Crosslinking agent composition for olefin copolymer, encapsulant composition for optical element containing the same, and encapsulant film for optical element

Abstract

The present invention relates to a crosslinking agent composition for an olefin copolymer, a sealing material composition for an optical element, a sealing material film for an optical element, and an optoelectronic device. By applying the compound of Chemical Formula 1 as a crosslinking aid to the crosslinking agent composition for an olefin copolymer or the sealing material composition for an optical element containing an olefin copolymer, excellent productivity can be exhibited, and a sealing material composition for an optical element and a sealing material film for an optical element having a high volume resistivity and a high light transmittance can be produced.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0085135, filed on July 11, 2022, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a crosslinking agent composition for an olefin copolymer, a sealing material composition for an optical element containing the same, and a sealing material film for an optical element. The present invention relates to a crosslinking agent composition for an olefin copolymer used in a sealing material composition for an optical element containing an olefin copolymer, a sealing material composition for an optical element containing the crosslinking agent, a sealing material film for an optical element manufactured using the same, and an optical element module containing the sealing material film for an optical element.

Background Art

[0003] As problems related to the global environment and energy become increasingly serious, solar cells have attracted attention as a clean and inexhaustible energy generation means. When solar cells are used outdoors, such as on the roofs of buildings, they are generally used in the form of modules. When manufacturing a solar cell module, in order to obtain a crystalline solar cell module, a protective sheet for a solar cell module (transparent protective member on the front side) / solar cell encapsulant / crystalline solar cell element / crystalline solar cell element / solar cell encapsulant / protective sheet for a solar cell module (protective member on the back side) are laminated in this order. On the other hand, in order to obtain a thin-film solar cell module, a thin-film solar cell element / solar cell encapsulant / protective sheet for a solar cell module (protective member on the back side) are laminated in this order.

[0004] As the above-mentioned solar cell encapsulant, generally, ethylene / vinyl acetate copolymer, ethylene / α-olefin copolymer, etc. are used. In addition, since the solar cell encapsulant is required to have long-term weather resistance, a light stabilizer is usually included as an additive. Also, considering the adhesion of the transparent protective member on the front side and the protective member on the back side, which is typically glass, a silane coupling agent is usually included in the solar cell encapsulant.

[0005] Specifically, ethylene / vinyl acetate copolymer (EVA) sheets have been widely used because they are excellent in transparency, flexibility, adhesiveness, etc. Ethylene-vinyl acetate copolymer (EVA) films are widely used because they are excellent in transparency, flexibility, adhesiveness, etc. However, when an EVA composition is used as a constituent material of a solar cell encapsulant, there is concern that components such as acetic acid gas generated by the decomposition of EVA may affect the solar cell element.

[0006] Ethylene / α-olefin copolymer can solve the problems of reduced lifespan and reliability because there is no problem of resin hydrolysis. However, since ethylene / α-olefin copolymer does not contain a polar group in the resin, it is inferior in miscibility with the polar crosslinking aid conventionally contained in the constituent material of the solar cell encapsulant, and it requires a very long time for impregnation, so there has been a problem in productivity.

[0007] Thus, in a situation where it is necessary to develop a crosslinking aid that can improve the productivity of a solar cell encapsulant containing an ethylene / α-olefin copolymer that has an excellent volume resistivity and can be usefully utilized as a substance that requires high insulation such as a solar cell encapsulant.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0009] The problem to be solved by the present invention is to provide an olefin-based copolymer crosslinking agent composition for use in crosslinking an olefin-based copolymer, which contains a crosslinking aid having excellent miscibility with the olefin-based copolymer.

[0010] Another problem to be solved by the present invention is to provide a sealing material composition for an optical element, which contains a crosslinking aid having excellent miscibility with an olefin copolymer and exhibits a high volume resistivity and thus excellent insulation properties.

[0011] Still another problem to be solved by the present invention is to provide a sealing material film for an optical element produced using the above-described sealing material composition for an optical element.

[0012] Still another problem to be solved by the present invention is to provide an optoelectronic device including the above-described sealing material film for an optical element.

Means for Solving the Problems

[0013] In order to solve the above problems, the present invention provides a crosslinking agent composition for an olefin copolymer, a sealing material composition for an optical element, a sealing material film for an optical element, and an optoelectronic device.

[0014] [1] The present invention provides a crosslinking agent composition for an olefin copolymer containing a compound represented by the following Chemical Formula 1.

[0015]

Chemical Formula

[0016] In the Chemical Formula 1, R1 to R4 are each independently an alkyl having 1 to 20 carbon atoms or an alkenyl having 2 to 20 carbon atoms, where two or more of R1 to R4 are each independently an alkenyl having 2 to 20 carbon atoms.

[0017] [2] The present invention provides the crosslinking agent composition for an olefin copolymer according to [1], wherein R1 to R4 are each independently an alkenyl having 2 to 20 carbon atoms.

[0018] [3] The present invention provides a crosslinking agent composition for an olefin copolymer according to [1] or [2], wherein R1 to R4 are each independently an alkenyl having 2 to 8 carbon atoms with a double bond at the terminal.

[0019] [4] The present invention provides a crosslinking agent composition for an olefin copolymer according to any one of [1] to [3], wherein the crosslinking aid compound of Chemical Formula 1 is tetraallyloxysilane.

[0020] [5] The present invention provides a crosslinking agent composition for an olefin copolymer according to [4], further comprising a second crosslinking aid compound other than the crosslinking aid compound of Chemical Formula 1.

[0021] [6] The present invention provides a crosslinking agent composition for an olefin copolymer according to [5], wherein the weight ratio of the crosslinking aid compound of Chemical Formula 1 to the second crosslinking aid compound is 1:0.2 to 1:9.0.

[0022] [7] The present invention provides a crosslinking agent composition for an olefin copolymer according to [5] or [6], wherein the second crosslinking aid compound comprises one or more selected from the group consisting of triallyl isocyanurate, triallyl cyanurate, diallyl phthalate, diallyl fumarate, diallyl maleate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.

[0023] [8] The present invention provides a crosslinking agent composition for an olefin copolymer according to any one of [1] to [7], wherein the crosslinking agent is one or more selected from the group consisting of organic peroxides, hydroperoxides, and azo compounds.

[0024] [9] In the present invention, the crosslinking agent is one or more selected from the group consisting of t-butyl cumyl peroxide, di-t-butyl peroxide, di-cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, t-butyl hydroperoxide, bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl peroxyisobutyrate, t-butyl peroxyacetate, t-butyl peroxy-2-ethylhexyl carbonate (TBEC), t-butyl peroxy-2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxyoctoate, t-butyl peroxyisopropyl carbonate, t-butyl peroxybenzoate, di-t-butyl peroxyphtalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)-3-hexyne, methyl ethyl ketone peroxide, cyclohexanone peroxide azobisisobutyronitrile, and azobis(2,4-dimethylvaleronitrile), and provides a crosslinking agent composition for an olefin copolymer according to any one of [1] to [8] above.

[0025]

[10] The present invention provides a crosslinking agent composition for an olefin copolymer according to any one of [1] to [9], wherein the silane coupling agent is at least one selected from the group consisting of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and p-styryltrimethoxysilane.

[0026]

[11] The present invention also provides a sealing material composition for an optical element, comprising an olefin polymer and the crosslinking agent composition for an olefin copolymer according to any one of [1] to

[10] .

[0027]

[12] The present invention provides a sealing material composition for an optical element according to

[11] , wherein the olefin copolymer is an ethylene / α-olefin copolymer.

[0028]

[13] The present invention also provides a sealing material film for an optical element, comprising an olefin copolymer and a structure derived from the compound of the following Chemical Formula 1.

[0029] [Chemical Formula]

[0030] In Chemical Formula 1, R1 to R4 are each independently an alkyl having 1 to 20 carbon atoms or an alkenyl having 2 to 20 carbon atoms, and here, two or more of R1 to R4 are alkenyls having 2 to 20 carbon atoms.

[0031]

[14] The present invention also provides an optoelectronic device, comprising an optical element and the sealing material film for an optical element according to

[13] . [Advantages of the Invention]

[0032] The crosslinking agent composition for olefin copolymers of the present invention contains, as a crosslinking aid, a compound having excellent miscibility with olefin copolymers, has a fast impregnation rate into olefin copolymers, and the encapsulant composition for optical elements produced using the same exhibits excellent volume resistivity and light transmittance, and thus can be widely used in various applications in the electrical and electronic industries. [Modes for Carrying Out the Invention]

[0033] Hereinafter, the present invention will be described in more detail so that the present invention can be easily understood.

[0034] The terms and words used in the description and claims of the present invention should not be construed as being limited to the ordinary or dictionary meanings. The inventors should interpret them in the meanings and concepts consistent with the technical idea of the present invention in accordance with the principle that they can appropriately define the concepts of the terms in order to describe their invention in the best way.

[0035] Each substituent defined in this specification will be described in detail as follows.

[0036] The term "alkyl" used in this specification means a linear or branched hydrocarbon residue unless otherwise specified.

[0037] The term "alkenyl" used in this specification means a linear or branched alkenyl group unless otherwise specified.

[0038] The branched chain may be alkyl having 1 to 20 carbon atoms; or alkenyl having 2 to 20 carbon atoms.

[0039] [Crosslinking Agent Composition for Olefin Copolymers] The crosslinking agent composition for olefin copolymers of the present invention contains a crosslinking agent, a silane coupling agent, and a crosslinking aid compound represented by the following Chemical Formula 1.

[0040]

Chem.

[0041] In Chemical Formula 1 above, R1 to R4 are each independently an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, and here, two or more of R1 to R4 are each independently an alkenyl group having 2 to 20 carbon atoms.

[0042] Also, in Chemical Formula 1 above, R1 to R4 may each independently be an alkenyl group having 2 to 20 carbon atoms.

[0043] Also, in Chemical Formula 1 above, R1 to R4 may each independently be an alkenyl group having 2 to 8 carbon atoms and having a double bond at the terminal.

[0044] Also, the crosslinking agent composition for an olefin copolymer according to an example of the present invention may specifically contain tetraallyloxysilane represented by the following Chemical Formula 2 as the compound of Chemical Formula 1.

[0045]

Chem.

[0046] The compound of Chemical Formula 1 contained in the crosslinking agent composition for an olefin copolymer of the present invention is contained as a crosslinking aid in the crosslinking agent composition for an olefin copolymer. The compound of Chemical Formula 1 shows excellent miscibility with the olefin copolymer and can show a fast impregnation rate. As a result, among the crosslinking agent, silane coupling agent, and crosslinking aid contained in the crosslinking agent composition used in the conventional olefin copolymer, by improving the absorption rate of the crosslinking aid that shows the slowest absorption rate with respect to the olefin copolymer, it is possible to achieve the effect of shortening the impregnation time of the crosslinking agent composition, achieve a short impregnation time, and exhibit excellent crosslinked physical properties with respect to the olefin copolymer.

[0047] When the crosslinking agent composition for an olefin copolymer of the present invention containing the compound of Chemical Formula 1 is applied as a crosslinking agent to a sealing material composition for an optical element containing an olefin copolymer, the sealing material composition for an optical element can exhibit a high degree of crosslinking, volume resistivity, and light transmittance.

[0048] Further, the crosslinking agent composition for an olefin copolymer may further contain a second crosslinking aid compound other than the compound of Chemical Formula 1 as a crosslinking aid.

[0049] As the second crosslinking aid, various crosslinking aids known in the art can be used. For example, compounds containing at least one or more unsaturated groups such as allyl groups or (meth)acryloxy groups may be included.

[0050] The second crosslinking aid may be a crosslinking aid containing at least one or more unsaturated groups. For example, polyallyl compounds such as triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate, or diallyl maleate are exemplified. Examples of the compound containing the (meth)acryloxy group include poly(meth)acryloxy compounds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate, but are not particularly limited thereto.

[0051] When the crosslinking aid composition for an olefin copolymer according to an example of the present invention further contains a second crosslinking aid compound other than the compound of Chemical Formula 1, the weight ratio of the compound of Chemical Formula 1 to the second crosslinking aid compound may be 1:0.20 to 9.0. Specifically, 1:0.20 to 6.0, 1:0.20 to 5.0, 1:0.20 to 4.0, 1:0.20 to 3.7, 1:0.25 to 5.0, 1:0.25 to 4.0, 1:0.25 to 3.7, 1:0.25 to 3.5, 1:0.25 to 3.2, 1:0.25 to 3.0, 1:0.3 to 3.7, 1:0.3 to 3.5, 1:0.3 to 3.2, 1:0.3 to 3.0, or 1:0.33 to 3.0 may be used.

[0052] When the crosslinking aid composition for an olefin copolymer according to an example of the present invention contains both the compound of Chemical Formula 1 and the second crosslinking aid compound, a higher degree of crosslinking can be achieved compared to the case of containing only the same amount of the compound of Chemical Formula 1. When it is applied to the encapsulant composition for an optical element, the encapsulant composition for an optical element can exhibit a high volume resistivity and can satisfy excellent light transmittance and adhesive strength.

[0053] When both the compound of Chemical Formula 1 and the second crosslinking aid are contained and the ratio of the second crosslinking aid to the compound of Chemical Formula 1 is increased to a certain amount or more, the degree of crosslinking increases and the vulcanization characteristics can be improved. When the ratio of the second crosslinking aid to the compound of Chemical Formula 1 is decreased, the degree of decrease in the impregnation rate can be reduced. Therefore, the ratio may be appropriately determined within the above range according to the physical properties to be exhibited. When the ratio of the second crosslinking aid is too large, the effect of improving the impregnation rate by using the compound of Chemical Formula 1 may not be preferably exhibited. When the ratio of the second crosslinking aid is too small, the additional effect obtained by the mixed use of the second crosslinking aid may not be preferably exhibited.

[0054] In the crosslinking aid composition for an olefin copolymer according to an example of the present invention, in order to achieve excellent vulcanization characteristics, degree of crosslinking, light transmittance, and adhesive strength, together with a shortened impregnation time of the crosslinking agent, both the compound of Chemical Formula 1 and the second crosslinking aid compound are contained, and the compound of Chemical Formula 1 and the second crosslinking aid compound may be contained in a weight ratio of 1:0.20 to 3.7, specifically, 1:0.25 to 3.7, 1:0.25 to 3.5, 1:0.25 to 3.2, 1:0.25 to 3.0, 1:0.3 to 3.7, 1:0.3 to 3.5, 1:0.3 to 3.2, 1:0.3 to 3.0, or 1:0.33 to 3.0. As the crosslinking agent, various crosslinking agents known in the art can be variously used as long as they can initiate radical polymerization or form crosslinking bonds, and one or more selected from the group consisting of organic peroxides, hydroperoxides, and azo compounds may be used.

[0055] Further, in an example of the present invention, the crosslinking agent may specifically be an organic peroxide.

[0056] The organic peroxide may be an organic peroxide having a 1-hour half-life temperature of 120 to 135 °C, for example, 120 to 130 °C, 120 to 125 °C, specifically, 121 °C. The "1-hour half-life temperature" means the temperature at which the half-life of the crosslinking agent becomes 1 hour. Depending on the 1-hour half-life temperature, the temperature at which the radical initiation reaction occurs efficiently is different. Therefore, when an organic peroxide having a 1-hour half-life temperature in the above range is used as the crosslinking agent, the radical initiation reaction, that is, the crosslinking reaction, can proceed effectively at the lamination process temperature for manufacturing the optoelectronic device.

[0057] Examples of the crosslinking agent include, but are not limited to, one or more selected from the group consisting of dialkyl peroxides such as t-butyl cumyl peroxide, di-t-butyl peroxide, di-cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne; hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, t-butyl hydroperoxide; diacyl peroxides such as bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dichlorobenzoyl peroxide; peroxy esters such as t-butyl peroxyisobutyrate, t-butyl peroxyacetate, t-butyl peroxy-2-ethylhexyl carbonate (TBEC), t-butyl peroxy-2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxy octoate, t-butyl peroxyisopropyl carbonate, t-butyl peroxybenzoate, di-t-butyl peroxyphtalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)-3-hexyne; and ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, lauryl peroxide, azobisisobutyronitrile, and azobis(2,4-dimethylvaleronitrile).

[0058] The silane coupling agent may be, for example, one or more selected from the group consisting of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane (MEMO), vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and p-styryltrimethoxysilane.

[0059] The crosslinking agent composition for the olefin copolymer may contain 20 to 80 parts by weight of the crosslinking agent, 5 to 30 parts by weight of the silane coupling agent, and 10 to 60 parts by weight of a crosslinking aid containing the crosslinking aid compound of Chemical Formula 1. The content of each component means the relative ratio between the weights of the respective components contained in the crosslinking agent composition for the olefin copolymer.

[0060] The crosslinking agent may be contained in the crosslinking agent composition for the olefin copolymer in an amount of 20 to 80 parts by weight. Specifically, it may be contained in an amount of 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 40 parts by weight or more, up to 80 parts by weight, 75 parts by weight or less, or 70 parts by weight or less. When the content of the crosslinking agent is too small, the crosslinking reaction hardly occurs when the olefin copolymer is used. When the content of the crosslinking agent is too large, the volume resistivity of the encapsulant for optical elements produced using the olefin copolymer may decrease. From this, when the crosslinking agent is contained in the crosslinking agent composition for the olefin copolymer within the above range, the encapsulant composition for optical elements using the same can preferably cause a crosslinking reaction and can be manufactured as an encapsulant for optical elements, and the manufactured encapsulant for optical elements can exhibit a high volume resistivity.

[0061] The silane coupling agent may be contained in the crosslinking agent composition for the olefin copolymer in an amount of 5 to 30 parts by weight. Specifically, it may be contained in an amount of 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, up to 20 parts by weight or less, 19 parts by weight or less, or 18 parts by weight or less. When the content of the silane coupling agent is too small, when the olefin copolymer is used, the adhesive force of the encapsulant composition for the optical element to the substrate, for example, the adhesive force of the encapsulant composition for the optical element to the glass substrate is low, so it is difficult to exhibit suitable performance as an encapsulant for the optical element. When the content of the silane coupling agent is too large, the volume resistivity of the encapsulant for the optical element decreases, which is not suitable. When the silane coupling agent is contained in the above range in the crosslinking agent composition for the olefin copolymer, the encapsulant composition for the optical element using the same exhibits excellent adhesiveness to the substrate of the optical element or the glass substrate on which the optical element is located, effectively prevents the penetration of moisture, etc., and enables the optical element to maintain excellent performance over a long period of time, and the encapsulant for the optical element can exhibit a high volume resistivity.

[0062] The crosslinking aid containing the crosslinking aid compound of Chemical Formula 1, that is, the crosslinking aid compound of Chemical Formula 1 as the crosslinking aid, or the total amount of the crosslinking aid compound of Chemical Formula 1 and the second crosslinking aid compound may be contained in the crosslinking agent composition for the olefin copolymer in an amount of 10 to 60 parts by weight. Specifically, it may be contained in an amount of 11 parts by weight or more, 12 parts by weight or more, 13 parts by weight or more, up to 60 parts by weight or less, 55 parts by weight or less, or 50 parts by weight or less.

[0063] The olefin copolymer to which the crosslinking agent composition for the olefin copolymer can be applied may satisfy, for example, (a) a density of 0.85 to 0.90 g / cc and (b) a melt index of 0.1 to 100 g / 10 min.

[0064] Specifically, the density (a) of the olefin copolymer may be 0.850 g / cc or more, 0.855 g / cc or more, 0.860 g / cc or more, 0.865 g / cc or more, or 0.870 g / cc to 0.900 g / cc or less, 0.895 g / cc or less, 0.890 g / cc or less, 0.885 g / cc or less, or 0.880 g / cc or less. If the density of the olefin copolymer is too high, the light transmittance of the encapsulant composition for optical elements using the same and the encapsulant for optical elements manufactured using the same may decrease due to the crystalline phase contained in the olefin copolymer. However, when the olefin copolymer satisfies the above density range, it can exhibit high light transmittance.

[0065] The melt index (b) of the olefin copolymer may be 0.1 g / 10 min or more, 0.5 g / 10 min or more, 1.0 g / 10 min or more, 1.5 g / 10 min or more, 2.0 g / 10 min or more, 2.5 g / 10 min or more, 5.0 g / 10 min or more, or 10.0 g / 10 min or more to 100 g / 10 min or less, 95 g / 10 min or less, 90 g / 10 min or less, 85 g / 10 min or less, 80 g / 10 min or less, 75 g / 10 min or less, 70 g / 10 min or less, 60 g / 10 min or less, or 50 g / 10 min or less. If the melt index of the olefin copolymer is too low or too high outside the above range, there may be a problem that the moldability of the encapsulant composition for optical elements deteriorates and stable extrusion is difficult. However, when the olefin copolymer satisfies the above melt index range, since the moldability of the encapsulant composition for optical elements is excellent, the encapsulant for optical elements and the encapsulant sheet for optical elements can be stably extruded.

[0066] Specifically, the olefin copolymer to which the crosslinking agent composition for an olefin copolymer according to an example of the present invention is applied may be an ethylene / α-olefin copolymer.

[0067] Generally, the density of an ethylene / α-olefin copolymer is affected by factors such as the type and content of monomers used during polymerization, the degree of polymerization, etc., and the copolymer is greatly influenced by the content of the comonomer. At this time, the higher the content of the comonomer, the lower-density ethylene / α-olefin copolymer is produced, but the content at which the comonomer can be introduced into the copolymer depends on the inherent copolymerizability of the catalyst.

[0068] The ethylene / α-olefin copolymer to which the crosslinking agent composition for olefin copolymers of the present invention is applied can exhibit the above-mentioned low density and excellent processability.

[0069] The ethylene / α-olefin copolymer is produced by copolymerizing ethylene and an α-olefin monomer. At this time, as the α-olefin, which means the part derived from the α-olefin monomer in the copolymer, α-olefins having 3 to 20 carbon atoms can be mentioned. Specifically, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, or 1-eicosene, etc. may be mentioned, and these may be one kind alone or a mixture of two or more kinds. Among them, the α-olefin may be 1-butene, 1-hexene, or 1-octene, and specifically, it may be 1-butene, 1-hexene, or a combination thereof.

[0070] Also, in the ethylene / α-olefin copolymer, the content of the α-olefin may be appropriately selected within the range that satisfies the above physical property requirements. Specifically, it may be more than 0 mol% and 99 mol% or less, or may be 10 mol% to 50 mol%, but is not limited thereto.

[0071] Also, the olefin copolymer may be an ethylene / α-olefin copolymer having a volume resistivity of 1.0×10 15 Ω·cm or more. Specifically, 3.0×10 15 Ω·cm or more, 5.0×10 15 Ω·cm, or 7.0×10 15It may be a copolymer having a volume resistivity of 10 Ω·cm or more. When the volume resistivity of the olefin copolymer is too low, there is a risk that the volume resistivity after crosslinking of the encapsulant composition for optical elements may not reach a suitable level. However, when the volume resistivity of the olefin copolymer satisfies the above value, the encapsulant composition for optical elements can exhibit excellent volume resistivity after crosslinking. The upper limit of the volume resistivity of the olefin copolymer is not particularly limited. However, considering the volume resistivity usually exhibited by olefin copolymers and the difficulty in manufacturing olefin copolymers with high volume resistivity, it is 9.9×10 17 Ω·cm or less, 9.0×10 17 Ω·cm or less, or 7.0×10 17 Ω·cm or less may be used.

[0072] [Encapsulant Composition for Optical Elements] The crosslinking agent composition for olefin copolymers of the present invention can be used together with an olefin copolymer to form an encapsulant composition for optical elements. The present invention provides an encapsulant composition for optical elements containing an olefin polymer and the crosslinking agent composition for olefin copolymers.

[0073] The description of the olefin copolymer and the encapsulant composition for optical elements is as described above.

[0074] The olefin copolymer may be contained in an amount of 80 to 99.5 parts by weight based on 100 parts by weight of the encapsulant composition for optical elements. Specifically, it may be contained in an amount of 80 parts by weight or more, 82 parts by weight or more, 85 parts by weight or more, 86 parts by weight or more, 87 parts by weight or more, or 88 parts by weight or more, up to 99.5 parts by weight or less, 99 parts by weight or less, or 98.5 parts by weight or less. When the content of the olefin copolymer contained in the encapsulant composition for optical elements is too small, it is difficult to suitably exhibit mechanical properties such as tear resistance and tear strength of the encapsulant for optical elements. Therefore, when the olefin copolymer is contained in the entire encapsulant composition for optical elements within the above range, it is possible to exhibit suitable mechanical properties as an encapsulant for optical elements.

[0075] The crosslinking agent composition for an olefin copolymer according to an example of the present invention may be used in an amount of 0.5 parts by weight to 20 parts by weight based on 100 parts by weight of the olefin copolymer. Specifically, the crosslinking agent composition for the olefin copolymer may be used in an amount of 0.5 parts by weight or more, 0.7 parts by weight or more, 0.8 parts by weight or more, 1 part by weight or more, 1.1 parts by weight or more, 1.2 parts by weight or more, 1.3 parts by weight or more, 1.4 parts by weight or more, or 1.5 parts by weight or more, up to 20 parts by weight or less, 18 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 8 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less, or 3 parts by weight or less based on 100 parts by weight of the olefin copolymer. When the amount of the crosslinking agent composition used with respect to the olefin copolymer is too small, the crosslinking reaction hardly occurs. When the amount of the crosslinking agent composition used is too large, the volume resistivity of the encapsulant for optical elements may decrease. When the crosslinking agent composition is used in the above ratio with respect to the olefin copolymer, the encapsulant composition for optical elements using the same can preferably cause a crosslinking reaction and can be manufactured as an encapsulant for optical elements, and the manufactured encapsulant for optical elements can exhibit a high volume resistivity.

[0076] In the encapsulant composition for an optical element according to an example of the present invention, the crosslinking auxiliary compound of Chemical Formula 1 may be contained in an amount of 0.1 to 9 parts by weight based on 100 parts by weight of the olefin copolymer. Specifically, the crosslinking auxiliary compound of Chemical Formula 1 may be contained in an amount of 0.1 part by weight or more, 0.2 part by weight or more, 0.3 part by weight or more, or 0.4 part by weight or more, and up to 9 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 6 parts by weight or less, 5 parts by weight or less, 4 parts by weight or less, 3 parts by weight or less, or 2 parts by weight or less based on 100 parts by weight of the olefin copolymer. When both the crosslinking auxiliary compound of Chemical Formula 1 and the second crosslinking auxiliary compound are used as crosslinking auxiliaries, the total amount thereof only needs to satisfy the above range. When the amount of the crosslinking auxiliary used with respect to the olefin copolymer is too small, the crosslinking reaction hardly occurs, and when the amount of the crosslinking auxiliary used is too large, the volume resistivity of the encapsulant for an optical element may decrease. When the crosslinking auxiliary is contained in the above ratio with respect to the olefin copolymer, the encapsulant composition for an optical element can suitably cause a crosslinking reaction to form an encapsulant for an optical element, and the formed encapsulant for an optical element can exhibit a high volume resistivity.

[0077] In addition to the above components, the encapsulant composition for an optical element may further appropriately contain various additives known in the art according to the application where the resin component is applied.

[0078] Examples of the additive include one or more additives selected from a light stabilizer, a UV absorber, a heat stabilizer, and the like.

[0079] The light stabilizer can capture the active species that initiate the photo-degradation of the resin and play a role in preventing photo-oxidation according to the application to which the composition is applied. The type of the light stabilizer that can be used is not particularly limited, and for example, known compounds such as hindered amine-based compounds or hindered piperidine-based compounds can be used.

[0080] The UV absorber can absorb ultraviolet rays from sunlight or the like according to the use of the composition, convert them into harmless thermal energy within the molecule, and prevent the active species that initiate photo-degradation in the resin composition from being excited. The specific types of UV absorbers that can be used are not particularly limited. For example, one or a mixture of two or more of benzophenone-based, benzotriazole-based, acrylonitrile-based, metal complex-based, hindered amine-based, inorganic UV absorbers such as ultrafine titanium oxide, or ultrafine zinc oxide can be used.

[0081] Examples of the heat stabilizer include phosphorus-based heat stabilizers such as tris(2,4-di-tert-butylphenyl) phosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl] ethyl ester phosphite, tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4'-diylbisphosphonate, and bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite; and lactone-based heat stabilizers such as the reaction product of 8-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene. One or two or more of the above may be used.

[0082] The contents of the light stabilizer, UV absorber, and / or heat stabilizer are not particularly limited. That is, the content of the additive can be appropriately selected in consideration of the use of the resin composition, the shape and density of the additive, etc., and is usually adjustable within the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the total solid content of the encapsulant composition for optical elements.

[0083] In addition, the encapsulant composition for optical elements can be molded by methods such as injection and extrusion, and can be utilized as various molded products. Specifically, it can be used as an encapsulant for encapsulating elements in various optoelectronic devices, such as solar cells. For example, it can also be used as an industrial material applicable to processes such as a temperature-rising lamination process, but its use is not limited to these.

[0084] The present invention also provides a sealing material film for an optical element produced using the above-described sealing material composition for an optical element.

[0085] The sealing material film for an optical element according to an embodiment of the present invention may include a structure derived from an olefin copolymer and a crosslinking auxiliary compound represented by the following Chemical Formula 1.

[0086] [Chemical Formula]

[0087] In Chemical Formula 1, R1 to R4 are each independently an alkyl having 1 to 20 carbon atoms or an alkenyl having 2 to 20 carbon atoms, and here, two or more of R1 to R4 are each independently an alkenyl having 2 to 20 carbon atoms.

[0088] The description of the olefin copolymer and the crosslinking auxiliary compound represented by Chemical Formula 1 is as described above.

[0089] Also, the sealing material film for an optical element according to another embodiment of the present invention may include structures respectively derived from the crosslinking auxiliary compound represented by Chemical Formula 1 and the second crosslinking auxiliary compound.

[0090] The description of the second crosslinking auxiliary compound and the description of the case where both the crosslinking auxiliary compound represented by Chemical Formula 1 and the second crosslinking auxiliary compound are used as crosslinking auxiliaries are as described above.

[0091] The present invention also provides an optoelectronic device including the above-described sealing material film for an optical element.

[0092] Examples Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are for illustrative purposes only, and the scope of the present invention is not limited thereto.

[0093] Example 1 25 parts by weight of tetraallyloxysilane (TAOS, manufactured by Gelest Inc.) and 75 parts by weight of triallyl isocyanurate (TAIC, manufactured by Sigma-Aldrich) were mixed and prepared as a crosslinking aid.

[0094] LUCENE, an ethylene / 1-butene copolymer TM 500 g of LF675 (LG Chem) was dried overnight in a convection oven at 40 °C. The above LUCENE TM The density of LF675 measured according to ASTM D1505 was 0.877 g / cm 3 and the melt index (190 °C, 2.16 Kg) measured according to ASTM D1238 was 14.0 g / 10 min. The temperature of the bowl of a viscometer (manufactured by Thermo Electron (Karsruhe) GmbH, Haake Modular Torque Viscometer) was set to 40 °C. After introducing the ethylene / α-olefin copolymer into the bowl, using an electric pipette, a crosslinking agent composition [1.00 phr (parts per hundred rubber) of t-butyl 1-(2-ethylhexyl) monoperoxycarbonate (TBEC, manufactured by Sigma-Aldrich) as a crosslinking agent, 0.50 phr of a mixture of TAOS and TAIC (25:75 weight ratio) prepared above as a crosslinking aid, 0.20 phr of methacryloxypropyltrimethoxysilane (MEMO, manufactured by Shin-Etsu) as a silane coupling agent] was introduced. While stirring at 40 rpm at 40 °C, the change in torque value over time was observed, and the impregnation was terminated when the torque value increased rapidly, and the impregnation completion time of the crosslinking agent composition was measured.

[0095] Thereafter, the impregnated sample was press-molded to an average thickness of 0.5 mm at a low temperature (under the condition of an extruder barrel temperature of 90 - 100 °C) where high-temperature crosslinking did not occur using a micro-extruder to produce a sheet-like sealing material film.

[0096] Example 2 As crosslinking aids, tetraallyloxy silane (TAOS) and triallyl isocyanurate (TAIC) were each prepared in amounts of 50 parts by weight and 50 parts by weight, respectively. After preparing the crosslinking aids in the same manner as in Example 1 except for changing their mixing ratio, a sealing material film was manufactured.

[0097] Example 3 As crosslinking aids, tetraallyloxy silane (TAOS) and triallyl isocyanurate (TAIC) were each prepared in amounts of 75 parts by weight and 25 parts by weight, respectively. After preparing the crosslinking aids in the same manner as in Example 1 except for changing their mixing ratio, a sealing material film was manufactured.

[0098] Example 4 Using only tetraallyloxy silane (TAOS) as the crosslinking aid, and changing the input amount from 0.50 phr to 0.25 phr, after preparing the crosslinking aid in the same manner as in Example 1, a sealing material film was manufactured.

[0099] Example 5 Using only tetraallyloxy silane (TAOS) as the crosslinking aid, after preparing the crosslinking aid in the same manner as in Example 1, a sealing material film was manufactured.

[0100] Example 6 Using only tetraallyloxy silane (TAOS) as the crosslinking aid, and changing the input amount from 0.50 phr to 1.00 phr, after preparing the crosslinking aid in the same manner as in Example 1, a sealing material film was manufactured.

[0101] Example 7 As crosslinking aids, tetraallyloxy silane (TAOS) and triallyl isocyanurate (TAIC) were each prepared in amounts of 10 parts by weight and 90 parts by weight, respectively. After preparing the crosslinking aids in the same manner as in Example 1 except for changing their mixing ratio, a sealing material film was manufactured.

[0102] Example 8 As a crosslinking aid, tetraallyloxy silane (TAOS) and triallyl isocyanurate (TAIC) were each prepared in amounts of 20 parts by weight and 80 parts by weight, respectively, and after preparing the crosslinking aid in the same manner as in Example 1 except for changing the mixing ratio, a sealing material film was produced.

[0103] Comparative Example 1 A crosslinking aid was prepared in the same manner as in Example 1 except that only triallyl isocyanurate (TAIC) was used as the crosslinking aid, and then a sealing material film was produced.

[0104] Table 1 below shows the crosslinking agent compositions used in Examples 1 to 8 and Comparative Example 1.

[0105]

Table 1

[0106] Experimental Example A 0.5 mm thick sealing material film (15 cm × 15 cm) produced above was placed between two release films (thickness: about 100 μm) and laminated and crosslinked in a vacuum laminator at a process temperature of 150 °C for a process time of 20 minutes (5 minutes of vacuum / 1 minute of pressurization / 14 minutes of continued pressure).

[0107] (1) Impregnation rate The crosslinking agent impregnation completion times measured in the processes of Examples 1 to 8 and Comparative Example 1 were listed in Table 2 below.

[0108] (2) Volume resistivity Testing was performed at room temperature based on ASTM D257. The prepared sample was placed in a Keithley 8009 Resistivity test fixture, and after applying a voltage of 1,000 V with a 6517B Electrometer / High Resistance meter connected thereto, the volume resistivity was measured.

[0109] (3) Vulcanization characteristics The cure properties were measured using Alpha Technologies' premier MDR in accordance with ASTM D5289. The test was performed at 150°C for 0 minutes to obtain a torque curve over time. The 150°C condition corresponds to the lamination temperature, and 20 minutes corresponds to the lamination time. The cure properties of the samples were compared using the difference between the maximum torque (MH) and minimum torque (ML) applied by the MDR during that time.

[0110] (4) Degree of crosslinking The crosslinked sheet was cut into 3 x 3 mm pieces using scissors. 2 Cut into pieces of 7×14cm 2 The sides and bottom of a 200 mesh iron net were sealed with staples. The sheet was placed in the iron net, and the weight of the sheet was measured. The amount of the sheet was adjusted to 0.49 to 0.51 g. After the sheet was placed, the top of the iron net was sealed with staples and the total weight of the sample was measured. A solution of 10 g of BHT (dibutylhydroxytoluene) in 1,000 g of xylene was poured into a 2 L cylindrical reactor, and 3 to 4 of the samples were placed in it. The reactor was heated, and reflux was stopped 5 hours after the start of boiling. The sample in the reactor was taken out with a metal scoop and washed with xylene. It was vacuum dried at 100°C overnight. The weight of the dried sample was measured to calculate the degree of crosslinking. The degree of crosslinking can be determined as the average value of 3 to 4 samples refluxed with xylene.

[0111] Crosslinking degree (%) = [(weight of sheet after reflux) / (weight of sheet before reflux)] × 100

[0112] (5) Light transmittance The light transmittance was measured at 200 nm to 1,000 nm using a Shimadzu UV-3600 spectrophotometer to obtain a light transmittance curve, and the values ​​at 280 to 380 nm and 380 to 1,100 nm were then confirmed. -Measurement mode: Transmittance -Wavelength interval: 1nm - Measurement speed: medium

[0113] (6) Measurement of adhesive strength After covering 40% of the glass substrate area with a sealing material film and covering the remaining 60% with a polyimide film, a fluorine-based solar backsheet was laminated thereon. Lamination was performed at a temperature of 150 °C for 20 minutes so that the sealing material film was adhered to the glass substrate while being crosslinked. A cut with a width of 1 cm was made in the sealing material film of the test piece so that the width of the measurement site was 1 cm.

[0114] An LRX Plus Universal Test Machine (manufactured by LLOYD) was equipped with a UTM sample holder and a 1 kN load cell. After fixing the end of the sealing material film adhered to the glass substrate and the end of the portion of the glass substrate where the sealing material film was not adhered, the adhesive strength was tested by pulling at 60 mm / min.

[0115]

Table 2

[0116] As can be confirmed from Table 2 above, when a crosslinking agent composition containing a crosslinking aid compound of Chemical Formula 1 was used as in Examples 1 to 8, compared with the case where only triallyl isocyanurate of Comparative Example 1 was used as a crosslinking aid, the impregnation completion time of the crosslinking agent could be shortened. Also, as in Examples 1 to 3, 7, and 8, when a certain amount or more of the crosslinking aid compound of Chemical Formula 1 was included together with triallyl isocyanurate as a crosslinking aid, the impregnation completion time of the crosslinking agent could be effectively shortened, and a high degree of crosslinking and a high volume resistivity could be achieved.

Claims

1. A crosslinking agent, a silane coupling agent, and a crosslinking aid compound represented by the following Chemical Formula 1, the crosslinking agent composition for an olefin copolymer containing the same. 【Chemical Formula 1】 (In the Chemical Formula 1, R １ ~R ４ are each independently an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, where R １ ~R ４ two or more of which are each independently an alkenyl group having 2 to 20 carbon atoms.)

2. Said R １ to R ４ are each independently alkenyl groups having 2 to 20 carbon atoms, the crosslinking agent composition for an olefin copolymer according to claim 1.

3. The aforementioned R １ to R ４ is each independently an alkenyl having 2 to 8 carbon atoms with a double bond at the terminal, and is the crosslinking agent composition for an olefin copolymer according to Claim 1.

4. The crosslinking agent composition for an olefin copolymer according to Claim 1, wherein the crosslinking aid compound represented by Chemical Formula 1 is tetraallyloxysilane.

5. The crosslinking agent composition for an olefin copolymer according to Claim 1, further comprising a second crosslinking aid compound other than the crosslinking aid compound represented by Chemical Formula 1.

6. The crosslinking agent composition for an olefin copolymer according to Claim 5, wherein the weight ratio of the crosslinking aid compound represented by Chemical Formula 1 to the second crosslinking aid compound is 1:0.2 to 1:9.

0.

7. The crosslinking agent composition for an olefin copolymer according to Claim 5, wherein the second crosslinking aid compound includes one or more selected from the group consisting of triallyl isocyanurate, triallyl cyanurate, diallyl phthalate, diallyl fumarate, diallyl maleate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.

8. The crosslinking agent composition for an olefin copolymer according to Claim 1, wherein the crosslinking agent is one or more selected from the group consisting of organic peroxides, hydroperoxides, and azo compounds.

9. The crosslinking agent is one or more selected from the group consisting of t-butyl cumyl peroxide, di-t-butyl peroxide, di-cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, t-butyl hydroperoxide, bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl peroxyisobutyrate, t-butyl peroxyacetate, t-butyl peroxy-2-ethylhexyl carbonate (TBEC), t-butyl peroxy-2-ethylhexanoate, t-butyl peroxypivalate, t-butyl peroxy octoate, t-butyl peroxyisopropyl carbonate, t-butyl peroxybenzoate, di-t-butyl peroxyphtalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-di(benzoylperoxy)-3-hexyne, methyl ethyl ketone peroxide, cyclohexanone peroxide azobisisobutyronitrile, and azobis(2,4-dimethylvaleronitrile), the crosslinking agent composition for an olefin copolymer according to claim 1.

10. The silane coupling agent is one or more selected from the group consisting of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and p-styryltrimethoxysilane, the crosslinking agent composition for an olefin copolymer according to claim 1.

11. An olefin copolymer, and A sealing material composition for an optical element, comprising the crosslinking agent composition for an olefin copolymer according to claim 1.

12. The sealing material composition for an optical element according to claim 11, wherein the olefin copolymer is an ethylene / α-olefin copolymer.

13. A sealing material film for an optical element, comprising an olefin copolymer and a structure derived from the compound of the following Chemical Formula 1. 【Chemical 2】 (In the Chemical Formula 1, R １ ~R ４ are each independently an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, where two or more of R １ ~R ４ are alkenyl groups having 2 to 20 carbon atoms.)

14. An optoelectronic device, comprising an optical element and the sealing material film for an optical element according to claim 13.

Images