Composition for forming silicone foam and silicone foam sheet

Abstract

The present invention relates to a composition for forming a silicone foam, a foam sheet comprising a silicone foam formed therefrom, and a secondary battery module comprising the foam sheet, the composition comprising: 100 parts by weight of a silicone mixture comprising at least one organopolysiloxane; 0.0001-0.05 parts by weight of a platinum catalyst; 20-80 parts by weight of a flame retardant; and 1-10 parts by weight of hollow glass.

Description

Composition for forming silicone foam and silicone foam sheet

[0001] The present invention relates to a composition for forming a silicone foam and a silicone foam sheet, and more specifically, to a composition for forming a silicone foam, a silicone foam sheet comprising a silicone foam formed therefrom, and a secondary battery module comprising a silicone foam sheet.

[0002] In order to enhance the stability of pouch cells within secondary battery modules, a conventional method has been used in which urethane foam sheets are inserted between the cells to prevent cell swelling during charging.

[0003] However, while urethane foam sheets possess excellent compression recovery properties that allow for expansion control, they have low flame retardancy, which limits the potential for fire to easily spread to surrounding cells if a secondary battery cell ignites.

[0004] Although there have been attempts to use silicone foam sheets with excellent heat resistance to improve such flame retardancy issues, problems arose in which the silicone foam stabilizer did not function effectively during the manufacturing process of the silicone foam sheets, making it difficult to form the foam uniformly and resulting in reduced durability.

[0005] Accordingly, there is a growing need for silicone foam sheets that satisfy both heat resistance and stability suitable for secondary batteries.

[0006] The present invention provides a composition for forming a silicone foam that can act as a buffer between cells in a secondary battery module and has excellent flame retardancy.

[0007] In addition, the present invention provides a silicone foam formed from the above-described silicone foam forming composition.

[0008] In addition, the present invention provides a foamed sheet comprising the above-mentioned silicone foam.

[0009] In addition, the present invention provides a secondary battery module comprising the above-mentioned silicone foam sheet.

[0010]

[0011] The problems that the present invention aims to solve are not limited to the problem(s) mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below.

[0012] To achieve the above objective, the present invention provides a composition for forming a silicone foam comprising 100 parts by weight of a silicone mixture containing at least one organopolysiloxane; 0.0001 to 0.05 parts by weight of a platinum catalyst; 20 to 80 parts by weight of a flame retardant; and 1 to 10 parts by weight of hollow glass.

[0013] Based on a total weight of 100 of the above silicone mixture, it may comprise 20 to 70 weight% of a first organopolysiloxane containing at least two unsaturated hydrocarbon groups; 20 to 70 weight% of a second organopolysiloxane containing at least two hydroxyl groups; 0 to 20 weight% of a third organopolysiloxane containing hydrogen groups at both ends; and 2 to 10 weight% of a fourth organopolysiloxane containing at least two hydrogen groups.

[0014] The first organopolysiloxane may have a molecular weight of 20,000 to 150,000 g / mol, a viscosity (at 25°C) of 500 to 130,000 cps, and an unsaturated hydrocarbon group of 0.01 to 0.05 mmol / g.

[0015] The above second organopolysiloxane may have a molecular weight of 2,000 to 120,000 g / mol, a viscosity (at 25°C) of 20 to 60,000 cps, and a hydroxyl group content of 0.017 to 3.0 mmol / g.

[0016] The above third organopolysiloxane may have a molecular weight of 3,500 to 30,000 g / mol, a viscosity (at 25°C) of 30 to 1,000 cps, and a hydrogen group (SiH) content of 0.07 to 2.0 mmol / g.

[0017] The above-mentioned fourth organopolysiloxane may have a molecular weight of 5,000 to 30,000 g / mol, a viscosity (at 25°C) of 20 to 500 cps, and a hydrogen group (SiH) content of 1.5 to 15.0 mmol / g.

[0018] The weight ratio of the first organopolysiloxane and the second organopolysiloxane may be 1:0.3 to 1:3.3.

[0019] The average particle size (D50) of the above hollow glass is 50 μm or more and 70 μm or less, and the density is 0.3 g / cm³ 3 It may be less than.

[0020] The platinum catalyst may comprise at least one selected from the group consisting of platinum β-diketone complexes, platinum-cyclic diene complexes, platinum halides, platinum-olefin complexes, platinum-alcoolat complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, platinum vinylsiloxane complexes (platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complexes), bis-(γ-picoline)-platinum dichloride, trimethylenedipyridine-platinum dichloride, dicyclopentadiene-platinum dichloride, cyclooctadiene-platinum dichloride, cyclopentadiene-platinum dichloride), bis(alkynyl)bis(triphenylphosphine)platinum complexes, bis(alkenyl)(cyclooctadiene)platinum complexes, and combinations thereof. there is.

[0021] The flame retardant may include at least one selected from the group consisting of aluminum hydroxide, magnesium hydroxide, barium hydroxide, zirconium hydroxide, magnesium carbonate, calcium carbonate, tin oxide, aluminum oxide, zinc borate, dolomite, hydrotalcite, wollastonite, silica, fluorine-based flame retardants, platinum flame retardants, and combinations thereof.

[0022] The viscosity of the above silicone foam sheet forming composition may be 20,000 to 150,000 cps.

[0023]

[0024] In addition, the present invention may provide a silicone foam sheet comprising: a substrate layer; and a silicone foam layer formed from a silicone foam forming composition according to claim 1 located on at least one surface of the substrate layer.

[0025] The above substrate layer may include at least one selected from the group consisting of PET (polyethylene terephthalate), PC (polycarbonate), PE (Polyethylene), PEN (Polyethylene naphthalate) and combinations thereof.

[0026] The thickness of the above silicone foam sheet is 0.5 to 5 mm, and the density is 0.25 to 0.45 g / cm³. 3 The surface hardness (Shore 00) is 20 to 50, the compressive strength (stress when compressed by 50% in the thickness direction) is 300 kPa or less, and the vertical flame retardancy may be UL94 V-0.

[0027] The average length of the pores in the above silicone foam layer may be 800 µm or less.

[0028]

[0029] In addition, the present invention provides a secondary battery module comprising the above-mentioned silicone foam sheet.

[0030] The composition for forming a silicone foam according to the present invention can provide a silicone foam with low density and low compressive strength because it includes hollow glass and can form uniform and fine pores.

[0031] In addition, the composition for forming a silicone foam according to the present invention is manufactured in a liquid form, which not only provides excellent workability but also can provide a silicone foam having excellent flame retardancy and heat resistance after curing.

[0032] In addition, the silicone foam of the present invention has the effect of excellent productivity because a continuous process is possible by using a method of coating a liquid silicone foam-forming composition onto a substrate film.

[0033]

[0034] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the invention or the claims.

[0035] FIG. 1 illustrates a laminated structure of a foamed sheet according to one embodiment of the present invention.

[0036] FIG. 2 illustrates a laminated structure of a foamed sheet according to one embodiment of the present invention.

[0037] FIG. 3 is an image of a cross-section of a foamed sheet according to one embodiment of the present invention taken with FE-SEM.

[0038] It should be noted that in the following description, only the parts necessary for understanding the embodiments of the present invention are described, and the description of other parts may be omitted to the extent that it does not detract from the gist of the present invention.

[0039] The terms and words used in the specification and claims described below should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely preferred embodiments of the invention and do not represent all aspects of the technical spirit of the invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0040] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “comprising,” or “having” are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0041] Where in this specification, when a quantity, concentration, or other value or parameter is given as an enumeration of a range, a preferred range, a preferred upper limit, and a preferred lower limit, it should be understood that any pair of any upper range limit or preferred value and any lower range limit or preferred value specifically discloses all ranges formed by any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether the range is disclosed separately.

[0042] Where a range of numerical values ​​is mentioned in this specification, unless otherwise stated, the range and the scope of the invention within that range are not intended to be limited to the specific values ​​mentioned when defining the range.

[0043] Throughout the specification, the same reference numerals refer to the same components. Additionally, in describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the invention.

[0044] When the positional relationship between two parts is described using expressions such as 'on', 'on the upper', 'on the lower', or 'next to', one or more other parts may be located between the two parts unless 'immediately' or 'directly' is used.

[0045] In describing drawings, positional relationships such as 'top,' 'upper part,' 'upper surface,' 'lower part,' 'lower part,' and 'lower surface' are described based solely on the drawing and do not represent absolute positional relationships. In other words, depending on the observation location, the positions of 'top' and 'lower part,' or 'upper surface' and 'lower surface,' may be interchanged.

[0046]

[0047] The present invention will be described in detail below.

[0048]

[0049] Composition for forming silicone foam

[0050] In one embodiment of the present invention, a composition for forming a foamed sheet is provided, comprising: a silicone mixture containing at least one organopolysiloxane; a platinum catalyst; a flame retardant; and hollow glass.

[0051] In one embodiment, the silicon mixture may comprise a first organopolysiloxane comprising at least two unsaturated hydrocarbon groups; a second organopolysiloxane comprising at least two hydroxyl groups; a third organopolysiloxane comprising hydrogen groups at both ends; and a fourth organopolysiloxane comprising at least two hydrogen groups.

[0052] The above-mentioned first organopolysiloxane reacts with the fourth organopolysiloxane to form a three-dimensional network structure.

[0053] In one embodiment, the first organopolysiloxane may include unsaturated hydrocarbon groups at both ends.

[0054] The above unsaturated hydrocarbon group may be a vinyl group, an allyl group, a butenyl group, a pentenyl group, or a hexenyl group, and specifically, may be a vinyl group.

[0055] In the present invention, the vinyl group may exist in a form bonded to a silicon atom (Si-Vi).

[0056] In one embodiment, the first organopolysiloxane undergoes an addition reaction with a fourth organopolysiloxane containing at least two hydrogen groups in the presence of the platinum catalyst to form a three-dimensional network structure, thereby having the effect of excellent elasticity.

[0057] Specifically, the Si-Vi group of the first organopolysiloxane and the Si-H group of the fourth organopolysiloxane react to form a Si-C bond, and the first organopolysiloxane molecule and the fourth organopolysiloxane molecule can cross-link with each other to form a three-dimensional network structure.

[0058] The first organopolysiloxane may be included in an amount of 20 to 70 weight percent based on 100 weight percent of the total silicone mixture. When the first organopolysiloxane is included in the above range, a cured structure with excellent mechanical strength and elasticity can be formed.

[0059] In one embodiment, the molecular weight of the first organopolysiloxane may be 20,000 to 150,000 g / mol.

[0060] In one embodiment, the viscosity (25°C) of the first organopolysiloxane may be 500 to 130,000 cps.

[0061] In one embodiment, the content of the unsaturated hydrocarbon group, specifically the vinyl group (SiVi), of the first organopolysiloxane may be 0.01 to 0.1 mmol / g.

[0062] In one embodiment, the first organopolysiloxane may be one or more of the following types.

[0063] The above-mentioned second organopolysiloxane reacts with the fourth organopolysiloxane to generate hydrogen gas and plays a role in forming pores of the foam.

[0064] In one embodiment, the second organopolysiloxane may include hydroxyl groups (SiOH) at both ends.

[0065] In the present invention, the hydroxyl group may exist in a form bonded to a silicon atom (Si-OH).

[0066] The second organopolysiloxane may be included in an amount of 20 to 70 weight percent based on 100 weight percent of the total silicone mixture. When the second organopolysiloxane is included in the above range, a foam having the low density desired in the present invention can be formed.

[0067] In one embodiment, the second organopolysiloxane can undergo a condensation reaction (dehydrogenation reaction) with a fourth organopolysiloxane containing at least two hydrogen groups in the presence of the platinum catalyst.

[0068] Specifically, the Si-OH group of the second organopolysiloxane and the Si-H group of the fourth organopolysiloxane can react to generate and release hydrogen (H2), thereby forming a siloxane (Si-O-Si) bond.

[0069] In one embodiment, the molecular weight of the second organopolysiloxane may be 2,000 to 120,000 g / mol.

[0070] In one embodiment, the viscosity (25°C) of the second organopolysiloxane may be 20 to 60,000 cps.

[0071] In one embodiment, the content of the hydroxyl group (SiOH) of the second organopolysiloxane may be 0.017 to 3.0 mmol / g.

[0072] In one embodiment, one or more of the second organopolysiloxanes may be used.

[0073] Specifically, the second organopolysiloxane may be used by mixing a relatively low-viscosity second organopolysiloxane containing hydroxyl groups (Si-OH) having 35 to 120 cps and a relatively high-viscosity second organopolysiloxane containing hydroxyl groups (Si-OH) having 3,000 to 6,000 cps. When using a mixture of second organopolysiloxanes with different viscosities, a foaming effect and a three-dimensional network structure can be achieved.

[0074] In one embodiment, the weight ratio of the low-viscosity second organopolysiloxane and the high-viscosity second organopolysiloxane may be 3 to 20:80 to 97, 10 to 20:80 to 90, or 15 to 20:80 to 85. When the low-viscosity second organopolysiloxane and the high-viscosity second organopolysiloxane are mixed in the above ratio, a foam having the low density and compressive strength desired in the present invention can be formed.

[0075] In one embodiment, the weight ratio of the first organopolysiloxane and the second organopolysiloxane may be 1:0.3 to 1:3.3, or 1:1. When the first organopolysiloxane and the second organopolysiloxane are mixed within the above range, addition and condensation reactions occur simultaneously, and bubbles are generated by hydrogen gas, forming a three-dimensional network to create a uniform and robust pore structure.

[0076] On the other hand, if the addition reaction and the condensation reaction do not occur simultaneously and the addition reaction occurs first, the material hardens before pores are formed, preventing sufficient foaming; conversely, if the condensation reaction occurs first, bubbles caused by hydrogen gas may become too large or degass before hardening, potentially forming non-uniform pores.

[0077] The above-mentioned third organopolysiloxane reacts with the first organopolysiloxane or the second organopolysiloxane to extend the polymer chains, thereby increasing mechanical strength, elasticity, and flexibility.

[0078] In one embodiment, the third organopolysiloxane may include hydrogen groups (SiH) at both ends.

[0079] In the present invention, hydrogen groups may exist in a form (SiH) bonded to silicon atoms. That is, the hydrogen groups included in the third organopolysiloxane may have a linear structure including hydrogen groups bonded to silicon atoms at both ends.

[0080] The third organopolysiloxane may be included in an amount of 0 to 20 weight% based on 100 weight% of the total silicone mixture. When the third organopolysiloxane is included in the above range, the polymer chain can be extended without hindering curing.

[0081] In one embodiment, the molecular weight of the third organopolysiloxane may be 3,500 to 30,000 g / mol.

[0082] In one embodiment, the viscosity (25°C) of the third organopolysiloxane may be 30 to 1,000 cps.

[0083] In one embodiment, the content of hydrogen groups (SiH) of the third organopolysiloxane may be 0.07 to 2.0 mmol / g.

[0084] In one embodiment, one or more types of the third organopolysiloxane may be used.

[0085] The above-mentioned fourth organopolysiloxane forms a three-dimensional network structure by undergoing an addition reaction with the first organopolysiloxane, and plays a role in forming pores by generating hydrogen gas through a condensation reaction with the second organopolysiloxane.

[0086] The above-mentioned fourth organopolysiloxane has a structure capable of contributing to a cross-linking reaction by including hydrogen groups bonded to at least two silicon atoms, and is functionally and structurally different from the third organopolysiloxane which includes hydrogen groups (SiH) at both ends that act as chain extensions. The above-mentioned fourth organopolysiloxane may be included in an amount of 2 to 10 weight% based on 100 weight% of the total silicon mixture. When the fourth organopolysiloxane is included in the above range, a uniform network structure is formed, resulting in excellent mechanical strength and elasticity, and a foaming amount capable of forming a foam with uniform pores and low density can be obtained.

[0087] In one embodiment, the molecular weight of the fourth organopolysiloxane may be 5,000 to 30,000 g / mol.

[0088] In one embodiment, the viscosity (25°C) of the fourth organopolysiloxane may be 20 to 500 cps.

[0089] In one embodiment, the content of hydrogen groups (SiH) of the fourth organopolysiloxane may be 1.5 to 15.0 mmol / g.

[0090] In one embodiment, the composition for forming the silicone foam may include at least two types of organopolysiloxanes containing hydrogen groups to control the curing speed and foaming speed. Specifically, it may include a third organopolysiloxane to increase flexibility and a fourth organopolysiloxane to promote curing and foaming.

[0091] In one embodiment, one or more of the fourth organopolysiloxanes may be used.

[0092] In one embodiment, the average particle size (D50) of the hollow glass may be 50 μm or more and 70 μm or less. In addition, the density of the hollow glass is 0.3 g / cm³ 3 Less than or equal to 0.1 to 0.3 g / cm³ 3It may be less than or equal to the above. When using hollow glass having the above average particle size range and density, bubbles generated by the curing reaction can be trapped between the hollow glass, preventing excessive growth of bubbles (pores), and a uniform bubble formation effect can be obtained.

[0093] In the present invention, the average particle size (D50) refers to the particle size corresponding to a volume-based cumulative fraction of 50% in the particle size distribution of hollow glass particles, and can be measured by a conventional particle size analysis method. For example, it can be measured by a laser diffraction particle size analysis method.

[0094] The above hollow glass may be included in an amount of 1 to 10 parts by weight or 1 to 5 parts by weight based on 100 parts by weight of the silicon mixture. When the hollow glass is included in the above range, bubbles generated by the curing reaction can be trapped between the hollow glass, preventing excessive growth of bubbles (pores), and a saturating effect can be obtained to form bubbles (pores) of a uniform size.

[0095] In one embodiment, the platinum catalyst is a platinum β-diketone complex, a platinum-cyclic diene complex, a platinum halide (H2PtCl6·6H2O, etc.), a platinum-olefin complex, a platinum-alcoolat complex, a platinum-ether complex, a platinum-aldehyde complex, a platinum-ketone complex, a platinum vinylsiloxane complex (platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex), a bis-(γ-picoline)-platinum dichloride, a trimethylenedipyridine-platinum dichloride, a dicyclopentadiene-platinum dichloride, a cyclooctadiene-platinum dichloride, a cyclopentadiene-platinum dichloride), a bis(alkynyl)bis(triphenylphosphine)platinum complex, It may include at least one selected from the group consisting of bis(alkenyl)(cyclooctadiene)platinum complexes and combinations thereof.

[0096] Specifically, the platinum catalyst may include at least one selected from the group consisting of platinum β-diketone complexes, platinum-cyclic diene complexes, and combinations thereof.

[0097] For example, the platinum β-diketone complex may be a trimethyl(acetylacetonate) platinum complex, a trimethyl(2,4-pentanedianate) platinum complex, a trimethyl(3,5-heptanedianate) platinum complex, a trimethyl(methylacetoacetate) platinum complex, a bis(2,4-pentanedianate) platinum complex, a bis(2,4-hexanedionate) platinum complex, a bis(2,4-heptanedianate) platinum complex, a bis(3,5-heptanedianate) platinum complex, a bis(1-phenyl-1,3-butanedianate) platinum complex, or a bis(1,3-diphenyl-1,3-propanedianate) platinum complex, etc.

[0098] For example, the platinum-cyclic diene complex is a (1,5-cyclooctadienyl) dimethyl platinum complex, a (1,5-cyclooctadienyl) diphenyl platinum complex, a (1,5-cyclooctadienyl) dipropyl platinum complex, a (2,5-norvonadiene) dimethyl platinum complex, a (2,5-norvonadiene) diphenyl platinum complex, a (cyclopentadienyl) dimethyl platinum complex, a (methylcyclopentadienyl) diethyl platinum complex, a (trimethylsilylcyclopentadienyl) diphenyl platinum complex, a (methylcycloocta-1,5-dienyl) diethyl platinum complex, a (cyclopentadienyl) trimethyl platinum complex, a (cyclopentadienyl) ethyl dimethyl platinum complex, a (cyclopentadienyl) acetyl dimethyl platinum complex, It may be a (methylcyclopentadienyl) trimethyl platinum complex, a (methylcyclopentadienyl) trihexyl platinum complex, a (trimethylsilyl cyclopentadienyl) trimethyl platinum complex, or a (dimethylphenylsilyl cyclopentadienyl) triphenyl platinum complex, a (cyclopentadienyl) dimethyltrimethylsilylmethyl platinum complex, etc.

[0099] When the above silicone foam forming composition uses at least one selected from the group consisting of platinum β-diketone complexes, platinum-cyclic diene complexes, and combinations thereof, which are platinum catalysts for photocuring, a dark reaction does not occur at room temperature, so the composition has the effect of excellent storage stability even without including a curing retardant.

[0100] In one embodiment, the platinum catalyst may be included in an amount of 0.0001 parts by weight or more and 0.05 parts by weight or less, 0.001 parts by weight or more and 0.04 parts by weight or less, or 0.01 parts by weight or more and 0.03 parts by weight or less, based on 100 parts by weight of the silicon mixture. When the platinum catalyst is included in the above range, the addition reaction and condensation reaction by photocuring or thermal curing proceed together, thereby curing simultaneously with foaming, which can improve productivity.

[0101] In one embodiment, the flame retardant may include at least one selected from the group consisting of aluminum hydroxide, magnesium hydroxide, barium hydroxide, zirconium hydroxide, magnesium carbonate, calcium carbonate, tin oxide, aluminum oxide, zinc borate, dolomite, hydrotalcite, wollastonite, silica, fluorine-based flame retardants, platinum flame retardants, and combinations thereof.

[0102] The flame retardant may be included in an amount of 20 to 80 parts by weight based on 100 parts by weight of the silicone mixture. When the flame retardant is included in the above range, it can be uniformly dispersed in the silicone mixture, a uniform coating film can be obtained after coating on the substrate film, and flame retardancy can be further improved.

[0103] In one embodiment, the viscosity of the silicone foam forming composition may be 20,000 to 150,000 cps, or 57,000 to 72,000 cps.

[0104] The above-mentioned silicone foam forming composition is in a liquid form, and can be easily coated onto a substrate layer described later.

[0105]

[0106] silicone foam sheet

[0107] In one embodiment of the present invention, a silicone foam sheet is provided comprising: a substrate layer; and a silicone foam layer formed from a composition for forming a silicone foam located on at least one surface of the substrate layer.

[0108] FIG. 1 schematically illustrates a silicone foam sheet (100) comprising: a substrate layer (110) according to one embodiment of the present invention; and a silicone foam layer (120) coated on at least one surface of the substrate layer (110). Referring to FIG. 1, the structure may have a silicone foam layer (120) laminated on one surface of the substrate layer (110).

[0109] FIG. 2 schematically illustrates a silicone foam sheet (200) comprising a substrate layer (210) according to one embodiment of the present invention; a silicone foam layer (220) coated on at least one surface of the substrate layer (210); and a substrate layer (210) located on the other surface of the silicone foam layer where the substrate layer is located. Referring to FIG. 2, the structure may have a substrate layer (210) laminated on both sides of the silicone foam layer (220).

[0110] In one embodiment, the silicone foam sheet may mean that, as necessary, the substrate layer is peeled off and only the silicone foam layer is included.

[0111] In one embodiment, the silicone foam layer can act as a cushioning member and preferably has impact resistance and compression resistance.

[0112] The above silicone foam may be formed from the aforementioned silicone foam forming composition, and details that overlap with the above are omitted.

[0113] In one embodiment, the silicone foam layer may be formed in a structure in which a plurality of foam layers are laminated to simultaneously exhibit excellent impact resistance and compression resistance effects.

[0114] The above silicone foam has a low density, so it can avoid significantly increasing the weight of the secondary battery and achieve lightweighting of the battery module.

[0115] In one embodiment, the thickness of the silicone foam layer may be 0.5 to 5 mm, 0.6 to 4.5 mm, 0.7 to 4 mm, 0.8 to 3.5 mm, 0.9 to 3 mm, or 1 to 2.5 mm. When the thickness of the silicone foam layer is formed within the above range, the force against external impact or swelling can be effectively dispersed.

[0116] In one embodiment, the density is 0.25 to 0.45 g / cm³ 3 The surface hardness (Shore 00) is 20 to 50, the compressive strength (stress when compressed by 50% in the thickness direction) is 300 kPa or less, and the vertical flame retardancy may be UL94 V-0.

[0117] The average length of the pores in the above silicone foam layer may be 800 µm or less.

[0118] In one embodiment, the substrate layer may be laminated on one or both sides of the silicone foam layer.

[0119] The above substrate layer may be a film comprising at least one selected from the group consisting of PET (polyethylene terephthalate), PC (polycarbonate), PE (Polyethylene), PEN (Polyethylene naphthalate) and combinations thereof, and specifically may be a film made of PET.

[0120] In one embodiment, the thickness of the substrate layer may be 25 to 150 mm. When the thickness of the substrate layer is formed within this range, the foam layer can be sufficiently supported without increasing the compressive strength.

[0121]

[0122] In one embodiment, the silicone foam sheet exhibits excellent properties regarding heat resistance and flame retardancy, and demonstrates excellent effects in terms of module reliability when applied to a secondary battery.

[0123] In one embodiment of the present invention, the silicone foam sheet is,

[0124] (a) A step of preparing a foaming agent liquid;

[0125] (b) a step of coating a foaming liquid on one surface of at least one substrate layer;

[0126] (c) a step of curing a foaming agent coated on one side of at least one substrate layer to form a silicone foam layer to produce a foamed sheet; can be manufactured by a roll-to-roll (R2R) coating method including the step of producing a foamed sheet.

[0127] In step (a) above, the foaming liquid may be the aforementioned silicone foam forming composition, and details that overlap with the above are omitted.

[0128] In step (B) above, the foaming liquid can be applied to one surface of the substrate layer using a roll coater. The roll coater can be a comma coater, a slot die coater, a rip coater, etc.

[0129] In one embodiment, the foaming liquid (e.g., foaming layer) coated on one side of the substrate layer may further include a separate substrate layer (hereinafter also referred to as an "upper substrate layer") on the other side.

[0130] In step (c) above, the composition for forming the silicone foam can form a silicone foam by photocuring or thermal curing.

[0131] Specifically, the substrate coated with the foaming agent liquid can be transferred to a heat curing chamber or a photocuring chamber, and foaming can occur simultaneously with curing by active energy (heat or light irradiation) to form a foam on the substrate layer. Next, the upper substrate layer can be peeled off and wound into a roll shape, or cut to a specific size to be manufactured into a sheet. The process from coating to roll winding or sheet formation is carried out as a continuous process to achieve high productivity.

[0132] The above-mentioned silicone foam-forming composition comprises a first organopolysiloxane containing at least two unsaturated hydrocarbon groups and a second organopolysiloxane containing at least two hydroxyl groups, and can improve productivity by simultaneously utilizing a condensation reaction (dehydrogenation reaction) and an addition reaction to simultaneously foam and cure.

[0133] Specifically, hydrogen gas molecules generated by the dehydrogenation reaction gather to form gas bubbles, and as they harden, they can form a silicone foam.

[0134] In one embodiment, the curing is performed by thermal curing at a temperature of 100 to 150°C or 2000 mJ / cm² 2 Up to 10,000 mJ / cm 2 It may be photocorrected with the amount of light.

[0135]

[0136] In the above photocuring, the irradiation light source can be selected from microwaves, infrared rays, visible light, ultraviolet rays, X-rays, and γ-rays, as well as α-rays, proton beams, neutron beams, and electron beams.

[0137]

[0138] secondary battery module

[0139] In one embodiment of the present invention, a secondary battery module comprising a silicon foam sheet is provided.

[0140] In one embodiment, the silicone foam sheet is the silicone foam sheet described above, and details that overlap with the description above are omitted.

[0141] In one embodiment, the silicone foam sheet included in the secondary battery module is inserted between cells within the secondary battery module and acts as a pad for cushioning to control cell swelling and prevent cell damage caused by cell expansion.

[0142] The above secondary battery module includes the above silicon foam layer and has excellent vibration absorption and repulsion force due to compression, thereby providing a secondary battery module with excellent dimensional stability even if cell swelling occurs.

[0143] In one embodiment, the silicone foam sheet effectively adheres the substrate layer and the silicone foam layer without including a separate adhesive between the layers, and even after combustion, the layers remain adhered without falling off, thereby providing a secondary battery module with excellent structural stability.

[0144]

[0145] The above description explains the technical concept of the present invention using one embodiment, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments described in this invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. The scope of protection of the present invention shall be interpreted by the claims, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

[0146]

[0147] <Example>

[0148] Example 1

[0149] silicone foam sheet

[0150] A silicone mixture was prepared by mixing 48.3g of the first organopolysiloxane, 3.4g of the second organopolysiloxane-1, 44.9g of the second organopolysiloxane-2, and 3.4g of the fourth organopolysiloxane. Based on 100 parts by weight of the silicone mixture, a composition for forming a silicone foam was prepared by mixing 0.025 parts by weight of a platinum catalyst, 60 parts by weight of a flame retardant, 1 part by weight of hollow glass, and 0.003 parts by weight of a coloring agent.

[0151] Subsequently, a silicone foam-forming composition was coated to a thickness of 0.5 mm between two PET films (XD500P 50 µm) using a roll-to-roll coating method, and a foam sheet was manufactured by irradiating a blacklight lamp from above and below for 4 minutes. At this time, the thickness of the manufactured foam sheet was 1.9 mm.

[0152]

[0153] Examples 2 to 6

[0154] In the above Example 1, a silicone foam sheet was prepared in the same manner as in Example 1, except that the content of the silicone mixture, hollow glass, flame retardant, and coloring agent, as well as the density and average particle size of the hollow glass, were adjusted as shown in Table 1 below.

[0155] Unit Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 1) g 48.3 g 48.3 g 48.3 g 48.3 g 3.4 g 3.4 g 44.9 g 44.9 g 44.9 g 44.9 g 44.9 g 4.4 g Silicon mixture 100 g 100 g 100 g 100 g 100 g Platinum catalyst weight parts 0.02 g 0.02 g 0.02 g 0.02 g 0.02 g 0.02 g Flame retardant 60 g 60 g 60 g Coloring agent 0.00 g 30.00 g 30.00 g 30.00 g 30.00 g Hollow glass 123 g Hollow glass density g / cm³ 30.150.150.150.150.1250.20 Hollow glass average particle size μm 606060606560 1) 1st organopolysiloxane: viscosity 65,000 cps, vinyl group (SiVi) content 0.03 mmol / g 2) 2nd organopolysiloxane-1: viscosity 45 cps, hydroxyl group (SiOH) content 2.5 mmol / g 3) 2nd organopolysiloxane-2: viscosity 5,000 cps, hydroxyl group (SiOH) content 0.07 mmol / g 4) 4th organopolysiloxane: viscosity 20 cps, hydrogen group (SiH) content 15.0 mmol / g Platinum catalyst: Pt(C5H7O2)2 Flame retardant: Aluminum hydroxide Coloring agent: Carbon black Hollow glass: Example K15 (3M) was used in Examples 1 to 4, K1 (3M) in Example 5, and K20 (3M) in Example 6.

[0156]

[0157] <Comparative Example>

[0158] Comparative Examples 1 to 9

[0159] In the above Example 1, a silicone foam sheet was prepared in the same manner as in Example 1, except that the content of the silicone mixture, hollow glass, flame retardant, and coloring agent, as well as the density and average particle size of the hollow glass, were adjusted as shown in Tables 2 and 3 below.

[0160]

[0161] Unit Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 1) g 48.3 48.3 48.3 48.3 48.3 2) 3.4 3.4 3.4 3.4 3.4 3.4 3.4 4.9 44.9 44.9 44.9 4) 3.4 3.4 3.4 3.4 3.4 4 Silicone mixture 100 100 100 100 100 Platinum catalyst parts by weight 0.02 50.02 50.02 50.02 50.02 50.02 5 Flame retardant 60 60 60 60 60 Colorant 0.00 30.00 30.00 30.00 30.00 3 Hollow glass 0.67 89 Hollow glass density g / cm³ 3-0.15 0.15 0.15 0.15 0.15 Hollow glass average particle size μm - 60 60 60 60 1) 1st organopolysiloxane: viscosity 65,000 cps, vinyl group (SiVi) content 0.03 mmol / g 2) 2nd organopolysiloxane-1: viscosity 45 cps, hydroxyl group (SiOH) content 2.5 mmol / g 3) 2nd organopolysiloxane-2: viscosity 5,000 cps, hydroxyl group (SiOH) content 0.07 mmol / g 4) 4th organopolysiloxane: viscosity 20 cps, hydrogen group (SiH) content 15.0 mmol / g Platinum catalyst: Pt(C5H7O2)2 Flame retardant: Aluminum hydroxide Coloring agent: Carbon black Hollow glass: In Comparative Examples 2 to 5, K15 Used.

[0162]

[0163] Unit Comparison Example 6 Comparison Example 7 Comparison Example 8 Comparison Example 9 1) g 48.3 48.3 48.3 48.3 2) 3.4 3.4 3.4 3.4 3) 44.9 44.9 44.9 4) 3.4 3.4 3.4 4 Silicon mixture 100 100 100 100 Parts by weight of platinum catalyst 0.02 5 0.02 5 0.02 5 0.025 5 Flame retardant 0.00 3 0.00 3 0.00 3 0.00 3 Hollow glass 105 55 Hollow glass density g / cm³ 3 0.15 0.2 2 0.3 2 0.38 Hollow glass average particle size μm 60 3 5 60 4 0 1) 1st organopolysiloxane: viscosity 65,000 cps, vinyl group (SiVi) content 0.03 mmol / g 2) 2nd organopolysiloxane-1: viscosity 45 cps, hydroxyl group (SiOH) content 2.5 mmol / g 3) 2nd organopolysiloxane-2: viscosity 5,000 cps, hydroxyl group (SiOH) content 0.07 mmol / g 4) 4th organopolysiloxane: viscosity 20 cps, hydrogen group (SiH) content 15.0 mmol / g Platinum catalyst: Pt(C5H7O2)2 Flame retardant: Aluminum hydroxide Hollow glass: K15 in Comparative Example 6, S22 (3M in Comparative Example 7 In Comparative Example 8, CNH32 (CNVISION) was used, and in Comparative Example 9, K38HS (3M) was used.

[0164]

[0165] <Experimental Example>

[0166] Experimental Example 1. Confirmation of Sperm Effect

[0167] To confirm the foaming effect according to the content and type of hollow glass (difference in density and average particle size) contained in the silicone foam sheets prepared in the above examples and comparative examples, the pores of the silicone foam sheets were measured. The results according to the type of hollow glass are shown in Table 4, and the results according to the change in the content of hollow glass are shown in Table 5 and Figure 3.

[0168] The pore size was determined by taking a cross-sectional image of the silicone foam sheet with FE-SEM, measuring the lengths of the major and minor axes of 20 pores, and calculating the average value.

[0169] Example 4 Example 5 Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Pore Size Major Axis (μm) 5 20 5 28 5 20 1 1 3 6 1 25 8 1 3 20 Minor Axis (μm) 2 8 2 28 5 28 0 4 6 2 4 4 6 4 60 Aspect Ratio 1.8 4 1.8 5 1.8 6 2.4 6 2.8 2 2.8 7

[0170]

[0171] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Pore Size Major Axis (μm) 583 598 589 520 157 74 25 Minor Axis (μm) 298 299 287 28259 724 8 Aspect Ratio 1.96 2.00 2.05 1.84 2.64 1.71

[0172] Referring to Table 5 above, in the case of Examples 1 to 6, the pores were uniform, and the average length of the major axis was limited to 500 to 600 μm, and the average length of the minor axis was limited to 280 to 300 μm. On the other hand, in Comparative Example 1, which did not contain hollow glass, the major axis grew to 1 mm or more, resulting in a decrease in the mechanical strength of the foamed sheet and an inability to obtain uniform physical properties. In Comparative Example 2, which contained hollow glass exceeding the aforementioned range, the growth of bubbles was suppressed, limiting the average length of the major axis to 500 μm or more, resulting in higher density and compressive strength. In Comparative Examples 7 to 9, the hollow glass failed to suppress the growth of pores, causing the major axis to grow to 1 mm or more, resulting in a decrease in the mechanical strength of the foamed sheet and an inability to obtain uniform physical properties.

[0173]

[0174] Experimental Example 2. Confirmation of physical properties of foamed sheet

[0175] The physical properties of silicone foam sheets prepared according to the content and type of hollow glass (difference in density and average particle size) contained in the silicone foam sheets prepared in the above examples and comparative examples were measured, and the results are shown in Tables 6 to 8 below.

[0176] - Viscosity (cPs): Measured using a Brookfield LV viscometer at 25°C with a rotation speed of 3 rpm. To ensure a uniform amount is applied and to maintain the shape until curing, a viscosity in the range of 50,000 to 150,000 cps is desirable.

[0177] - Measurement of foam sheet thickness (mm): Measure the thickness at three points on a specimen measuring 100x100mm using a Peacock H-20 thickness gauge and calculate the average value.

[0178] - Measurement of Foaming Ratio: Calculated by dividing the thickness of the foamed sheet by the coating gap. When the foaming ratio is 3 times or greater, the density is 0.4 g / cm³. 3 Below can be obtained, and low compressive strength can be obtained.

[0179] - Foam sheet density (g / cm²) 3 Measurement: The weight of a specimen measuring 100 x 100 mm is measured using a precision balance, and the measurement is obtained by dividing the weight by the volume calculated from the thickness and area of ​​the aforementioned foam sheet. The density is 0.4 g / cm³. 3 If it is below this level, low compressive strength can be obtained.

[0180] - CFD (Compression Force Deflection) measurement: Using a Universal Testing Machine, specimens (50 mm x 50 mm) were stacked to a thickness of 4 mm and compressed at a speed of 8 mm / min to measure the compressive strength according to the compression ratio. When the compressive strength is 300 kPa or less when compressed by 50%, it can effectively buffer the expansion of the secondary battery cell.

[0181]

[0182] - Measurement of maximum compression ratio: During the above CFD measurement, the compression ratio when compressed to a compressive strength of 800 kPa was measured as the maximum compression ratio. If the maximum compression ratio is 70% or higher, it can effectively buffer the expansion of the secondary battery cell.

[0183]

[0184] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Composition Viscosity (cPs) 5 7,000 7 2,000 7 9,000 7 3,000 8 5,000 7 2,000 Foam Sheet Thickness (mm) 1.90 1.8 5 1.7 5 1.6 7 1.6 5 1.70 Foaming Ratio 4.2 4.1 3.9 3.7 3.3 3.4 Foam Sheet Density (g / cm³) 3 )0.36 0.35 0.37 0.36 0.39 0.38 Surface Hardness 38 40 41 45 49 47 CFD 50%(kPa) 140 17 21 50 20 72 11 198 Maximum Compression (%) 79 77 78 76 72 73

[0185]

[0186] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Composition Viscosity (cPs) 5 7,000 9 6,000 1 2 7,000 1 3 8,000 1 5 2,000 Foam Sheet Thickness (mm) 2.0 3 1.6 3 1.6 3 1.5 1 1.45 Foaming Ratio 4.5 3.3 3.3 3.0 2.9 Foam Sheet Density (g / cm³) 3 )0.39 0.38 0.37 0.39 0.4 Surface Hardness 38 47 46 50 53 CFD 50%(kPa) 118 215 211 24 53 14 Maximum Compression (%) 8 17 37 46 9 68

[0187]

[0188] Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Composition Viscosity (cPs) 178,000 96,000 73,000 82,000 Foam Sheet Thickness (mm) 1.40 1.63 1.66 1.72 Foaming Ratio 2.8 3.3 3.3 3.4 Foam Sheet Density (g / cm³) 3 )0.40 0.38 0.37 0.38 Surface Hardness 54 46 45 51 CFD 50%(kPa) 39 1.19 15 51 62 170 Maximum Compression (%) 64.78 78 78 77

[0189] It was confirmed that if the hollow glass content exceeded the aforementioned range, the viscosity of the foaming composition increased, resulting in poor coating properties and reduced foaming properties, causing the foaming ratio to drop to 3 times or less. In addition, there was a problem where the foamed sheet became hard, increasing surface hardness and compressive strength, which reduced cushioning properties.

[0190] In addition, if the content of the cylindrical glass is 10 parts by weight or more, the foaming ratio decreases to 3 times or less, the surface hardness increases to 50 or more, and the compressive strength increases to 300 kPa, resulting in a decrease in performance as a cushioning material.

[0191]

[0192] Although the present invention has been described above with reference to embodiments, the present invention is not limited by the embodiments disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.

[0193]

[0194] 100, 200: Foam sheet

[0195] 110, 210: Record layer

[0196] 120, 220: Silicone foam layer

Claims

1. 100 parts by weight of a silicone mixture comprising at least one organopolysiloxane; 0.0001 to 0.05 parts by weight of platinum catalyst; 20 to 80 parts by weight of flame retardant; and A composition for forming a silicone foam comprising 1 to 10 parts by weight of hollow glass.

2. In Paragraph 1, Based on a total weight of 100 of the above silicone mixture, 20 to 70 weight% of a first organopolysiloxane comprising at least two unsaturated hydrocarbon groups; 20 to 70 weight% of a second organopolysiloxane comprising at least two hydroxyl groups; 0 to 20 weight% of a third organopolysiloxane containing hydrogen groups at both ends; and A composition for forming a silicone foam comprising 2 to 10 weight% of a fourth organopolysiloxane containing at least two hydrogen groups.

3. In Paragraph 1, The above-mentioned first organopolysiloxane is a composition for forming a silicone foam having a molecular weight of 20,000 to 150,000 g / mol, a viscosity (at 25°C) of 500 to 130,000 cps, and an unsaturated hydrocarbon group of 0.01 to 0.1 mmol / g.

4. In Paragraph 1, The above second organopolysiloxane is a composition for forming a silicone foam having a molecular weight of 2,000 to 120,000 g / mol, a viscosity (25°C) of 20 to 60,000 cps, and a hydroxyl group content of 0.017 to 3.0 mmol / g.

5. In Paragraph 1, The above-mentioned third organopolysiloxane is a composition for forming a silicone foam having a molecular weight of 3,500 to 30,000 g / mol, a viscosity (at 25°C) of 30 to 1,000 cps, and a hydrogen group (SiH) content of 0.07 to 2.0 mmol / g.

6. In Paragraph 1, The above-mentioned fourth organopolysiloxane is a composition for forming a silicone foam having a molecular weight of 5,000 to 30,000 g / mol, a viscosity (at 25°C) of 20 to 500 cps, and a hydrogen group (SiH) content of 1.5 to 15.0 mmol / g.

7. In Paragraph 1, A composition for forming a silicone foam, wherein the weight ratio of the first organopolysiloxane and the second organopolysiloxane is 1:0.3 to 1:3.

3.

8. In Paragraph 1, The average particle size (D50) of the above hollow glass is 50 μm or more and 70 μm or less, and the density is 0.3 g / cm³ 3 A composition for forming silicone foam with the following characteristics.

9. In Paragraph 1, The above platinum catalyst comprises at least one selected from the group consisting of platinum β-diketone complexes, platinum-cyclic diene complexes, platinum halides, platinum-olefin complexes, platinum-alcoolat complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, platinum vinylsiloxane complexes (platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complexes), bis-(γ-picoline)-platinum dichloride, trimethylenedipyridine-platinum dichloride, dicyclopentadiene-platinum dichloride, cyclooctadiene-platinum dichloride, cyclopentadiene-platinum dichloride), bis(alkenyl)bis(triphenylphosphine)platinum complexes, bis(alkenyl)(cyclooctadiene)platinum complexes, and combinations thereof, silicon Composition for forming foam.

10. In Paragraph 1, The above flame retardant is a composition for forming a silicone foam comprising at least one selected from the group consisting of aluminum hydroxide, magnesium hydroxide, barium hydroxide, zirconium hydroxide, magnesium carbonate, calcium carbonate, tin oxide, aluminum oxide, zinc borate, dolomite, hydrotalcite, wollastonite, silica, fluorine-based flame retardants, platinum flame retardants, and combinations thereof.

11. [Correction pursuant to Rule 91 24.06.2026] A silicone foam-forming composition according to Paragraph 1, wherein the viscosity of the silicone foam-forming composition is 20,000 to 150,000 cps.

12. Substrate layer; and A silicone foam sheet comprising: a silicone foam layer formed from a silicone foam forming composition according to claim 1 located on at least one surface of the above-mentioned substrate layer.

13. In Paragraph 12, The above substrate layer is a silicone foam sheet comprising at least one film selected from the group consisting of PET (polyethylene terephthalate), PC (polycarbonate), PE (Polyethylene), PEN (Polyethylene naphthalate), and combinations thereof.

14. In Paragraph 12, The thickness of the above silicone foam sheet is 0.5 to 5 mm, and the density is 0.25 to 0.45 g / cm³. 3 A silicone foam sheet having a surface hardness (Shore 00) of 20 to 50, a compressive strength (stress when compressed by 50% in the thickness direction) of 300 kPa or less, and vertical flame retardancy of UL94 V-0.

15. [Correction pursuant to Rule 91 24.06.2026] In Paragraph 12, a silicone foam sheet in which the average length of the pores of the silicone foam layer is 800 μm or less.

16. A secondary battery module comprising a silicone foam sheet according to paragraph 1.

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