CN103442880A - Process for producing solar cell sealing sheet - Google Patents

Abstract

The present invention is a process for producing a solar cell sealing sheet, the process comprising conducting the following steps (a), (b), and (c) in the this order: a step (a) in which a resin composition that has been melted by heating is formed into a sheet and then cooled to obtain a web sheet; a step (b) in which at least one surface of the web sheet obtained in the step (a) is heated for 22-55 seconds to elevate, during this heating, the temperature of this surface to a temperature not lower than the melting point of the resin composition that constitutes this surface; and a step (c) in which the surface of the web sheet which has been heated in the step (b) is made to have a temperature within a specific range, and an embossing roller is subsequently pushed against this surface to form an embossed pattern in the surface. Thus, a solar cell sealing sheet which suffers little heat shrinkage and in which a distinct embossed pattern has been formed can be efficiently produced at low cost.

Description

The manufacture method of solar cell sealing sheet material

Technical field

The present invention relates to the manufacture method of solar cell sealing sheet material.Particularly, relate to that to be suitable for manufacturing heat shrink little, and surface is formed with the manufacture method of the sheet of the solar cell sealing sheet material of projection clearly.

Background technology

In recent years, from the aspect such as prevent of effective utilization of resource, environmental pollution, consider, the solar cell that sunshine is directly changed into to electric energy receives publicity, thereby has carried out various exploitations.Solar cell generally is configured to take sensitive surface guard member that glass substrate is representative and being called as between the back-protective part of backboard, with solar cell sealing sheet material (below, be called seal stock) sealed solar energy battery unit.

As solar module, the general following manufacture of silicon metal type solar cell of main flow.At first, laminated glass substrate, seal stock, solar battery cell (silicon generating element), seal stock and backboard successively.The sealing sheet material generally consists of vinyl-vinyl acetate copolymer (below, be called EVA).Then by vacuum lamination, this laminated body is heated under vacuum, the seal stock heating and melting is carried out to crosslinking curing.Like this, manufacture the bubble-freely bonding solar module formed of each member of formation.

In the manufacture of such solar module, if the contraction during heating of seal stock is large, the silicon generating element breakage sometimes due to this contraction distortion, or move the position of unit sometimes.Therefore, for seal stock, the contraction while requiring heating is little.In addition in recent years, for the resource that effectively utilizes silicon metal, reduce the cost for universal solar module, the thickness of silicon generating element is thinned to 100 μ m left and right, and then becomes and be easy to breakage.Therefore, the requirement that the heat shrink of seal stock is reduced is further strong.Therefore, studied the whole bag of tricks of the heat shrink rate that reduces seal stock.(for example, patent documentation 1).

In addition, except above-mentioned requirement when manufacturing, for solar module, in order to use for a long time afterwards in manufacture, its reliability is extremely important.The representative undesirable condition occurred in solar module as long-term use, the reduction of the generated energy that the bad orders such as peeling off between solar battery cell and seal stock, expansion are arranged, accompanies therewith.The reason of these undesirable condition phenomenons may not be clear and definite, but be studied from the raw material aspect that forms seal stock.For example, studied the viscosity of adjusting the EVA that forms seal stock method (patent documentation 2), add the method (patent documentation 3) of silane coupler etc. for the adhesive strength that improves solar battery cell and seal stock.

In addition, also carried out various research from the configuration aspects of seal stock.In order to prevent the long-term expansion followed etc. of using, each member of formation of the inside modules after just having manufactured is bonding with the bubble-free state of trying one's best is important.Therefore, in order to be easy to the purpose of leadage air when the vacuum lamination, attempt forming various projections, the depressions such as embossing shape on the surface of seal stock.In addition, these projections, depression are that pressing pressure in order to prevent due to lamination causes the solar battery cell purposes such as operability damaged, that improve seal stock to form sometimes.About pattern of indentations, its shape, the degree of depth etc. have been proposed to detailed protocol (patent documentation 4,5).

As described above, when manufacturing seal stock, form embossing shape clearly on the surface of seal stock and become important in the heat shrink that reduces seal stock.As the method proposed up to now, when disclosing casting and having used the sheet that the extruder such as double screw extruder extrudes from T-shaped die head, form the embossing shape below the mouth mould is tight, is then reduced as required the method (patent documentation 6) of the annealing in process of heat shrink on sheet.

The prior art document

Patent documentation

Patent documentation 1: TOHKEMY 2000-084996 communique

Patent documentation 2: TOHKEMY 2002-170971 communique

Patent documentation 3: TOHKEMY 2000-183382 communique

Patent documentation 4: TOHKEMY 2006-134970 communique

Patent documentation 5: TOHKEMY 2002-185027 communique

Patent documentation 6: TOHKEMY 2010-100032 communique

Summary of the invention

Invent problem to be solved

The manufacture method of patent documentation 6 is, after the surface of the sheet in manufacturing process (below, be called the operation sheet) forms the embossing shape, this operation sheet carried out to annealing in process.Therefore, if for the heat shrink that makes seal stock reduces and the operation sheet is heated fully, by this heating, be formed on the embossing shape collapse on the surface of operation sheet.If relax the heating of operation sheet in order to keep the embossing shape on the contrary, annealing in process becomes insufficient.Like this, in the manufacture method of patent documentation 6, having the reduction of heat shrink concurrently is very difficult with forming the embossing shape lucidly.

In addition, method as the heat shrink that reduces seal stock, generally speaking, as patent documentation 1 is also disclosed, used when resin molding is carried with the conveyer with a plurality of rollers, make the peripheral speed of roller of entrance side faster etc. than the peripheral speed of the roller of outlet side, and make the operation sheet shrink to reduce the method for heat shrink.Yet, in the method, owing in annealing in process, sheet being stretched, so heat shrink remove insufficient, need to be the implemented for long periods annealing in process of 1～2 minute.

In addition, the situation that the seal stock consisted of EVA contains crosslinking agent is many, and the forming temperature of operation sheet becomes low temperature, therefore a large amount of residual overstrains on the operation sheet.And this overstrain is often inhomogeneous at the width of the operation sheet of wide cut.If the operation sheet of such state is carried out to annealing in process as described above, the flatness of generating plate is impaired, and it is inhomogeneous that thickness becomes, or the undesirable condition such as the operation sheet is tortuous in annealing in process.In addition, by a plurality of rollers clamping pressurizations for the operation sheet of such state, it is very difficult implementing continuously embossing processing etc.

Therefore, the objective of the invention is, providing can be when fully reducing the heat shrink of seal stock, and forms the manufacture method of embossing shape clearly on the surface of seal stock.

For solving the method for problem

In order to solve above-mentioned problem, the manufacture method of solar cell sealing sheet material of the present invention is characterised in that, carries out successively following operation (a), operation (b) and operation (c).

Operation (a): will be by heating melting resin combination be shaped to sheet, then carry out cooling, thereby obtain the operation of operation sheet

Operation (b): at least one surface heating of the operation sheet that will be obtained by above-mentioned operation (a) 22～55 seconds adds the operation of the temperature more than the fusing point of hankering making this surperficial temperature reach the resin combination that forms this surface portion at this

Operation (c): the temperature on the surface of the operation sheet that will be heated in above-mentioned operation (b) is (fusing point of the resin combination of above-mentioned formation surface portion-10 ℃)～(fusing point of the resin combination of above-mentioned formation surface portion+20 ℃), then to this surface, press dandy roll, form the operation of embossing shape on this surface

The effect of invention

According to the present invention, can be low-cost and to manufacture efficiently heat shrink little, and be formed with the solar cell sealing sheet material of embossing shape clearly.

The accompanying drawing explanation

Fig. 1 is the generalized schematic of an example that shows the manufacture method of solar cell sealing sheet material of the present invention.

Fig. 2 is the generalized schematic of an example that shows the manufacture method of solar cell sealing sheet material in the past.

Fig. 3 is the figure that the method for the height that is determined at the projection that simultaneously forms bossed solar cell sealing sheet material is described.

Fig. 4 is that explanation is determined at the figure of method of height that two sides forms the projection of bossed solar cell sealing sheet material.

Fig. 5 is the figure of length D that shows the base of projection.

The specific embodiment

[manufacture method of solar cell sealing sheet material]

The manufacture method of solar cell sealing sheet material of the present invention is carried out following operation (a), operation (b) and operation (c) successively.

Operation (a): will be by heating melting resin combination be shaped to sheet, then carry out cooling, thereby obtain the operation of operation sheet.

Operation (b): at least one surface heating of the operation sheet that will be obtained by above-mentioned operation (a) 22～55 seconds adds the operation of the temperature more than the fusing point of hankering making this surperficial temperature reach the resin combination that forms this surface portion at this.

Operation (c): the temperature on the surface of the operation sheet that has made to be heated in above-mentioned operation (b) is (fusing point of the resin combination of above-mentioned formation surface portion-10 ℃)～(fusing point of the resin combination of above-mentioned formation surface portion+20 ℃), then to this surface, press dandy roll, form the operation of embossing shape on this surface.

Below, the manufacture method for solar cell sealing sheet material of the present invention, describe with reference to accompanying drawing.Fig. 1 is the generalized schematic that shows the embodiment of one of manufacture method of the present invention.

[operation (a): film making process]

At first, operation (a) is described.Operation (a) is, material resin is shaped to sheet, and it is cooling and obtain the operation of operation sheet.Below, operation (a) is called to film making process.

In film making process in Fig. 1, be provided with at high temperature and material resin and additive fusing mixing extruder 11, the pressure that reduces resin to be changed and make the operation sheet cooling curing of the gear pump 31 of the thickness stabilisation of sheet, the die head 12 that will be extruded into by mixing molten resin sheet, the high temperature that will be extruded and be shaped to polishing roll 13a, 13b and the 13c of the operation sheet of solid.

As extruder 11, can use single screw extrusion machine, double screw extruder.While using double screw extruder, from the aspects such as mixing property of productivity, resin and additive, consider it is preferred.In the situation that use single screw extrusion machine, owing to being full of by resin in extruder, so the pressure of the die head of extruder front end part changes smallerly, thereby do not need necessarily to arrange the weigh feeder such as gear pump 31.In the situation that use double screw extruder, due to the state in being filled not in extruder, therefore the weigh feeders such as gear pump 31 preferably are set between extruder and die head.

Material resin and the additive put in extruder 11 can drop into the mixture that has carried out in advance mixing with mixer, mixer etc., also can distinguish individually and drop into.In addition, can use the feed additive of side direction midway from extruder, or if method that the additive of liquid is added with injection pump etc. etc.

Although the temperature that material resin and additive are carried out when mixing is relevant with kind, the viscosity of the resin used, be preferably (fusing point of material resin+10 ℃)～scope of (fusing point of material resin+60 ℃).In addition, so-called fusing point, be to measure in (DSC) at means of differential scanning calorimetry in the present invention, the endothermic peak temperature while having carried out heating up with 10 ℃/minute.In the situation that as seal stock and the general EVA sheet used is crosslinked in order to make EVA, often contain organic peroxide as additive.Therefore, should be noted that and do not make organic peroxide decompose as far as possible and carry out mixing.Therefore, as resin temperature, in the situation that the EVA that for example fusing point is 70 ℃ of left and right preferably carries out mixing the scope of 80～130 ℃.The scope of 100～120 ℃ more preferably.If be less than 80 ℃, mixing property becomes insufficient, and the possibility of the uniformly dispersed reduction of additive is arranged.The possibility that the degraded appearance of seal stock consequently, is arranged.If surpass 130 ℃,, in the situation that cooperation organic peroxide organic peroxide can decompose, the quality of seal stock is unstable, and continuous production also reduces sometimes in addition.

In addition, in the operation of Fig. 1, the method as the film making process sheet, be provided with extruder, but also can use the known distinct methods such as moulding that undertaken by stack.

, use die head 12 and be extruded as sheet by material resin with additive melts and carried out mixing molten resin by extruder 11 grades.As die head 12, can use T-shaped die head, circular mode first-class.Flat die head is because the sheet width according to extruding becomes the wide shape of width, if therefore be installed on extruder become T-shapedly, therefore is generically and collectively referred to as T-shaped die head.In addition, for T-shaped die head, in differences such as width holdup time of die head, flow velocitys, the problem such as in uneven thickness of width while therefore being easy to occur heating process sheet in problem, the operation (b) such as thickness deviation.In order to address these problems, also preferably use circular die cylindraceous.Circular die is, for resin extruded one-tenth is cylindric, thereby it cut to the die head cylindraceous that it is shaped to sheet, and it is more even that the physical property of the width of sheet is easy to become.

In addition, in the situation that use T-shaped die head, also can use a plurality of extruders that different resin combinations is extruded, making the operation sheet by coextrusion methods such as feed block mode, multimode modes is that lamination forms.By forming such lamination, form, each layer can separate as seal stock necessary function, can reduce costs by regulating additive capacity.

Polishing roll 13a, the 13b for the operation sheet that uses die head 12 to carry out extruding, 13c and be formed as sheet.Polishing roll is for molten resin is carried out to thickness and the operation piece conveying device prima facie figuration, that consist of a plurality of rollers of sheet with pair of rolls clamping pressurization simultaneously.Each roller formed possess the temperature that is adjusted to cooling, the plastic property that is suitable for molten resin mechanism, adjust gap between each roller and the mechanism of moulding pressure.In addition, as required, preferably by flowing through the water transfer of cooling water isothermal, prevent the adhesion of operation sheet, mouldability is improved.The temperature of cooling water preferably is adjusted into the scope of 0～30 ℃.Be positioned at the composition of the polishing roll 13a of upstream side according to used resin in polishing roll, the resin of high temperature is easy to be adhered to the surface of roller sometimes, therefore preferably at surface coiling silicon rubber etc., release property is improved.In addition for transporting is improved, the 13b of opposed roll that also preferably makes to be positioned at the polishing roll 13a of upstream side is the metallic roll with the planar configuration of surface of sand.The planar surface roughness about sand, 10 mean roughness Rz that define in JIS B0601-1994 are preferably the scope of 2～10 μ m left and right.At the surface of polishing roll 13a coiling silicon rubber etc., and the 13b of opposed roll is had in the situation of metallic roll of the planar configuration of surface of sand, the thickness of the silicon rubber on the surface of polishing roll 13a is preferably 3～10mm, more preferably 4～8mm.If the thickness of silicon rubber is less than 3mm, the transfer printing of the planar pattern of sand becomes insufficient, sometimes adhesion operation sheet on the free roll for delivery of the operation sheet etc.If the thickness of silicon rubber surpasses 10mm, the heat from molten resin in the rubber surface accumulation of heat, so the resin of sometimes adhering on roller.

[operation (b): annealing in process operation]

Next operation (b) is described.The purpose of operation (b) is, removes the overstrain that the operation sheet of moulding in film making process has, and the heat shrink of operation sheet is reduced.For operation (b), can enumerate on one side and be heated with the heater 16 be arranged in annealing furnace 15, on one side on a plurality of conveying rollers 17 by the method for operation sheet etc.Below, operation (b) is called to annealing operation.

For the heater 16 of heating process sheet, so long as can the heating process sheet, be not particularly limited, can use the known methods such as ceramic heater, stainless steel heater, sheath heater.Particularly the mode by the infrared heating sheet, due to can heating equably on the thickness direction of sheet, be therefore preferred.In addition, also can preferably use the heating of being undertaken by heating agents such as hot blast, steam, the method contacted with warmed-up roller etc.These heating means can be used separately, also can combine some methods and use.

For delivery of the conveying roller 17 of operation sheet, in order to carry the operation sheet be heated, preferred release property excellence.Therefore, can use processing by embossing, the compound such as thermal spraying metal, metal oxide and establish on irregular metallic roll the roller of fluororesin such as being coated with polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer, perfluoro alkoxy alkane on surface.Perhaps, can use the surperficial circumvolution of metallic roll carried out paper that the coating of release property processes, film etc. and roller.The means of giving of these release properties there is no need to be particularly limited, and can use known method in the past.Degree as the release property of these rollers, be preferably by the method for JIS Z0237-2009 defined, to the peel strength of ニ チ バ Application Co., Ltd. cellophane adhesive tape processed, is the material below 5N/mm.In addition, about the conveying roller 17 in stove, the situation that can control individually its speed according to the contraction of operation sheet, owing to removing heat shrink in the efficiency highland, is therefore preferred.

Heater 16 and conveying roller 17, be arranged in annealing furnace 15, make to try one's best in few situation with contacting of extraneous air, and the temperature stabilization in stove, the heat treatment of operation sheet is stable, is therefore preferred.In addition, in order to make temperature in the stove purpose of stabilisation equably, by warm-air supply, to stove, be one of preferred configuration.

In addition as required, preferably a pair roller 14 is located to the upstream of annealing furnace 15.By roll 14 is set, can block the impact of annealing in process operation on film making process, be therefore preferred.Particularly, the impact of the contraction in the time of can preventing the heating process sheet on film making process, or make the supply stabilisation of the operation sheet of annealing operation.

In addition, preferably between the outlet of annealing furnace 15 and dandy roll 20, be provided with in advance sheet and take out roller 18.Sheet takes out roller 18 and undertakes the effect of from annealing furnace 15, taking out the operation sheet.If do not have sheet to take out roller 18, sometimes in the roller in annealing furnace 17 between the roller of close outlet side and embossing working roll 20 the operation sheet be stretched and deform.In addition, during annealing in process, the heat shrink of operation sheet exists inhomogeneous and produces fold etc. at the width of operation sheet sometimes, and therefore in order to remove this fold, sheet takes out roller 18 and also is preferably Stretching rollers (bow action roller).Preferably sheet takes out roller 18 and similarly gives in advance release property with the conveying roller 17 in stove in addition.

In addition, sheet takes out roller 18, if its surface temperature is too low, the operation sheet of sometimes supplying with to dandy roll is cooled, the transfer printing reduction of embossing shape.On the contrary, if surface temperature is too high, the operation sheet is adhered to sheet and takes out roller 18 sometimes, and it is difficult that the conveying of operation sheet becomes.Therefore, the surface temperature of sheet taking-up roller 18 is preferably adjusted the scope that temperature is 20～80 ℃ in advance.The temperature that further preferably is made as in advance the operation sheet exported with annealing furnace equates or the surface temperature below it.The surface temperature of taking out roller 18 as chankings is higher than the surface temperature of the operation sheet out from annealing furnace, and the operation sheet is adhered to roller sometimes.

For the temperature that prevents the operation sheet reduces, annealing furnace 15 is preferably as far as possible short with the distance of dandy roll 20.Therefore, many heel pieces also can be set and take out rollers 18, but be preferred still less the time, preferably at the most below 3, more preferably 1 or 2.

When annealing in process operation and ensuing operation (c) are carried out continuously, the surface temperature of preferably controlling from annealing furnace 15 operation sheet out be imported into dandy roll operation (c) in the surface temperature of operation sheet.Therefore, in order to hold exactly the surface temperature of operation sheet, and the surface temperature of the operation sheet before measuring the exit portion of annealing furnace 15 and being about to carry out embossing processing, thereby non-contact infrared thermometer 33 preferably is set.In addition, a plurality of contactless thermometers preferably also are set in annealing furnace 15, carry out the surface temperature of instrumentation operation sheet.

In the annealing in process operation, heated until make at least one surperficial maximum temperature of operation sheet become the above temperature of fusing point of the resin combination that forms this surface portion.To the surface of this warmed-up side, in ensuing operation (c), implement embossing processing.Here, so-called " forming the resin combination of surface portion ", in the situation that the operation sheet is single-layer sheet, is the resin combination that forms this operation sheet, in the situation that the operation sheet is lamination, the laminated sheet of a plurality of layers being arranged, is the resin combination of layer that forms the surface of a warmed-up side.Even implementing to make maximum temperature is only the such annealing in process of temperature that is less than the fusing point of resin combination, the effect that reduces the heat shrink rate is also insufficient, or needs to process for a long time.In addition, the maximum temperature on surface is preferably in the temperature range of (fusing point+5 ℃ of resin combination that forms the surface portion of a warmed-up side)～(forming the fusing point+35 ℃ of resin combination of the surface portion of a warmed-up side).If the excess Temperature in annealing in process, the operation sheet is adhered to conveying roller sometimes, or flatness reduces, or as former thus in ensuing operation (c) the generation fold.For example, in the situation that the operation sheet formed by the EVA resin of 71 ℃ of fusing points, the surface in the annealing in process operation be up to the scope that temperature is preferably 76～106 ℃.

The time of heating process sheet, the operation sheet is trapped in the scope that the time in annealing furnace is 22～55 seconds.Be this heat time heating time, for the operation sheet be cooled by polishing roll 13, make the surface temperature of operation sheet reach above needed time of melting temperature and the total of carrying out for reducing the time of the annealing in process of heat shrink after reaching more than melting temperature.If be less than 22 seconds heat time heating time, removing of heat shrink becomes insufficient.Even surpass 55 seconds and heat heat time heating time, effect also can be saturated, is only that the length of annealing furnace is ineffectually elongated.The lower limit of heat time heating time was preferably more than 22 seconds, more preferably more than 25 seconds.The upper limit of heat time heating time so long as can remove fully heat shrink and get final product, preferably the short time, is preferably below 45 seconds, more preferably below 40 seconds.

[operation (c): embossing manufacturing procedure]

Next for operation (c), describe.Operation (c) is that the operation sheet that the heating by annealing operation is become to the condition of high temperature is implemented embossing processing, forms the operation of embossing shape on operation sheet surface.In operation (c), be provided with for form dandy roll 20, embossing opposed roll 19 and the chill roll 21 of embossing shape on the operation sheet.After, this operation (c) is called to the embossing manufacturing procedure.

On the surface of dandy roll 20, with the embossing shape that will form on the operation sheet, apply accordingly the engraving of this embossing shape of having overturn.That the embossing formed on the operation sheet is shaped as is randomly shaped, geometry pattern etc., as long as determine as required.Yet, if the formation of embossing shape is insufficient, the transporting of operation sheet, be easy to while being rolled into web-like stick together, or be difficult for leadage air while making solar module, have and become the possibility that produces the reason of bubble in module.The cone-shapeds such as that the pattern of the engraving that the surface of dandy roll is applied can adopt is hemispherical, pyrometric cone, quadrangular pyramid, hexagonal cone, circular cone, to make their top be flat trapezoidal shape.In addition, these shapes can be for mixing the pattern existed.Wherein, be preferably hemispherical and/or quadrangular pyramid shape.Here " hemispherical and quadrangular pyramid shape ", refer to the hemispherical engraving that mixes the pattern existed with the quadrangular pyramid shape.From at seal stock, during to the pushing of solar battery cell, be not vulnerable to concentrated load, and the scatteredload aspect being considered equably, is preferably hemispherical.In addition, from the catoptrical inhomogeneous difficult generation of seal stock, the aspect that has excellent surface quality is considered, is preferably the quadrangular pyramid shape.And, have the hemispherical and pattern quadrangular pyramid shape in order to show these the hemispherical and features quadrangular pyramid shape, also to be preferably to mix.Make hemispherical the mixing with the quadrangular pyramid shape in situation about existing, as long as ratio separately is according to more needing which kind of feature and arbitrary decision.It is all particularly preferably hemispheric pattern.

In the situation that the engraving on dandy roll surface is excessively dark, add the large pressing pressure of needs in man-hour at embossing, it is large-scale that equipment becomes.Therefore, although the degree of depth of the engraving of dandy roll is relevant with the thickness of operation sheet, be preferably in the scope of 65～350 μ m.In addition, the degree of depth of the engraving of so-called dandy roll, mean from the center of dandy roll to the distance on the surface (implementing the part of engraving) of dandy roll and center from dandy roll poor to the distance of the deepest part of the recess (part of paddy) of engraving.The degree of depth of this engraving, according to JISB0601 (2001), is meaned by the maximum height Pz (μ m) that uses the surface roughness measurement machine to measure.

Preferably on the surface of dandy roll, further apply the depression of the degree of depth 1～20 μ m.The dandy roll that is applied with so small depression by employing carries out embossing processing, can form on the surface of sheet small projection.Consequently, the sliding of sheet improves, easy operating, and the light scattering due to small projection in addition, the white raising of sheet, the inspection of therefore adhering to foreign matter etc. becomes easy.Small depression like this can be by after applying engraving to the dandy roll surface, implements known blasting treatment etc. and easily form.The degree of depth of small depression can add particle size, the pressure condition in man-hour according to sandblast and be adjusted.

With the opposed embossing opposed roll 19 of dandy roll, for the transfer printing to the operation sheet of the engraving that improves the dandy roll surface, and preferably use on metallic roll circumvolution that the roller of rubber is arranged.About the kind of rubber, for silicon rubber, nitrile rubber, neoprene etc., be not particularly limited, be preferably the rubber of the scope that the A type hardness tester according to JIS K6253-2006 is 65～85 °.Lower than 65 °, surpass 85 °, the transfer printing reduction of embossing shape sometimes.In these rubber, silicon rubber is most preferred, because its release property with the operation sheet that at high temperature is easy to adhesion is good.

In the embossing manufacturing procedure, make to be supplied to the passing through the annealing in process operation of operation sheet of dandy roll and in the temperature on the warmed-up surface temperature range for (forming the fusing point-10 ℃ of this surperficial resin combination)～(form the fusing point of this surperficial resin combination+20 ℃).If be less than (fusing point of resin combination-10 ℃), the transfer printing reduction of embossing shape.If surpass (fusing point of resin combination+20 ℃), the excess Temperature of the operation sheet in annealing operation is easy to occur fold etc. in annealing operation.For example, in the situation that the layer of face side is 71 ℃ by fusing point, an EVA resin forms, and embossing adds in the scope that the surface temperature in man-hour is 61～91 ℃.

In addition, about the press pressure of dandy roll 20, the linear pressure that the operation sheet is subject to is preferably the scope of 150～500N/cm.The scope of 200～450N/cm more preferably.If linear pressure is less than 150N/cm, the transfer printing reduction of embossing shape sometimes.If the additional linear pressure that surpasses 500N/cm needs to make equipment enlarging, in this case, the life-span of opposed rubber rollers can reduce.

In prior art shown in Fig. 2, the press pressure of dandy roll 13b ', although high, linear pressure 100N/cm left and right is sufficient.Infer that this is because the temperature of the resin be extruded from T-shaped die head, in the situation that for example used the EVA resin that fusing point is 71 ℃, mostly be the scope of 100～120 ℃, owing to being the condition of high temperature, therefore, for the transfer printing of embossing shape, linear pressure 100N/cm left and right is sufficient.On the other hand, in manufacture method of the present invention, carry out embossing processing as mentioned above in the temperature range of (fusing point of resin combination-10 ℃)～(fusing point of resin combination+20 ℃).Like this, if embossing adds the surface temperature step-down of the operation sheet in man-hour, be difficult for transfer printing embossing shape, therefore preferably improve embossing and process needed press pressure.That is, preferably making linear pressure is more than 150N/cm.In addition, alleged linear pressure in the present invention, be by roller press loading divided by the face length of roller value.

In addition, in the processing of the embossing than under lower temperature, in order to improve the transfer printing of embossing shape, preferably make the operation sheet embrace in dandy roll 20 like this.Particularly, preferably to the scope that attached angle is 30～270 ° of embracing of dandy roll.If only give shallow embossing, embrace attached angle and can be less than 30 °, in order to give the embossing of shape deeply and clearly, preferably making to embrace attached angle is more than 30 °.In addition, embrace attached angle can be simply by the length of the circular arc of the part of contact operation sheet 32 on dandy roll 20 and the ratio calculating of the circumference of dandy roll.For example, in the situation that embrace an attached angle, be 90 °, refer to that 1/4 the suitable part of length at the circumference with dandy roll contacts the operation sheet.

The surface temperature of the dandy roll 20 in this embossing manufacturing procedure is preferably below (fusing point-20 ℃ of the resin combination of the surface portion of a side of formation transfer printing embossing shape).If the temperature of dandy roll is low, the release property of operation sheet improves, and the operation sheet is difficult for being wound on roller.Consequently, the load while from dandy roll, peeling off the operation sheet is alleviated, and can obtain the better solar cell sealing sheet material of quality.

From the dandy roll demoulding, by chill roll 21 refrigerating work procedure sheets, make the surface temperature of operation sheet promptly be reduced near room temperature the operation sheet.

For by masking, annealing in process are removed heat shrink in this wise, and formed the operation sheet 32 of embossing shape, after being desirable width in defect inspection, by the size adjusting of operation sheet, be wound into web-like by up-coiler etc., or cut into the section of desired length, and for the manufacture of solar module.

[solar cell sealing sheet material]

Next the solar cell sealing sheet material is described.Seal stock is preferably the individual bumps that surface has height 60～300 μ m.There is the independently projection more than height 60 μ m by the surface at seal stock, thereby during vacuum lamination that can be when manufacturing solar module, air that will be residual between seal stock and solar battery cell is removed efficiently from multiple directions, suppresses the generation of bubble.In addition, can make seal stock disperse the pushing force of solar battery cell, suppress the generation that unit breaks.If the shape on seal stock surface is not individual bumps, but continuous groove shape, degassed on the direction perpendicular to groove becomes insufficient, and residual air becomes bubble.In addition, if the height of projection is below 300 μ m, concentrated suppressed to the loading at top of projection during vacuum lamination, can prevent that solar battery cell from breaking.Here, so-called " individual bumps ", be when being conceived to the bottom surface of projection, the projection of the scope that the length D on base described later is 70～6000 μ m.

In addition, individual bumps is preferably, and seal stock is being clamped with flat board, and the pressure that through-thickness is given 50kPa is compressed and makes bowing, when the top of projection enlarges with the dull and stereotyped zone contacted, derive from 2 interregional gaps of guaranteeing 20～800 μ m of 2 adjacent protrusions.

Individual bumps is preferably, and the ratio (T/D) of the base length (D) of the height of projection (T) and projection is 0.05～0.80, and more preferably 0.15～0.80.If the T/D ratio is less than 0.05, the resiliency of seal stock becomes insufficient sometimes.If T/D is than surpassing 0.80, projection produces the concentrated load at top, and generating unit breaks sometimes.The height T of projection measures as follows.At first, illustrate a bossed situation of tool.The face of a bossed side of seal stock is made as to the A face, the face of a unpolarized side is made as to the B face.As shown in Figure 3, the distance from the summit of the projection of A face to the B face is made as to Tmax, the distance from the unpolarized part of A face to the B face is made as to Tmin.The height T that the difference of this Tmax and Tmin is projection.Next the bossed situation of two side's tools is described.A face of seal stock is made as to the A face, another face is made as to the B face.As shown in Figure 4, distance from the summit of the projection of A face to the unpolarized part of B face is made as to TAmax, distance from the summit of the projection of B face to the unpolarized part of A face is made as to TBmax, the distance from the unpolarized part of A face to the unpolarized part of B face is made as to Tmin.The height TA of the projection that the difference of this TAmax and Tmin is the A face, the height TB of the projection that the difference of TBmax and Tmin is the B face.The length on the base of so-called projection is the outer circumference diameter D of the projection shown in Fig. 5.In addition, being shaped as in polygonal, the oval-shaped situations such as triangle, hexagon of the bottom surface of projection, the diameter of the minimum proper circle that the length on the base of projection is the shape that comprises bottom surface.About above-mentioned Tmax, Tmin, D, the observation of the sheet that can be undertaken by the employing stereomicroscope is measured.

The height T of preferred projection is 60～300 μ m as mentioned above.In the situation that the height T of projection is 60 μ m, the length of the base D of projection is preferably 75～1200 μ m, more preferably 75～400 μ m.In the situation that the height T of projection is 300 μ m, the length of the base D of projection is preferably 375～6000 μ m, more preferably 375～2000 μ m.

The number of individual bumps is preferably every 1cm ²the one-sided area of sheet is 40～2300.More preferably 40～1100.If individual bumps is less than 40/cm ², sometimes generating unit break, bubble.If surpass 2300/cm ², above-mentioned T/D is than increasing, and due to the concentrated load to the projection top, generating unit breaks sometimes.

The heat shrink rate that seal stock is preferably the mobile direction of sheet while in the warm water of 80 ℃, placing 1 minute is below 30%.More preferably below 25%.Here, " being placed in warm water ", little at the proportion of seal stock, seal stock swims in the situation on surface of warm water, be by seal stock from pushing and not sinking in warm water, at this, under floating state, place.On the other hand, great at the ratio of seal stock, under seal stock, sink in the situation in warm water, be not by seal stock from supported underneath, and place under the state of this sinking.In addition, so-called " sheet flow direction ", be the mobile direction of operation sheet in the manufacturing process of seal stock.In general vacuum lamination operation in the manufacture of solar module, to seal stock fully till melting during, to the sheet pressurization and do not vacuumized without under load state, carry out the melting of seal stock and degassed.Now, the contraction of seal stock in without load state, therefore occurs due to the high temperature exposure 80 ℃ of left and right in seal stock, and generating unit breaks, misplaces as a result.The present inventors are conceived to breaking, misplacing of unit and are studied, found that, in vacuum lamination, reproduce when under load state, the operation sheet being placed to 1 minute, if sheet flows, the heat shrink rate of direction is below 30%, can further suppress breaking of unit.The so-called state reproduced in this vacuum lamination is to place the state of operation sheet in the warm water of 80 °.In addition, with the heat shrink rate of the direction of the flow direction quadrature of sheet, than flow direction pettiness, get final product, be not particularly limited, but be preferably below 5%.

The cone-shapeds such as that the shape of individual bumps is preferably is hemispherical, pyrometric cone, quadrangular pyramid, hexagonal cone, circular cone, to make their top be flat trapezoidal shape.In addition, can have for mixing the state of these shape for lugs.Wherein, be preferably hemispherical and/or quadrangular pyramid shape.Here so-called " hemispherical and quadrangular pyramid shape ", refer to that hemispheric projection mixes the surface configuration of existence with the projection of quadrangular pyramid shape.When pushing to solar battery cell, from being difficult for that solar battery cell is applied to concentrated load, and can disperse equably the loading aspect to consider, be preferably hemispherical.In addition, catoptrical inhomogeneous from being difficult for generation, the aspect that has excellent surface quality consideration, also preferred quadrangular pyramid shape.And, in order to show these the hemispherical and features quadrangular pyramid shape, also preferably make the hemispherical shape existed of mixing with the quadrangular pyramid shape.In the situation that make hemispherically with the quadrangular pyramid shape, to mix existence, as long as ratio separately is according to more needing which kind of feature and at random determining.It is all particularly preferably hemispheric pattern.

Seal stock of the present invention preferably further has the projection of height 1～15 μ m at the face with individual bumps.By having so small projection, the sliding of sheet improves, and easy operating becomes.In addition, the light scattering due to small projection, the white raising of sheet, the inspection of therefore adhering to foreign matter etc. becomes easy.

Small projection like this can realize by the manufacture method of the present invention of implementing embossing processing after annealing operation.After implementing embossing processing, by heating, implement in the method in the past of annealing in process, sometimes highly for the above large projection of several 10 μ m also remains in sheet after heat treated, but the small projection that height is several μ m left and right is along with heat treatment disappears.

In addition, the height of small projection is the following numerical value obtained of measuring.For the surface of sheet, according to JIS B0601 (2001), use known laser microscope, such as the キ ー エ Application ス of Co., Ltd. laser microscope VK-X100 processed etc., the sheet surface is taken with multiplying power 400.In the roughness curve of the image of gained, the Rz value in the time of reaching cutoff 0.080mm is made as the height of small projection.

In the application, the index of the resiliency of the seal stock broken as the unit of estimating for suppressing solar cell, the resilience stress of sheet when employing is compressed 100 μ m by bossed through-thickness of the tool of seal stock.Relation to the resiliency of the unit disruptiveness of solar cell and seal stock conducts in-depth research, and found that, the resilience stress broken that can suppress unit is preferably below 70kPa.In addition, above-mentioned resilience stress obtains as follows: it is below 5 μ m that use has compression displacement, the compression test device that compression load is the following resolving power of 100Pa, measure by flat pressurization terminal the pressing speed with 0.02mm/s, the resilience stress (kPa) of sheet when bossed through-thickness of the tool of seal stock pressurizeed to 100 μ m, thus obtain.If the resilience stress of seal stock is below 70kPa,, by so that bossed mode contacted with solar battery cell of tool carried out lamination, carries out vacuum lamination, thereby can suppress breaking of solar battery cell.In addition, the shape of seal stock and face bossed opposition side of tool, be not particularly limited, but the aspects such as adhesion that prevent seal stock while manufacturing from solar module consider preferably have the small projection of height 2～10 μ m left and right.

The thickness of seal stock is preferably 50～1500 μ m.More preferably 100～1000 μ m, be particularly preferably 200～800 μ m.If be less than 50 μ m, the resiliency of solar cell sealing sheet material lacks sometimes, or considers to have problems from the viewpoint of operability.If surpass in addition 1500 μ m, the reduction of productive reduction, adaptation becomes problem sometimes.In addition, about the thickness of seal stock, in the one side at seal stock only, forming in bossed situation, is from the summit of projection to the distance of the face with bossed opposition side of tool.On the two sides of seal stock, forming in bossed situation, is from the summit of the projection of a face to the distance on the summit of the projection of opposing face.

Like this, for the surface at seal stock forms individual bumps exactly, or the heat shrink rate of seal stock is suppressed in specific scope, preferably by manufacture method of the present invention, manufactures seal stock.

[forming the raw material of solar cell sealing sheet material]

Next the resin combination that forms seal stock is described.In addition, the preferred resin combination that at least forms the surface portion that forms a bossed side meets the composition of the following resin combination illustrated etc.Certainly, the whole resin combination that more preferably forms the operation sheet meets the composition etc. of the resin combination of following explanation.

The resin combination that forms seal stock preferably comprises polyolefin-based resins.As polyolefin-based resins, can enumerate homo-polypropylene, the propylene of take is that be principal component with the polypropylene-based resins such as copolymer other monomer, ethylene-propylene-butene terpolymers, low density polyethylene (LDPE), ultra-low density polyethylene, straight chain shape low density polyethylene (LDPE), medium density polyethylene, high density polyethylene (HDPE), the ethene of take is that be principal component and polyethylene-based resin, the polyolefin thermoplastic elastomer (TPE)s etc. such as copolymer other monomer.As take ethene that be principal component with copolymer other monomer, can enumerate ethene-alpha-olefin copolymer, ethene-unsaturated monomer copolymer.As alpha-olefin, alpha-olefin can be enumerated ethene, propylene, 1-butylene, isobutene, 1-amylene, 2-methyl-1-butene alkene, 3-methyl-1-butene, 1-hexene, 1-heptane, 1-octene, 1-nonene, 1-decene etc.As unsaturated monomer, can enumerate vinyl acetate, acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate or vinyl alcohol etc.In addition to these polyolefin-based resins, use as required silane compound, carboxylic acid, glycidyl compound etc. to carry out a small amount of copolymerization or modification is one of preferred form.

In these polyolefin-based resins, from the transparency important as the solar cell sealing material, consider with the viewpoints such as cementability of solar battery cell, preferably use vinyl-vinyl acetate copolymer, ethylene-methyl methacrylate methyl ester copolymer, by low density polyethylene (LDPE) with olefinic unsaturated silane compound modification and resin etc.In the situation that use vinyl-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, the content of copolymer composition is preferably the scope of 15～40 quality %.

In addition, the resin combination of formation seal stock preferably comprises organic peroxide.As long as organic peroxide is to decompose and the organic peroxide of generation free radical in the temperature more than 100 ℃, any organic peroxide can be used, as long as the storage stability of temperature, the heating binding temperature while making solar module and crosslinking agent itself while considering to manufacture the solar cell sealing sheet material etc. are selected.Particularly, preferably the decomposition temperature of 10 hours half-life is the organic peroxide more than 70 ℃.As the example of such organic peroxide, can enumerate 1,1-bis-(tertiary hexyl peroxidating) cyclohexane, normal-butyl 4,4-bis--(tert-butyl hydroperoxide) valerate, 2,5-dimethyl-2,5-bis-(tert-butyl hydroperoxide) hexane, two-tert-butyl peroxide, two-tertiary hexyl peroxide, 2,5-dimethyl-2,5-bis-(tert-butyl hydroperoxide) hexin-3, the disuccinic acid peroxide, two (4-tert-butylcyclohexyl) peroxy dicarbonate, 1,1,3,3-tetramethyl butyl peroxidating-2 ethyl hexanoic acid ester, tertiary hexyl peroxidating-2 ethyl hexanoic acid ester, tert-butyl hydroperoxide-2 ethyl hexanoic acid ester, tertiary hexyl peroxidating isopropyl monocarbonate, two (4-tert-butylcyclohexyl) peroxy dicarbonate, tert-butyl hydroperoxide-3,5,5-tri-methyl hexanoic acid ester, the tert-butyl hydroperoxide laurate, tert-butyl hydroperoxide-2-ethylhexyl monocarbonate, tert-butyl hydroperoxide-2 ethyl hexanoic acid ester, the tert-butyl hydroperoxide isobutyrate, the tert-butyl hydroperoxide acetic acid esters, the different pelargonate of tert-butyl hydroperoxide, t-amyl peroxy-2 ethyl hexanoic acid ester, t-amyl peroxy caprylic acid ester, the different pelargonate of t-amyl peroxy, t-amyl peroxy-2-ethylhexyl carbonic ester, two-t-amyl peroxy thing, 1,1-bis-(tert-butyl hydroperoxide) cyclohexane, ethyl 3,3-bis-(tert-butyl hydroperoxide) butyrate, 1,1-bis-(t-amyl peroxy) cyclohexane etc.These organic peroxides can be used in combination more than two kinds.The content of these organic peroxides is preferably 0.1～5 mass parts with respect to polyolefin-based resins 100 mass parts.More preferably 0.1～3 mass parts, be particularly preferably 0.2～2 mass parts.If the content of organic peroxide is less than 0.1 mass parts, sometimes can not make polyolefin-based resins crosslinked.Even surpass 5 mass parts, contain, hanging down containing producing effect except this, undecomposed organic peroxide remains in seal stock, and the possibility that becomes deteriorated year in year out reason is arranged.

The resin combination that forms seal stock can further comprise crosslinking coagent, silane series coupling agent, light stabilizer, ultra-violet absorber, antioxidant etc.

Crosslinking coagent is the multi-functional monomer that has a plurality of unsaturated bonds in molecule, be that the living radical compound produced with decomposition by organic peroxide reacts, and in order to make polyolefin-based resins evenly, the efficiency highland is crosslinked and use.As the example of these crosslinking coagents, can enumerate isocyanuric acid triallyl ester, cyanuric acid alkatriene propyl diester, trimethylolpropane tris (methyl) acrylate, pentaerythrite three (methyl) acrylate, three ［ (methyl) acryloxy ethyl ］ isocyanuric acid ester, dihydroxy methylpropane four (methyl) acrylate, pentaerythrite four (methyl) acrylate, pentaerythrite ethyoxyl four (methyl) acrylate, dipentaerythritol five (methyl) acrylate, dipentaerythritol six (methyl) acrylate, divinylbenzene etc.These crosslinking coagents can be distinguished use separately, also can two or more also use.In addition, in the present invention, " (methyl) acrylate " refers to " acrylate or methacrylate ".

In these crosslinking coagents, be particularly preferably isocyanuric acid triallyl ester, trimethylolpropane tris (methyl) acrylate.The content added in the situation of these crosslinking coagents is to be preferably 0～5 mass parts with respect to polyolefin-based resins 100 mass parts.More preferably 0.1～3 mass parts, be particularly preferably 0.3～3 mass parts.Even surpass 5 mass parts, contain, the raising of effect is also very little, becomes the cost ascending factor.

Silane series coupling agent is preferably used for the cementability that improves the various members such as solar cell sealing sheet material and solar battery cell, backboard, glass.Content in the situation of interpolation silane series coupling agent is, with respect to polyolefin-based resins 100 mass parts, to be preferably the scope of 0.05～2 mass parts.If be less than 0.05 mass parts, low containing producing effect.Even surpass 2 mass parts, contain, the raising effect of cementability is also low.As silane series coupling agent, be not particularly limited, can enumerate and for example be selected from the alkoxysilane compound containing trialkylsilyl group in molecular structure with at least a kind of functional group in methacryloxy, acryloxy, epoxy radicals, sulfydryl, urea groups, NCO, amino, hydroxyl.As its concrete example, can enumerate γ-methacryloxypropyl methyl dimethoxysilane, γ-methacryloxypropyl trimethoxy silane, γ-methacryloxypropyl methyldiethoxysilane, the alkoxysilane compound containing trialkylsilyl group in molecular structure that γ-methacryloxypropyl trimethoxy silane etc. contain methacryloxy, the alkoxysilane compound containing trialkylsilyl group in molecular structure that γ-acryloxy propyl trimethoxy silicane etc. contains acryloxy, γ-glycidoxypropyltrime,hoxysilane, γ-glycidoxy propyl-triethoxysilicane, the alkoxysilane compound containing trialkylsilyl group in molecular structure that β-(3,4-epoxycyclohexyl) ethyl trimethoxy silane etc. contains epoxy radicals, γ mercaptopropyitrimethoxy silane, the alkoxysilane compound containing trialkylsilyl group in molecular structure that γ-sulfydryl propyl-triethoxysilicane etc. contains sulfydryl, γ-urea groups propyl-triethoxysilicane, the alkoxysilane compound containing trialkylsilyl group in molecular structure that γ-urea groups propyl trimethoxy silicane etc. contains urea groups, γ-NCO propyl-triethoxysilicane, γ-NCO propyl trimethoxy silicane, the alkoxysilane compound containing trialkylsilyl group in molecular structure that γ-NCO propyl group methyl dimethoxysilane etc. contains NCO, γ-(2-amino-ethyl) aminopropyl methyl dimethoxysilane, γ-(2-amino-ethyl) TSL 8330, gamma-amino propyl trimethoxy silicane etc. contains amino alkoxysilane compound containing trialkylsilyl group in molecular structure, γ-hydroxypropyl trimethoxy silane, the alkoxysilane compound containing trialkylsilyl group in molecular structure that γ-hydroxypropyl triethoxysilane etc. contains hydroxyl etc.Wherein, from the viewpoint of the compatibility with polyolefin-based resins, consider, be preferably the alkoxysilane compound containing trialkylsilyl group in molecular structure that contains methacryloxy, more preferably γ-methacryloxypropyl trimethoxy silane.

The resin combination that forms seal stock preferably further comprises ultra-violet absorber.Ultra-violet absorber is harmful ultraviolet ray of absorb irradiating in light, is transformed into harmless heat energy in molecule, prevents from exciting the material of the deteriorated spike of the light that causes in macromolecule.As ultra-violet absorber, can use known material.For example can use benzophenone series, BTA system, triazine system, salicylic acid system, cyanoacrylate system etc.Can use a kind in them, also can two or more be used in combination.

As the benzophenone series ultra-violet absorber, for example can enumerate, 2, 2 '-dihydroxy-4, 4 '-bis-(hydroxymethyl) benzophenone, 2, 2 '-dihydroxy-4, 4 '-bis-(2-hydroxyethyl) benzophenone, 2, 2 '-dihydroxy-3, 3 '-dimethoxy-5, 5 '-bis-(hydroxymethyl) benzophenone, 2, 2 '-dihydroxy-3, 3 '-dimethoxy-5, 5 '-bis-(2-hydroxyethyl) benzophenone, 2, 2 '-dihydroxy-3, 3 '-bis-(hydroxymethyl)-5, 5 '-dimethoxy-benzophenone, 2, 2 '-dihydroxy-3, 3 '-bis-(2-hydroxyethyls)-5, 5 '-dimethoxy-benzophenone, 2, 2-dihydroxy-4, 4-dimethoxy-benzophenone etc.

As BTA, it is ultra-violet absorber, for example can enumerate, 2-(2 '-hydroxyl-5 '-(hydroxymethyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-5 '-(2-hydroxyethyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-5 '-(3-hydroxypropyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-3 '-methyl-5 '-(hydroxymethyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-3 '-methyl-5 '-(2-hydroxyethyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-3 '-methyl-5 '-(3-hydroxypropyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-the 3 '-tert-butyl group-5 '-(hydroxymethyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-the 3 '-tert-butyl group-5 '-(2-hydroxyethyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-3 '-tertiary octyl group-5 '-(hydroxymethyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-3 '-tertiary octyl group-5 '-(2-hydroxyethyl) phenyl)-2H-BTA, 2-(2 '-hydroxyl-3 '-tertiary octyl group-5 '-(3-hydroxypropyl) phenyl)-2H-BTA etc., or 2, 2 '-di-2-ethylhexylphosphine oxide (6-(2H-BTA-2-yl)-4-(hydroxymethyl) phenol), 2, 2 '-di-2-ethylhexylphosphine oxide (6-(2H-BTA-2-yl)-4-(2-hydroxyethyl) phenol), 2, 2 '-di-2-ethylhexylphosphine oxide (6-(2H-BTA-2-yl)-4-(3-hydroxypropyl) phenol), 2, 2 '-di-2-ethylhexylphosphine oxide (6-(2H-BTA-2-yl)-4-(4-hydroxybutyl) phenol), 3, 3-{ 2, 2 '-bis-(6-(2H-BTA-2-yl)-1-hydroxyl-4-(2-hydroxyethyl) phenyl) } propane, 2, 2-{ 2, 2 '-bis-(6-(2H-BTA-2-yl)-1-hydroxyl-4-(2-hydroxyethyl) phenyl) } butane, 2, 2 '-oxygen base two (6-(2H-BTA-2-yl)-4-(2-hydroxyethyl) phenol), 2, 2 '-bis-(6-(2H-BTA-2-yl)-4-(2-hydroxyethyl) phenol) amine etc.

As triazine, it is ultra-violet absorber, for example can enumerate, 2-(2-hydroxy-4-hydroxymethyl ylmethyl phenyl)-4, 6-diphenyl-s-triazine, 2-(2-hydroxy-4-hydroxymethyl ylmethyl phenyl)-4, 6-two (2, the 4-3,5-dimethylphenyl)-s-triazine, 2-(2-hydroxyl-4-(2-hydroxyethyl) phenyl)-4, 6-diphenyl-s-triazine, 2-(2-hydroxyl-4-(2-hydroxyethyl) phenyl)-4, 6-two (2, the 4-3,5-dimethylphenyl)-s-triazine, 2-(2-hydroxyl-4-(2-hydroxyl-oxethyl) phenyl)-4, 6-diphenyl-s-triazine, 2-(2-hydroxyl-4-(2-hydroxyl-oxethyl) phenyl)-4, 6-two (2, the 4-3,5-dimethylphenyl)-s-triazine, 2-(2-hydroxyl-4-(3-hydroxyl propoxyl group) phenyl)-4, 6-diphenyl-s-triazine, 2-(2-hydroxyl-4-(3-hydroxyl propoxyl group) phenyl)-4, 6-two (2, the 4-3,5-dimethylphenyl)-s-triazine, 2-(2-hydroxyl-4-(4-hydroxybutyl) phenyl)-4, 6-diphenyl-s-triazine, 2-(2-hydroxyl-4-(4-hydroxybutyl) phenyl)-4, 6-two (2, the 4-3,5-dimethylphenyl)-s-triazine, 2-(2-hydroxyl-4-(4-hydroxyl butoxy) phenyl)-4, 6-diphenyl-s-triazine, 2-(2-hydroxyl-4-(4-hydroxyl butoxy) phenyl)-4, 6-two (2, the 4-3,5-dimethylphenyl)-s-triazine, 2-(2-hydroxy-4-hydroxymethyl ylmethyl phenyl)-4, two (2-hydroxy-4-methyl the phenyl)-s-triazine of 6-, 2-(2-hydroxyl-4-(2-hydroxyethyl) phenyl)-4, two (2-hydroxy-4-methyl the phenyl)-s-triazine of 6-, 2-(2-hydroxyl-4-(2-hydroxyl-oxethyl) phenyl)-4, two (2-hydroxy-4-methyl the phenyl)-s-triazine of 6-, 2-(2-hydroxyl-4-(3-hydroxypropyl) phenyl)-4, two (2-hydroxy-4-methyl the phenyl)-s-triazine of 6-, 2-(2-hydroxyl-4-(3-hydroxyl propoxyl group) phenyl)-4, two (2-hydroxy-4-methyl the phenyl)-s-triazine of 6-etc.

Be ultra-violet absorber as salicylic acid, can enumerate phenyl salicytate, to tert-butyl-phenyl salicylate, OPS p octylphenyl salicylate etc.

Be ultra-violet absorber as cyanoacrylate, can enumerate 2-ethylhexyl-2-cyano group-3,3 '-diphenylacrylate ester, ethyl-2-cyano group-3,3 '-diphenylacrylate ester etc.

In these ultra-violet absorbers, from the painted viewpoint of ultraviolet radiation absorption effect and ultra-violet absorber itself, consider, most preferably be the ultra-violet absorber of benzophenone series.

In the situation that add above-mentioned ultra-violet absorber, with respect to polyolefin-based resins 100 mass parts, be preferably 0.05～3 mass parts.0.05～2.0 mass parts more preferably.If content is less than 0.05 mass parts, low containing producing effect, if surpass 3 mass parts, tend to painted.

The resin combination that forms seal stock preferably further comprises light stabilizer.Light stabilizer is, supplements the free radical kind harmful to polymer, do not produce the material of new free radical.As light stabilizer, preferably using hindered amine is light stabilizer.

As hindered amine, it is light stabilizer, can enumerate decanedioic acid two (2, 2, 6, 6-tetramethyl-1 (octyl group oxygen base)-4-piperidyl) ester, by 1, the mixture that the reaction product 70 quality % of 1-dimethyl ethyl hydroperoxides and octane and polypropylene 30 quality % form, two (1, 2, 2, 6, 6-pentamethyl-4-piperidyl) ［ ［ 3, 5-two (1, the 1-dimethyl ethyl)-4-hydroxy phenyl ］ methyl ］ the butylmalonic acid ester, two (1, 2, 2, 6, 6-pentamethyl-4-piperidyl) sebacate and methyl isophthalic acid, 2, 2, 6, 6-pentamethyl-4-piperidyl sebacate mixture, two (2, 2, 6, 6-tetramethyl-4-piperidyl) sebacate, four (2, 2, 6, 6-tetramethyl-4-piperidyl)-1, 2, 3, 4-butane tetracarboxylic acid esters, four (1, 2, 2, 6, 6-pentamethyl-4-piperidyl)-1, 2, 3, 4-butane tetracarboxylic acid esters, 2, 2, 6, 6-tetramethyl-4-piperidyl-1, 2, 3, 4-butane tetracarboxylic acid esters and tridecyl-1, 2, 3, the mixture of 4-butane tetracarboxylic acid esters, 1, 2, 2, 6, 6-pentamethyl-4-piperidyl-1, 2, 3, 4-butane tetracarboxylic acid esters and tridecyl-1, 2, 3, the mixture of 4-butane tetracarboxylic acid esters, it is poly-that ［ { 6-(1, 1, 3, the 3-tetramethyl butyl) amino-1, 3, 5-triazine-2, 4-bis-bases } { (2, 2, 6, 6-tetramethyl-4-piperidyl) imino group } hexa-methylene { (2, 2, 6, 6-tetramethyl-4-piperidyl) imino group } ］, dimethyl succinate and 4-hydroxyl-2, 2, 6, the polymer of 6-tetramethyl-1-piperidines ethanol, N, N ', N ' ', N ' ' '-tetra--(4, 6-pair-(butyl-(N-methyl-2, 2, 6, 6-tetramethyl piperidine-4-yl) amino)-triazine-2-yl)-4, 7-diaza decane-1, 10-diamines and above-mentioned dimethyl succinate and 4-hydroxyl-2, 2, 6, the mixture of the polymer of 6-tetramethyl-1-piperidines ethanol, dibutylamine 1, 3, 5-triazine N, N '-bis-(2, 2, 6, 6-tetramethyl-4-piperidyl-1, 6-hexamethylene diamine and N-(2, 2, 6, 6-tetramethyl-4-piperidyl) condensation polymer of butylamine etc.It is a kind of that above-mentioned hindered amine is that light stabilizer can be used separately, also can more than two kinds, mix use.

Wherein, as hindered amine, be light stabilizer, preferably use two (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl isophthalic acid, 2,2,6, the mixture of 6-pentamethyl-4-piperidyl sebacate and methyl-4-piperidyl sebacate, two (2,2,6,6-tetramethyl-4-piperidyl) sebacate.In addition, hindered amine is that preferably to use fusing point be that hindered amine more than 60 ℃ is light stabilizer to light stabilizer.

The content that adds hindered amine and be in the situation of light stabilizer is to be preferably 0.05～3.0 mass parts with respect to polyolefin-based resins 100 mass parts.0.05～1.0 mass parts more preferably.If content is less than 0.05 mass parts, stabilization effect is insufficient, even surpass 3.0 mass parts, contains, and also can become factor painted, that cost rises.

In addition, in the scope that does not encumber effect of the present invention, as known additive, can contain as required antioxidant, fire retardant, flame retardant, plasticizer, lubricant, colouring agent etc.

[solar module]

The formation of solar module is the layer that contains sensitive surface guard member, back-protective part, is configured between this sensitive surface protective agent and back-protective part and is sealed with by seal stock solar battery cell.As seal stock used herein, can use the seal stock obtained by manufacture method of the present invention, also can use the above-mentioned seal stock of individual bumps that has on surface.

The seal stock obtained by manufacture method of the present invention, the heat shrink when material laminate of above-mentioned formation is integrated is little.Therefore, residual stress during moulding between solar battery cell and seal stock, between sensitive surface guard member and seal stock, between back-protective part and seal stock is little, becomes the solar module of long-term excellent in te pins of durability.

In addition, above-mentioned have a seal stock of individual bumps on surface, owing to can making the pushing force to solar battery cell when the material laminate of above-mentioned formation is integrated disperse, so the residual stress between solar battery cell and seal stock can reduce.In addition, also entrapped air pockets not in seal.Therefore, become the solar module of long-term excellent in te pins of durability.

Embodiment

Below show the determination method of using in the present embodiment.As long as no specializing, measuring the n number is 5, adopts mean value.

(1) thickness of sheet

For the seal stock molded, measure the thickness of 20 arbitrarily at width, obtain average thickness.Analyzer has used ミ Star ト ヨ society calibrator processed (547-301 type).About the thickness of seal stock, in the one side at seal stock only, form in bossed situation, measure from the summit of projection to the distance of the face with bossed opposition side of tool.Form in bossed situation on the two sides of seal stock, measure from the summit of the projection of a face to the distance on the summit of the projection of opposing face.

(2) rising height

The moving direction of the sheet with manufacture the time (below, referred to as the MD direction) rectangular direction (width), cut off seal stock in the mode at the top by projection.The thickness direction cross section of the seal stock that cut off is observed at whole width of sheet with stereomicroscope.

In a bossed situation of tool of seal stock, the face of the bossed side of seal stock is made as to the A face, the face of unpolarized side is made as to the B face.As shown in Figure 3, the distance from the summit of the projection of A face to the B face is made as to Tmax, the distance from the unpolarized part of A face to the B face is made as to Tmin.Then, calculated the height T of projection by formula (i).

·T(μm)＝Tmax－Tmin···(i)

In the bossed situation of the two sides of seal stock tool, a face of seal stock is made as to the A face, another face is made as to the B face.As shown in Figure 4, distance from the summit of the projection of A face to the unpolarized part of B face is made as to TAmax, distance from the summit of the projection of B face to the unpolarized part of A face is made as to TBmax, the distance from the unpolarized part of A face to the unpolarized part of B face is made as to Tmin.Then, calculated the height TA of the projection of A face by formula (ii), calculated the height TB of the projection of B face by formula (iii).

·TA(μm)＝TAmax－Tmin···(ii)

·TB(μm)＝TBmax－Tmin···(iii)。

(3) depth of pattern of dandy roll

For the surface of dandy roll, according to JIS B0601 (2001), under the condition determination of datum length 20mm, loading 0.75mN, finding speed 0.3mm/s, measure.Measure and use the small-sized roughness tester SJ401 of ミ Star ト ヨ society's system, use the diamond stylus of 60 °, circular cone, front end radius of curvature 2 μ m to be measured.This measured value is made as to the depth of pattern Pz value (μ m) of dandy roll.

(4) embossing transferring rate

The value that the rising height T (μ m) that will measure in above-mentioned (2) (or rising height TA (μ m) or rising height TB (μ m)) obtains divided by the depth of pattern Pz of the dandy roll of measuring in above-mentioned (3) is made as the embossing transferring rate.

Embossing transferring rate (%)=T/Pz * 100.

(5) heat shrink rate

From seal stock, cutting out is the test film of the plane square shape of 120mm on one side.On this test film, TD direction central portion during fabrication, vacate the interval of 100mm and draw the straight line (5cm) of two parallel TD directions.And, (each 5 places) marking in the position by each straight line 6 deciles.

Next, test film is placed 60 seconds in being heated to the warm water of 80 ℃.Proportion at seal stock is little, and seal stock swims in the situation on warm water surface, at this, under floating state, places.Ratio at seal stock is great, and seal stock sinks in the situation in warm water, under the state of this sinking, places.After 60 seconds, test film is taken out from warm water, in the normal-temperature water of 20 ℃, dipping is 10 seconds and, after cooling, remove the moisture on sheet surface.

Measure the interval A (mm) of opposed each mark that 5 each mark done from the straight line of drawing at test film done to another straight line with vernier, based on following formula, calculate the heat shrink rate, obtain the mean value at 5 places.

Heat shrink rate (%)=(100-A)/100 * 100.

(6) form the melt flow rate (MFR) of the resin combination of seal stock

For resin combination, according to JIS K7210 (1999) " test method of the melt mass flow rate of plastics-thermoplastic (MFR) and melt volume-flow rate (MVR) ", under the experimental condition of 190 ℃ of temperature, load 2.16kg, measure.

(7) the base length (D) of projection

Bossed of the tool of sheet is observed with stereomicroscope, measured base length (D).Being shaped as in polygonal, the oval-shaped situations such as triangle, hexagon of the bottom surface of projection, measure the diameter of the minimum proper circle that comprises above-mentioned shape.

(8) unit disruptiveness

Cut out the test film of the plane square shape that 2 one side are 180mm from seal stock.In many crystalline solar cells unit, (3 busbars, size 156mm is square, thickness 200 μ m) upper soldering interconnector (thickness 280 μ m, width 2mm), make the solar battery cell with interconnector.Prepare glass plate (size 180mm is square, thickness 3mm) and polyester solar cell backboard (size 180mm is square, thickness 240 μ m).Lamination seal stock, solar battery cell, seal stock, backboard successively on glass plate.Now, bossed of the tool of seal stock carries out lamination contiguously with solar battery cell.For this laminated body, 145 ℃ of temperature, vacuumize 30 seconds, suppress 1 minute, pressure and keep carrying out vacuum lamination under the condition of 10 minutes, make solar module.For the solar module of gained, by solar cell EL image testing device, take luminescent image, the break length (mm) of total crackle of section of determination unit.This test is repeated 3 times, obtain the mean value of total crack length.

(9) bubble number

By the bubble number in the solar module of making in visual counting above-mentioned (8).Obtain the mean value of 3 tests.

(10) resilience stress

From seal stock, cutting out is the test film of the plane square shape of 120mm on one side.Then, use the カ ト ー テ ッ Network superzapping contracting testing machine KES FB-3 of society, from bossed of the tool of test film, the flat pressurization terminal by diameter 16mm pressurizes to seal stock with speed 20 μ m/ second, the resilience stress (kPa) of the sheet when measuring through-thickness and pressurizeing 100 μ m.This test is repeated 3 times, obtain the mean value of resilience stress.

(embodiment 1)

According to the manufacture method shown in Fig. 1, make the solar cell sealing sheet material

Operation (a): film making process

Use double screw extruder as extruder 11, to contain EVA (vinyl acetate content: 28 quality %, melt flow rate (MFR): 15g/10 minute, fusing point: 71 ℃) 100 mass parts, tert-butyl hydroperoxide-2-ethylhexyl monocarbonate (1 hour half life temperature: 119 ℃) 0.7 mass parts, isocyanuric acid triallyl ester 0.3 mass parts, γ-methacryloxypropyl trimethoxy silane 0.2 mass parts, ESCALOL 567 0.3 mass parts, two (1, 2, 2, 6, 6-pentamethyl-4-piperidyl) resin combination of sebacate 0.1 mass parts is supplied to the extruder 11 that is set as 80 ℃ and carries out melting mixing.Resin combination after mixing is extruded from the T-shaped die head 12 of 105 ℃ of being held in be connected with extruder 11.The die lip width of the T-shaped die head that used in addition is 1300mm, and the die lip gap is 0.8mm.

By the resin combination extruded like this by being held in polishing roll 13a, 13b, the 13c of 20 ℃ and cooling curing is made sheet.The temperature of the operation sheet in the moment of discharging from T-shaped die head in addition, is 107 ℃.The width of operation sheet now is 1150mm in addition, and thickness is 450 μ m, and transporting velocity is 10m/ minute.

Operation (b): annealing in process operation

Next, under the condition of putting down in writing at table 1, implement annealing in process.

About heating, use ceramic heater 16, conveying roller 17 is used that to take the distance between centers of roller be the such spaced diameter 150mm of 200mm and the conveying roller that has the metallic roll of " teflon (registration mark) " to form at surface-coated.Annealing furnace 15 has used the annealing furnace that heat-insulating material forms of having reeled on the housing of SUS system.In addition, from entrance bottom and the outlet bottom of annealing furnace 15, with wind speed, 1m/sec is blown into hot blast.

Operation (c): embossing manufacturing procedure

The condition of putting down in writing according to table 1, implement embossing processing continuously with annealing in process.

Embossing processing is following to be implemented: the dandy roll 20 that the operation sheet that will transfer out from annealing furnace is 120 μ m by depth of pattern and being wound with between the embossing opposed roll 19 of silicon rubber of 75 ° of hardness of thickness 10mm.

Estimate heat shrink rate and the embossing transferring rate of the solar cell sealing sheet material of gained.Show the result in table 1.As shown in table 1, obtained the heat shrink rate very little, and clearly transfer printing there is the solar cell sealing sheet material of pattern of indentations.

(embodiment 2)

The temperature of the hot blast in operation (b) is made as to 87 ℃, heter temperature is made as to 320 ℃, the holdup time in stove is made as to 29 seconds, in addition, by with embodiment 1 same procedure, making seal stock.Because the surface temperature of operation sheet reduces, so the heat shrink rate becomes greatly a little, embossing transferring rate step-down a little in addition, but it is very little to have obtained similarly to Example 1 the heat shrink rate, and clearly transfer printing has the solar cell sealing sheet material of pattern of indentations.

(embodiment 3)

The temperature of the hot blast in operation (b) is made as to 80 ℃, heter temperature is made as to 300 ℃, the holdup time in stove is made as to 30 seconds, linear pressure is made as to 450N/cm, in addition, by with embodiment 1 same procedure, making seal stock.Because the surface temperature of operation sheet further reduces, therefore the heat shrink rate becomes large a little, embossing transferring rate step-down a little in addition, but it is very little to have obtained similarly to Example 1 the heat shrink rate, and clearly transfer printing has the solar cell sealing sheet material of pattern of indentations.

(embodiment 4)

Linear pressure in operation (c) is made as to 200N/cm, in addition, by with embodiment 3 same procedure, making seal stock.The embossing transferring rate is step-down a little, but has obtained similarly to Example 3 the solar cell sealing sheet material that clearly transfer printing has pattern of indentations.

(embodiment 5)

Hot blast temperature in operation (b) is made as to 110 ℃, the holdup time in stove is made as to 27 seconds, the linear pressure in operation (c) is made as to 200N/cm, in addition, by method similarly to Example 1, make sheet.The surface temperature of operation sheet raises, and has therefore obtained the heat shrink rate very little, and the embossing transferring rate is solar cell sealing sheet material clearly also.

(embodiment 6)

The attached angle of embracing to dandy roll in operation (c) is made as to 45 °, in addition, by with embodiment 5 same procedure, making seal stock.Diminish owing to embracing attached angle, diminish thereby the embossing transferring rate is some, but the sheet for thering is good outward appearance.

(embodiment 7)

The transporting velocity of the operation sheet in operation (b) is made as to 7m/min, hot blast temperature is made as to 110 ℃, heter temperature is made as to 300 ℃, holdup time in stove is made as to 39 seconds, linear pressure in operation (c) is made as to 120N/cm, in addition, make seal stock by method similarly to Example 1.The heat time heating time of operation sheet is elongated, and surface temperature uprises, and therefore can make the heat shrink rate and significantly reduce, even linear pressure hangs down also the sheet of embossing shape clearly.

(comparative example 1～5)

Condition shown in application table 2, in addition, make the solar cell sealing sheet material by method similarly to Example 1.

(comparative example 6,7)

Implement embossing processing by the manufacture method in the past shown in Fig. 2 just from T-shaped die head is extruded, then carry out annealing in process.The annealing in process device is device similarly to Example 1, and the dandy roll 13b ' of the tight back of T-shaped die head is used the roller that depth of pattern is 120 μ m.

[table 1]

[table 2]

(result)

Solar cell sealing sheet material as shown in table 1, as to be made by embodiment 1～7, the heat shrink rate is little, and the embossing transferring rate is high, and transfer printing lucidly has the embossing shape.

Use these solar cell sealing sheet materials, by known method in the past, make solar module, when result is made in module, unit dislocation, or unit breaks, or bubble is sneaked into such undesirable condition and is not occurred.

Therefore in comparative example 1, the sheet temperature of the temperature during due to annealing in process, dandy roll 20 entrances is all low, is that the heat shrink rate is also large, and the embossing transferring rate is low sheet also.In comparative example 3, due to the interval enlarged between annealing furnace outlet and dandy roll entrance, so the reduction of the temperature of sheet, the embossing transferring rate has reduced.In comparative example 4, because the sheet surface temperature in annealing furnace is low, therefore can not fully reduce the heat shrink rate.

In comparative example 2, on dandy roll, circumvolution operation sheet, can not obtain sample.

In comparative example 5, because the annealing in process time is short, therefore can not fully reduce the heat shrink of solar cell sealing sheet material.

In comparative example 6,7, owing to giving the embossing shape with polishing roll, so the embossing shape is unclear, but if heat shrink is reduced, embossing shape collapse, if keep the embossing shape, can not reduce heat shrink.

(embodiment 8)

Operation (a): film making process

To contain EVA (vinyl acetate content: 28 quality %, melt flow rate (MFR): 15g/10 minute (190 ℃), fusing point: 71 ℃) 100 mass parts, tert-butyl hydroperoxide-2-ethylhexyl monocarbonate (1 hour half life temperature: 119 ℃) 0.7 mass parts, isocyanuric acid triallyl ester 0.3 mass parts, γ-methacryloxypropyl trimethoxy silane 0.2 mass parts, ESCALOL 567 0.3 mass parts, two (1, 2, 2, 6, 6-pentamethyl-4-piperidyl) resin combination of sebacate 0.1 mass parts is supplied to double screw extruder the melting mixing that is set as 80 ℃.Resin combination after mixing is extruded from the T-shaped die head of 105 ℃ of being held in be connected with double screw extruder.The die lip width of T-shaped die head is 1300mm in addition, and the die lip gap is 0.8mm.

By this EVA sheet by being held in the polishing roll of 20 ℃ and cooling curing.The sheet temperature in the moment that in addition, the EVA sheet is discharged from T-shaped die head is 107 ℃.Sheet width now is 1150mm in addition, and the thickness of sheet is 450 μ m, and the sheet transporting velocity is 10m/ minute.Next, implement continuously annealing in process, embossing processing.

Operation (b): annealing in process operation

Annealing in process is carried out as follows: arrange and surface temperature is set as to the ceramic heater of 350 ℃, take the distance between centers of roller as the such spaced diameter 150mm of 250mm and the metallic roll of " teflon (registration mark) " is arranged at surface-coated, being wound with on the housing of SUS system in the annealing furnace of heat-insulating material and passing through.In addition, from entrance bottom and the outlet bottom of stove, with wind speed, 1m/sec is blown into hot blast.

Operation (c): embossing manufacturing procedure

Embossing processing is following to be implemented: the sheet that will take out from annealing furnace, and with 450/cm ²the dandy roll and being wound with between the opposed roll of silicon rubber of 75 ° of hardness of thickness 10mm of depiction that has depth of pattern and be the matrix of 180 μ m, diameter 460 μ m and semi-spherical shape passes through.

In addition, above-mentioned create conditions as follows in detail.

The sheet surface temperature of annealing furnace entrance: 23 ℃

Hot blast temperature: 93 ℃

The maximum temperature on the sheet surface in annealing furnace: 90 ℃

The sheet surface temperature of annealing furnace outlet: 90 ℃

The sheet holdup time in annealing furnace: 28 seconds

The sheet speed of annealing furnace 15 outlets: 9.6m/min

The sheet surface temperature of dandy roll entrance: 78 ℃

Dandy roll temperature: 15 ℃

The linear pressure of dandy roll: 350N/cm

The attached angle of embracing to dandy roll: 120 °.

Unit disruptiveness, bubble number when the heat shrink rate of the seal stock of evaluation gained and resilience stress, module are manufactured.Show the result in table 3.As shown in table 3, be that sheet heat shrink rate is little, the seal stock that unit breaks, bubble is few when module is manufactured.

(embodiment 9)

Dandy roll in operation (c) is changed to 450/cm ²having depth of pattern is 120 μ m, and the dandy roll of the depiction of the matrix of diameter 460 μ m and semi-spherical shape, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 3, is that sheet heat shrink rate is little, the seal stock that unit breaks, bubble is few when module is manufactured.

(embodiment 10)

Dandy roll in operation (c) is changed to 450/cm ²having depth of pattern is 300 μ m, and the dandy roll of the depiction of the matrix of diameter 460 μ m and semi-spherical shape, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 3, is that sheet heat shrink rate is little, the seal stock that unit breaks, bubble is few when module is manufactured.

(embodiment 11)

Dandy roll in operation (c) is changed to 980/cm ²having depth of pattern is 300 μ m, and the dandy roll of the depiction of the matrix of diameter 330 μ m and semi-spherical shape, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 3, is that sheet heat shrink rate is little, the seal stock that unit breaks, bubble is few when module is manufactured.

(embodiment 12)

Dandy roll in operation (c) is changed to 840/cm ²having depth of pattern is 180 μ m, and the dandy roll of the depiction of the matrix of outer circumference diameter 460 μ m and quadrangle cone shape, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 3, and some generations although unit when module is manufactured breaks, be the seal stock that sheet heat shrink rate is little, bubble is few.

(embodiment 13)

Do not implement annealing in process, by infrared heater, the sheet surface temperature is heated to 90 ℃, implement embossing processing, in addition, by method similarly to Example 8, make seal stock.

The seal stock of gained is as shown in table 3, although the heat shrink rate of sheet is large, the some generations of breaking of unit when module is manufactured, be the seal stock that bubble is few.

(embodiment 14)

The EVA resin is changed to the EVA resin of melt flow rate (MFR) 10g/10 minute, in addition, by method similarly to Example 8, make seal stock.The seal stock of gained is as shown in table 3, and some generations although unit when module is manufactured breaks, be the seal stock that sheet heat shrink rate is little, bubble is few.

(embodiment 15)

Dandy roll in operation (c) is changed to 45/cm ²having depth of pattern is 180 μ m, and the dandy roll of the depiction of the matrix of outer circumference diameter 2000 μ m and quadrangle cone shape, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 3, although sheet heat shrink rate is little, the some generations of breaking of unit when module is manufactured, be the seal stock that bubble is few.

(reference example 1)

The unreal line processing of exerting pressure, in addition, make and implement until the seal stock of annealing in process supplies in evaluation by method similarly to Example 8.

The seal stock of gained is as shown in table 4, although the heat shrink rate of sheet is little, the unit while manufacturing for module breaks, and produces in a large number the seal stock of bubble.

(reference example 2)

Dandy roll in operation (c) is changed to the dandy roll of the depiction that depth of pattern is 180 μ m and the groove (groove width 460 μ m) that has continuous semi-circular shape in the direction of rotation of roller, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 4, although sheet heat shrink rate is little, unit when module is manufactured breaks few, is the seal stock that bubble is many.

(reference example 3)

Dandy roll in operation (c) is changed to 450/cm ²having depth of pattern is 50 μ m, and the dandy roll of the depiction of the matrix of diameter 460 μ m and semi-spherical shape, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 4, the seal stock that although sheet heat shrink rate is little, the unit while manufacturing for module breaks, bubble is many.

(reference example 4)

Dandy roll in operation (c) is changed to 4500/cm ²having depth of pattern is 180 μ m, and the dandy roll of the depiction of the matrix of diameter 150 μ m and semi-spherical shape, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 4, although sheet heat shrink rate is little, bubble is few, and the unit while manufacturing for module breaks many seal stocks.

(reference example 5)

Dandy roll in operation (c) is changed to 7/cm ²having depth of pattern is 180 μ m, and the dandy roll of the depiction of the matrix of diameter 3800 μ m and semi-spherical shape, in addition, make seal stock by method similarly to Example 8.

The seal stock of gained is as shown in table 4, although sheet heat shrink rate is little, and the seal stock that the unit while manufacturing for module breaks and bubble is many.

[table 3]

[table 4]

The industry utilizability

The present invention can be suitable for the manufacture method of solar cell sealing sheet material very much.Particularly, owing to reducing heat shrink, there is pattern of indentations clearly, therefore can prevent unit when module is manufactured the position skew, the bubble in module is sneaked into etc., can improve significantly the productivity of module.

The explanation of symbol

1 operation sheet

11 double screw extruders

12 die heads

13a polishing roll (surface is without Carving Machining)

13b polishing roll (surface is without engraving)

13b ' dandy roll (there is Carving Machining on surface)

13c polishing roll (surface is without Carving Machining)

14 rolls

15 annealing furnaces

16 heaters

17 conveying rollers

18 are taken out roller

19 embossing opposed roll

20 dandy rolls

21 chill rolls

31 gear pumps

32 throughput directions

33 non-contact infrared thermometers.

Claims (11)

1. the manufacture method of a solar cell sealing sheet material, carry out following operation (a), operation (b) and operation (c) successively,

Operation (a): will be by heating melting resin combination be shaped to sheet, then carry out cooling, thereby obtain the operation of operation sheet;

Operation (b): at least one surface heating of the operation sheet that will be obtained by described operation (a) 22～55 seconds adds the operation of the temperature more than the fusing point of hankering making this surperficial temperature reach the resin combination that forms this surface portion at this;

Operation (c): the temperature on the surface of the operation sheet that has made to be heated in described operation (b) is (fusing point of the resin combination of described formation surface portion-10 ℃)～(fusing point of the resin combination of described formation surface portion+20 ℃), then to this surface, press dandy roll, form the operation of embossing shape on this surface.

2. the manufacture method of solar cell sealing sheet material according to claim 1, in described operation (c), when pressing described operation sheet surperficial with described dandy roll, making the linear pressure that this surface is subject to is 150～500N/cm.

3. the manufacture method of solar cell sealing sheet material according to claim 1 and 2, in described operation (c), when pressing described operation sheet surperficial with described dandy roll, make the surface temperature of this dandy roll for below (fusing point of the resin combination of described formation surface portion-20 ℃).

4. according to the manufacture method of the described solar cell sealing sheet material of any one of claim 1～3, in described operation (a), use single screw extrusion machine or double screw extruder will be by described heating melting resin combination extrude and be shaped to sheet from die head.

5. according to the manufacture method of the described solar cell sealing sheet material of any one of claim 1～4, the resin combination of described formation surface portion comprises polyolefin-based resins and organic peroxide.

6. a solar cell sealing sheet material, be the solar cell sealing sheet material obtained by the described manufacture method of any one of claim 1～5,

The resin combination of described formation surface portion comprises polyolefin-based resins,

Be formed with the individual bumps of every square centimeter, surface with 40～2300 height 60～300 μ m of described embossing shape, and the height T of this individual bumps and the ratio T/D of base length D are 0.05～0.80.

7. solar cell sealing sheet material according to claim 6, when described solar cell sealing sheet material is placed to 1 minute in the warm water of 80 ℃, the flow heat shrink rate of direction of the sheet of sealing sheet material is below 30%.

8. according to the described solar cell sealing sheet material of claim 6 or 7, described individual bumps be shaped as hemispherical and/or quadrangular pyramid shape.

9. according to the described solar cell sealing sheet material of any one of claim 6～8, when the face with described projection by described solar cell sealing sheet material compresses 100 μ m along the thickness direction of sealing sheet material, the resilience stress of sheet is below 70kPa.

10. according to the described solar cell sealing sheet material of any one of claim 6～9, bossed of the tool of described solar cell sealing sheet material further has the projection of height 1～15 μ m.

11. a solar module, it is configured to: the layer that contains sensitive surface guard member, back-protective part and be configured between this sensitive surface guard member and back-protective part and be sealed with by the described solar cell sealing sheet material of any one of claim 6～10 solar battery cell.

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