Additive for crosslinking aid composition for olefin copolymer, crosslinking agent composition, and encapsulant composition for optical element

Abstract

The present invention relates to a crosslinking auxiliary composition for an olefin-based copolymer, a crosslinking agent, and an additive for an encapsulant composition for an optical element, and by using the same in the production of an encapsulant composition for an optical element, an encapsulant composition for an optical element and an encapsulant film for an optical element having high volume resistivity and light transmittance can be produced.

Description

Technical Field

[0001] The present invention claims the benefit of priority based on Korean Patent Application No. 10-2021-0154113 filed on November 10, 2021, 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 aid composition for an olefin copolymer, a crosslinking agent composition, and an additive for a sealing material composition for an optical element, and to a crosslinking aid composition for an olefin copolymer used in a sealing material composition for an optical element containing an olefin copolymer, a crosslinking agent composition containing the crosslinking aid, and an additive.

Background Art

[0003] As global environmental problems and energy problems are becoming increasingly serious, solar cells have attracted attention as a clean and non-depletable energy generation means. When solar cells are used outdoors, such as on the roofs of buildings, they are generally used in module form. 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, an ethylene / vinyl acetate copolymer or an ethylene / alpha-olefin copolymer is used. In addition, since long-term weather resistance is required for the solar cell encapsulant, a light stabilizer is usually included as an additive. Also, in consideration of the adhesion to the transparent protective member on the front side or the protective member on the back side typified by 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 due to their excellent transparency, flexibility, adhesiveness, etc. Ethylene-vinyl acetate copolymer (EVA) films are widely used due to their excellent transparency, flexibility, adhesiveness, etc. However, when using an EVA composition 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 / alpha-olefin copolymers have been able to solve the problems of reduced lifespan and reliability because there are no problems with resin hydrolysis. However, since ethylene / alpha-olefin copolymers do not contain polar groups in the resin, conventionally, their miscibility with polar crosslinking aids contained as constituent materials of solar cell encapsulants has decreased, and it takes a very long time for impregnation, resulting in a problem with productivity.

[0007] Thus, there is a need to develop a crosslinking aid that can improve the productivity of a solar cell encapsulant containing an ethylene / alpha-olefin copolymer, which can be usefully utilized as a substance requiring high insulation, such as a solar cell encapsulant, because of its excellent volume resistivity.

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 a crosslinking aid composition for an olefin-based copolymer containing a crosslinking aid having excellent miscibility with an olefin-based copolymer.

[0010] Another problem to be solved by the present invention is to provide a crosslinking agent composition for an olefin copolymer used for crosslinking the olefin copolymer.

[0011] Still another problem to be solved by the present invention is to provide an additive for a sealing material composition for an optical element.

Means for Solving the Problems

[0012] In order to solve the above problems, the present invention provides a crosslinking aid composition for an olefin copolymer, a crosslinking agent composition, and an additive for a sealing material composition for an optical element.

[0013] [1] The present invention provides a crosslinking aid composition for an olefin copolymer containing a compound of the following Chemical Formula 1.

Chemical Formula

[0014] [2] The present invention provides a crosslinking aid composition for an olefin copolymer, in the above [1], wherein in the Chemical Formula 1, m, n, and o are each independently an integer of 0 to 2.

[0015] [3] The present invention provides a crosslinking aid composition for an olefin copolymer, in the above [1] or [2], wherein the compound of Chemical Formula 1 is tetravinyltin.

[0016] [4] The present invention provides a crosslinking aid composition for an olefin copolymer, in any one of the above [1] to [3], wherein the crosslinking aid composition for an olefin copolymer further contains a crosslinking aid containing at least one or more unsaturated groups.

[0017] [5] The present invention provides a crosslinking aid composition for an olefin copolymer, in [4] above, wherein the weight ratio of the compound of Chemical Formula 1 and a crosslinking aid containing at least one or more unsaturated groups is 20:80 to 80:20.

[0018] [6] The present invention provides a crosslinking aid composition for an olefin copolymer, in [4] or [5] above, wherein the crosslinking aid containing at least one or more unsaturated groups includes one or more selected from the group consisting of triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate, diallyl maleate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.

[0019] [7] Further, the present invention provides a crosslinking agent composition for an olefin copolymer containing a crosslinking agent, a silane coupling agent, and a compound of the following Chemical Formula 1. [Chemical Formula] In Chemical Formula 1, l, m, n, and o are each independently an integer from 0 to 4.

[0020] [8] The present invention provides a crosslinking agent composition for an olefin copolymer, in [7] above, wherein the crosslinking agent is one or two or more selected from the group consisting of organic peroxides, hydroperoxides, and azo compounds.

[0021] [9] In the present invention, in the above [7] or [8], the crosslinking agent is 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 one or more olefin copolymers.

[0022]

[10] In any one of the above [7] to [9], the silane coupling agent of the present invention provides a crosslinking agent composition for one or more olefin copolymers 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.

[0023]

[11] The present invention also provides an additive for a sealing material composition for an optical element containing a compound of the following Chemical Formula 1. [Chemical Formula] In Chemical Formula 1 above, l, m, n, and o are each independently an integer from 0 to 4. [Advantages of the Invention]

[0024] The crosslinking aid composition for an olefin copolymer, the crosslinking agent composition, and the additive for a sealing material composition for an optical element of the present invention contain a tin-containing compound having excellent miscibility with an olefin copolymer, quickly impregnate the olefin copolymer, and the sealing material composition for an optical element produced using the same exhibits excellent volume resistivity and light transmittance. Therefore, it can be widely used for various applications in the electric and electronic industries. [Embodiments for Carrying Out the Invention]

[0025] Hereinafter, the present invention will be described in more detail to facilitate understanding of the present invention.

[0026] In the description and claims of the present invention, terms and words used should not be construed as limited to their ordinary or dictionary meanings. In accordance with the principle that the inventors can appropriately define the concepts of terms in order to explain their invention in the best way, they should be construed in meanings and concepts consistent with the technical idea of the present invention.

[0027] [Crosslinking Aid Composition for Olefin Copolymer] The crosslinking aid composition for an olefin copolymer of the present invention is characterized by containing a compound of the following Chemical Formula 1.

[0028] [Chem.]

[0029] In Chemical Formula 1 above, l, m, n, and o are each independently an integer from 0 to 4.

[0030] Also, in Chemical Formula 1, l, m, n, and o can each independently be an integer from 0 to 2.

[0031] Also, the crosslinking aid composition for an olefin copolymer according to an example of the present invention can specifically contain tetravinyltin as the compound of Chemical Formula 1.

[0032] The compound of Chemical Formula 1 contained in the crosslinking aid composition for an olefin copolymer of the present invention can be included as a crosslinking aid in the crosslinking aid composition for an olefin copolymer. Since the compound of Chemical Formula 1 exhibits excellent miscibility with the olefin copolymer, it can show a fast impregnation rate. Further, when the crosslinking aid composition for an olefin copolymer of the present invention containing the compound of Chemical Formula 1 is applied as a crosslinking aid to a sealing material composition for an optical element containing the olefin copolymer, the sealing material composition for the optical element can exhibit a high degree of crosslinking, volume resistance, and light transmittance.

[0033] Further, the crosslinking aid composition for the olefin copolymer may further contain a crosslinking aid other than the compound of Chemical Formula 1.

[0034] As the 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 can be included.

[0035] Examples of the crosslinking aid containing at least one or more unsaturated groups include polyallyl compounds such as triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate, or diallyl maleate. Examples of the compound containing the (meth)acryloxy group include poly(meth)acryloxy compounds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, etc., but are not particularly limited thereto.

[0036] When the crosslinking aid composition for the olefin copolymer according to an example of the present invention further contains a crosslinking aid containing at least one or more unsaturated groups other than the compound of Chemical Formula 1, the weight ratio of the compound of Chemical Formula 1 and the additional crosslinking aid can be 20:80 to 80:20. Specifically, it can be 21:79 to 79:21, 22:78 to 78:22, 23:77 to 77:23, 24:76 to 76:24, 25:75 to 75:25.

[0037] When a crosslinking aid composition for an olefin copolymer according to an example of the present invention contains both the compound of Chemical Formula 1 and a crosslinking aid containing at least one or more unsaturated groups, when applying this to a sealing material composition for an optical element, the sealing material composition for an optical element can satisfy high volume resistance, fast immersion rate, excellent light transmittance, and adhesion, and can achieve a higher degree of crosslinking compared to the case of containing only the compound of Chemical Formula 1. When both the compound of Chemical Formula 1 and the crosslinking aid are included, and the ratio of the crosslinking aid to the compound of Chemical Formula 1 increases, the light transmittance can increase with respect to the usage amount of the same amount of the crosslinking aid. As the ratio of the crosslinking aid decreases, the immersion rate, volume resistance, and degree of crosslinking improve. Therefore, the ratio can be appropriately determined within the above range according to the physical properties to be exhibited.

[0038] The crosslinking aid composition for an olefin copolymer according to an example of the present invention can be used in an amount of 0.1 to 9 parts by weight with respect to 80 to 99 parts by weight of the olefin copolymer. Specifically, the crosslinking aid composition for the olefin copolymer can be used 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, 0.4 part by weight or more, 0.5 part by weight or more, 0.6 part by weight or more, 0.7 part by weight or more, 0.8 part by weight or more, or 1 part by weight or more 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, or 3 parts by weight or less with respect to 80 to 99 parts by weight of the olefin copolymer. If the usage amount of the crosslinking aid composition is too small with respect to the olefin copolymer, the crosslinking reaction is difficult to occur. If the usage amount of the crosslinking aid composition is too large, the volume resistance of the sealing material for the optical element may decrease. When the crosslinking aid composition is used in the above ratio with respect to the olefin copolymer, the sealing material composition for the optical element can appropriately cause a crosslinking reaction and can be manufactured as a sealing material for the optical element, and the manufactured sealing material for the optical element can exhibit high volume resistance.

[0039] The olefin copolymer to which the crosslinking aid composition for the olefin copolymer can be applied can 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.

[0040] Specifically, the (a) density of the olefin copolymer can 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 or more 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, 0.880 g / cc or less, 0.875 g / cc or less, or 0.870 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 this and the encapsulant for optical elements manufactured using this 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.

[0041] The (b) melt index of the olefin copolymer can 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 deviates from the above range and is too low or too high, 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 it has excellent moldability of the encapsulant composition for optical elements, the encapsulant for optical elements and the encapsulant sheet for optical elements can be stably extruded.

[0042] Before the crosslinking aid composition for an olefin copolymer according to an example of the present invention is applied, the olefin copolymer can specifically be an ethylene / alpha-olefin copolymer.

[0043] Generally, the density of an ethylene / alpha-olefin copolymer is affected by factors such as the type and content of monomers used during polymerization, the degree of polymerization, etc. In the case of a copolymer, it is greatly affected by the content of the comonomer. Here, the higher the content of the comonomer, the more likely it is to produce a low-density ethylene / alpha-olefin copolymer, and the content at which the comonomer can be introduced into the copolymer can be dependent on the copolymerizability inherent to the catalyst.

[0044] The ethylene / alpha-olefin copolymer to which the crosslinking aid composition for an olefin copolymer of the present invention is applied exhibits a low density as described above and can exhibit excellent processability.

[0045] The ethylene / alpha-olefin copolymer is produced by copolymerizing ethylene and an alpha-olefin monomer. Here, the alpha-olefin, which means a portion derived from the alpha-olefin monomer in the copolymer, is a C4 - C20 alpha-olefin, 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. Among these, it can be one kind alone or a mixture of two or more kinds.

[0046] Among them, the alpha-olefin can be 1-butene, 1-hexene or 1-octene, and preferably can be 1-butene, 1-hexene, or a combination thereof.

[0047] In addition, in the ethylene / alpha-olefin copolymer, the content of the alpha-olefin can be appropriately selected within a range that satisfies the above physical property requirements. Specifically, it can be more than 0 and 99 mol% or less, or 10 to 50 mol%, but is not limited thereto.

[0048] In addition, the olefin copolymer can be an ethylene alpha-olefin copolymer having a volume resistivity of 1.0×10 15 Ω·cm or more. Specifically, it can be a copolymer having 3.0×10 15 Ω·cm or more, 5.0×10 15 Ω·cm, 7.0×10 15 Ω·cm or more, 1.0×10 16 Ω·cm or more, 3.0×10 16 Ω·cm or more, or 5.0×10 16 Ω·cm or more. When the volume resistivity of the olefin copolymer is too low, the volume resistivity after crosslinking of the sealing material composition for the optical element cannot reach an appropriate level. However, when the volume resistivity of the olefin copolymer satisfies the above value, the sealing material composition for the optical element 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 the olefin copolymer and the inconvenience in the production of the olefin copolymer having a high volume resistivity, those having 9.9×10 16 Ω·cm or less, 9.0×10 16 Ω·cm or less, 7.0×10 16 Ω·cm or less, 5.0×10 16 Ω·cm or less, 3.0×10 16 Ω·cm or less, 2.5×10 16 Ω·cm or less, or 2.0×10 16 Ω·cm or less can be used.

[0049] [Crosslinking Agent Composition for Olefin Copolymer] In addition, the present invention provides a crosslinking agent composition for an olefin copolymer.

[0050] Specifically, the crosslinking agent composition for the olefin copolymer of the present invention can contain a crosslinking agent, a silane coupling agent, and a compound represented by the following Chemical Formula 1.

[0051] A crosslinking agent, A silane coupling agent, A crosslinking agent composition for an olefin copolymer containing a compound represented by the following Chemical Formula 1:

[0052]

Chemical Formula

[0053] In Chemical Formula 1, l, m, n, and o are each independently an integer from 0 to 4.

[0054] The crosslinking agent composition for the olefin copolymer can contain a crosslinking aid composition for the olefin copolymer according to an example of the present invention as described above, and together with this, it contains a crosslinking agent and a silane coupling agent.

[0055] As the crosslinking agent, various crosslinking agents known in the technical field 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 can be used.

[0056] Also, in an example of the present invention, the crosslinking agent can specifically be an organic peroxide.

[0057] The organic peroxide can 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, preferably 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 within the above range is used as the crosslinking agent, the radical initiation reaction, that is, the crosslinking reaction, can be effectively carried out at the lamination process temperature for manufacturing the optoelectronic device.

[0058] 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, and 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, and t-butyl hydroperoxide; diacyl peroxides such as bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, and 2,4-dichlorobenzoyl peroxide; peroxyesters 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, and 2,5-dimethyl-2,5-di(benzoylperoxy)-3-hexyne; and ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, lauryl peroxide, azo compounds such as azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile).

[0059] The silane coupling agent can 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.

[0060] The compound of Chemical Formula 1 contained in the crosslinking agent composition for the olefin copolymer is as described above in the crosslinking aid composition for the olefin copolymer, and the content regarding the further crosslinking aid is the same. That is, the crosslinking agent composition for the olefin copolymer can contain the crosslinking aid composition for the olefin copolymer.

[0061] The crosslinking agent composition for the olefin copolymer can contain 1 to 90 parts by weight of the crosslinking agent, 0.1 to 20 parts by weight of the silane coupling agent, and 1 to 90 parts by weight of the compound of Chemical Formula 1. The content of each component can mean the relative ratio between the weights of the respective components contained in the crosslinking agent composition for the olefin copolymer.

[0062] The crosslinking agent can be contained in the crosslinking agent composition for the olefin copolymer in an amount of 1 to 90 parts by weight. Specifically, it can be contained in an amount of 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, 10 parts by weight or more to 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, 30 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 resistance of the encapsulant for optical elements manufactured using the olefin copolymer may decrease. 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 this can appropriately 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 resistance.

[0063] The silane coupling agent can be contained in the crosslinking agent composition for the olefin copolymer in an amount of 0.1 to 20 parts by weight. Specifically, it can be contained in an amount of 0.1 part by weight or more, 0.2 part by weight or more, 0.5 part by weight or more, 0.7 part by weight or more, 0.9 part by weight or more, 1.0 part by weight or more, or 1.5 parts by weight or more to 20 parts by weight or less, 18 parts by weight or less, 17 parts by weight or less, 15 parts by weight or less, 12 parts by weight or less, 10 parts by weight or less, 8 parts by weight or less, 7 parts by weight or less, 5 parts by weight or less, or 4 parts by weight or less. When the content of the silane coupling agent is too small, when using the olefin copolymer, the adhesion of the encapsulant composition for optical elements to the substrate, for example, the adhesion of the encapsulant composition for optical elements to a glass substrate is low, and it is difficult to exhibit appropriate performance as an encapsulant for optical elements. When the content of the silane coupling agent is too large, the volume resistance of the encapsulant for optical elements decreases, which is not appropriate. When the silane coupling agent is contained in the above range in the crosslinking agent composition for the olefin copolymer, the encapsulant composition for optical elements using this shows excellent adhesiveness to the substrate of the optical element or the glass substrate where the optical element is located, effectively prevents moisture penetration, etc., and the optical element can maintain excellent performance for a long time, and the encapsulant for optical elements can exhibit a high volume resistance.

[0064] The compound of Chemical Formula 1 can be contained in the crosslinking agent composition for the olefin copolymer in an amount of 1 to 9 parts by weight. Specifically, it can be contained in an amount of 1 part by weight or more, 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more, 8 parts by weight or more, or 10 parts by weight or more to 90 parts by weight or less, 80 parts by weight or less, 70 parts by weight or less, 60 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, or 30 parts by weight or less.

[0065] The crosslinking agent composition for an olefin copolymer according to an example of the present invention can be used in an amount of 0.21 to 20 parts by weight based on 80 to 99 parts by weight of the olefin copolymer. The crosslinking aid composition for the olefin copolymer can be used in an amount of specifically 0.21 parts by weight or more, 0.25 parts by weight or more, 0.30 parts by weight or more, 0.40 parts by weight or more, 0.50 parts by weight or more, 0.60 parts by weight or more, 0.70 parts by weight or more, 0.80 parts by weight or more, or 1.0 part by weight or more to 20 parts by weight or less, 19 parts by weight or less, 18 parts by weight or less, 17 parts by weight or less, 16.5 parts by weight or less, 16 parts by weight or less, or 15 parts by weight or less based on 80 to 99 parts by weight of the olefin copolymer. If the amount of the crosslinking agent composition used with respect to the olefin copolymer is too small, the crosslinking reaction hardly occurs, and if the amount of the crosslinking agent composition used is too large, the volume resistance of the encapsulant for an optical element may decrease. When the crosslinking agent composition is used in the above ratio with respect to the olefin copolymer, the encapsulant composition for an optical element using the same can appropriately cause a crosslinking reaction and can be manufactured as an encapsulant for an optical element, and the manufactured encapsulant for an optical element can exhibit a high volume resistance.

[0066] The encapsulant composition for an optical element to which an additive for a crosslinking aid composition for an olefin copolymer or an encapsulant composition for an optical element according to an embodiment of the present invention is applied can increase the volume resistance after crosslinking. Specifically, the increase amount can be 1.5 times or more, 1.6 times or more, 1.65 times or more, 1.7 times or more, or 1.8 times or more, and can be 200 times or less, or 100 times or less.

[0067] In addition, the encapsulant composition for an optical element to which an additive for a crosslinking aid composition for an olefin copolymer or an encapsulant composition for an optical element according to an embodiment of the present invention is applied can exhibit excellent light transmittance after crosslinking. Specifically, in the wavelength range of 380 nm to 1100 nm, the light transmittance can be 92.0% or more, specifically 92.1% or more or 92.2% or more.

[0068] [Additive for Encapsulant Composition for Optical Element] The present invention also provides an additive for a sealing material composition for an optical element, which contains a compound of the following Chemical Formula 1.

[0069] [Chemical Formula]

[0070] In Chemical Formula 1, l, m, n, and o are each independently an integer from 0 to 4.

[0071] The description of the compound of Chemical Formula 1 is the same as the description of the compound of Chemical Formula 1 included in the crosslinking aid composition for an olefin copolymer and the crosslinking agent composition for an olefin copolymer.

[0072] The additive for a sealing material composition for an optical element according to an example of the present invention can be used in an amount of 0.1 to 9 parts by weight with respect to 80 to 99 parts by weight of an olefin copolymer. Specifically, the additive for a sealing material composition for an optical element can be used 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, 0.4 part by weight or more, 0.5 part by weight or more, 0.6 part by weight or more, 0.7 part by weight or more, 0.8 part by weight or more, or 1 part by weight or more 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, or 3 parts by weight or less with respect to 80 to 99 parts by weight of an olefin copolymer. When the amount of the additive for a sealing material composition for an optical element used with respect to the olefin copolymer is too small, the crosslinking reaction hardly occurs. When the amount of the additive for a sealing material composition for an optical element used is too large, the volume resistance of the sealing material for an optical element may decrease. When the additive for a sealing material composition for an optical element is used in the above ratio with respect to the olefin copolymer, the sealing material composition for an optical element can appropriately cause a crosslinking reaction and can be manufactured as a sealing material for an optical element, and the manufactured sealing material for an optical element can exhibit a high volume resistance.

[0073] When the additives for the crosslinking aid composition for the olefin copolymer, the crosslinking agent composition for the olefin copolymer, and the encapsulant composition for the optical element are used in the encapsulant composition for the optical element, they can be used together with the olefin copolymer. The olefin copolymer can be contained in an amount of 80 to 99 parts by weight, specifically 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 to 99 parts by weight or less, 98 parts by weight or less, 97 parts by weight or less, 96 parts by weight or less, or 95 parts by weight or less, based on 100 parts by weight of the encapsulant composition for the optical element. If the content of the olefin copolymer contained in the encapsulant composition for the optical element is too small, it is difficult to appropriately exhibit the mechanical properties such as tear resistance and tear strength of the encapsulant for the optical element. Therefore, when the olefin copolymer is contained in the above range in the entire encapsulant composition for the optical element, it can exhibit appropriate mechanical properties as an encapsulant for the optical element.

[0074] In addition, the additive for the encapsulant composition for the optical element can further contain one or more selected from light stabilizers, UV absorbers, heat stabilizers, etc., as required.

[0075] The light stabilizer can play a role of capturing the active species at the start of photo-degradation of the resin and preventing photo-oxidation according to the application to which the composition is applied. The types of light stabilizers that can be used are not particularly limited, and for example, known compounds such as hindered amine compounds or hindered piperidine compounds can be used.

[0076] The UV absorber can play a role of absorbing ultraviolet rays from sunlight, etc., according to the application of the composition, converting them into harmless thermal energy within the molecule, and preventing the active species at the start of photo-degradation in the resin composition from being excited. The specific types of UV absorbers that can be used are not particularly limited, and 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.

[0077] 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'-diyl bisphosphonate, 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 more of the above can be used.

[0078] 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 adjusted 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.

[0079] In addition to the above components, the encapsulant composition for optical elements can further appropriately contain various additives known in the art according to the use to which the resin component is applied.

[0080] In addition, the encapsulant composition for optical elements can be molded by methods such as injection and extrusion and used as various molded products. Specifically, it can be used as an encapsulant for encapsulating elements in various optoelectronic devices, such as solar cells, and can also be used as an industrial material applied to, for example, a temperature rise lamination process, but the use is not limited thereto.

[0081] 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.

[0082] Example 1 0.5 parts by weight of triallyl isocyanurate (TAIC) and 0.125 parts by weight of tetravinyltin (TVT) were used as crosslinking aids.

[0083] Examples 2 to 4 Crosslinking aids were prepared in the same manner as in Example 1, except that the amounts of triallyl isocyanurate (TAIC) and tetravinyltin (TVT) were varied as shown in Table 1 below.

[0084] Example 5 0.625 parts by weight of tetravinyltin (TVT) was used as a crosslinking aid.

[0085] Examples 6 and 7 Crosslinking aids were prepared in the same manner as in Example 5, except that the amount of tetravinyltin (TVT) was varied as shown in Table 1 below.

[0086] Comparative Example 1 0.5 parts by weight of triallyl isocyanurate (TAIC) was used as a crosslinking aid.

[0087] Comparative Example 2 0.5 parts by weight of tetravinylsilane (TVS) was used as a crosslinking aid.

[0088] Comparative Example 3 1.0 parts by weight of triallyl isocyanurate (TAIC) was used as a crosslinking aid.

[0089] [Table 1]

[0090] Example 1A LUCENE manufactured by LG Chem, which is an ethylene / 1-butene copolymer TM 500 g of LF675 was dried overnight using a convection oven at 40 °C. The density of the LUCENE TM LF675 measured according to ASTM D1505 was 0.877 g / cm3 It is as follows. The melt index (at 190°C, 2.16 Kg) measured in accordance with ASTM D1238 is 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 at 40°C. After charging the ethylene / alpha-olefin copolymer into the bowl, using an electric pipette, as a crosslinking agent, 1 phr (parts per hundred rubber) of t-butyl 1-(2-ethylhexyl) monoperoxycarbonate (TBEC, manufactured by Sigma-Aldrich), as a crosslinking aid, 0.625 phr of the crosslinking aid manufactured in Example 1 above, and as a silane coupling agent, 0.2 phr of methacryloxypropyltrimethoxysilane (MEMO, manufactured by Shin-Etsu) were charged. While stirring at 40 rpm, the change in torque value over time was observed, and the impregnation was terminated when the torque value increased rapidly.

[0091] Thereafter, the impregnated sample was press-molded using a micro-extruder at a low temperature (under the condition that the extruder barrel temperature was 90 to 100°C) so as not to be crosslinked at a mean thickness of 0.5 mm to produce a sheet-like sealing material film.

[0092] Examples 2A to 7A The same process as in Example 1A was carried out except that, as the crosslinking aid, Examples 2 to 7 were used instead of Example 1.

[0093] Comparative Examples 1A to 3A The same process as in Example 1A was carried out except that, instead of the crosslinking aid of Example 1, the crosslinking aids of Comparative Examples 1 to 3 were used.

[0094] Experimental Example (1) Impregnation rate The pre-soaking end times before aging and the soaking end times after aging were measured for each of Examples 1A to 7A and Comparative Example 2A, and after calculating the time taken for impregnation, they were shown in Table 2. Also, the soaking end times were measured for Comparative Examples 1A and 3A, and after calculating the time taken for impregnation, they were shown in Table 2.

[0095] (2) Volume resistance For the ethylene / alpha-olefin copolymers used in each of Examples 1A to 7A and Comparative Examples 1A to 3A, at a temperature of 23 ± 1 °C and a humidity condition of 50 ± 3%, using an Agilent 4339B High-Resistance meter (manufactured by Agilent Technologies, Inc.), a voltage of 1000 V was applied for 600 seconds to measure the volume resistance.

[0096] Also, each of the impregnated resins produced in Examples 1A to 7A and Comparative Examples 1A to 3A was press-molded at a low temperature (under the condition of an extruder barrel temperature of 90 to 100 °C) so as not to be cross-linked at a high temperature using a micro extruder to produce sheet-like test pieces with an average thickness of 0.5 mm. Thereafter, the test pieces were cross-linked at 150 °C for 20 minutes. For each of the cross-linked test pieces, at a temperature of 23 ± 1 °C and a humidity condition of 50 ± 3%, using an Agilent 4339B High-Resistance meter (manufactured by Agilent Technologies, Inc.), a voltage of 1000 V was applied for 600 seconds to measure the volume resistance.

[0097] (3) Light transmittance Using a Shimadzu UV-3600 spectrophotometer, the light transmittance was measured at 200 nm to 1,000 nm to obtain a light transmittance curve, and then the values at 280 to 380 nm and the values at 380 to 1100 nm were confirmed.

[0098] - Measurement mode: transmittance - Wavelength interval: 1 nm - Measurement speed: medium

[0099] (4) Measurement of yellow index For each of the crosslinked test pieces produced by the measurement of the above (2) volume resistance, the yellowness index was measured in accordance with ASTM E313.

[0100] [Table 2]

[0101] As can be confirmed from Table 2 above, when using the crosslinking aid compositions of Examples 1 to 7, the impregnation completion time of the crosslinking agent can be shortened compared to the case of using triallyl isocyanurate of Comparative Examples 1 and 3 as the crosslinking aid, and it was confirmed that the volume resistance of the olefin copolymer composition can be significantly improved after crosslinking. Also, when using the crosslinking aid compositions of Examples 1 to 7, the volume resistance of the olefin copolymer composition can be significantly improved after crosslinking compared to the case of using tetravinylsilane of Comparative Example 2 as the crosslinking aid, and it was confirmed that a high light transmittance is also exhibited after crosslinking. When tetravinylsilane of Comparative Example 2 was used as the crosslinking aid, although it was excellent in the effect of shortening the impregnation completion time of the crosslinking agent, the effect of improving the volume resistance of the olefin copolymer composition after crosslinking was not sufficient compared to Examples 1 to 7, and the light transmittance after crosslinking was not sufficient.

Claims

1. A crosslinking aid composition for an olefin copolymer, comprising a compound of the following Chemical Formula 1. 【Chemical 1】 In Chemical Formula 1, l, m, n, and o are each independently an integer from 0 to 4.

2. The crosslinking aid composition for an olefin copolymer according to Claim 1, wherein in Chemical Formula 1, m, n, and o are each independently an integer from 0 to 2.

3. The crosslinking aid composition for an olefin copolymer according to Claim 1, wherein the compound of Chemical Formula 1 is tetravinyltin.

4. The crosslinking aid composition for an olefin copolymer according to Claim 1, further comprising a crosslinking aid containing at least one unsaturated group.

5. The crosslinking aid composition for an olefin copolymer according to Claim 4, wherein the weight ratio of the compound of Chemical Formula 1 and the crosslinking aid containing at least one unsaturated group is 20:80 to 80:

20.

6. The crosslinking aid containing at least one unsaturated group according to Claim 4 includes one or more selected from the group consisting of triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate, diallyl maleate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate. The crosslinking aid composition for an olefin copolymer according to Claim 4.

7. A crosslinking agent composition for an olefin copolymer, comprising a silane coupling agent, and a compound of the following Chemical Formula 1. 【Chemical 2】 In Chemical Formula 1, l, m, n, and o are each independently an integer from 0 to 4.

8. The crosslinking agent composition for an olefin copolymer according to Claim 7, 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 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), the crosslinking agent composition for an olefin copolymer according to claim 7.

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 (MEMO), vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and p-styryltrimethoxysilane, the crosslinking agent composition for an olefin copolymer according to claim 7.

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