CN104380481A

CN104380481A - Solar cell sealing material and solar cell module

Info

Publication number: CN104380481A
Application number: CN201380031931.1A
Authority: CN
Inventors: 池永成伸; 竹内文人; 伊藤智章
Original assignee: Mitsui Chemicals Tohcello Inc
Current assignee: Mitsui Chemicals Tohcello Inc
Priority date: 2012-06-19
Filing date: 2013-05-21
Publication date: 2015-02-25
Anticipated expiration: 2033-05-21
Also published as: CN104380481B; JP5940661B2; JPWO2013190940A1; WO2013190940A1; TWI586739B; TW201402678A

Abstract

This solar cell sealing material contains an ethylene-alpha-olefin copolymer, an organic peroxide and an ultraviolet absorbent, and the ultraviolet absorbent is a benzotriazole-based ultraviolet absorbent that is represented by general formula (1) or (2). (In general formula (1), R1 represents a hydrogen atom or an alkyl group having 1-6 carbon atoms; and R2-R4 may be the same or different, and each represents a hydrogen atom, an alkyl group having 1-20 carbon atoms, a hydroxyl group, an alkoxy group having 1-22 carbon atoms or an alkyloxycarbonyl group having 1-22 carbon atoms.) (In general formula (2), R1 represents the above-mentioned substituent; and R5-R8 may be the same or different, and each represents a hydrogen atom, an alkyl group having 1-20 carbon atoms, a hydroxyl group, an alkoxy group having 1-22 carbon atoms or an alkyloxycarbonyl group having 1-22 carbon atoms.)

Description

Solar cell sealing material and solar module

Technical field

The present invention relates to solar cell sealing material and solar module.

Background technology

In the seriousness increase process of global environmental problems, energy problem etc., as clean and do not worry that the exhausted energy generates means, solar cell receives publicity.When by the outdoor application such as roof parts of solar cell at building, generally use with the form of solar module.

Above-mentioned solar module, generally speaking, is manufactured by following steps.First, manufacture the crystal type solar cell device formed by polycrystal silicon, monocrystalline silicon etc. and (below, be expressed as generating element or unit.), or amorphous silicon, silicon metal etc. are formed on the substrates such as glass the very thin film of several μm and the thin film solar cell element etc. obtained.

Next; in order to obtain crystal type solar module, carry out lamination according to the order of solar module screening glass (face side transparent protection member)/solar cell sealing material/crystal type solar cell device/solar cell sealing material/solar module screening glass (rear side protection component).

On the other hand, in order to obtain thin film solar cell module, carry out lamination according to the order of thin film solar cell element/solar cell sealing material/solar module screening glass (rear side protection component).Then, they vacuumized by utilizing and adds the laminating etc. of thermo-compressed, manufacturing solar module.The solar module of such manufacture has weatherability, is also suitable for the outdoor application such as roof parts at building.

As solar cell sealing material, vinyl-vinyl acetate copolymer (EVA) film, due to excellences such as the transparency, flexibility and cementabilities, is therefore widely used.Wherein, as the ultraviolet of long term maintenance excellence the solar cell sealing film of property can be blocked, propose the solar cell sealing film (with reference to patent documentation 1) comprising vinyl-vinyl acetate copolymer, organic peroxide and BTA system ultra-violet absorber.But when the constituent material using EVA composition as solar cell sealing material, the compositions such as the acetic acid gas that worry EVA decomposes and produces bring the possibility of impact on solar cell device.

On the other hand, the solar cell sealing material resin combination (for example, referring to patent documentation 2) be made up of ethene-alpha-olefin copolymer, organic peroxide and silane coupler is proposed.It is said the thermal endurance of this solar cell sealing material resin combination, the transparency, flexibility and excellent in adhesion to glass substrate.

In addition, the exploitation of solar cell device is also carried out actively, as the solar cell device of high conversion efficiency, by the light in the short wavelength region near absorption 300 ~ 700nm amorphous silicon and absorb the long wavelength region near 400 ~ 1300nm light crystal type silicon lamination and the tandem type solar cell device that obtains circulates just in the market.

Prior art document

Patent documentation

Patent documentation 1: Japanese Unexamined Patent Publication 2011-201928 publication

Patent documentation 2: International Publication No. 2010/114028 pamphlet

Summary of the invention

Invent problem to be solved

But, the discoveries such as the present inventor, although the solar cell sealing material resin combination cementability described in patent documentation 2 is abundant, but weatherability is insufficient, the transparency particularly near wavelength 500nm is poor, and tandem type solar module has the tendency that can not contribute to improving conversion efficiency.

Therefore, problem of the present invention also maintains the solar cell sealing material of photopermeability after being to provide weatherability excellence, for a long time Ultraviolet radiation.

For solving the means of problem

The present inventor etc. conduct in-depth research repeatedly to weatherability.Consequently find, containing BTA system ultra-violet absorber, the solar cell sealing material that comprises ethene-alpha-olefin copolymer, weatherability is excellent, also maintains photopermeability, thus complete the present invention after long Ultraviolet radiation.

That is, according to the present invention, solar cell sealing material shown below is provided.

[1]

A kind of solar cell sealing material, it is characterized in that, be the solar cell sealing material comprising ethene-alpha-olefin copolymer, organic peroxide and ultra-violet absorber,

Above-mentioned ultra-violet absorber is the BTA system ultra-violet absorber shown in following general formula (1) or (2).

(in formula, R ₁represent the alkyl of hydrogen atom or carbon number 1 ~ 6, R ₂~ R ₄can be the same or different, represent the alkyl of hydrogen atom, carbon number 1 ~ 20, hydroxyl, the alkoxyl of carbon number 1 ~ 22 or the alkyloxycarbonyl of carbon number 1 ~ 22.)

(in formula, R ₁represent the alkyl of hydrogen atom or carbon number 1 ~ 6, R ₅~ R ₈can be the same or different, represent the alkyl of hydrogen atom, carbon number 1 ~ 20, hydroxyl, the alkoxyl of carbon number 1 ~ 22 or the alkyloxycarbonyl of carbon number 1 ~ 22.)

[2]

Solar cell sealing material according to [1], is characterized in that, in above-mentioned general formula (1), and R ₁represent hydrogen atom, R ₂~ R ₄mutual difference.

[3]

Solar cell sealing material according to [1] or [2], is characterized in that, in above-mentioned general formula (2), and R ₁represent hydrogen atom, R ₅with R ₈identical, R ₆with R ₇identical.

[4]

Solar cell sealing material according to any one of [1] ~ [3], the content of the above-mentioned ultra-violet absorber in solar cell sealing material is 0.05 ~ 5.0 weight portion relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion.

[5]

Solar cell sealing material according to any one of [1] ~ [4], above-mentioned ethene-alpha-olefin copolymer meets following important document a1) ~ a4).

A1) derive from the Component units of ethene containing proportional be 80 ~ 90mol%, derive from the Component units of the alpha-olefin of carbon number 3 ~ 20 containing proportional be 10 ~ 20mol%.

A2) according to ASTM D1238,190 DEG C, to measure the MFR obtained under the condition of 2.16kg loading be 10 ~ 50g/10 minute.

A3) measuring according to ASTM D1505 the density obtained is 0.865 ~ 0.884g/cm ³.

A4) measuring according to ASTM D2240 the Xiao A hardness obtained is 60 ~ 85.

[6]

Solar cell sealing material according to any one of [1] ~ [5], according to ASTM D1238,190 DEG C, the MFR that measures the above-mentioned ethene-alpha-olefin copolymer obtained under the condition of 2.16kg loading is 10 ~ 27g/10 minute.

[7]

Solar cell sealing material according to any one of [1] ~ [6], 1 minute half life temperature of above-mentioned organic peroxide is 100 ~ 170 DEG C, and the content of above-mentioned organic peroxide is 0.1 ~ 3 weight portion relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion.

[8]

Solar cell sealing material according to any one of [1] ~ [7], it comprises silane coupler further,

The content of above-mentioned silane coupler is 0.1 ~ 5 weight portion relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion.

[9]

Solar cell sealing material according to any one of [1] ~ [8], it comprises hindered phenol system stabilizer further,

The content of above-mentioned hindered phenol system stabilizer is 0.005 ~ 0.1 weight portion relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion.

[10]

Solar cell sealing material according to any one of [1] ~ [9], it comprises hindered amine system light stabilizer further,

The content of above-mentioned hindered amine system light stabilizer is 0.01 ~ 2.0 weight portion relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion.

[11]

Solar cell sealing material according to any one of [1] ~ [10], it comprises phosphorus system stabilizer further,

The content of above-mentioned phosphorus system stabilizer is 0.005 ~ 0.5 weight portion relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion.

[12]

Solar cell sealing material according to any one of [1] ~ [11], it comprises crosslinking coagent further,

The content of above-mentioned crosslinking coagent is 0.05 ~ 5 weight portion relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion.

[13]

Solar cell sealing material according to any one of [1] ~ [12], it is by after above-mentioned ethene-alpha-olefin copolymer, above-mentioned organic peroxide and above-mentioned ultra-violet absorber melting mixing, and sheet ground extrusion molding obtains.

[14]

Solar cell sealing material according to any one of [1] ~ [13], it is sheet.

[15]

A kind of solar module, it possesses:

Face side transparent protection member,

Rear side protection component,

Solar cell device, and

Sealant, described sealant makes the solar cell sealing material described in any one of [1] ~ [14] crosslinked and formed, and above-mentioned solar cell device is sealed in above-mentioned face side transparent protection member and above-mentioned rear side is protected between component.

[16]

Solar module according to [15], silicon metal and amorphous silicon lamination form by above-mentioned solar cell device.

The effect of invention

According to the present invention, after excellent, the long Ultraviolet radiation of weatherability can be provided, also maintain the solar cell sealing material of photopermeability.

According to the present invention, by using such solar cell sealing material, can provide except above-mentioned each excellent, also not damaging the outward appearance of solar cell, the solar module of the economy excellences such as cost.

Solar cell sealing material of the present invention can crystal type solar module, thin film solar cell module, tandem type solar module whole in use, but particularly can be provided in tandem type solar cell device and do not hinder the raising of conversion efficiency and the solar module of the economy excellences such as cost.

Accompanying drawing explanation

Above-mentioned purpose and other objects, features and advantages are come clear and definite further by the preferred implementation of the following stated and appended the following drawings thereof.

Fig. 1 is the sectional view of the execution mode schematically showing solar module of the present invention.

Fig. 2 is the plane graph schematically showing the sensitive surface of solar cell device and a configuration example at the back side.

Embodiment

Below, accompanying drawing is used to be described embodiments of the present invention.In addition, in whole accompanying drawing, same symbol is enclosed to same inscape, suitably omits the description.In addition, about " ~ ", if do not specialized, then represent above to following.

1. about solar cell sealing material

(ethene-alpha-olefin copolymer)

The solar cell sealing material of present embodiment ethene-alpha-olefin copolymer used is by carrying out copolymerization to obtain by the alpha-olefin of ethene and carbon number 3 ~ 20.As alpha-olefin, usually can be used alone the alpha-olefin of a kind of carbon number 3 ~ 20 or combinationally use two or more.As the alpha-olefin of carbon number 3 ~ 20, the alpha-olefin of straight-chain or branched can be enumerated, such as, propylene, 1-butylene, 1-amylene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butylene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecylene etc.Wherein preferably carbon number is the alpha-olefin of less than 10, particularly preferably is the alpha-olefin that carbon number is 3 ~ 8.Consider to be preferably propylene, 1-butylene, 1-amylene, 1-hexene, 4-methyl-1-pentene and 1-octene from the easiness obtained.

In addition, ethene-alpha-olefin copolymer can be random copolymer, also can be block copolymer, but is preferably random copolymer from the viewpoint of flexibility.

In addition, the ethene-alpha-olefin copolymer that the solar cell sealing material of present embodiment is used can be ethene, the alpha-olefin of carbon number 3 ~ 20 and the copolymer of unconjugated polyene formation.Alpha-olefin as described above, as unconjugated polyene, can enumerate 5-ethylidene-2-norborene (ENB), 5-vinyl-2-norborene (VNB), bicyclopentadiene (DCPD) etc.These unconjugated polyenes can be used alone a kind, or two or more combinationally uses.

The ethene-alpha-olefin copolymer that the solar cell sealing material of present embodiment is used can be used together aromatic ethenyl compound, such as, styrene, o-methyl styrene, a methyl styrene, p-methylstyrene, neighbour, p-dimethyl styrene, methoxy styrene, vinyl benzoic acid, vinylbenzoate, vinyl benzyl yl acetate, hydroxy styrenes, to the phenylethylene such as chlorostyrene, divinylbenzene; 3-phenylpropen, 4-phenylpropen, AMS, carbon number are cyclic olefin such as cyclopentene, cycloheptene, norborene, the 5-methyl-2-norborene etc. of 3 ~ 20.

The solar cell sealing material of present embodiment preferably meets following important document a1 ~ a4 further.

(important document a1)

What ethene-alpha-olefin copolymer comprised the derive from Component units of ethene be preferably 80 ~ 90mol% containing proportional, be more preferably 80 ~ 88mol%, more preferably 82 ~ 88mol%, be particularly preferably 82 ~ 87mol%.What ethene-alpha-olefin copolymer comprised derives from the Component units of the alpha-olefin of carbon number 3 ~ 20 (below, also be designated as " alpha-olefin unit ") containing proportional be preferably 10 ~ 20mol%, be more preferably 12 ~ 20mol%, more preferably 12 ~ 18mol%, is particularly preferably 13 ~ 18mol%.

If the alpha-olefin unit that ethene-alpha-olefin copolymer comprises containing proportional for more than 10mol%, then can obtain the high transparency.In addition, easily can carry out the extrusion molding under low temperature, such as, can realize the extrusion molding of less than 130 DEG C.Therefore, even if when refining in ethene-alpha-olefin copolymer into organic peroxide, also can suppress the carrying out of the cross-linking reaction in extruder, can prevent the sheet of solar cell sealing material from producing the deteriorated appearance of gelatinous foreign matter and sheet.In addition, due to the flexibility of appropriateness can be obtained, therefore can prevent from, when solar module laminated into type, the cracking of solar cell device, the defect etc. of membrane electrode occur.

If the alpha-olefin unit that ethene-alpha-olefin copolymer comprises containing proportional for below 20mol%, then the crystallization rate of ethene-alpha-olefin copolymer becomes appropriateness, therefore the sheet extruded from extruder can not be clamminess, stripping on chill roll is easy, effectively can obtain the sheet of the solar cell sealing material of sheet.In addition, because sheet is not clamminess, therefore can prevent adhesion, the stretching out property of sheet becomes good.In addition, the reduction of thermal endurance can also be prevented.

(important document a2)

According to ASTM D1238,190 DEG C, the melt flow rate (MFR) (MFR) that measures the ethene-alpha-olefin copolymer obtained under the condition of 2.16kg loading is generally 0.1 ~ 50g/10 minute, be preferably 2 ~ 50g/10 minute, be more preferably 10 ~ 50g/10 minute, more preferably 10 ~ 40g/10 minute, be particularly preferably 12 ~ 27g/10 minute, most preferably be 15 ~ 25g/10 minute.The MFR of ethene-alpha-olefin copolymer can by adjusting polymerization reaction described later time polymerization temperature, polymerization pressure and polymerization system in ethene and the monomer concentration of alpha-olefin and the molar ratio etc. of hydrogen concentration adjust.

(calendering formation)

If MFR is more than 0.1g/10 minute and is less than 10g/10 minute, then can manufacture sheet by calendering formation.If MFR is more than 0.1g/10 minute and is less than 10g/10 minute, the mobility then comprising the resin combination of ethene-alpha-olefin copolymer is low, therefore preferred in the pollution that can prevent the laminater caused by the molten resin oozed out when sheet and solar cell device lamination.

(extrusion molding)

In addition, if MFR is more than 2g/10 minute, preferred MFR is more than 10g/10 minute, then the mobility comprising the resin combination of ethene-alpha-olefin copolymer improves, and productivity during sheet extrusion molding can be made to improve.

If MFR is less than 50g/10 minute, then molecule quantitative change is large, therefore can suppress the attachment of the roll surface to chill roll etc., does not therefore need to peel off, can be shaped to the sheet of uniform thickness.In addition, owing to being formed, there is the resin combination of " hardness ", therefore can the sheet of easily shaping more than 0.1mm.In addition, because crosslinking feature during solar module laminated into type improves, it therefore can be made to be cross-linked fully, suppress the reduction of thermal endurance.

If MFR is less than 27g/10 minute, then drawdown when can sheet be suppressed further shaping, can the wide sheet of forming width, and crosslinking feature and thermal endurance improve further, can obtain the best solar cell sealing material sheet.

In addition, when not carrying out the crosslinking Treatment of resin combination in the lamination operation of solar module described later, the impact melt extruding the decomposition of organic peroxide in operation is little, therefore MFR also can be used for more than 0.1g/10 minute and be less than 10g/10 minute, be preferably more than 0.5g/10 minute and be less than the resin combination of 8.5g/10 minute, obtaining sheet by extrusion molding.When the organic peroxide content of resin combination is below 0.15 weight portion, also MFR can be used for more than 0.1g/10 minute and be less than the resin combination of 10g/10 minute, the forming temperature at 170 ~ 250 DEG C while carrying out silane-modified process or micro-crosslinking Treatment manufactures sheet by extrusion molding.If MFR is within the scope of this, be then preferred in the pollution that can prevent the laminater caused by the molten resin oozed out when sheet and solar cell device lamination.

(important document a3)

The density measuring the ethene-alpha-olefin copolymer obtained according to ASTM D1505 is preferably 0.865 ~ 0.884g/cm ³, be more preferably 0.866 ~ 0.883g/cm ³, more preferably 0.866 ~ 0.880g/cm ³, be particularly preferably 0.867 ~ 0.880g/cm ³.The density of ethene-alpha-olefin copolymer, can adjusting containing the proportional proportional balance that contains with alpha-olefin unit by ethylene unit.If that is, improve ethylene unit containing proportional, then crystallinity uprises, and can obtain the ethene-alpha-olefin copolymer that density is high.On the other hand, if containing of reduction ethylene unit is proportional, then crystallinity step-down, can obtain low density ethene-alpha-olefin copolymer.

If the density of ethene-alpha-olefin copolymer is 0.884g/cm ³below, then crystallinity step-down, can improve the transparency.In addition, the extrusion molding transfiguration under low temperature is easy, such as, can carry out extrusion molding below 130 DEG C.Therefore, even if refine in ethene-alpha-olefin copolymer into organic peroxide, also can prevent the carrying out of the cross-linking reaction in extruder, the sheet of solar cell sealing material can be suppressed to produce gelatinous foreign matter, suppress the deteriorated appearance of sheet.In addition, because flexibility is high, therefore can prevent from occurring as the cracking of the unit of solar cell device, the defect etc. of membrane electrode when solar module laminated into type.

On the other hand, if the density of ethene-alpha-olefin copolymer is 0.865g/cm ³above, then can accelerate the crystallization rate of ethene-alpha-olefin copolymer, the sheet therefore extruded from extruder is not easily clamminess, and the stripping transfiguration on chill roll is easy, easily can obtain the sheet of solar cell sealing material.In addition, because sheet is not easily clamminess, therefore can suppress the generation of adhesion, the stretching out property of sheet is improved.In addition, owing to being cross-linked fully, the reduction of thermal endurance can therefore be suppressed.

(important document a4)

The Xiao A hardness measuring the ethene-alpha-olefin copolymer obtained according to ASTM D2240 is preferably 60 ~ 85, is more preferably 62 ~ 83, and more preferably 62 ~ 80, be particularly preferably 65 ~ 80.The Xiao A hardness of ethene-alpha-olefin copolymer can adjusting in above-mentioned number range containing proportional, density domination by the ethylene unit by ethene-alpha-olefin copolymer.That is, the Xiao A hardness containing proportional height, ethene-alpha-olefin copolymer that density is high of ethylene unit uprises.On the other hand, the Xiao A hardness step-down containing proportional low, low density ethene-alpha-olefin copolymer of ethylene unit.

If Xiao A hardness is more than 60, then ethene-alpha-olefin copolymer becomes and is not easily clamminess, and can suppress adhesion.In addition, when solar cell sealing material is processed as sheet, the stretching out property of sheet also can be made to improve, the reduction of thermal endurance can also be suppressed.

On the other hand, if Xiao A hardness is less than 85, then crystallinity step-down, can improve the transparency.In addition, because flexibility is high, therefore can prevent when solar module laminated into type as the cracking of the unit of solar cell device, the breakage etc. of membrane electrode.

In addition, the solar cell sealing material of present embodiment, meeting following important document further is also preferred mode.

(melting peak)

Ethene-alpha-olefin copolymer, measure based on means of differential scanning calorimetry the scope that the melting peak of (DSC) is preferably present in 30 ~ 90 DEG C, be preferably present in the scope of 33 ~ 90 DEG C further, be particularly preferably present in the scope of 33 ~ 88 DEG C.If melting peak is less than 90 DEG C, then degree of crystallinity step-down, the flexibility of the solar cell sealing material of gained improves, and therefore can prevent the cracking of unit, the defect of membrane electrode when solar module laminated into type.On the other hand, if melting peak is more than 30 DEG C, then moderately can improve the flexibility of resin combination, therefore easily can obtain solar cell sealing material sheet by extrusion molding.In addition, can prevent by the adhesion caused of being clamminess of sheet, suppress the deterioration of the stretching out property of sheet.

(volume intrinsic resistance)

The solar cell sealing material of present embodiment, according to JIS K6911, measures the volume intrinsic resistance obtained be preferably 1.0 × 10 with temperature 100 DEG C, applying voltage 500V ¹³~ 1.0 × 10 ¹⁸Ω cm.The solar cell sealing material that volume intrinsic resistance is large has the tendency having and suppress PID phenomenon that such characteristic occurs.In addition, irradiate in the time-bands of sunlight, for solar module in the past, module temperature becomes such as more than 70 DEG C sometimes, therefore from the viewpoint of long-term reliability, compared with the volume intrinsic resistance under the normal temperature in the past reported (23 DEG C), more require the volume intrinsic resistance under hot conditions, the volume intrinsic resistance of temperature 100 DEG C becomes important.

According to JIS K6911, with temperature 100 DEG C, apply voltage 500V and measures the volume intrinsic resistance that obtains (below, also referred to as " volume intrinsic resistance ".) be more preferably 1.0 × 10 ¹⁴~ 1.0 × 10 ¹⁸Ω cm, more preferably 5.0 × 10 ¹⁴~ 1.0 × 10 ¹⁸Ω cm, is particularly preferably 1.0 × 10 ¹⁵~ 1.0 × 10 ¹⁸Ω cm.If fruit volume intrinsic resistance is 1.0 × 10 ¹³more than Ω cm, then 85 DEG C, also can suppress the generation of about 1 day PID phenomenon in a short time in constant temperature and moisture test under 85%rh.If fruit volume intrinsic resistance is 1.0 × 10 ¹⁸below Ω cm, then sheet becomes and not easily produces electrostatic, therefore can the absorption of preventing pollution thing, can suppress to be mixed into pollutant in solar module and the reduction causing generating efficiency, long-term reliability.

In addition, if fruit volume intrinsic resistance is 5.0 × 10 ¹⁴more than Ω cm, then 85 DEG C, have the tendency that the generation of PID phenomenon can be made to extend further in constant temperature and moisture test under 85%rh, thus preferably.Volume intrinsic resistance is after being shaped to sealing material sheet, is cross-linked and measures after being processed into smooth sheet with vacuum laminator, hot press, crosslinked stove etc.In addition, the sheet in module laminate body measures after other layer of removing.

(content of aluminium element)

The content of the aluminium element (following, to be also designated as " Al ") that ethene-alpha-olefin copolymer comprises is preferably 10 ~ 500ppm, is more preferably 20 ~ 400ppm, more preferably 20 ~ 300ppm.Al content depend on add in the polymerization process of ethene-alpha-olefin copolymer organoalurrunoxy compound, organo-aluminum compound concentration.

When Al content is more than 10ppm, the concentration of the degree that the organoalurrunoxy compound added in the polymerization process of ethene-alpha-olefin copolymer, organo-aluminum compound can fully can show with the activity of Metallocenic compound is added, and does not therefore need to add react with Metallocenic compound and form the compound of ion pair.When adding the compound of this formation ion pair, sometimes the compound of this formation ion pair remains in ethene-alpha-olefin copolymer, thus cause the reduction of electrical characteristic (having the tendency that the electrical characteristic under such as waiting high temperature at 100 DEG C reduces), but such phenomenon can be prevented.In addition, in order to reduce Al content, deliming process is carried out in needs acid, alkali, acid residual in rewarding ethene-alpha-olefin copolymer, alkali cause the tendency of the corrosion of electrode, in order to implement deliming process, the cost of ethene-alpha-olefin copolymer also uprises, but does not need such deliming process.

In addition, if Al content is below 500ppm, then can prevent the carrying out of the cross-linking reaction in extruder, therefore can prevent the sheet of solar cell sealing material generation gel foreign matter from causing the deteriorated appearance of sheet.

As the method controlling the aluminium element that ethene-alpha-olefin copolymer as described above comprises, such as, by the polymerization activity of the Metallocenic compound of the manufacturing condition of concentration in manufacturing process of (II-1) organoalurrunoxy compound described in the manufacture method that adjusts ethene-alpha-olefin copolymer described later and (II-2) organo-aluminum compound or ethene-alpha-olefin copolymer, the aluminium element that ethene-alpha-olefin copolymer comprises can be controlled.

(manufacture method of ethene-alpha-olefin copolymer)

Ethene-alpha-olefin copolymer can manufacture as catalyst by using Ziegler compound, vfanadium compound, Metallocenic compound etc.Various Metallocenic compounds shown below are wherein preferably used to manufacture as catalyst.As Metallocenic compound, such as, the Metallocenic compound that Japanese Unexamined Patent Publication 2006-077261 publication, Japanese Unexamined Patent Publication 2008-231265 publication, Japanese Unexamined Patent Publication 2005-314680 publication etc. are described can be used.But, also can use the Metallocenic compound with the Metallocenic compound different structure described in these patent documentations, also can combinationally use more than two kinds Metallocenic compounds.

As the polymerization reaction using Metallocenic compound, form such as shown below can be enumerated as suitable examples.

Be selected from and react with above-mentioned Metallocenic compound (I) by (II-1) organoalurrunoxy compound, (II-2) and under forming the existence of the catalyst for olefines polymerizing of at least one compound (also referred to as co-catalyst) in the group that the compound of ion pair and (II-3) organo-aluminum compound form comprising known Metallocenic compound and (II), supply ethene and more than one the monomer be selected from alpha-olefin etc.

React with above-mentioned Metallocenic compound (I) as (II-1) organoalurrunoxy compound, (II-2) and form compound and (II-3) organo-aluminum compound of ion pair, such as, the Metallocenic compound that Japanese Unexamined Patent Publication 2006-077261 publication, Japanese Unexamined Patent Publication 2008-231265 publication and Japanese Unexamined Patent Publication 2005-314680 publication etc. are described can also be used.But, also can use the Metallocenic compound with the Metallocenic compound different structure described in these patent documentations.These compounds separately or can contact in advance and put in polymerization atmosphere.In addition, such as also can support in described Inorganic particulate oxide carriers such as Japanese Unexamined Patent Publication 2005-314680 publications and use.

In addition, the compound forming ion pair preferably by not using in fact above-mentioned (II-2) and above-mentioned Metallocenic compound (I) to react manufactures, and can obtain the ethene-alpha-olefin copolymer of excellent electrical characteristic.

React as (II-2) and above-mentioned Metallocenic compound (I) and form ion pair compound (below, sometimes referred to as " ionic compound (II) ".), Japanese Unexamined Patent Publication 1-501950 publication, Japanese Unexamined Patent Publication 1-502036 publication, Japanese Unexamined Patent Publication 3-179005 publication, Japanese Unexamined Patent Publication 3-179006 publication, Japanese Unexamined Patent Publication 3-207703 publication, Japanese Unexamined Patent Publication 3-207704 publication, described lewis acid, ionic compound, borane compound and the caborane compounds etc. such as No. USP5321106 can be enumerated.In addition, as ionic compound (II), heteropoly compound and different polyvoltine compound can also be enumerated.

The polymerization of ethene-alpha-olefin copolymer can be undertaken by any one in the liquid polymerizations such as known gaseous polymerization, slurry polymerization process and solution polymerization process.Carry out preferably by liquid polymerizations such as solution polymerization process.At use Metallocenic compound as described above, when carrying out the copolymerization of the alpha-olefin of ethene and carbon number 3 ~ 20 and manufacture ethene-alpha-olefin copolymer, the Metallocenic compound of (I) is generally 10 with every 1 liter of reaction volume ^-9~ 10 ^-1mole, be preferably 10 ^-8~ 10 ^-2mole such amount uses.

Compound (II-1) is generally 1 ~ 10000 with the mol ratio [(II-1)/M] of the whole transition metal atoms (M) in compound (II-1) and compound (I), and 10 ~ 5000 such amounts that are preferably use.Compound (II-2) is to be generally 0.5 ~ 50 with the mol ratio [(II-2)/M] of the whole transition metal (M) in compound (I), and 1 ~ 20 such amount that is preferably uses.Compound (II-3) is generally 0 ~ 5 mM with every 1 liter of polymerization volume, is preferably about 0 ~ 2 mM of such amount and uses.

In solution polymerization process, under the existence of Metallocenic compound as described above, by carrying out the copolymerization of the alpha-olefin of ethene and carbon number 3 ~ 20, co-monomer content can be manufactured efficiently high, composition narrowly distributing, the ethene-alpha-olefin copolymer of narrow molecular weight distribution.Here, the mol ratio that adds of the alpha-olefin of ethene and carbon number 3 ~ 20 is generally ethene: alpha-olefin=10:90 ~ 99.9:0.1, be preferably ethene: alpha-olefin=30:70 ~ 99.9:0.1, more preferably ethene: alpha-olefin=50:50 ~ 99.9:0.1.

So-called " solution polymerization process " is the general name of carrying out the method for being polymerized under the state being dissolved with polymer in nonactive hydrocarbon solvent described later.Polymerization temperature in solution polymerization process is generally 0 ~ 200 DEG C, is preferably 20 ~ 190 DEG C, more preferably 40 ~ 180 DEG C.In solution polymerization process, when polymerization temperature is lower than 0 DEG C, its polymerization activity reduces terrifically, and the heat extraction of heat of polymerization also becomes difficulty, impracticable from the viewpoint of productivity.In addition, if polymerization temperature is more than 200 DEG C, then polymerization activity reduces terrifically, therefore impracticable from the viewpoint of productivity.

Polymerization pressure is generally normal pressure ~ 10MPa gauge pressure, under being preferably the condition of normal pressure ~ 8MPa gauge pressure.Copolymerization can be undertaken by the either method in batch (-type), semi continuous, continous way.Reaction time is (when copolyreaction is implemented by continuity method, for mean residence time) different from the difference of the condition such as catalyst concn, polymerization temperature, suitably can select, but be generally 1 minute ~ 3 hours, be preferably 10 minutes ~ 2.5 hours.In addition, also can be divided into different more than 2 sections of reaction condition to be polymerized.The molecular weight of the ethene-alpha-olefin copolymer of gained also can be regulated by the hydrogen concentration in change polymerization system, polymerization temperature.In addition, the amount also can passing through used compound (II) regulates.When adding hydrogen, about its amount, the ethene-alpha-olefin copolymer that every 1kg generates is about 0.001 ~ 5,000NL is suitable.In addition, be present in the vinyl of the molecular end of the ethene-alpha-olefin copolymer of gained and ethenylidene can by improving polymerization temperature, do one's utmost minimizing and add hydrogen amount to adjust.

The solvent used in solution polymerization process is generally nonactive hydrocarbon solvent, and the boiling point be preferably under normal pressure is the saturated hydrocarbons of 50 DEG C ~ 200 DEG C.Specifically, the aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, dodecane, kerosene can be enumerated; The clicyclic hydrocarbons such as pentamethylene, cyclohexane, methyl cyclopentane.In addition, benzene,toluene,xylene etc. are aromatic hydrocarbon based; The halogenated hydrocarbons such as ethlyene dichloride, chlorobenzene, carrene also fall into the category of " nonactive hydrocarbon solvent ", do not limit it and use.

As mentioned above, in solution polymerization process, not only can use the in the past conventional organoalurrunoxy compound being dissolved in aromatic hydrocarbon, and the modified methylaluminoxane as MMAO being dissolved in aliphatic hydrocarbon, clicyclic hydrocarbon can be used.Consequently, if as polymerisation in solution solvent and adopt aliphatic hydrocarbon, clicyclic hydrocarbon, be then mixed into the possibility of aromatic hydrocarbon in the ethene-alpha-olefin copolymer can almost to get rid of completely in polymerization system, generated.That is, solution polymerization process also has and can alleviate carrying capacity of environment, can make to minimize such feature to the impact of health.In addition, in order to suppress the uneven of physics value, preferably by the ethene-alpha-olefin copolymer obtained by polymerization reaction and other composition of adding as required by arbitrary method melting, implement mixing, granulation etc.

(organic peroxide)

The solar cell sealing material of present embodiment comprises organic peroxide.Radical initiator during cross-linking reaction when the radical initiator during graft modification of organic peroxide as silane coupler and ethene-alpha-olefin copolymer and solar module laminated into type as ethene-alpha-olefin copolymer and using.By to ethene-alpha-olefin copolymer graft modification silane coupler, can obtain and protect with face side transparent protection member, rear side the solar module that the cementability of component, unit, electrode is good.In addition, by cross-linked ethylene-alpha olefin copolymer, thermal endurance, solar module excellent in adhesion can be obtained.

As long as the organic peroxide of preferred use can to the organic peroxide of ethene-alpha-olefin copolymer graft modification silane coupler or cross-linked ethylene-alpha olefin copolymer, be not particularly limited, but the balance of the crosslinking rate during productivity from extrudate piece is shaping and solar module laminated into type is considered, 1 minute half life temperature of organic peroxide is preferably 100 ~ 170 DEG C.If half life temperature was more than 100 DEG C in 1 of organic peroxide minute, then the solar cell sealing sheet obtained by resin combination when extrudate piece is shaping becomes and not easily produces gel, therefore can suppress the rising of the torque of extruder and make sheet easily shaping.In addition, owing to can suppress concavo-convex in the generation of the surface of sheet because of the jello produced in extruder, therefore deteriorated appearance can be prevented.In addition, when applying voltage, owing to can prevent sheet inside from ftractureing, the reduction of breakdown voltage can therefore be prevented.In addition, the reduction of poisture-penetrability can also be prevented.In addition, due to can suppress sheet surface produce concavo-convex, therefore when the lamination process of solar module and face side transparent protection member, unit, electrode, rear side protect the adaptation of component to become good, cementability also improves.If extrusion temperature shaping for extrudate piece is reduced to less than 90 DEG C, although then can be shaping, productivity significantly reduces.If half life temperature was less than 170 DEG C in 1 of organic peroxide minute, then the reduction of crosslinking rate when can suppress solar module laminated into type, therefore can prevent the productive reduction of solar module.In addition, the thermal endurance of solar cell sealing material, the reduction of cementability can also be prevented.

As organic peroxide, known organic peroxide can be used.As the preferred concrete example of the organic peroxide of 1 minute half life temperature in the scope of 100 ~ 170 DEG C, dilauroyl peroxide can be enumerated, 1,1,3,3-tetramethyl butyl peroxidating-2 ethyl hexanoic acid ester, diperoxy benzoyl, t-amyl peroxy-2 ethyl hexanoic acid ester, tert-butyl hydroperoxide-2 ethyl hexanoic acid ester, tert-butyl hydroperoxide isobutyrate, tert-butyl hydroperoxide maleate, 1,1-bis-(t-amyl peroxy)-3,3,5-trimethyl-cyclohexane, 1,1-bis-(t-amyl peroxy) cyclohexane, the different pelargonate of t-amyl peroxy, t-amyl peroxy caprylic acid ester, 1,1-bis-(tert-butyl hydroperoxide)-3,3,5-trimethyl-cyclohexane, 1,1-bis-(tert-butyl hydroperoxide) cyclohexane, t-butylperoxyisopropyl carbonic ester, tert-butyl hydroperoxide-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-bis-(benzoyl peroxidating) hexane, t-amyl peroxy benzoic ether, tert-butyl hydroperoxide acetic acid esters, the different pelargonate of tert-butyl hydroperoxide, 2,2-bis-(tert-butyl hydroperoxide) butane, tert butyl peroxy benzoate etc.Be preferably dilauroyl peroxide, t-butylperoxyisopropyl carbonic ester, tert-butyl hydroperoxide acetic acid esters, the different pelargonate of tert-butyl hydroperoxide, tert-butyl hydroperoxide-2-ethylhexyl carbonate, tert butyl peroxy benzoate etc.Above-mentioned organic peroxide can be used alone one, also can more than two kinds used in combination.

The content of the organic peroxide in solar cell sealing material, relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion, is preferably 0.1 ~ 3 weight portion, is more preferably 0.2 ~ 3 weight portion, is particularly preferably 0.2 ~ 2.5 weight portion.

If the content of organic peroxide is more than 0.1 weight portion, then can suppress the reduction of the crosslinking feature such as crosslinking degree, crosslinking rate of solar cell sealing material, make silane coupler good to the graft reaction of the main chain of vinyl copolymer, suppress the reduction of thermal endurance, cementability.

If the content of organic peroxide is below 3.0 weight portions, then the solar cell sealing sheet obtained by resin combination when extrudate piece is shaping does not produce gel, can suppress the torque of extruder, and sheet is shaping becomes easy.Sheet also owing to not producing jello in extruder, and therefore the surface of sheet does not have concavo-convex, and outward appearance is good.In addition, owing to not having gel, even if therefore apply voltage, the cracking caused by the jello of sheet inside does not occur yet, and therefore insulation breakdown resistance is good.In addition, poisture-penetrability is also good.In addition, owing to not having concavo-convex on sheet surface, therefore when the lamination process of solar module and face side transparent protection member, unit, electrode, rear side protect the cementability of component also good.

(ultra-violet absorber)

The solar cell sealing material of present embodiment comprises general formula (1) or the BTA system ultra-violet absorber shown in (2).The light deterioration of BTA system ultra-violet absorber is few, has excellent durability.In addition, there is the absorbability under the wavelength of below 300nm, and at more than 340nm, there is maximum level wavelength, excellent at the ultraviolet absorption ability of wide wavelength region may, and can long term maintenance ultraviolet absorption ability, the reduction of the conversion efficiency of solar module can be suppressed.

The R of above-mentioned formula (1) and (2) ₁as long as in the alkyl straight-chain of carbon number 1 ~ 6 or the alkyl of branched.As abovementioned alkyl, specifically, methyl, ethyl, n-pro-pyl, isopropyl, normal-butyl, isobutyl group, the tert-butyl group, sec-butyl, n-pentyl, isopentyl, neopentyl, tertiary pentyl and n-hexyl etc. can be enumerated.

As the R of above-mentioned formula (1) and (2) ₂~ R ₄or R ₅~ R ₈in the alkyl of carbon number 1 ~ 20, methyl, ethyl, n-pro-pyl, isopropyl, normal-butyl, isobutyl group, the tert-butyl group, sec-butyl, n-pentyl, isopentyl, neopentyl, tertiary pentyl, n-hexyl, nonyl, decyl, dodecyl, undecyl, tridecyl, myristyl, pentadecyl, cetyl, heptadecyl, octadecyl, nonadecyl and eicosyl etc. can be enumerated.

The R of above-mentioned formula (1) and (2) ₂~ R ₄or R ₅~ R ₈as long as in the alkoxyl straight-chain of carbon number 1 ~ 22 or the alkoxyl of branched.Specifically, methoxyl group, ethyoxyl, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, just own oxygen base and n-octyloxy etc. can be enumerated.

The R of above-mentioned formula (1) and (2) ₂~ R ₄or R ₅~ R ₈in the alkyloxycarbonyl of carbon number 1 ~ 22, as long as the carbon number of moieties be 1 ~ 22, the alkyloxycarbonyl of straight-chain or branched.Specifically, methoxycarbonyl, ethoxy carbonyl, isopropoxy carbonyl, n-butoxycarbonyl, isobutoxy carbonyl, s-butoxycarbonyl, tert-butoxycarbonyl, positive hexyloxy carbonyl and n-octyloxy carbonyl etc. can be enumerated.

In above-mentioned formula (1), R ₁represent hydrogen atom, R ₂~ R ₄can be the same or different, but preferably can enumerate the alkyl of carbon number 1 ~ 10.

As the BTA system ultra-violet absorber shown in above-mentioned formula (1), specifically, 2-(2H-1,2,3-BTA-2-base)-4,6-DI-tert-butylphenol compounds can be enumerated, 2-(the chloro-2H-1 of 5-, 2,3-BTA-2-base)-4,6-DI-tert-butylphenol compounds, 2-(2H-1,2,3-BTA-2-base)-4,6-di-tert-pentyl phenols, 2-(the chloro-2H-1 of 5-, 2,3-BTA-2-base)-4,6-di-tert-pentyl phenols, 2-(2H-1,2,3-BTA-2-base)-4-TBP, 2-(the chloro-2H-1 of 5-, 2,3-BTA-2-base)-4-TBP, 2-(2H-1,2,3-BTA-2-base)-4-methylphenol, 2-(the chloro-2H-1 of 5-, 2,3-BTA-2-base)-4-methylphenol, 2-(2H-1,2,3-BTA-2-base)-6-dodecyl-4-methylphenol, 2-(the chloro-2H-1 of 5-, 2,3-BTA-2-base)-6-dodecyl-4-methylphenol, 2-(2H-1,2,3-BTA-2-base)-4-methyl-6-tert-butylphenol, 2-(the chloro-2H-1 of 5-, 2,3-BTA-2-base)-4-methyl-6-tert-butylphenol, 2-(2H-1,2,3-BTA-2-base)-paracresol, 2-(the chloro-2H-1 of 5-, 2,3-BTA-2-base)-paracresol, two (1-methyl isophthalic acid-phenylethyl) phenol of 2-(2H-1,2,3-BTA-2-base)-4,6-, two (1-methyl isophthalic acid-phenylethyl) phenol of 2-(the chloro-2H-1 of 5-, 2,3-BTA-2-base)-4,6-, 2-(2,4-dihydroxy phenyl)-2H-1,2,3-BTA, 2-(2H-1,2,3-BTA-2-base)-4-tert-octyl phenol, 2-(2H-1,2,3-BTA-2-base)-6-tert-butyl-4-methyl-Phenol, 2-(2H-1,2,3-BTA-2-base)-4-methyl-6-tert amyl phenol, 2-(2H-1,2,3-BTA-2-base)-4-methyl-6-tert octyl phenol, 2-(2H-1,2,3-BTA-2-the base)-4-tert-butyl group-6-methylphenol, 2-(2H-1,2,3-BTA-2-base)-6-methyl-4-tert-amyl phenol, 2-(2H-1,2,3-BTA-2-base)-6-methyl-4-tert-octyl phenol, 2-(2H-1,2,3-BTA-2-base)-4-dodecyl-6-methylphenol, 2-(2H-1,2,3-BTA-2-base)-5-thanatol, 2-(2H-1,2,3-BTA-2-base)-5-butoxy phenol, 2-(2H-1,2,3-BTA-2-base)-5-octyl group oxygen base phenol, 2-(2H-1,2,3-BTA-2-base)-5-benzoyloxy phenol, 2-(2H-1,2,3-BTA-2-base)-4-methyl-6-(3,4,5,6-tetrahydrochysene phthalimido methyl) phenol, 2-(4-acryloxy-2-hydroxy phenyl)-2H-1,2,3-BTA, 2-(4-pi-allyl oxygen base-2-hydroxy phenyl)-2H-1,2,3-BTA etc.

In above-mentioned formula (2), preferred R ₁represent hydrogen atom, R ₅with R ₈identical, R ₆with R ₇identical.

As the BTA system ultra-violet absorber shown in above-mentioned formula (2), specifically, can 2 be enumerated, 2 '-di-2-ethylhexylphosphine oxide [6-(2H-1,2,3-BTA-2-base)-4-(1,1,3,3-tetramethyl butyl) phenol], 4,4 '-di-2-ethylhexylphosphine oxide [2-(2H-1,2,3-BTA-2-base)-5-thanatol], 4,4 '-di-2-ethylhexylphosphine oxide [2-(2H-1,2,3-BTA-2-base)-5-butoxy phenol], 4,4 '-di-2-ethylhexylphosphine oxide [2-(2H-1,2,3-BTA-2-base)-5-octyl group oxygen base phenol] etc.They can be used alone a kind, also can two or more is used in combination.

Wherein, as the BTA system ultra-violet absorber shown in above-mentioned formula (1), preferably 2-(2H-1 can be enumerated, 2,3-BTA-2-base)-6-dodecyl-4-methylphenol and 2-(2H-1,2,3-BTA-2-base)-4,6-di-tert-pentyl phenols.

The content of the ultra-violet absorber in the solar cell sealing material of present embodiment, is preferably 0.05 ~ 5.0 weight portion relative to ethene-alpha-olefin copolymer 100 weight portion, is more preferably 0.1 ~ 4.5 weight portion.If the content of ultra-violet absorber is in above-mentioned scope, then the balancing good of weathering stability, crosslinking feature, therefore preferably.

(silane coupler)

Preferably comprise olefinic unsaturated silane compound further.The content of the olefinic unsaturated silane compound in the solar cell sealing material of present embodiment, relative to ethene-alpha-olefin copolymer 100 weight portion, is preferably 0.1 ~ 5 weight portion, is more preferably 0.1 ~ 4 weight portion, is particularly preferably 0.1 ~ 3 weight portion.

If the content of olefinic unsaturated silane compound is more than 0.1 weight portion, then cementability improves.On the other hand, if the content of olefinic unsaturated silane compound is below 5 weight portions, then the balance of the Cost And Performance of solar cell sealing material is good, and, can suppress when the lamination of solar module for making the addition of the organic peroxide of olefinic unsaturated silane compound and ethene-alpha-olefin copolymer graft reaction, the solar cell sealing sheet obtained by resin combination when extrudate piece is shaping becomes and not easily produces gel, therefore can suppress the rising of the torque of extruder, make sheet easily shaping.In addition, owing to can suppress concavo-convex in the generation of the surface of sheet because of the jello produced in extruder, the deterioration of outward appearance can therefore be prevented.In addition, can prevent applying voltage time slice inside and ftracture, therefore can prevent the reduction of breakdown voltage.In addition, the reduction of poisture-penetrability can also be prevented.In addition, due to can suppress sheet surface produce concavo-convex, therefore when the lamination process of solar module and face side transparent protection member, unit, electrode, rear side protect the adaptation of component to become good, cementability also improves.

Olefinic unsaturated silane compound can use known compound, is not particularly limited.Specifically, vinyltriethoxysilane, vinyltrimethoxy silane, vinyl three ('beta '-methoxy ethyoxyl) silane, γ-glycidoxypropyltrime,hoxysilane, γ aminopropyltriethoxy silane, γ-methacryloxypropyl trimethoxy silane etc. can be used.Preferably can enumerate cementability good γ-glycidoxypropyl group methoxy silane, γ aminopropyltriethoxy silane, γ-methacryloxypropyl trimethoxy silane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxy silane, 3-glycidoxypropyl dimethoxysilane, 3-glycidoxypropyltrime,hoxysilane, 3-glycidoxypropyl diethoxy silane, 3-glycidoxypropyl group triethoxysilane etc.Preferably can enumerate the good 3-methacryloxypropyl trimethoxy silane of cementability, 3-methacryloxypropyl, 3-acryloxypropyl trimethoxy silane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxy silane, 3-glycidoxypropyltrime,hoxysilane, 3-glycidoxypropyl diethoxy silane.

(hindered amine system light stabilizer)

The solar cell sealing material of present embodiment preferably comprises hindered amine system light stabilizer further.By comprising hindered amine system light stabilizer, the free radical kind harmful to ethene-alpha-olefin copolymer can be caught, suppress the generation of new free radical.

As hindered amine system light stabilizer, two (2,2 can be used, 6,6-tetramethyl-4-piperidyl) sebacate, poly-[{ 6-(1,1,3,3-tetramethyl butyl) amino-1,3,5-triazine-2,4-bis-base } { (2,2,6,6-tetramethyl-4-piperidyl) imino group } hexa-methylene { (2,2,6,6-tetramethyl-4-piperidyl) imino group] etc. hindered amine system, hindered piperidine based compound etc.

In addition, the low molecular weight hindered amine system light stabilizer of following general formula (3) can also be used.

In above-mentioned general formula (3), R ₁, R ₂represent hydrogen, alkyl etc.R ₁with R ₂can be the same or different.R ₁and R ₂be preferably hydrogen or methyl.R ₃represent hydrogen, alkyl, alkenyl etc.R ₃be preferably hydrogen or methyl.

As the hindered amine system light stabilizer shown in above-mentioned general formula (3), specifically, 4-acryloxy-2 can be enumerated, 2, 6, 6-tetramethyl piperidine, 4-acryloxy-1, 2, 2, 6, 6-pentamethvl, 4-acryloxy-1-ethyl-2, 2, 6, 6-tetramethyl piperidine, 4-acryloxy-1-propyl group-2, 2, 6, 6-tetramethyl piperidine, 4-acryloxy-1-butyl-2, 2, 6, 6-tetramethyl piperidine, 4-methacryloxy-2, 2, 6, 6-tetramethyl piperidine, 4-methacryloxy-1, 2, 2, 6, 6-pentamethvl, 4-methacryloxy-1-ethyl-2, 2, 6, 6-tetramethyl piperidine, 4-methacryloxy-1-butyl-2, 2, 6, 6-tetramethyl piperidine, 4-crotons acyloxy-2, 2, 6, 6-tetramethyl piperidine, 4-crotonocyl Oxy-1-propyl group-2, 2, 6, 6-tetramethyl piperidine etc.

In addition, the HMW hindered amine system light stabilizer shown in following formula can also be used.So-called HMW hindered amine system light stabilizer, refers to that molecular weight is the hindered amine system light stabilizer of 1000 ~ 5000.

The content of the hindered amine system light stabilizer in the solar cell sealing material of present embodiment, relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion, be preferably 0.01 ~ 2.0 weight portion, be more preferably 0.01 ~ 1.6 weight portion, be particularly preferably 0.05 ~ 1.6 weight portion.If the content of hindered amine system light stabilizer is more than 0.01 weight portion, then weatherability and thermal endurance good.If the content of hindered amine system light stabilizer is below 2.0 weight portions, then can suppress the annihilation of the free radical produced by organic peroxide, cementability, thermal endurance, crosslinking feature are good.

(hindered phenol system stabilizer)

The solar cell sealing material of present embodiment preferably comprises hindered phenol system stabilizer further.By comprising hindered phenol system stabilizer, the free radical kind harmful to ethene-alpha-olefin copolymer can be caught in the presence of oxygen, suppress the generation of new free radical, can oxidative degradation be prevented.

As hindered phenol system stabilizer, known compound can be used, can enumerate such as, 1, 1, 3-tri--(2-methyl-4-hydroxyl-5-tert-butyl-phenyl) butane, 4, 4 '-butylidene-bis(3-methyl-6-t-butyl phenol), 2, 2-thiobis (4-methyl-6-tert-butylphenol), 7-octadecyl-3-(4 '-hydroxyl-3 ', 5 '-di-tert-butyl-phenyl) propionic ester, four-[methylene-3-(3 ', 5 '-di-t-butyl-4 '-hydroxy phenyl) propionate methane, pentaerythrite-four [3-(3, 5-di-tert-butyl-hydroxy phenyl) propionic ester], triethylene glycol-bis-[3-(the 3-tert-butyl group-5-methyl-4-hydroxy phenyl) propionic ester], 1, 6-hexylene glycol-bis-[3-(3, 5-di-tert-butyl-hydroxy phenyl) propionic ester], 2, two (just pungent sulfenyl)-6-(the 4-hydroxyl-3 of 4-, 5-di-tert-butyl amido)-1, 3, 5-triazine, three-(3, 5-di-tert-butyl-4-hydroxyl benzyl)-isocyanuric acid ester, 2, 2-sulfo--di ethylene bis [3-(3, 5-di-tert-butyl-hydroxy phenyl) propionic ester], N, N '-hexa-methylene two (3, 5-di-t-butyl-4-hydroxyl)-hydrocinnamamide, 2, two [(pungent sulfenyl) the methyl]-orthoresol of 4-, 3, 5-di-tert-butyl-4-hydroxyl benzyl-phosphonate ester-diethyl ester, four [methylene (3, 5-di-t-butyl-4-hydroxy hydrocinnamate)] methane, octadecyl-3-(3, 5-di-tert-butyl-hydroxy phenyl) propionic ester, 3, 9-pair [2-{3-(3-tertiary butyl-4-hydroxy-5-aminomethyl phenyl) propionyloxy }-1, 1-dimethyl ethyl]-2, 4, 8, 10-tetra-oxaspiro [5.5] hendecane etc.Wherein, pentaerythrite-four [3-(3,5-di-tert-butyl-hydroxy phenyl) propionic ester], octadecyl-3-(3,5-di-tert-butyl-hydroxy phenyl) propionic ester is particularly preferably.

The content of the hindered phenol system stabilizer in the solar cell sealing material of present embodiment, relative to ethene-alpha-olefin copolymer 100 weight portion, be preferably 0.005 ~ 0.1 weight portion, be more preferably 0.01 ~ 0.1 weight portion, be particularly preferably 0.01 ~ 0.06 weight portion.If the content of hindered phenol system stabilizer is more than 0.005 weight portion, then thermal endurance is good, in the heat-proof aging test under the high temperature of such as more than 120 DEG C, has the tendency of the xanthochromia that can suppress solar cell sealing material.If the content of hindered phenol system stabilizer is below 0.1 weight portion, then the crosslinking feature of solar cell sealing material is good, and thermal endurance, cementability are good.

In addition, under constant temperature and humidity, if with have alkalescence hindered amine system light stabilizer and use, then the hydroxyl of hindered phenol stabilizer forms salt, form the two quinone methides of conjugation of quinone and dimerization, there is the tendency being easy to the xanthochromia causing solar cell sealing material, if but hindered phenol system stabilizer is below 0.1 weight portion, then can suppress the xanthochromia of solar cell sealing material.

(phosphorus system stabilizer)

The solar cell sealing material of present embodiment preferably comprises phosphorus system stabilizer further.If comprise phosphorus system stabilizer, then the decomposition of organic peroxide when can suppress extrusion molding, can obtain the sheet that outward appearance is good.If comprise hindered amine system light stabilizer, hindered phenol system stabilizer, then also can fall into oblivion the free radical of generation, the sheet that production outward appearance is good, but extrude in operation at sheet and consume stabilizer, have the tendency that the long-term reliability such as thermal endurance, weatherability reduces.

As phosphorus system stabilizer, known compound can be used, can enumerate such as, three (2,4-di-tert-butyl-phenyl) phosphite ester, two [2,4-two (1,1-dimethyl ethyl)-6-aminomethyl phenyl] ethyl ester phosphorous acid, four (2,4-di-tert-butyl-phenyl) [1,1-xenyl]-4,4 '-two base biphosphinate and two (2,4-di-tert-butyl-phenyl) pentaerythritol diphosphites etc.Wherein, three (2,4-di-tert-butyl-phenyl) phosphite ester is preferably.

The content of the phosphorus system stabilizer in the solar cell sealing material of present embodiment, relative to ethene-alpha-olefin copolymer 100 weight portion, is preferably 0.005 ~ 0.5 weight portion, is more preferably 0.01 ~ 0.5 weight portion, is particularly preferably 0.02 ~ 0.2 weight portion.If the content of phosphorus system stabilizer is more than 0.005 weight portion, then the decomposition of organic peroxide when can suppress extrusion molding, can obtain the sheet that outward appearance is good.In addition, thermal endurance is good, in the heat-proof aging test under the high temperature of such as more than 120 DEG C, has the tendency of the xanthochromia that can suppress solar cell sealing material.If the content of phosphorus system stabilizer is below 0.5 weight portion, then the crosslinking feature of solar cell sealing material is good, and thermal endurance, cementability are good.In addition, have no the impact of the acid band produced by the decomposition of phosphorus system stabilizer, also corrosion of metals does not occur.

In addition, although there is the stabilizer in same a part with phosphite ester structure and hindered phenol structure, but in large quantities containing in the composition of organic peroxide as the solar cell sealing material of present embodiment, suppress the performance of decomposition of organic peroxide insufficient during extrusion molding, have and generate gel and the tendency that can not get the good sheet of outward appearance.

(other additive)

Form in the resin combination of the solar cell sealing material of present embodiment, within the scope without prejudice to the object of the present invention, can suitably containing the various compositions beyond the above each composition described in detail.Can enumerate such as, the various polyolefin beyond ethene-alpha-olefin copolymer; Polystyrene, ethene based block copolymer; Acrylic polymer etc.The content of the various compositions in solar cell sealing material, relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion, is preferably 0.0001 ~ 50 weight portion, is more preferably 0.001 ~ 40 weight portion.In addition, also can suitably containing more than one the additive in the various resin be selected from addition to the polyolefin and/or various rubber, plasticizer, filler, pigment, dyestuff, antistatic agent, antiseptic, mould inhibitor, fire retardant, crosslinking coagent, other heat-resisting stabilizing agent and dispersant etc. except hindered phenol system stabilizer and phosphorus system stabilizer.

As other heat-resisting stabilizing agent except hindered phenol system stabilizer and phosphorus system stabilizer, specifically, the lactone system heat-resisting stabilizing agents such as the reaction product of 3-hydroxyl-5,7-di-t-butyls-furans-2-ketone and ortho-xylene can be enumerated; The zinc salt, 4 of the zinc salt of myristyl thiodipropionate, dilauryl thiodipropionate, distearyl thiodipropionate, two-tridecyl thiodipropionate, pentaerythrite-four-(β-lauryl-thiopropionate), 2-mercaptobenzimidazole, 2-mercaptobenzimidazole, 2 mercaptomethyl benzimidazole, 2 mercaptomethyl benzimidazole, 4 '-thiobis (the 6-tert-butyl group-3-methylphenol), 2,6-di-t-butyl-4-(4, two (the pungent sulfenyl)-1 of 6-, 3,5-triazine-2-base is amino) the sulphur system heat-resisting stabilizing agent such as phenol; Amine system heat-resisting stabilizing agent etc.

Particularly, when containing crosslinking coagent, the content of the crosslinking coagent in the solar cell sealing material of present embodiment, relative to ethene-alpha-olefin copolymer 100 weight portion, is preferably 0.05 ~ 5 weight portion, is more preferably 0.1 ~ 3 weight portion.If the content of crosslinking coagent is in above-mentioned scope, then can has the cross-linked structure of appropriateness, thermal endurance, mechanical properties, cementability can be improved, therefore preferably.

As crosslinking coagent, can use for the normally used known crosslinking coagent of olefin-based resin.Such crosslinking coagent is the compound in molecule with more than one double bond.Specifically, the mono acrylic esters such as tert-butyl acrylate, lauryl acrylate, acrylic acid cetyl ester, stearyl acrylate base ester, 2-methoxyethyl acrylate, ethyl carbitol acrylate, methoxyl group tripropylene glycol acrylate can be enumerated; The monomethacrylates such as Tert-butyl Methacrylate, lauryl methacrylate, cetyl ester, stearyl methacrylate, methoxyl group glycolmethacrylate, methoxy polyethylene glycol methacrylate-styrene polymer; 1,4-butanediol diacrylate, 1, the diacrylates such as 6-hexanediyl ester, 1,9-nonanediol diacrylate, neopentylglycol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethyleneglycol diacrylate, tripropylene glycol diacrylate, polypropyleneglycol diacrylate; 1,3-butanediol dimethylacrylate, 1, the dimethylacrylates such as 6-hexanediol dimethacrylate, 1,9-nonanediol dimethylacrylate, neopentylglycol dimethacrylate, ethylene glycol dimethacrylate, dimethacrylate, TEGDMA, polyethylene glycol dimethacrylate; The triacrylates such as trimethylolpropane triacrylate, tetramethylol methane triacrylate, pentaerythritol triacrylate; The trimethyl acrylic esters such as trimethylol-propane trimethacrylate, trimethylolethane trimethacrylate methacrylate; The tetraacrylate such as tetramethylol methane tetraacrylate, tetramethylol methane tetraacrylate; The di vinyl aromatic such as divinylbenzene, di isopropenylbenzene compounds of group; The cyanurate such as triallylcyanurate, cyanacrylate; The diallyl compounds such as diallyl phthalate; Triallyl compound; Paraquinonedioxime, p, p ' oxime such as-dibenzoyl quininie dioxime; The maleimides such as phenyl maleimide.

More preferably diacrylate in these crosslinking coagents; Dimethylacrylate; Di vinyl aromatic compounds of group; The triacrylates such as trimethylolpropane triacrylate, tetramethylol methane triacrylate, pentaerythritol triacrylate; The trimethyl acrylic esters such as trimethylol-propane trimethacrylate, trimethylolethane trimethacrylate methacrylate; The tetraacrylate such as tetramethylol methane tetraacrylate, tetramethylol methane tetraacrylate; The cyanurate such as triallylcyanurate, cyanacrylate; The diallyl compounds such as diallyl phthalate; Triallyl compound; Paraquinonedioxime, p, p ' oxime such as-dibenzoyl quininie dioxime; The maleimides such as phenyl maleimide.In addition, in these crosslinking coagents, particularly preferably be cyanacrylate, the bubble of the solar cell sealing material after lamination occurs, the balance of crosslinking feature is the most excellent.

The solar cell sealing material of present embodiment, by relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion, the content of ultra-violet absorber is 0.05 ~ 5.0 weight portion, the content of organic peroxide is 0.1 ~ 3 weight portion, the content of hindered phenol system stabilizer is 0.005 ~ 0.1 weight portion, the content of hindered amine system light stabilizer is 0.01 ~ 2.0 weight portion, and the content of phosphorus system stabilizer is that the resin combination of 0.005 ~ 0.5 weight portion formed is optimal way.

In addition, the solar cell sealing material of present embodiment, by relative to above-mentioned ethene-alpha-olefin copolymer 100 weight portion, the content of ultra-violet absorber is 0.1 ~ 4.5 weight portion, the content of organic peroxide is 0.2 ~ 2.5 weight portion, the content of hindered phenol system stabilizer is 0.01 ~ 0.06 weight portion, and the content of hindered amine system light stabilizer is 0.05 ~ 1.6 weight portion, and the content of phosphorus system stabilizer is that the resin combination of 0.02 ~ 0.2 weight portion formed is particularly preferred mode.

The solar cell sealing material of present embodiment; weatherability is excellent, and protects the balancing good of the cementability of the various solar cell components such as component, membrane electrode, aluminium, solar cell device, thermal endurance, the balance of extrusion molding and crosslinking feature, the transparency, flexibility, outward appearance, electrical characteristic, electrical insulating property, poisture-penetrability, electrode corrosion, technology stability with face side transparent protection member, rear side.Therefore, be suitable as the solar cell sealing material of known solar module and use.Normally used method can be utilized as the manufacture method of the solar cell sealing material of present embodiment, but carry out melt blending to manufacture preferably by kneader, Banbury mixer, extruder etc.Particularly preferably by manufacturing by quantity-produced extruder.

Solar cell sealing material, to be sheet be also its global shape one of preferred embodiment.In addition, there is at least one deck and comprise the sheet of above-mentioned resin combination and the solar cell sealing material obtained with other layer of Composite also can be applicable to using.The thickness of the layer of solar cell sealing material is generally 0.01 ~ 2mm, is preferably 0.05 ~ 1.5mm, is more preferably 0.1 ~ 1.2mm, more preferably 0.2 ~ 1mm, is particularly preferably 0.3 ~ 0.9mm, most preferably be 0.3 ~ 0.8mm.If thickness is within the scope of this, then can suppress the breakage of face side transparent protection member, solar cell device, membrane electrode etc. in lamination operation, and, by guaranteeing sufficient light transmittance, thus high light energy output can be obtained.In addition, the laminated into type of the solar module under low temperature can be carried out, therefore preferably.

The forming method of solar cell sealing material sheet is not particularly limited, but can adopt known various forming method (cast molding, extrudate piece is shaping, inflation is shaping, injection moulding, compression forming, calendering formation etc.).Particularly, in an extruder, by ethene-alpha-olefin copolymer and ultra-violet absorber of the present invention, organic peroxide, silane coupler and hindered amine system light stabilizer as required, hindered phenol system stabilizer, phosphorus system stabilizer, crosslinking coagent, such as in the bags such as polybag, manpower blending is carried out with other additive, use Henschel mixer, rotating cylinder, the stirring mixers such as high-speed mixer carry out after blending, the resin combination being combined with ethene-alpha-olefin copolymer and various additive is put in the shaping hopper of extrudate piece, carry out melting mixing, carry out extrudate piece shaping simultaneously, the solar cell sealing material obtaining sheet is most preferred execution mode.

In addition, utilize extruder once to granulate with the resin combination fitted in, so by extrusion molding, compressing carry out sheet time, generally speaking pass through from water layer, or use the extruder cooling line material of imderwater cutting machine formula, cutting and obtain particle.Therefore, due to attachment of moisture, therefore the deterioration of additive particularly silane coupler occurs, and such as, when again carrying out sheet with extruder, silane coupler condensation reaction is each other carried out, and has the tendency that cementability reduces, therefore not preferred.In addition, by ethene-alpha-olefin copolymer and except organic peroxide, additive (hindered phenol system stabilizer beyond silane coupler, phosphorus system stabilizer, hindered amine system light stabilizer, the stabilizers such as ultra-violet absorber) use extruder masterbatch in advance after, blending organic peroxide, silane coupler, again with extruder etc. carry out sheet shaping when, also due to hindered phenol system stabilizer, phosphorus system stabilizer, hindered amine system light stabilizer, the stabilizers such as ultra-violet absorber two degree pass through extruder, therefore stabilizer deterioration is had, weatherability, the tendency that the long-term reliabilities such as thermal endurance reduce, therefore not preferred.

As extrusion temperature scope, extrusion temperature is 100 ~ 130 DEG C.If make extrusion temperature be more than 100 DEG C, then the productivity of solar cell sealing material can be made to improve.If make extrusion temperature be less than 130 DEG C, then become when resin combination being obtained solar cell sealing material with extruding Bigpian and not easily gelation occurs.Therefore, the rising of the torque of extruder can be prevented, make sheet easily shaping.In addition, not easily produce concavo-convex owing to becoming on the surface of sheet, therefore can prevent deteriorated appearance.In addition, can suppress to ftracture in applying voltage time slice inside, therefore can prevent the reduction of breakdown voltage.In addition, the reduction of poisture-penetrability can also be suppressed.In addition, due to become on sheet surface not easily produce concavo-convex, therefore when the lamination process of solar module and face side transparent protection member, unit, electrode, rear side protect the adaptation of component to become good, excellent in adhesion.

In addition, be when being such as less than 10g/10 minute at the MFR of ethene-alpha-olefin copolymer, use by by molten resin with (stack) rolling of warmed-up metallic roll thus make desired by the sheet of thickness, the calendering formation machine of film, while carrying out ethene-alpha-olefin copolymer and silane coupler, organic peroxide, ultra-violet absorber, light stabilizer, heat-resisting stabilizing agent and the melting mixing of other additive that uses as required, carry out calendering formation, also can obtain the solar cell sealing material of sheet.

As calendering formation machine, known various calendering formation machine can be used, mixing mill, tri-roll press machine, four-roll calender can be used.As four-roll calender, I type, S type, inverted L shape, Z-type, tiltedly Z-type etc. can be used especially.In addition, also preferred before imposing on stack, in advance vinylite composition is heated to the temperature of appropriateness, such as, arranging Banbury mixer, kneader, extruder etc. is also one of preferred embodiment.The temperature range of calendering formation preferably makes roll temperature be generally 40 ~ 100 DEG C.

In addition, embossing processing can be implemented to the surface of the sheet of solar cell sealing material (or layer).Processed the sheet surface decorating solar cell sealing material by embossing, thus can prevent sealing material sheet each other or the adhesion of sealing material sheet and other sheet etc.In addition, because embossing makes the storage elastic modulus of solar cell sealing material (solar cell sealing material sheet) reduce, therefore in the buffering that will become when solar cell sealing material sheet and solar cell device lamination solar cell device etc., thus the breakage of solar cell device can be prevented.

The total volume V of the recess of the per unit area of the sheet of solar cell sealing material _hwith the apparent volume V of the sheet of solar cell sealing material _apercentage (V _h/ V _avoidage P (%) shown in) × 100 is preferably 10 ~ 50%, is more preferably 10 ~ 40%, and more preferably 15 ~ 40%.In addition, the apparent volume V of the sheet of solar cell sealing material _aobtain by unit are is multiplied by the maximum ga(u)ge of solar cell sealing material.If voidage P is more than 10%, then the modulus of elasticity of solar cell sealing material can be made fully to reduce, therefore can obtain sufficient resiliency.Therefore, in the manufacturing process of module, when carrying out lamination process (pressurization operation) with the two-stage, for crystal type solar cell, the cracking of solder silicon unit, silicon unit and electrode are fixed can be prevented, for thin film solar cell, the cracking of silver electrode can be prevented.That is, if the voidage comprising the solar cell sealing material of the sheet formed by resin combination is more than 10%, even if then when being applied with pressure partly to solar cell sealing material, the protuberance being applied with pressure also can be out of shape in the mode shriveled.Therefore, when lamination process, even if be such as applied with large pressure partly to silicon unit etc., also can prevent silicon unit from ftractureing.In addition, if the voidage of solar cell sealing material is more than 10%, then the passage of air can be guaranteed, therefore can be degassed well when lamination process.Therefore, residual air in solar module and deteriorated appearance can be prevented, or the corrosion of generating electrodes due to the moisture in residual air when Long-Time Service.In addition, when lamination, the space that the resin combination of flowing produces tails off, and therefore can prevent the outside of each adherend being exuded to solar module and pollution layer press.

On the other hand, if voidage P is less than 80%, then air can be degassed well when the pressurization of lamination process, therefore can prevent residual air in solar module.Therefore, the deterioration of the outward appearance of solar module can be prevented, also can not the corrosion of generating electrodes due to the moisture in residual air when Long-Time Service.In addition, air can be degassed well when the pressurization of lamination process, and therefore the bond area of solar cell sealing material and adherend increases, and can obtain sufficient adhesive strength.

Voidage P can obtain by calculating as following.Implement the apparent volume V of the solar cell sealing material of embossing processing _a(mm ³) by the maximum ga(u)ge t of solar cell sealing material _max(mm) with unit are (such as 1m ²=1000mm × 1000mm=10 ⁶mm ²) long-pending, calculate as following formula (12).

V _A(mm ³)＝t _max(mm)×10 ⁶(mm ²) (12)

On the other hand, the actual volume V of the solar cell sealing material of this unit are ₀(mm ³) pass through the proportion ρ (g/mm of the resin of formation solar cell sealing material ³) and per unit area (1m ²) the actual weight W (g) of solar cell sealing material substitute into following formula (13) and calculate.

V ₀(mm ³)＝W/ρ (13)

The total volume V of the recess of the per unit area of solar cell sealing material _h(mm ³), as shown in following formula (14), by from " the apparent volume V of solar cell sealing material _a" in deduct " actual volume V ₀" calculate.

V _H(mm ³)＝V _A-V ₀＝V _A-(W/ρ) (14)

Therefore, voidage P (%) can obtain as follows.

Voidage P (%)=(V _h/ V _a) × 100

＝((V _A-(W/ρ))/V _A)×100

＝(1-W/(ρ·V _A))×100

＝(1-W/(ρ·t _max·10 ⁶))×100

Voidage P (%) can be obtained by above-mentioned calculating formula, but also can by carrying out microscope photographing to the cross section of the solar cell sealing material of reality, the face that implements embossing processing, and carries out image procossing etc. and obtain.

To be processed by embossing and the degree of depth of the recess formed is preferably 20 ~ 95% of the maximum ga(u)ge of solar cell sealing material, be more preferably 50 ~ 95%, be more preferably 65 ~ 95%.Sometimes by the maximum ga(u)ge t of the degree of depth D of recess relative to sheet _maxpercentage be called " degree of depth rate " of recess.

The degree of depth of the recess of so-called embossing processing, represent by embossing process the male and fomale(M&F) of the solar cell sealing material obtained, the difference of height D in the most deep of the top of protuberance and recess.In addition, the maximum ga(u)ge t of so-called solar cell sealing material _maxwhen carrying out embossing processing to a face of solar cell sealing material, represent (the solar cell sealing material thickness direction) distance from the top of the protuberance in a face to another face, when implementing embossing processing to two faces of solar cell sealing material, represent (solar cell sealing material thickness direction) distance of the top of the protuberance from the top of the protuberance in a face to another face.

Embossing processing can be implemented the one side of solar cell sealing material, also can implement two sides.When increasing the degree of depth of recess of embossing processing, preferably only formed in the one side of solar cell sealing material.When only implementing embossing processing to the one side of solar cell sealing material, the maximum ga(u)ge t of solar cell sealing material _maxfor 0.01mm ~ 2mm, be preferably 0.05 ~ 1mm, be more preferably 0.1 ~ 1mm, more preferably 0.15 ~ 1mm, more preferably 0.2 ~ 1mm, more preferably 0.2 ~ 0.9mm, be particularly preferably 0.3 ~ 0.9mm, most preferably be 0.3 ~ 0.8mm.If the maximum ga(u)ge t of solar cell sealing material _maxwithin the scope of this, then can suppress the breakage of face side transparent protection member, solar cell device, membrane electrode etc. in lamination operation, even if the laminated into type of solar module also can be carried out in lower temperature, therefore preferably.In addition, solar cell sealing material can guarantee sufficient light transmittance, and the solar module employing this solar cell sealing material has high light energy output.

In addition, this sheet can be used as solar cell sealing material with the leaflet form cut into according to solar module size or the roll form that can cut according to size before being about to make solar module.As the solar cell sealing material (solar cell sealing material sheet) of the sheet of the preferred implementation of present embodiment as long as have the layer that at least one deck formed by solar cell sealing material.Therefore, the number of plies of the layer formed by the solar cell sealing material of present embodiment can be one deck, also can be more than two layers.The viewpoint reduced costs from making structure simple, and the boundary reflection of doing one's utmost between reducing layer and effectively utilize the considerations such as the viewpoint of light, be preferably one deck.

Solar cell sealing material sheet, the layer that can only be formed by the solar cell sealing material of present embodiment is formed, and also can have the layer (following, to be also designated as " other layer ") beyond the layer containing solar cell sealing material.As the example of other layer, if according to object classification, then the hard conating, adhesive linkage, anti-reflection layer, gas barrier layer, stain-proofing layer etc. for surface or back-protective can be enumerated.If according to material classification, then the layer formed by uv curing resin, the layer formed by thermosetting resin, the layer formed by vistanex, the layer formed by carboxyl acid modified vistanex, the layer formed by fluorine resin, the layer formed by cyclic olefin (being total to) polymer, the layer etc. that formed by inorganic compound can be enumerated.

The layer formed by the solar cell sealing material of present embodiment and the position relationship of other layer are not particularly limited, and suitably select preferred layer to form according to the relation with object of the present invention.That is, other layer can be arranged between more than the 2 layers layers formed by solar cell sealing material, also can be arranged on the outermost layer of solar cell sealing material sheet, can also be arranged on place in addition.In addition, only other layer can be set in the one side of the layer formed by solar cell sealing material, also other layer can be set on two sides.The number of plies of other layer is not particularly limited, and can arrange other layer of the arbitrary number of plies, also can not arrange other layer.

The viewpoint reduced costs from making structure simple, and do one's utmost reduce boundary reflection and effectively utilize the considerations such as the viewpoint of light, other layer is not set and only makes solar cell sealing material sheet with the layer that the solar cell sealing material by present embodiment is formed.But, if there is other necessary or useful layer according to the relation with object, as long as then suitably arrange other such layer.For the laminating method of the layer formed by the solar cell sealing material of present embodiment when arranging other layer and other layer, be not particularly limited, but be preferably known melt extruder coextrusion such as using cast molding machine, extrudate piece forming machine, inflation forming machine, injection (mo(u)lding) machine and obtain the method for laminated body, or on one deck shaping in advance melting or another layer of heated lamination and obtain the method for laminated body.In addition, can by employing suitable bonding agent (such as, maleic anhydride modified vistanex (the trade name " ADOMER (registered trade mark) " of Mitsui Chemicals, Inc., the trade name " MODIC (registered trade mark) " etc. of Mitsubishi Chemical Ind), unsaturated polyolefin etc. low (non-) crystallinity soft polymer, with the acrylic acid series bonding agent that ethene/acrylic ester/maleic anhydride terpolymer (trade name " Bondine (registered trade mark) " etc. of Zhu Hua CdF chemical company) is representative, Ethylene/vinyl acetate based copolymer, or comprise their adhesive resin composition etc.) dry lamination method or lamination methods etc. carry out lamination.As bonding agent, preferably use the bonding agent with the thermal endurance of about 120 ~ 150 DEG C, Polyester or urethane adhesive etc. can be illustrated as the bonding agent be applicable to.In addition, in order to improve two-layer cementability, such as, silane system coupling processing, titanium system coupling processing, corona treatment, plasma treatment etc. can be used.

2. about solar module

Solar module, can enumerate such as, is usually clamped by the solar cell device solar cell sealing material sheet formed by polycrystal silicon etc. and lamination, and then by crystal type solar module that two sides in table covers with screening glass.That is, typical solar module is the such formation of solar module screening glass (face side transparent protection member)/solar cell sealing material/solar cell device/solar cell sealing material/solar module screening glass (rear side protection component).But, as the solar module one of preferred embodiment of present embodiment, be not limited to above-mentioned formation, in the scope not damaging object of the present invention, suitably can omit a part for above-mentioned each layer, or layer other than the above is suitably set.As layer other than the above, such as adhesive linkage, impact absorbing layer, coating layer, anti-reflection layer, back side reflector and light diffusion layer etc. again can be enumerated.These layers are not particularly limited, but can consider to arrange the object of each layer, characteristic and arranging in position.

(solar module of crystalline silicon)

Fig. 1 is the sectional view of the execution mode schematically showing solar module of the present invention.In addition, in FIG, an example of the formation of the solar module 20 of crystalline silicon is shown.As shown in Figure 1; solar module 20 has the solar cell device 22 of the multiple crystalline silicon be electrically connected by interconnector 29, a pair face side transparent protection member 24 clamping this solar cell device 22 and rear side protection component 26, between these protection component and multiple solar cell devices 22, be filled with sealant 28.Sealant 28 is by after the sealing material laminating used for solar batteries making present embodiment, adds thermo-compressed and obtains, connecting with the electrode of the sensitive surface and the back side that are formed at solar cell device 22.So-called electrode is the collector component formed respectively at sensitive surface and the back side of solar cell device 22, comprises current collection line described later, attached lug bus and back electrode layer etc.

Fig. 2 is the plane graph schematically showing the sensitive surface of solar cell device and a configuration example at the back side.In fig. 2, an example of the sensitive surface 22A of solar cell device 22 and the formation of back side 22B is shown.As shown in Fig. 2 (A), at the sensitive surface 22A of solar cell device 22, be formed with the many current collection lines 32 being formed as wire and collect electric charge with from current collection line 32 and attached lug bus (busbar) 34A be connected with interconnector 29 (Fig. 1).In addition, as shown in Fig. 2 (B), at the back side 22B of solar cell device 22, whole face is formed with conductive layer (backplate) 36, is formed thereon and collects electric charge and attached lug bus (busbar) 34B be connected with interconnector 29 (Fig. 1) from conductive layer 36.The live width of current collection line 32 is such as about 0.1mm; The live width of attached lug bus 34A is such as about 2 ~ 3mm; The live width of attached lug bus 34B is such as about 5 ~ 7mm.The thickness of current collection line 32, attached lug bus 34A and attached lug bus 34B is such as about 20 ~ 50 μm.

Current collection line 32, attached lug bus 34A and attached lug bus 34B preferably comprise the high metal of conductivity.Comprise gold, silver, copper etc. in the example of the metal that such conductivity is high, but from considerations such as conductivity, aspects that corrosion resistance is high, be preferably silver, silver compound, containing silver-colored alloy etc.Conductive layer 36 not only comprises the high metal of conductivity, and makes the photoelectric conversion efficiency of solar cell device improve the considerations such as such viewpoint from the light reflection made suffered by sensitive surface, also preferably comprises the high composition of light reflective, such as aluminium.Current collection line 32, attached lug bus 34A, attached lug bus 34B and conductive layer 36 are by after the conduction material coatings comprising the high metal of above-mentioned conductivity is become the coating thickness of 50 μm by such as screen painting by the sensitive surface 22A of solar cell device 22 or back side 22B, drying, is formed at such as 600 ~ 700 DEG C of sintering as required.

Face side transparent protection member 24, owing to being configured in sensitive surface side, therefore needs for transparent.In the example of face side transparent protection member 24, comprise transparency glass plate, transparent resin film etc.On the other hand, rear side protection component 26 does not need for transparent, and its material is not particularly limited.In the example of rear side protection component 26, comprise glass substrate, plastic film etc., but from the viewpoint of durability, the transparency, be applicable to using glass substrate.

Solar module 20 can be obtained by arbitrary manufacture method.Solar module 20, such as, can be obtained by following operation: obtain by the operation of rear side protection component 26, solar cell sealing material, multiple solar cell device 22, solar cell sealing material and face side the transparent protection member 24 successively laminated body of lamination; This laminated body is carried out pressurization by laminating machine etc. makes it fit, the operation simultaneously heated as required; After above-mentioned operation, and then as required heat treated is carried out to laminated body, by the operation that above-mentioned sealing material is solidified.

In solar cell device, be usually configured with the collecting electrodes of the electricity for taking out generation.In the example of collecting electrodes, comprise bus bar electrode, finger electrode etc.Generally speaking, collecting electrodes can adopt the structure being configured in the surface of solar cell device and the two sides at the back side, if but at sensitive surface configuration collecting electrodes, then because collecting electrodes covers light, therefore may produce the such problem of decrease of power generation.

In addition, in order to make generating efficiency improve, the back contacted solar cell element do not needed at sensitive surface configuration collecting electrodes can be used.In a form of back contacted solar cell element, in the rear side set by the opposition side of the sensitive surface of solar cell device, be arranged alternately p doped region and n doped region.In other form of back contacted solar cell element, in the substrate being provided with through hole (through hole), form p/n engage, form the doped layer of (sensitive surface) side, surface until the bore periphery portion of through-hole wall and rear side, the electric current of sensitive surface is taken out in side overleaf.

Generally speaking, in solar cell system, above-mentioned solar module is connected in series several to tens of, even the small-scale system of house is also used with 50V ~ 500V, uses with 600 ~ 1000V in the large-scale system being called as large-sized solar generating.For the housing of solar module, use aluminium chassis etc. for the purpose of intensity maintenance etc., the situation that from the viewpoint of in safety, aluminium chassis is grounded (earth) is many.Consequently, by solar cell power generation, between the face side transparent protection member face low with sealing material phase ratio resistance and solar cell device, produce by the voltage difference caused that generates electricity.

Consequently, for the solar cell sealing material be sealed between generator unit and face side transparent protection member or aluminium chassis, the electrical characteristic that high electrical insulating property, high resistance etc. are good is required.

(solar module of thin film silicon system (amorphous silicon system))

The solar module of thin film silicon system can be, (1) is by the module of face side transparent protection member (glass substrate)/Thinfilm solar cell component/sealant/rear side protection component successively lamination; (2) by the module etc. of face side transparent protection member/sealant/Thinfilm solar cell component/sealant/rear side protection component successively lamination.Face side transparent protection member, rear side protection component and sealant same with the situation of above-mentioned " solar module of crystalline silicon ".

(1) Thinfilm solar cell component in form such as comprises transparent electrode layer/pin type silicon layer/back electrode layer successively.In the example of transparent electrode layer, comprise In ₂o ₃, SnO ₂, ZnO, Cd ₂snO ₄, ITO is (at In ₂o ₃in with the addition of Sn and obtain) etc. semiconductor system oxide.Back electrode layer comprises such as Ag films layer.Each layer is by plasma CVD (chemical vapour deposition (CVD)) method, sputtering method and being formed.Sealant configures in the mode connected with back electrode layer (such as Ag films layer).Because transparent electrode layer is formed on face side transparent protection member, therefore sealant is not often configured between face side transparent protection member and transparent electrode layer.

(2) metal film layer (such as, Ag films layer) that the Thinfilm solar cell component of form comprises such as transparent electrode layer/pin type silicon layer/metal forming successively or is configured on thermal endurance polymeric membrane.In the example of metal forming, comprise stainless steel steel foil etc.In the example of thermal endurance polymeric membrane, comprise polyimide film etc.Transparent electrode layer and pin type silicon layer are formed by CVD, sputtering method as described above.That is, the pin type silicon layer metal film layer that is formed at metal forming or configures on thermal endurance polymeric membrane; And then transparent electrode layer is formed at pin type silicon layer.In addition, the metal film layer be configured on thermal endurance polymeric membrane also can be formed by CVD, sputtering method.

In this case, sealant is configured between transparent electrode layer and face side transparent protection member respectively; And metal forming or thermal endurance polymeric membrane and rear side are protected between component.Like this, the sealant obtained by solar cell sealing material connects with the electrode of the current collection line of solar cell device, attached lug bus and conductive layer etc.In addition, the Thinfilm solar cell component of the form of (2), because silicon layer is thinner than the solar cell device of crystalline silicon, therefore not easily damaged due to the impact from outside when pressurization when solar module manufactures, above-mentioned module work.Therefore, compared with used with the solar module of crystalline silicon, the flexibility of the solar cell sealing material that film solar battery module is used can be low.On the other hand, the electrode due to above-mentioned Thinfilm solar cell component is metal film layer as described above, and therefore when due to corrosion when deterioration, generating efficiency may significantly reduce.

In addition, as other solar module, the solar module employing silicon in solar cell device is had.Employ in solar cell device in the solar module of silicon, mixed type (HIT type) solar module by silicon metal and amorphous silicon lamination can be enumerated, by many maqting types (tandem type) solar module of silicon layer laminations different for absorbing wavelength region, rear side set by the opposition side of the sensitive surface of solar cell device is alternately provided with the back contacted solar cell module of p doped region and n doped region, by the spherical silicon type solar module etc. that countless spherical silicon particle (diameter about 1mm) combines with the concave mirror (doubling as electrode) of the diameter 2 ~ 3mm improving light gathering.In addition, employing in solar cell device in the solar module of silicon, also can enumerating the field effect type solar module etc. with the structure effect with the p-type window layer of the amorphous silicon type of pin connected structure being in the past replaced as " inversion layer brought out by field effect " by " transparency electrode by having insulated ".In addition, the GaAs system solar module of the GaAs employing monocrystalline in solar cell device can be enumerated; As solar cell device, replace silicon and employ the CIS being called as the I-III-VI group compound of chalcopyrite system or CIGS (chalcopyrite system) solar module that are made up of Cu, In, Ga, Al, Se, S etc.; Employ CdTe-CdS system solar cell, the Cu of Cd compound film as solar cell device ₂znSnS ₄(CZTS) solar module etc.The solar cell sealing material of present embodiment can be used as the solar cell sealing material of these all solar modules.Wherein, many maqting types (tandem type) of the silicon layer that lamination has mixed type (HIT type) solar module of silicon metal and amorphous silicon, lamination has absorbing wavelength region different can be suitable for.

Particularly, be stacked in the sealing sheet material layers under the photovoltaic cell forming solar module, need that there is the cementability with the sealing sheet material layers on the top being stacked in photovoltaic cell, electrode, back-protective layer.In addition, in order to keep the flatness at the back side of the solar cell device as photovoltaic cell, need that there is thermoplasticity.In addition, in order to protect the solar cell device as photovoltaic cell, the excellence such as marresistance, impact absorbency is needed.

As above-mentioned sealing sheet material layers, preferably there is thermal endurance.When manufacturing particularly preferably in solar module, can not owing to vacuumizing and adding the Long-Time Service of the heat effect, solar module etc. in laminating of thermo-compressed etc. time the heat effect etc. of sunlight etc., and the resin combination making formation seal sheet material layers goes bad, or deteriorated or decomposition.Suppose the strippings such as the additive that this resin combination comprises or generate analyte, then they will act on the electromotive force face (component side) of solar cell device, make its deterioration such as function, performance.Therefore, the characteristic that thermal endurance has as the sealing sheet material layers of solar module is absolutely necessary.

In addition, the preferred moisture resistance of above-mentioned sealing sheet material layers is excellent.In this case, can prevent the moisture of the rear side from solar module through, can prevent the photovoltaic cell of solar module burn into deterioration.

Above-mentioned sealing sheet material layers is different from the filling oxidant layer be stacked on photovoltaic cell, does not need necessarily have the transparency.The solar cell sealing material of present embodiment has above-mentioned characteristic, can be suitable as the solar cell sealing material of thin film solar cell module of the solar cell sealing material of the rear side of crystal type solar module, not resistance to moisture penetration.

The solar module of present embodiment, in the scope not damaging object of the present invention, can suitably have arbitrary component.Typically, adhesive linkage, impact absorbing layer, coating layer, anti-reflection layer, back side reflector, light diffusion layer etc. again can be set, but be not limited to these.The position arranging these layers is not particularly limited, and can consider to arrange the object of such layer and the characteristic of such layer, arranges in position.

(solar module face side transparent protection member)

The solar module face side transparent protection member that solar module is used; be not particularly limited; but owing to being positioned at the outermost layer of solar module; therefore preferably have with weatherability, water-repellancy, stain resistance, mechanical strength for representative, for guaranteeing the performance of the long-term reliability of solar module when outdoor exposure.In addition, in order to effectively utilize sunlight, be preferably optical loss little, the high sheet of the transparency.

As the material of solar module with face side transparent protection member, the resin molding, glass substrate etc. that are formed by mylar, fluororesin, acrylic resin, cyclic olefin (being total to) polymer, vinyl-vinyl acetate copolymer etc. can be enumerated.Resin molding is preferably the mylar, particularly pet resin of excellence in the transparency, intensity, cost etc., fluororesin etc. that weatherability is good.As the example of fluororesin, there are tetrafluoroethylene-ethylene copolymer (ETFE), polyfluoroethylene resin (PVF), polyvinylidene fluoride resin, polyflon (PTFE), tetrafluoraoethylene-hexafluoropropylene copolymer (FEP), poly-borontrifluoride ethylene chloride resin (PCTFE).From the viewpoint of weatherability, polyvinylidene fluoride resin is excellent, but from having weatherability and mechanical strength consideration concurrently, tetrafluoroethylene-ethylene copolymer is excellent.In addition, in order to the cementability improved with form the material sealing other layers such as sheet material layers, preferably corona treatment, plasma treatment are carried out to face side transparent protection member.In addition, also the sheet implementing stretch processing in order to improve mechanical strength can be used, such as biaxial stretch-formed polypropylene foil.

When as solar module with face side transparent protection member use glass substrate, the full light transmittance of wavelength 350 ~ 1400nm light of glass substrate is preferably more than 80%, is more preferably more than 90%.As above-mentioned glass substrate, general use the blank glass that the absorption in infrared portion is few, even but backboard glass, as long as to be below 3mm then few on the impact of the output characteristic of solar module for thickness.In addition, in order to improve the mechanical strength of glass substrate, tempered glass can be obtained by heat treatment, but also can use without heat treated kickboard glass.In addition, in order to the sensitive surface lateral inhibition at glass substrate is reflected, the coating of antireflection can also be carried out.

(solar module rear side protects component)

Solar module solar module rear side used protects component; be not particularly limited; but owing to being positioned at the outermost layer of solar module, therefore require each characteristic such as weatherability, mechanical strength in the same manner as above-mentioned face side transparent protection member.Therefore, solar module rear side can be made up of the material same with face side transparent protection member and protect component.That is, rear side protection component also can be used as face side transparent protection member and the above-mentioned various materials that use.Especially, mylar and glass can preferably be used.In addition, rear side protection component, due to not premised on the passing through of sunlight, therefore not necessarily requires the transparency required in face side transparent protection member.Therefore, in order to strengthen the mechanical strength of solar module, or in order to prevent from being caused by variations in temperature distortion, warpage, can reinforcement plate be puted up.Reinforcement plate preferably can use such as steel plate, plastic plate, FRP (fiberglass-reinforced plastic) plate etc.

In addition, the solar cell sealing material of present embodiment can protect component integrated with solar module rear side.By making solar cell sealing material and solar module rear side protect component integrated, the operation when module assembled, solar cell sealing material and solar module rear side protection component being cut into module size can be shortened.In addition, by making to be by the superimposed operation of integrated sheet by the operation that solar cell sealing material and solar module rear side protect component superimposed respectively, also can shorten, omitting superimposed operation.When making solar cell sealing material and solar module rear side protect component integrated, solar cell sealing material and solar module rear side protect the laminating method of component, are not particularly limited.In laminating method, be preferably known melt extruders such as using cast molding machine, extrudate piece forming machine, inflation forming machine, injection (mo(u)lding) machine and carry out coextrusion and obtain the method for laminated body; Melting or another layer of heated lamination on shaping in advance one deck and obtain the method for laminated body.

In addition, also can by employing suitable bonding agent (such as, maleic anhydride modified vistanex (the trade name " ADOMER (registered trade mark) " of Mitsui Chemicals, Inc., the trade name " MODIC (registered trade mark) " etc. of Mitsubishi Chemical Ind), unsaturated polyolefin etc. low (non-) crystallinity soft polymer, with the acrylic acid series bonding agent that ethene/acrylic ester/maleic anhydride terpolymer (trade name " Bondine (registered trade mark) " etc. of Zhu Hua CdF chemical company) is representative, Ethylene/vinyl acetate based copolymer, or comprise their adhesive resin composition etc.) dry lamination method or lamination methods etc. carry out lamination.

As bonding agent, preferably there is the bonding agent of the thermal endurance of about 120 ~ 150 DEG C, specifically, be preferably Polyester or urethane adhesive etc.In addition, in order to make the cementability of two layers improve, can at least one layer of embodiment as silane system coupling processing, titanium system coupling processing, corona treatment, plasma treatment etc.

(solar cell device)

As long as solar module solar cell device used can utilize the photovoltaic effect of semiconductor and the module generated electricity, be then not particularly limited.Solar cell device can use such as silicon (monocrystalline system, many systems of crystallization, noncrystalline (amorphous) are) solar cell, compound semiconductor (III-III race, II-VI group, other) solar cell, wet type solar cell, organic semiconductor solar cell etc.Wherein, from the viewpoint of the balance etc. of power generation performance and cost, be preferably polycrystal silicon solar cell.

Silicon solar cell element, compound semiconductor solar cell device all have excellent characteristic as solar cell device, but are knownly easy to damaged because of the stress, impact etc. from outside.The solar cell sealing material of present embodiment, due to flexibility excellence, therefore absorbs the stress to solar cell device, impact etc., prevents the effect of the breakage of solar cell device large.Therefore, in the solar module of present embodiment, the layer formed by the solar cell sealing material of present embodiment preferably directly engages with solar cell device.In addition, if solar cell sealing material has thermoplasticity, even if then once after making solar module, also can take out solar cell device with comparalive ease, therefore recirculation is excellent.Because the vinylite composition of the solar cell sealing material forming present embodiment has thermoplasticity, therefore also having thermoplasticity as solar cell sealing material entirety, is also preferred from the viewpoint of recirculation.

(metal electrode)

The formation of the metal electrode that solar module is used and material, be not particularly limited, but in concrete example, have the laminated construction of nesa coating and metal film.Nesa coating is by SnO ₂, the formation such as ITO, ZnO.Metal film is formed by the metal such as silver, gold, copper, tin, aluminium, cadmium, zinc, mercury, chromium, molybdenum, tungsten, nickel, vanadium.These metal films can be used alone, also can alloy as Composite and using.Nesa coating and metal film are formed by methods such as CVD, sputtering, evaporations.

About metal electrode, such as following method can be enumerated: use the IPA (isopropyl alcohol) of usual well-known rosin series solder flux, water soluble flux, the aqueous solution of water, after electrode surface coating solder flux, drying is carried out with heater, warm braw, then the solder passed into solder fusing groove has melted melts liquid, at the surface-coated solder of metal electrode, then heat and solar cell device and metal electrode or metal electrode carried out each other the method that engages.In recent years, also adopt and be directly coated with solder flux and solder at bonding station or be only coated with solder, solar cell device and metal electrode or metal electrode are carried out each other the method engaged.

(manufacture method of solar module)

The feature of the manufacture method of the solar module of present embodiment is; comprise following operation: the solar cell sealing material of face side transparent protection member, present embodiment, solar cell device (unit), solar cell sealing material and rear side protection component successively lamination is formed the operation of laminated body by (i), and the laminated body of gained is pressurizeed and heats and the operation of integration by (ii).

In operation (i), the mode preferably becoming solar cell device side with the face being formed with concaveconvex shape (embossed shapes) of solar cell sealing material configures.

In operation (ii), conventionally use vacuum laminator or hot press, the laminated body obtained is heated and pressurize and integration (sealing) in operation (i).In sealing, because the resiliency of the solar cell sealing material of present embodiment is high, therefore can prevent the damage of solar cell device.In addition, because out gassing is good, therefore there is no being involved in of air yet, rate of finished products can manufacture the goods of high-quality well.

When manufacturing solar module, make the ethene-alpha-olefin based resin composition crosslinking curing of formation solar cell sealing material.This cross-linking process step can carry out with operation (ii) simultaneously, also can carry out after operation (ii).

When carrying out cross-linking process step after operation (ii), in operation (ii), temperature 125 ~ 160 DEG C, vacuum pressure 10 to hold in the palm under following condition heating in vacuum 3 ~ 6 minutes; Then, the pressurization under the atmospheric pressure of about 1 ~ 15 minute is carried out, by above-mentioned laminated body integration.The cross-linking process step carried out after operation (ii) can be undertaken by general method, such as, the continous way of tunnel type can be used to be cross-linked stove, board-like batch (-type) also can be used to be cross-linked stove.In addition, cross linking conditions is generally and carries out about 20 ~ 60 minutes at 130 ~ 155 DEG C.

On the other hand, when carrying out cross-linking process step with operation (ii) simultaneously, the heating-up temperature in operation (ii) is made to be 145 ~ 170 DEG C, make be 6 ~ 30 minutes the pressing time under atmospheric pressure, in addition can with operate in the same manner as carrying out the situation of cross-linking process step after operation (ii) and carry out.The solar cell sealing material of present embodiment is by having excellent crosslinking feature containing specific organic peroxide, the bonding process through the two-stage is not needed in operation (ii), can at high temperature terminate at short notice, the cross-linking process step carried out after can being omitted in operation (ii), can improve the productivity of module significantly.

In any case; the manufacture of the solar module of present embodiment; as long as not decompose on Low molecular weight and in the such temperature of the solar cell sealing material melting of present embodiment; temporary bond solar cell sealing material on solar cell device, protection material, then heats up and carries out the crosslinked of bonding and sealing material fully.Selection can meet the such additive formulations of each condition, such as, as long as select kind and the impregnation amount of above-mentioned crosslinking agent and above-mentioned crosslinking coagent etc.

In addition, the above-mentioned crosslinked gel fraction preferably proceeding to the ethene-alpha-olefin copolymer after being cross-linked becomes the degree of 50 ~ 95%.Gel fraction is more preferably 50 ~ 90%, and more preferably 60 ~ 90%, most preferably be 65 ~ 90%.Calculating of gel fraction can be undertaken by following method.Such as, take the sample 1g of sealing material sheet from solar module, the Soxhlet carried out in boiling toluene extracts 10 hours.Extract 30 order stainless (steel) wires are filtered, net is carried out 8 hours drying under reduced pressure at 110 DEG C.Measure the weight remaining in online remnant, the weight remaining in online remnant is set to gel fraction relative to the ratio (%) of sample size before treatment (1g).

If above-mentioned gel fraction is more than above-mentioned lower limit, then the thermal endurance of solar cell sealing material becomes good, can suppress the reduction of the high strength xenon exposure experiment of the constant temperature and moisture test of such as 85 DEG C × 85%RH, black dish temperature 83 DEG C, the thermal cycling test of-40 DEG C ~ 90 DEG C, the cementability in heat resistant test.On the other hand, if gel fraction is below above-mentioned higher limit, then become the solar cell sealing material with high flexibility, the temperature tracing ability in the thermal cycling test of-40 DEG C ~ 90 DEG C improves, and therefore can prevent to peel off.

(generating equipment)

The excellence such as productivity, generating efficiency, life-span of the solar module of present embodiment.Therefore, employ the excellences such as the cost of the generating equipment of such solar module, generating efficiency, life-span, there is practical high value.Above-mentioned generating equipment, outdoor, be all applicable to Long-Time Service within doors, be such as arranged at the roof in house, utilize as the portable power source towards outdoor activities such as camping, the utilization etc. as the accessory power supply of automobile batteries group.

Embodiment

Below, specifically describe the present invention based on embodiment, but the present invention is not limited to these embodiments.

(1) assay method

[ethylene unit and alpha-olefin unit containing proportional]

After filtering making sample 0.35g heating for dissolving and solution glass filter (G2) of obtaining in hexachlorobutadiene 2.0ml, adding deuterated benzene 0.5ml, loading in the NMR pipe of internal diameter 10mm.Use the JNM GX-400 type NMR determinator of NEC Inc., carry out at 120 DEG C ¹³c-NMR measures.Cumulative number is more than 8000 times.According to gained ¹³c-NMR spectrum, containing of the ethylene unit in quantitative copolymer is proportional proportional with containing of alpha-olefin unit.

[MFR]

According to ASTM D1238,190 DEG C, measure the MFR of ethene-alpha-olefin copolymer under the condition of 2.16kg loading.

[density]

According to ASTM D1505, measure the density of ethene-alpha-olefin copolymer.

[Xiao A hardness]

By ethene-alpha-olefin copolymer 190 DEG C of heating 4 minutes, after 10MPa pressurization, pressurize cooling 5 minutes until normal temperature and obtain the thick sheet of 3mm with 10MPa.Use the sheet of gained, according to ASTMD2240, measure the Xiao A hardness of ethene-alpha-olefin copolymer.

[weathering test]

After the sheet of gained being cut into the size of 12cm × 7.5cm, not there is in the scope being used in wavelength 350 ~ 800nm the blank glass (thickness 3.2mm) absorbing territory, according to the sheet sample of the solar cell sealing material of the order laminated thickness 500 μm of blank glass/solar cell sealing material/blank glass on this blank glass, with 150 DEG C, vacuum 5 minutes, pressurization crimp with laminater (NPC society system, LM-110X160S) lamination for 5 minutes.Then, keep 45 minutes in the baking oven of 150 DEG C, produce laminated body.

Next, for above-mentioned laminated body, use the promotion weathering test machine (KU-R5NW, Daipla Wintes society system) using metal halide lamp as light source, in the air of temperature 80 DEG C, the uitraviolet intensity irradiated under 300 ~ 400nm is 1000W/m ²ultraviolet take out after 250 hours.

During the transparency is evaluated, for the accelerated test sample of gained, the spectrophotometer (trade name " U-3010 ") being used in Inc. of Hitachi is provided with the spectrophotometer of the integrating sphere of φ 150mm, measures the full light transmittance of light splitting of in the wavelength region may of 350 ~ 800nm, in above-mentioned laminated body sheet sample.And, measurement result is multiplied by standard light D65 and standard luminescent efficiency V (λ), calculates the full light transmittance (Tvis) of visible ray.

Evaluate the difference of the transmissivity before and after the test under the 450nm of the laminated body of gained.

Zero: the difference of transmissivity is less than 5%

△: the difference of transmissivity is more than 5% and be less than 8%

×: the difference of transmissivity is more than 8%

(2) synthesis of ethene-alpha-olefin copolymer

(synthesis example 1)

Possessing the supply port of continuous polymerization device of internal volume 50L of agitator using the supply of the ratio of 8.0mmol/hr as the toluene solution of the methylaluminoxane of co-catalyst, using the supply of the ratio of 0.025mmol/hr as two (1 of major catalyst, 3-dimethylcyclo-pentadienyl) the hexane slurry of zirconium dichloride, with the hexane solution of the ratio of 0.5mmol/hr supply triisobutyl aluminium, using use as catalyst solution and polymer solvent, dehydration refining after the total of the n-hexane mode that becomes 20L/hr supply continuously dehydration refining after n-hexane.Supply ethene continuously with the ratio of 3kg/hr at other supply port of polymerizer, supply 1-butylene with the ratio of 15kg/hr continuously, supply hydrogen continuously with the ratio of 5NL/hr simultaneously, polymerization temperature 90 DEG C, total pressure 3MPaG, carries out continuous solution polymerization under the condition of 1.0 hours residence times.N-hexane/the toluene mixed solution of the ethene-alpha-olefin copolymer generated in polymerizer is discharged continuously via the outlet be arranged at bottom polymerizer, imports to chuck portion with 3 ~ 25kg/cm ²in the tube connector be heated by steam, become 150 ~ 190 DEG C to make the n-hexane/toluene mixed solution of ethene-alpha-olefin copolymer.

In addition, before being about to arrive tube connector, setting up the supply port for injecting the methyl alcohol as catalysqt deactivation agent, injecting methyl alcohol and the n-hexane/toluene mixed solution collaborated in ethene-alpha-olefin copolymer with the speed of about 0.75L/hr.At the tube connector inside holding of carrying vapour chuck at the n-hexane/toluene mixed solution of the ethene-alpha-olefin copolymer of about 190 DEG C, the aperture being arranged at the pressure-control valve of tube connector terminal part by adjustment makes it maintain about 4.3MpaG, thus is transported to continuously in flash tank.In addition, in the transfer in flash tank, carry out solution temperature and the setting of pressure adjusting valve opening, maintain about 180 DEG C with the temperature making the pressure in flash tank maintain the steam portion in about 0.1MPaG, flash tank.Then, by by the single axle extruding machine of die temperature in 180 DEG C, with tank cooling line material, with particle pelleter cutting line material, ethene-alpha-olefin copolymer is obtained as particle.Output is 2.2kg/hr.Physical property is shown in Table 1.

(synthesis example 2)

Respectively using the supply of the ratio of 0.012mmol/hr as the hexane solution of [dimethyl (tert-butylamides) (tetramethyl-η 5-cyclopentadienyl group) silane] titanium chloride of major catalyst, using the supply of the ratio of 0.05mmol/hr as the triphenylcarbenium of co-catalyst the toluene solution of (four pentafluorophenyl groups) borate, with the hexane solution of the ratio of 0.4mmol/hr supply triisobutyl aluminium, and with the ratio of 5kg/hr supply 1-butylene, with the ratio of 100NL/hr supply hydrogen, operate in the same manner as above-mentioned synthesis example 1 in addition and obtain ethene-alpha-olefin copolymer.Output is 1.3kg/hr.Physical property is shown in Table 1.

(synthesis example 3)

Two (p-methylphenyl) methylene (cyclopentadienyl group) respectively using the supply of the ratio of 0.003mmol/hr as major catalyst (1, Isosorbide-5-Nitrae, 4,7,7,10,10-prestox-1,2,3,4,7,8,9,10-octahydro dibenzo (b, h)-fluorenyl) hexane solution of zirconium dichloride, using the supply of the ratio of 3.0mmol/hr as the toluene solution of the methylaluminoxane of co-catalyst, with the hexane solution of the ratio of 0.6mmol/hr supply triisobutyl aluminium; With the ratio of 4.3kg/hr supply ethene; Replace 1-butylene and supply 1-octene with the ratio of 6.4kg/hr; The mode that the total of the n-hexane after refining using 1-octene and the dehydration that uses as catalyst solution and polymer solvent becomes 20L/hr supply continuously dehydration refining after n-hexane; With the ratio of 40NL/hr supply hydrogen; And make polymerization temperature be 130 DEG C, operate in the same manner as synthesis example 1 in addition and obtain ethene-alpha-olefin copolymer.Output is 4.3kg/hr.Physical property is shown in Table 1.

[table 1]

	Synthesis example 1	Synthesis example 2	Synthesis example 3
				The kind of alpha-olefin	1-butylene	1-butylene	1-octene
Alpha-olefin unit containing proportional [mol%]	14	17	11
				Ethylene unit containing proportional [mol%]	86	83	89
MFR [g/10 minute]	20	11	48
				Shore A Hardness [-]	70	62	84
Density [g/cm ³]	0.870	0.886	0.884

(3) manufacture of solar cell sealing material (sheet)

(embodiment 1)

Relative to ethene-alpha-olefin copolymer 100 weight portion of synthesis example 1, 1 minute half life temperature as organic peroxide has been coordinated to be tert-butyl hydroperoxide-2-ethylhexyl carbonate 1.0 weight portion of 166 DEG C, as the 2-(2H-1 of BTA system ultra-violet absorber, 2, 3-BTA-2-base)-6-dodecyl-4-methylphenol 0.3 weight portion, as 3-methacryloxypropyl trimethoxy silane 0.5 weight portion of silane coupler, as cyanacrylate 1.2 weight portion of crosslinking coagent, as two (2 of hindered amine system light stabilizer, 2, 6, 6-tetramethyl-4-piperidyl) sebacate 0.2 weight portion, as the octadecyl-3-(3 of hindered phenol system stabilizer, 5-di-tert-butyl-hydroxy phenyl) propionic ester 0.05 weight portion, as three (2 of phosphorus system stabilizer, 4-di-tert-butyl-phenyl) phosphite ester 0.1 weight portion.

At single axle extruding machine (the screw diameter 20mm φ of Thermo plastic Inc., L/D=28) the upper installation T-shaped die head of rack-style (die lip shape: 270 × 0.8mm), under the condition of die head temperature 100 DEG C, with roll temperature 30 DEG C, winding speed 1.0m/min, chill roll uses dandy roll to carry out shaping, obtains the embossing sheet (solar cell sealing material sheet) of maximum ga(u)ge 500 μm.The voidage of the sheet of gained is 28%.The various evaluation results of the sheet of gained are shown in Table 2.

(embodiment 2 ~ 4)

Be set to the cooperation shown in table 2, in addition, operate in the same manner as the above embodiments 1 and obtain embossing sheet (solar cell sealing material sheet).The voidage of the sheet of gained is all 28%.The various evaluation results of the sheet of gained are shown in Table 2.

(comparative example 1)

[table 2]

Ultra-violet absorber 1:2-(2H-1,2,3-BTA-2-base)-6-dodecyl-4-methylphenol

Ultra-violet absorber 2:2-(2H-1,2,3-BTA-2-base)-4,6-di-tert-pentyl phenols

Ultra-violet absorber 3:2,2 '-di-2-ethylhexylphosphine oxide [6-(2H-1,2,3-BTA-2-base)-4-(1,1,3,3-tetramethyl butyl) phenol]

Ultra-violet absorber 4:2-hydroxyl-4-n-octyl oxygen base benzophenone

The application advocates that the Japanese patent application laid proposed by June 19th, 2012 is willing to the priority based on 2012-138261, its whole disclosure is incorporated into herein.

Claims

1. a solar cell sealing material, is characterized in that, is the solar cell sealing material comprising ethene-alpha-olefin copolymer, organic peroxide and ultra-violet absorber,

Described ultra-violet absorber is the BTA system ultra-violet absorber shown in following general formula (1) or (2),

In formula, R ₁represent the alkyl of hydrogen atom or carbon number 1 ~ 6, R ₂~ R ₄can be the same or different, represent the alkyl of hydrogen atom, carbon number 1 ~ 20, hydroxyl, the alkoxyl of carbon number 1 ~ 22 or the alkyloxycarbonyl of carbon number 1 ~ 22,

In formula, R ₁represent the alkyl of hydrogen atom or carbon number 1 ~ 6, R ₅~ R ₈can be the same or different, represent the alkyl of hydrogen atom, carbon number 1 ~ 20, hydroxyl, the alkoxyl of carbon number 1 ~ 22 or the alkyloxycarbonyl of carbon number 1 ~ 22.

2. solar cell sealing material according to claim 1, is characterized in that, in described general formula (1), and R ₁represent hydrogen atom, R ₂~ R ₄mutual difference.

3. solar cell sealing material according to claim 1, is characterized in that, in described general formula (2), and R ₁represent hydrogen atom, R ₅with R ₈identical, R ₆with R ₇identical.

4. solar cell sealing material according to claim 1, the content of described ultra-violet absorber is 0.05 ~ 5.0 weight portion relative to described ethene-alpha-olefin copolymer 100 weight portion.

5. solar cell sealing material according to claim 1, described ethene-alpha-olefin copolymer meets following important document a1) ~ a4),

A1) derive from the Component units of ethene containing proportional be 80 ~ 90mol%, derive from the Component units of the alpha-olefin of carbon number 3 ~ 20 containing proportional be 10 ~ 20mol%;

A2) according to ASTM D1238,190 DEG C, to measure the MFR obtained under the condition of 2.16kg loading be 10 ~ 50g/10 minute;

A3) measuring according to ASTM D1505 the density obtained is 0.865 ~ 0.884g/cm ³;

A4) measuring according to ASTM D2240 the Xiao A hardness obtained is 60 ~ 85.

6. solar cell sealing material according to claim 1, according to ASTM D1238,190 DEG C, the MFR that measures the described ethene-alpha-olefin copolymer obtained under the condition of 2.16kg loading is 10 ~ 27g/10 minute.

7. solar cell sealing material according to claim 1,1 minute half life temperature of described organic peroxide is 100 ~ 170 DEG C, and the content of described organic peroxide is 0.1 ~ 3 weight portion relative to described ethene-alpha-olefin copolymer 100 weight portion.

8. solar cell sealing material according to claim 1, relative to described ethene-alpha-olefin copolymer 100 weight portion, comprises silane coupler 0.1 ~ 5 weight portion further.

9. solar cell sealing material according to claim 1, relative to described ethene-alpha-olefin copolymer 100 weight portion, comprises hindered phenol system stabilizer 0.005 ~ 0.1 weight portion further.

10. solar cell sealing material according to claim 1, relative to described ethene-alpha-olefin copolymer 100 weight portion, comprises hindered amine system light stabilizer 0.01 ~ 2.0 weight portion further.

11. solar cell sealing materials according to claim 1, relative to described ethene-alpha-olefin copolymer 100 weight portion, comprise phosphorus system stabilizer 0.005 ~ 0.5 weight portion further.

12. solar cell sealing materials according to claim 1, relative to described ethene-alpha-olefin copolymer 100 weight portion, comprise crosslinking coagent 0.05 ~ 5 weight portion further.

13. solar cell sealing materials according to claim 1, it is by by after described ethene-alpha-olefin copolymer, described organic peroxide and described ultra-violet absorber melting mixing, and sheet ground extrusion molding obtains.

14. solar cell sealing materials according to claim 1, it is sheet.

15. 1 kinds of solar modules, it possesses:

Face side transparent protection member,

Rear side protection component,

Solar cell device, and

Sealant, described sealant is formed by making solar cell sealing material according to claim 1 crosslinked, and described solar cell device is sealed in described face side transparent protection member and described rear side is protected between component.

16. solar modules according to claim 15, silicon metal and amorphous silicon lamination form by described solar cell device.