KR102379431B1 - Release film for asphalt waterproof sheet and preparing method thereof - Google Patents

Abstract

The present invention relates to a release film for an asphalt waterproof sheet comprising a substrate layer, and a release layer formed on the lower surface of the substrate layer; and a method for manufacturing the same. The release film itself has excellent strength and has no deformation of shapes or physical properties of the release film during processing or storage, thereby being stably attached on an adherend and effectively protecting the same. The release film has excellent solvent resistance and heat resistance. Also, the release film for an asphalt waterproof sheet of the present invention has excellent peeling force for an asphalt waterproof sheet, and has advantages of stably maintaining physical properties of the release film itself and peeling force for the adherend even after a long period of time is elapsed in the state of being attached to the asphalt waterproof sheet.

Description

Release film for asphalt waterproof sheet and manufacturing method thereof {Release film for asphalt waterproof sheet and preparing method thereof}

The present invention relates to a release film for an asphalt waterproofing sheet and a method for manufacturing the same, and more particularly, a release film for an asphalt waterproofing sheet that maintains the shape and stable performance of the release film for a long period of time, and has an excellent release force for an asphalt substrate, and It relates to a manufacturing method thereof.

The release film is a thin film that can be easily peeled off and removed from the product when necessary while protecting the product from external foreign substances or light impact by being attached to the surface of the product that needs protection.

Such a release film is sometimes used to protect the adhesive layer of a sheet having an adhesive layer, and is also used to protect the surface of various products such as electronic products, semiconductors, automobiles, and displays.

In this way, the release film is stably attached to the surface of the product until it is peeled off, and when necessary, it should be easily peeled off from the product without damage to the product or the release film.

In order to impart these properties, the release film may be prepared by applying and curing a silicone release agent or a fluorine release agent that functions as a protective layer and forms a release layer on a base film having no adhesive force.

When the release film is manufactured in this way, the release layer and the base film are separated by static electricity during peeling, and the release layer is attached to the product surface. In order to prevent this, in general, antistatic treatment is essential carried out together

On the other hand, the asphalt waterproofing sheet includes an asphalt layer showing waterproof performance and a protective layer provided on the asphalt layer, if necessary, a center material layer is provided at the center or lower part of the asphalt layer, and an adhesive layer is provided on the lower part, It is constructed so that the asphalt waterproofing sheet is attached to the surface to be waterproofed by the asphalt layer or the adhesive layer.

At this time, a release film is attached to the lower surface of the asphalt layer or the lower surface of the pressure-sensitive adhesive layer, which protects the adhesive layer until construction, and then the release film is removed during construction.

However, in this case, the release layer is damaged by the solvent contained in the asphalt layer or the adhesive layer, or the release layer has adhesive strength over time and is not easily peeled from the product, but rather the release layer and the base film are peeled off. A part of the release layer may remain in the product, or a part of the adhesive layer or the asphalt layer may be attached to the release layer and peel off from the asphalt waterproofing sheet.

Accordingly, it is necessary to develop a release film for an asphalt waterproofing sheet that can secure stable physical properties of the release layer while having excellent adhesion between the base film and the release layer forming the release film.

Registered Patent No. 10-1714901 (Registered on Mar. 3, 2017)

An object of the present invention is to provide a release film for an asphalt waterproofing sheet that maintains the shape and stable performance of the release film for a long period of time, and has an excellent release force for an asphalt substrate, and a method for manufacturing the same.

One embodiment of the present invention for achieving the object as described above, the base layer; and a release layer formed on the lower surface of the base layer.

The base layer may include high density polyethylene (HDPE), ethylene propylene diene terpolymer (EPDM), dicumyl peroxide (DCP), vinyltriethoxysilane, and carbon filler.

The release layer may be formed of a release composition including a silicone resin, a solvent, and an additive.

The silicone resin may be obtained by reacting poly dimethyl siloxane, dimethyl diphenyl polysiloxane, and alkoxy silane.

Another embodiment of the present invention relates to a method for manufacturing a release film for an asphalt waterproofing sheet according to an embodiment of the present invention, high density polyethylene (HDPE), ethylene propylene diene terpolymer (EPDM), dicumyl peroxide (DCP) ), preparing a base layer comprising a vinyl triethoxysilane and a carbon filler; and applying a release composition including a silicone resin, a solvent, and an additive to the lower surface of the base layer and drying to form a release layer.

In this case, the silicone resin may be obtained by reacting poly dimethyl siloxane, dimethyl diphenyl polysiloxane, and alkoxy silane.

The release film for asphalt waterproofing sheets of the present invention has excellent strength of the release film itself, and there is no deformation or physical property deformation of the release film during processing or storage, so it can be stably attached to an adherend and effectively protected, and solvent resistance , has the advantage of excellent heat resistance.

In addition, the release film for asphalt waterproofing sheet of the present invention has excellent peeling power to the asphalt waterproofing sheet, and the properties of the release film itself and the peeling force to the adherend are stable even after a long period of time has elapsed while being attached to the asphalt waterproofing sheet. has the advantage of being maintained.

1 is a cross-sectional view of a release film according to an embodiment of the present invention.

Before describing in detail through preferred embodiments of the present invention, terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and meanings consistent with the technical spirit of the present invention and should be interpreted as a concept.

Throughout this specification, "%" used to indicate the concentration of a specific substance is (weight/weight)%, solid/liquid (weight/volume)%, and liquid, unless otherwise specified. /liquid means (volume/volume)%.

Throughout this specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, an embodiment of the present invention will be described. However, the scope of the present invention is not limited to the following preferred embodiments, and those skilled in the art can implement various modified forms of the contents described herein within the scope of the present invention.

The present invention relates to a release film for an asphalt waterproofing sheet and a method for manufacturing the same, and more particularly, a release film for an asphalt waterproofing sheet that maintains the shape and stable performance of the release film for a long period of time, and has an excellent release force for an asphalt substrate, and It relates to a manufacturing method thereof.

One embodiment of the present invention relates to a release film for an asphalt waterproofing sheet.

1 is a cross-sectional view of a release film for an asphalt waterproofing sheet according to an embodiment of the present invention.

The release film 10 for an asphalt waterproofing sheet according to an embodiment of the present invention includes a base layer 11; and a release layer 12 formed on the lower surface of the base layer 11 .

The base layer 11 is a central layer that forms the strength of the release film 10 for an asphalt waterproofing sheet, and has excellent tensile strength, durability, weather resistance and elasticity, Excellent adhesion. Accordingly, damage to the release film 10 can be prevented when the release film 10 is wound, unwound, adhered, and peeled off, and in particular, the substrate layer 11 and It is possible to prevent peeling and floating between the release layers 12 .

The base layer 11 is preferably formed to a thickness of 20 to 350 μm to ensure sufficient strength and elasticity, but if it is less than 10 μm, it may be difficult to secure sufficient strength, so it may be difficult to implement a function as a central layer, and 350 μm If it exceeds, there is a problem in that the resistance to bending is weakened due to the decrease in elasticity, and the release film 10 may be pushed or peeled from the asphalt sheet when winding or unwinding the asphalt sheet to which the release film 10 is attached. Therefore, it is preferable to be formed in the above-described thickness range.

As such, the base layer 11 is required to secure sufficient strength, elasticity and weather resistance, and since resistance to heat exposed when the release layer 12 is formed is required, HDPE (high strength, elasticity, weather resistance and heat resistance) excellent in strength, elasticity, weather resistance and heat resistance is required. density polyethylene) as the main component.

Specifically, the base layer 11 includes HDPE, ethylene propylene diene terpolymer (EPDM), dicumyl peroxide (DCP), vinyl triethoxysilane and carbon filler, and more specifically, with respect to 100 parts by weight of HDPE, 15 to 38 parts by weight of EPDM, 5 to 12 parts by weight of DCP, 1 to 8 parts by weight of vinyltriethoxysilane, and 5 to 22 parts by weight of carbon filler.

The HDPE is a polymer having excellent strength, tensile performance, heat resistance and weather resistance, and is added to secure excellent basic physical properties of the base layer 11 .

The EPDM is added to improve the impact strength of the base layer 11, and as EPDM is added, the elasticity of the base layer 11 is slightly lowered, but the impact strength is significantly improved to significantly improve the durability of the base layer 11 can be improved

To this end, EPDM is preferably included in an amount of 15 to 38 parts by weight based on 100 parts by weight of HDPE, when it is included in less than 15 parts by weight, a sufficient impact strength improvement effect cannot be obtained, and when it exceeds 38 parts by weight, the impact strength is significantly improved, but the elasticity is excessively lowered, and the compatibility with HDPE is lowered due to an excessive content of EPDM, and a phenomenon of layer separation occurs.

The DCP is a component added to ensure compatibility between HDPE and EPDM, and is included in an amount of 5 to 12 parts by weight based on 100 parts by weight of HDPC. In the case of exceeding the part, not only compatibility is not further improved, but there may be a problem in that the physical properties of the base layer 11 are rather deteriorated due to an excessive DCP content in the base layer 11 .

The vinyl triethoxysilane is a component added to improve the bonding strength between the HDPE and EPDM components in the base layer 11 and the inorganic filler, and improves the bonding strength with the inorganic filler without impairing the physical properties of the base layer 11 . It is preferably included in an amount of 1 to 8 parts by weight based on 100 parts by weight of HDPE.

The carbon filler is a component added to improve hardness and strength of the base layer 11, and nano-sized graphene, carbon nanotubes, carbon black, etc. may be used as the carbon filler. In addition, since the antistatic performance is given to the base layer 11 by the carbon filler, the release layer 12 and the base layer 11 are separated by static electricity during peeling, and accordingly the release layer 12 is used as an asphalt waterproofing sheet. to avoid adhesion problems.

In this case, a carbon filler having a particle size of 200 to 800 nm may be used in order to uniformly mix the carbon filler, prevent aggregation of the carbon filler, and prevent protrusion to the surface of the substrate layer 11 .

The carbon filler may be included in an amount of 5 to 22 parts by weight based on 100 parts by weight of HDPE, and when it is included in less than 5 parts by weight, the effect of improving the hardness and strength of the base layer 11 is insignificant, and sufficient antistatic performance is not ensured. , When it exceeds 22 parts by weight, since the hardness of the base layer 11 is excessively increased to deteriorate the tensile properties, it is preferable to be included within the above-described weight range.

The surface roughness, ie, roughness, of the lower surface of the base layer 11 may be 20 to 70 μm, and as it has such a high surface roughness, the adhesive strength with the release layer 12 is improved, so that the release layer 12 is the base material. It may not be easily separated from the layer 11 .

To this end, the corona discharge treatment may be performed on the lower surface of the base layer 11 at a voltage of 2 to 7 kW for 0.3 to 1.5 seconds.

The release layer 12 is formed on the lower surface of the base layer 11 , and provides an appropriate peeling force to the release film 10 . In order to form a sufficient peeling force on the release layer 12 while ensuring sufficient strength of the release layer 12 itself, the thickness of the release layer 12 is preferably formed in a range of 1 to 10 μm.

The release layer 12 may be formed by applying a release composition including a silicone resin, a solvent, and an additive to the lower surface of the base layer 11 and then drying.

The release composition may include 10 to 40 parts by weight of a solvent and 1 to 10 parts by weight of an additive based on 100 parts by weight of the silicone resin.

The silicone resin is a component added to provide an appropriate peeling force to the release layer 12, and the release layer 12 is attached to the asphalt waterproofing sheet by the silicone resin and can be easily peeled off if necessary.

Such a silicone resin may be obtained by reacting two or more siloxane compounds having different molecular weights.

Specifically, the silicone resin may be obtained by reacting polydimethyl siloxane, dimethyl diphenyl polysiloxane and alkoxy silane, wherein the polydimethyl siloxane has a weight average molecular weight of 30,000 to 50,000 g/mol, and that of dimethyl diphenyl polysiloxane The weight average molecular weight may be 1,000 to 5,000 g/mol.

When these are reacted to obtain a silicone resin, a catalyst may be added to initiate and accelerate the reaction. In this case, various known catalysts such as a metal catalyst, a metal oxide catalyst, and a complex oxide catalyst may be used, preferably A highly reactive platinum catalyst can be used.

It is preferable that the weight average molecular weight of the silicone resin is 85,000 to 120,000 g/mol, and when the weight average molecular weight of the silicone resin is within this range, the surface tension of the release layer 12 is not too high or low, so the release layer ( 12), appropriate strength and peeling force can be implemented.

Specifically, the silicone resin may be obtained by reacting 12 to 30 parts by weight of dimethyl diphenyl polysiloxane and 5 to 15 parts by weight of alkoxysilane with respect to 100 parts by weight of polydimethylsiloxane.

The polydimethylsiloxane expresses the basic physical properties of a silicone resin, has excellent strength and weather resistance, has an appropriate adhesive strength, and is adhered to the adherend, and is easily peeled off when necessary.

As the polydimethyl siloxane, a high molecular weight polydimethyl siloxane having a weight average molecular weight of 30,000 to 50,000 g/mol may be used. and silicone resin having elasticity and thermal stability.

More preferably, polydimethyl siloxane capped with hydroxyl groups at both ends may be used as polydimethyl siloxane, and hydrogen bonds are formed by hydroxyl groups at both ends in the silicone resin, and polymer chains are entangled to form a network structure. By doing so, the strength of the silicone resin itself is increased, and accordingly, there is an advantage in that it is possible to more effectively prevent the release layer 12 from being damaged when the release film 10 is peeled off.

The dimethyl diphenyl polysiloxane can prevent damage to the release layer 12 during processing by improving the heat resistance of the silicone resin, and improve the adhesion of the release layer 12 to the base layer 11, so that the release film ( 10) when separating the asphalt waterproofing sheet, the release layer 12 is peeled from the base layer 11, it is possible to prevent the problem of adhesion to the asphalt waterproofing sheet.

The dimethyl diphenyl polysiloxane may be included in an amount of 12 to 30 parts by weight based on 100 parts by weight of polydimethyl siloxane, and when it is included in less than 12 parts by weight, heat resistance is improved, and the base layer 11 and the release layer 12 are peeled off The effect of preventing the problem appears insignificant, and when it exceeds 30 parts by weight, the hardness of the release layer 12 is excessively lowered, so that the shape of the release layer 12 cannot be maintained and easily damaged by an external impact. , it is preferably included within the above-described weight range.

The dimethyl diphenyl polysiloxane preferably has a weight average molecular weight of 1,000 to 5,000 g/mol. As such, dimethyl diphenyl polysiloxane exhibits a significantly lower molecular weight than poly dimethyl siloxane, so that the viscosity of the silicone resin increased by poly dimethyl siloxane can be significantly lowered. it becomes possible In addition, when the silicone resin is prepared by reacting a siloxane compound having a significantly different molecular weight as described above, the elasticity and tensile properties of the silicone resin are remarkably improved. damage can be prevented more effectively.

The alkoxy silane acts as a crosslinking agent during the silicone resin formation reaction to form a more robust network structure of the silicone resin, thereby improving the strength of the release layer 12 itself and the adhesion to the base layer 11 . As such, as the alkoxysilane is added, the adhesive force of the release layer 12 itself increases, but the strength also increases, so that when the release film 10 is peeled off, the release layer 12 is not easily damaged and the adherend surface is asphalt waterproofing. It can be easily separated from the sheet.

Such alkoxy silanes are preferably 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, methyl (3-glycidoxypropyl) dimethoxysilane, methyl (3-glycidoxy Propyl) at least one of diethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, and 3-(3,4-epoxycyclohexyl)propyl trimethoxysilane may be used.

Alkoxy silane may be included in an amount of 5 to 15 parts by weight based on 100 parts by weight of polydimethylsiloxane. When it is included in less than 5 parts by weight, the above-described effect is insignificant, and when it exceeds 15 parts by weight, the elasticity of the silicone resin is lowered. Since there is a problem that the release layer 12 is attached to the asphalt waterproofing sheet, which is the adherend surface, due to the increase in adhesive force while the additional strength improvement is insignificant, it is preferable to be included within the above-described weight range.

The solvent disperses the silicone resin, uniformly mixes each component included in the release composition, and lowers the viscosity of the release composition so that it can be applied in a desired shape and thickness.

When the content of the solvent is less than 10 parts by weight, this effect is not obtained, and when it exceeds 40 parts by weight, the viscosity is excessively reduced and there is a problem that the shape is not maintained and flows down when applied to the base layer 11, so the above-mentioned weight It is preferable to be included within the range.

As such a solvent, an organic solvent may be used, and preferably, acetone, dimethyl carbonate, t-butyl acetate, etc., which are solvents exempted from the regulation of volatile organic compounds, may be used.

Among them, in the case of acetone and dimethyl carbonate, t-butyl acetate, which has relatively low volatility as a solvent, and can secure working time, is used as a solvent because it has a problem of deterioration of workability because drying proceeds excessively quickly during operation due to strong volatility. It is more preferable to use

The additive is a component added to improve the physical properties of the release composition, and in order to secure the basic physical properties of the release layer 12 while obtaining the effect of improving the properties by the additive, the additive is 1 to 10 parts by weight based on 100 parts by weight of the silicone resin. It may be included in parts by weight.

As the additive, a heat stabilizer, an antifoaming agent, a dispersing agent, a fragrance, a pigment and a filler may be used.

The heat stabilizer is a component added to improve the thermal stability of the release composition, and is added to prevent denaturation or damage of the release composition due to heat applied when the release layer 12 is formed. As such a heat stabilizer, for example, dibutyltin dioxide or dioctyltin oxide may be used.

The antifoaming agent is a component added to form the release layer 12 having a smoother, more uniform shape and uniform physical properties by removing air bubbles in the release composition. Fatty acid ester type, alcohol type, phosphoric acid ester type, metal soap type, silicone type defoaming agent, etc. can be used as such an antifoaming agent.

The dispersant is a component added to uniformly mix each component in the release composition, and any known dispersant may be used without particular limitation. For example, an acrylic dispersant, a urethane-based dispersant, a polycarbonate-based dispersant, a polyester-based dispersant, and a polyolefin-based dispersant may be used, but is not limited thereto.

The pigment is a component added to impart color to the release composition, for example, lead chromate salt, titanium dioxide, calcium carbonate, barium sulfate, aluminum silicate, talc, graphite, carbon black, iron oxide green, iron oxide red and metal oxide or Fillers coated with these may be used, but are not limited thereto.

The fragrance is a component added to suppress the characteristic odor of the silicone resin included in the release composition, and various commonly used fragrances or fragrances may be used.

The filler is a component added to improve the strength of the release layer 12, and includes calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, barium sulfate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, talc, mica, glass fiber, silica, Various types of fillers commonly used, such as diatomaceous earth, alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, graphite, and carbon fiber, may be used.

At this time, in order to prevent phenomena such as aggregation of the filler, protrusion to the outside of the release layer 12, detachment, etc., the particle size of the filler is preferably formed in the range of 50 to 300 nm.

Hydroxytyrosol may be additionally added to the release composition, and in this case, may be added in an amount of 1 to 5 parts by weight based on 100 parts by weight of the silicone resin. When hydroxytyrosol is added to the release composition, the heat resistance, water resistance, and strength of the release layer 12 are improved, so that the durability of the release layer 12 is improved.

When the content of hydroxytyrosol is less than 1 part by weight, it is difficult to obtain the above-described effects, and when it exceeds 5 parts by weight, the peeling properties of the release layer 12 may be deteriorated due to hydroxytyrosol. It is preferably included within the weight range.

Meanwhile, an antistatic layer 13 may be additionally formed on the upper surface of the base layer 11 . The antistatic layer 13 contains sodium rosinate, and may be formed by applying an aqueous sodium rosinate solution on the upper surface of the base layer 11 and drying it. There is an advantage that can additionally prevent the defect of the release film 10 by

On the other hand, another embodiment of the present invention relates to a method of manufacturing a release film for an asphalt waterproofing sheet, and since the release film for an asphalt waterproofing sheet according to an embodiment of the present invention can be manufactured according to the present manufacturing method, overlapping description is omitted.

First, the manufacturing method of the release film 10 for an asphalt waterproofing sheet according to this embodiment is high density polyethylene (HDPE), ethylene propylene diene terpolymer (EPDM), dicumyl peroxide (DCP), vinyl triethoxysilane and carbon filler. Preparing a base layer 11 comprising a; and applying a release composition containing a silicone resin, a solvent, and an additive to the lower surface of the base layer 11 and drying it to form a release layer 12 .

First, the step of preparing the base layer 11 is based on 100 parts by weight of HDPE, 15 to 38 parts by weight of EPDM, 5 to 12 parts by weight of DCP, 1 to 8 parts by weight of vinyl triethoxysilane, and 5 to 22 parts by weight of carbon filler. This is a step of processing the composition including parts by weight into a film having a thickness of 20 to 350 μm.

In this way, the corona discharge treatment may be additionally performed on the base layer 11 processed in the form of a film if necessary. Specifically, corona discharge treatment may be performed on the lower surface of the base layer 11, and as the corona discharge treatment is performed in this way, the roughness of the lower surface of the base layer 11 on which the release layer 12 will be formed increases, , thus, there is an advantage that can be more strongly adhered when the release composition is applied to the lower surface of the base layer 11 in a later step.

The corona discharge treatment may be performed for 0.3 to 1.5 seconds at a voltage of 2 to 7 kW, and when it is performed less than the voltage range or less than the time range, it is difficult to form sufficient illuminance, and it is difficult to form a sufficient illuminance, exceed the voltage range or the time If the corona discharge treatment is performed for a longer time than the range, since the base layer 11 itself may be damaged, it is preferable that the corona discharge treatment is performed within the range satisfying the above-described treatment conditions.

Next, in the step of forming the release layer 12, a release composition comprising 10 to 40 parts by weight of a solvent and 1 to 10 parts by weight of an additive is applied to the lower surface of the base layer 11 based on 100 parts by weight of the silicone resin, It is a step of forming the release layer 12 by drying.

Application of the release composition is performed using various painting tools such as rollers, sprays, brushes, etc., or by immersing only the lower surface of the base layer 11 in a container containing the release composition, or the lower surface of the base layer 11 is the upper part It can be carried out by various coating methods used for coating the composition in the art, such as carried out by applying the release composition using a bar coater after disposing to face the .

As such, the release layer 12 may be formed by coating the release composition on the lower surface of the base layer 11 and then drying it.

Preferably, a hot air drying method may be applied as the drying method, and the temperature of the hot air may be 80 to 120 °C. If it exceeds, the base layer 11 or the release layer 12 may be damaged due to excessive heat, so it is preferable to dry with hot air at the above-mentioned temperature.

On the other hand, in order to further improve the antistatic performance of the release film 10, the step of forming the antistatic layer 13 on the upper surface of the base layer 11 may be further performed.

In this case, there is no problem whether any of the steps in which the antistatic layer 13 is formed and the step in which the release layer 12 is formed is performed first, it may be performed at the same time. In addition, when corona discharge treatment is performed on the base layer 11, corona discharge treatment is performed on both sides of the base layer 11 in order to improve the adhesive strength between the antistatic layer 13 and the base layer 11. it is preferable

The antistatic layer 13 may be performed by applying an antistatic composition, sodium rosinate aqueous solution, to the upper surface of the base layer 11 and drying with hot air. Since the coating method of the antistatic composition or the hot air drying method is the same as the method performed when forming the release layer 12 , the overlapping description will be omitted.

Hereinafter, specific actions and effects of the present invention will be described through an embodiment of the present invention. However, this is presented as a preferred example of the present invention, and the scope of the present invention is not limited according to the embodiments.

[Production Example]

First, with respect to 100 parts by weight of HDPE, a mixture of 22 parts by weight of EPDM, 8 parts by weight of DCP, 5 parts by weight of vinyltriethoxysilane and 15 parts by weight of graphene powder (average particle size 350-400 nm) as a carbon filler is heat-pressed. Thus, a base layer having a thickness of about 50 μm was prepared.

Next, the upper and lower surfaces of the base layer were corona-discharged at a voltage of 5 kW for 0.8 seconds to surface-treat to form a roughness of about 40 μm on both sides of the base layer.

Next, a release composition comprising 18 parts by weight of t-butyl acetate as a solvent and 8 parts by weight of an additive is applied to the lower surface of the base layer in a thickness of 10 μm with respect to 100 parts by weight of a silicone resin having a weight average molecular weight of about 100,000 g/mol. A release layer was formed by hot air drying at about 95° C. to prepare a release film for an asphalt waterproofing sheet of Example 1.

At this time, as the silicone resin, 14 weights of dimethyl diphenyl polysiloxane having a weight average molecular weight of about 3,000 g/mol based on 100 parts by weight of polydimethyl siloxane capped at both ends with hydroxyl groups having a weight average molecular weight of about 40,000 g/mol A silicone resin obtained by reacting parts and 8 parts by weight of 3-glycidoxypropyl trimethoxysilane as an alkoxy silane under a platinum catalyst was used.

In addition, as additives, 4 parts by weight of dibutyltin dioxide, 2 parts by weight of a polyester-based dispersant, 1 part by weight of calcium carbonate as a pigment, and a fragrance were used.

[Experimental Example 1]

The same release film as in Example 1 was prepared, but the content of dimethyl diphenyl polysiloxane used to prepare the silicone resin included in the release layer was changed as shown in Table 1 below. In Table 1, the content of dimethyl diphenyl polysiloxane means a weight ratio with respect to 100 parts by weight of polydimethyl siloxane capped at both ends with hydroxyl groups.

Next, the tear strength of each Example and Comparative Example was measured by the method of ASTM D 1004.

In addition, after preparing 5 samples of each Example and Comparative Example, respectively, the peeling force in a room at about 26°C and a relative humidity of 55% was measured based on FINAT test method no.10 using a 1-inch TESA7475 tape. Specifically, the room temperature peel strength, which is the force required for peeling at an angle of 180°, peeling speed of 0.3 m/min, and 5 m/min, was measured, and Table 1 shows the average values thereof. In addition, when the release layer was damaged even in one sample during peeling, "X" was indicated.

Dimethyl Diphenyl
Polysiloxane (parts by weight) tear strength
(kg _f /cm) peel strength
(g _f /in, 0.3 m/min) peel strength
(g _f /in, 5 m/min) Comparative Example 1 0 68 21.4 42.3 Comparative Example 2 8 102 13.8 17.5 Example 1 14 196 10.3 14.4 Example 2 20 208 9.6 17.0 Example 3 28 213 9.8 19.2 Comparative Example 3 33 222 9.5 X

Referring to the results of Table 1, when dimethyl diphenyl polysiloxane was added, it was found that tear strength and peel strength were improved. In particular, it was confirmed that the tear strength and peel strength were significantly improved when the content of dimethyl diphenyl polysiloxane was 12 parts by weight or more. However, when the content of dimethyl diphenyl polysiloxane was 30 parts by weight or more, the peeling rate was It was found that the release layer was damaged when the amount of dimethyl diphenyl polysiloxane was excessive. .

Therefore, from the results of this experiment, in order to obtain the effect of improving the tear strength and peel strength by dimethyl diphenyl polysiloxane, and at the same time, to prevent excessive adhesion to the adherend and deterioration of the strength of the release layer, dimethyl diphenyl during the manufacture of silicone resin It was confirmed that the polysiloxane is preferably included in an amount of 12 to 30 parts by weight, more preferably 14 to 28 parts by weight, based on 100 parts by weight of polydimethyl siloxane.

[Experimental Example 2]

The same release film as the release film of Example 1 was prepared, but by further adding hydroxytyrosol in the content shown in Table 2 to the release composition used in preparing the release layer. In Table 2, the content of hydroxytyrosol means a weight ratio with respect to 100 parts by weight of the silicone resin.

Thereafter, the tear strength of each release film, the peel strength when peeled at a peeling rate of 0.3 m/min, and the peel strength after aging were measured, and the results are shown in Table 2.

Peel strength after aging was measured by performing a peel test based on FINAT test method no. After measurement using 5 samples each, the average value was calculated and described in Table 2, and when the release layer was damaged during peeling, it was marked with "X".

hydroxy tyrosol
(parts by weight) tear strength
(kg _f /cm) Room temperature peel strength
(g _f /in, 26°C) high temperature peel strength
(g _f /in, 85℃) Example 1 0.0 196 10.3 22.5 Example 4 1.0 224 10.7 13.9 Example 5 2.5 229 11.1 14.2 Example 6 5.0 235 11.0 14.7 Example 7 6.5 238 X X

Referring to the results of Table 2, when hydroxytyrosol is added, the tear strength is improved, and the difference in peel strength at room temperature and high temperature is not large. When hydroxytyrosol is added, the durability of the release layer It could be confirmed that this aging was stable even under severe conditions. However, as can be seen from the results of Example 7, when the content of hydroxytyrosol was excessive, both the peeling properties at room temperature and high temperature of the release layer were rather poor. .

Therefore, it was confirmed from the results of this experiment that hydroxytyrosol was added in order to improve the durability of the release layer, but preferably included in an amount of 1 to 5 parts by weight based on 100 parts by weight of the silicone resin.

The present invention is not limited to the specific embodiments and descriptions described above, and without departing from the gist of the present invention claimed in the claims, any person skilled in the art to which the invention pertains can implement various modifications and such modifications shall fall within the protection scope of the present invention.

10: release film 11: base layer
12: release layer 13: antistatic layer

Claims (5)

base layer; and
Including; a release layer formed on the lower surface of the base layer;
The release layer is formed of a release composition comprising 100 parts by weight of a silicone resin, 10 to 40 parts by weight of a solvent, and 1 to 10 parts by weight of an additive,
The silicone resin, polydimethyl siloxane 100 parts by weight, dimethyl diphenyl polysiloxane 12 to 30 parts by weight and alkoxy silane 5 to 15 parts by weight of the release film for asphalt waterproofing sheet, characterized in that obtained by reacting. The method of claim 1,
The base layer, HDPE (high density polyethylene), EPDM (ethylene propylene diene terpolymer), DCP (dicumyl peroxide), vinyl triethoxysilane and a carbon filler, characterized in that it comprises a, asphalt waterproofing sheet release film. delete delete A method for producing the release film for an asphalt waterproofing sheet according to claim 1 or 2,
Preparing a base layer comprising high density polyethylene (HDPE), ethylene propylene diene terpolymer (EPDM), dicumyl peroxide (DCP), vinyltriethoxysilane and carbon filler; and
Forming a release layer by applying and drying a release composition comprising 100 parts by weight of a silicone resin, 10 to 40 parts by weight of a solvent, and 1 to 10 parts by weight of an additive on the lower surface of the base layer;
The silicone resin, 100 parts by weight of polydimethylsiloxane, 12 to 30 parts by weight of dimethyl diphenyl polysiloxane, and 5 to 15 parts by weight of alkoxysilane, characterized in that obtained by reacting, the method for producing a release film for asphalt waterproofing sheet.

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