 90,000 includes oppanol B15SFN (trade name, manufactured by BASF), and a commercially available polyisobutylene having a weight average molecular weight of 200,000 includes opanol B30SF (trade name, manufactured by BASF).

Hygroscopic agent The hygroscopic agent used in the present invention is composed of at least quick lime or zeolite, and enters the multilayer glass from the periphery when the periphery of the multilayer glass is sealed with the hot melt seal composition of the present invention. It is blended for adsorbing and retaining moisture, and the weight increase rate when adsorbing moisture is suitably 10 to 30%, more preferably 20 to 25%. If it is less than 10%, sufficient adsorption performance cannot be maintained, and if it exceeds 30%, the moisture absorption performance is high and storage stability is insufficient. In particular, with respect to quicklime to be blended, those having good dispersibility with respect to polyisobutylene and having the surface of the particles treated with fatty acid or the like are suitable. Commercially available quicklime is CML # 31 (trade name, surface fatty acid-treated quicklime, weight increase rate upon moisture adsorption: 20%, manufactured by Omi Chemical Co., Ltd.), and commercially available zeolite is Mizuka Sieves 5AP (tradename, moisture adsorption). The weight increase rate at the time: 24%, manufactured by Mizusawa Chemical).

  The blending amount of the hygroscopic agent is 20 to 60 parts by weight, more preferably 30 to 50 parts by weight with respect to 100 parts by weight of the polyisobutylene. If it is 20 parts by weight or less, the hygroscopic effect is insufficient, and if it exceeds 60 parts by weight, the insulating property is lowered. If it is 30 parts by weight or less, the moisture absorption effect tends to be insufficient, and if it exceeds 50 parts by weight, the insulating property tends to decrease.

Silane-modified polyolefin As the silane-modified polyolefin, a silylated amorphous poly-α-olefin polymer can be preferably used. Examples of the amorphous α-olefin polymer before silylation include homopolymers and copolymers such as atactic polypropylene and atactic polybutene 1, and copolymers or terpolymers such as ethylene, propylene and butylene. A commercially available product of the silane-modified polyolefin is vestoplast 206 (viscosity: 5 ± 1 Pa · s / 190 ° C., manufactured by Eponic Degussa).

  The compounding quantity of silane modified polyolefin is 15-45 weight part with respect to 100 weight part of said polyisobutylene, More preferably, it is 20-40 weight part. If it is 15 parts by weight or less, the adhesion is poor, and if it exceeds 45 parts by weight, the flowability and insulation at high temperature melting are insufficient. If it is 20 parts by weight or less, the adhesion tends to be poor, and if it exceeds 40 parts by weight, the flowability and insulation during melting at high temperature tend to be insufficient.

  In addition to the silylated amorphous poly-α-olefin polymer, crystalline silane-modified polyolefin can be used as long as the properties of the present invention are not impaired. Commercially available crystalline silane-modified polyolefin is Lincron SL800 (trade name, silane-modified ethylene-octene random copolymer, density: 0.868 g / cm 3, crystal melting peak temperature: 54 ° C. and 116 ° C., crystal melting heat: 22J / G and 4 J / g).

Filler The filler used in the present invention comprises at least one selected from any of talc, kaolin clay, and carbon black. These fillers have the effect of improving the reinforcing property and the effect of improving the moisture permeability, and those in which the particle surface is treated with a coupling agent (vinyl silane or amino silane) can also be used. The average particle size of the filler is 1 nm to 1000 μm, more preferably 10 nm to 100 μm.

  The blending amount of the filler is 50 to 200 parts by weight, more preferably 80 to 150 parts by weight, with respect to 100 parts by weight of the polyisobutylene. If it is 50 parts by weight or less, the reinforcing effect is insufficient, and if it exceeds 200 parts by weight, the adhesion is insufficient. If it is 80 parts by weight or less, the reinforcing effect and moisture permeability tend to be insufficient, and if it exceeds 150 parts by weight, the adhesion tends to be insufficient.

  As commercially available calcium carbonate, there is BF200 (trade name, average particle diameter 5.5 μm, manufactured by Bihoku Powdered Company), and as talc, talc MS (trade name, average particle diameter 20 μm, manufactured by Nippon Talc Co., Ltd.), Kaolin clay. As ST-KE (trade name, vinylsilane-treated calcined kaolin clay, average particle size 2.2 μm, manufactured by Shiraishi Calcium Co., Ltd.), carbon black, Asahi Thermal Carbon (trade name, manufactured by Asahi Thermal Co., Ltd.) and MA100 (trade name) , Manufactured by Mitsubishi Chemical).

Thixotropy imparting agent The thixotropic agent used in the present invention is a hot melt seal composition according to the present invention having a complex viscosity η ^* in a dynamic viscoelasticity measurement at a measurement frequency of 1.0 Hz and 150 ° C. of 16000 to It is in the range of 27000 Pa · s, and is blended for the purpose of adjusting the energy loss tan δ at a measurement frequency of 0.01 Hz and 150 ° C. to a range of 0.4 to 0.9. This complex viscosity η ^* is related to the coating workability and the sag difficulty when the hot melt seal composition according to the present invention is melted and applied at a temperature of about 150 ° C. If it exceeds s, the coating workability becomes poor, and 16000 Pa.s. If it is less than s, sagging may occur. The energy loss tan δ is related to the generation of vacancies with the naked eye when cured at a temperature of about 150 ° C. for about 80 hours. When tan δ exceeds 0.9, the vacancies are generated.

  As the thixotropic agent, dry fumed silica is preferably used, and more preferably hydrophobic. Commercially available hydrophobic fumed silica includes Leolosil PM20L (trade name, manufactured by Tokuyama) and Aerosil RY200S (trade name, manufactured by Nippon Aerosil Co., Ltd.).

  Hereinafter, the hot melt seal composition according to the present application will be specifically described with reference to Examples and Comparative Examples.

Example 1 to Example 7
In the formulation shown in Table 1, opanol B30SF is used as polyisobutylene A1 having a weight average molecular weight of 200,000, opanol B15SFN is used as polyisobutylene having a weight average molecular weight of 90,000 as polyisobutylene A2, CML # 31 is used as humectant B, and silane modified. Bestplast 206 as polyolefin C1, Linklon SL800N as silane-modified polyolefin C2, Talc MS as filler D1, Asahi Thermal Carbon as filler D2, Kaolin clay ST-KE as filler D3, Calcium carbonate as filler D4 BF200, Leolosil PM20L as thixotropic agent E1 and Aerosil RY200S (used, test kneader (1L) as thixotropic agent E2 should be heated to 160 ° C. The hot melt seal compositions of Examples 1 to 7 and Comparative Examples 1 to 9 were obtained.

Evaluation items and evaluation methods

The hot melt seal compositions of Examples 1 to 7 and Comparative Examples 1 to 9 were applied to a laminate glass plate at a thickness of 0.7 mm, and removed at 135 ° C., 150 ° C. and 160 ° C. for 5 minutes. After airing, pressing was performed at a pressure of 60 kPa for 15 minutes, and the state was visually observed. A hot melt seal composition having no bubbles mixed was evaluated as ◯, and a bubble having bubbles was rated as x.

The hot melt seal compositions of Examples 1 to 7 and Comparative Examples 1 to 9 were applied at a thickness of 0.7 mm on the appearance-changing glass plate, deaerated at 150 ° C. for 5 minutes, and then at a pressure of 60 kPa. It was pressed for 15 minutes and then allowed to stand at 150 ° C. for 24, 48, and 80 hours, and the presence or absence of voids in the hot melt seal composition was visually observed. The case where no vacancies occurred was evaluated as ◯, and the case where vacancies occurred was evaluated as x.

Energy loss tan δ
The energy loss tan δ was measured using RHEO stress 600 manufactured by HAAKE Corporation at a test specimen thickness of 4.0 mm, an auto tension of 1.0 N, 150 ° C., and a frequency of 0.01 Hz. A tan δ of 0.4 to 0.9 was evaluated as ◯, and a value exceeding 0.9 was evaluated as ×.

Complex viscosity η ^*
Using a Rheo stress 600 manufactured by HAAKE Corporation, the complex viscosity η ^* is measured at a specimen thickness of 4.0 mm, auto tension 0.5 N, 150 ° C., frequency 1.0 Hz, and it is 1600-27000 Pa · s. Was evaluated as ○, and other than this as ×.

The hot melt seal compositions of Examples 1 to 7 and Comparative Examples 1 to 9 were applied in a thickness of 0.7 mm to a glass plate having a shear adhesion strength and a shear adhesion failure state of 20 mm × 50 mm × 3 m. Immediately, the glass plate having the same shape is placed so as to overlap with a width of 10 mm. After vacuum degassing at 150 ° C. for 5 minutes, press at 55 kPa pressure for 15 minutes. Thereafter, after further curing at 23 ° C. for 24 hours, two glass plates were pulled at a tensile rate of 20 mm / min, the fracture strength was measured, and the fracture strength per unit area was defined as shear adhesion strength (N / mm ² ). 0.4 N / mm ² or more was evaluated as “good”, and less than 0.4 N / mm ^{2 was} evaluated as “x”. Moreover, the fracture surface at the time of fracture was evaluated visually, 100% cohesive fracture of the hot melt seal composition was evaluated as “good”, and the others were marked as “x”.

The hot melt seal compositions of Examples 1 to 7 and Comparative Examples 1 to 9 were applied to a glass plate having a heat-resistant adhesive 20 mm × 50 mm × 3 mm thickness to a thickness of 0.7 mm, and immediately the same shape The glass plate is placed so as to overlap with a width of 10 mm. In this state, after vacuum degassing at 150 ° C. for 5 minutes, each specimen is pressed at 55 kPa pressure for 15 minutes. The test specimen was cured at 156 ° C. for 1000 hours, slowly cooled to 23 ° C., then pulled on two glass plates at a tensile speed of 20 mm / min, measured for fracture strength, and the fracture strength per unit area was determined as shear adhesion strength (N / Mm ² ). Separately from this, each specimen after pressing for 15 minutes is prepared and cured at 23 ° C. for 24 hours. Similarly, the shear adhesion strength (N / mm ² ) of the test specimen is measured, and the measured value is defined as the initial shear adhesion strength (N / mm ² ). For each of the yellowing-resistant hot melt seal compositions of Examples 1 to 4 and Comparative Examples 1 to 10, the initial shear adhesion strength (N / mm ² ) is 156 ° C. × 1000 hours later. The strength (N / mm ² ) was removed, and when the value was 0.5 or more, it was evaluated as ◯, and less than 0.5 was evaluated as x.

Evaluation results The evaluation results are shown in Table 2. In Examples 1 to 7, all evaluation items were “good”.

Claims (5)

Polyisobutylene, quick lime as a hygroscopic agent , silylated amorphous poly-α-olefin polymer as a silane-modified polyolefin , a filler selected from talc, kaolin clay, and carbon black , and a hydrophobic fume as a thixotropic agent and Doshirika consists, measurement frequency 1.0 Hz, the range complex viscosity eta ^* is 16000~27000Pa · s in a dynamic viscoelasticity measurement at 0.99 ° C., measurement frequency 0.01 Hz, energy at 0.99 ° C. A hot melt seal composition for a solar cell module, wherein the loss tan δ is in the range of 0.4 to 0.9. The hot melt seal composition for a solar cell module according to claim 1, wherein the polyisobutylene comprises polyisobutylene having a weight average molecular weight of 150,000 to 250,000 and polyisobutylene having a weight average molecular weight of 80,000 to 100,000. . The hot-melt seal composition for a solar cell module according to claim 1 or 2, wherein the hygroscopic agent is contained in an amount of 20 to 60 parts by weight with respect to 100 parts by weight of polyisobutylene. The hot-melt seal composition for solar cell modules according to any one of claims 1 to 3, wherein the silane-modified polyolefin is contained in an amount of 15 to 45 parts by weight with respect to 100 parts by weight of polyisobutylene. The hot-melt seal composition for a solar cell module according to any one of claims 1 to 4, wherein the filler contains 50 to 200 parts by weight with respect to 100 parts by weight of polyisobutylene.