WO2004009357A1

WO2004009357A1 - Heat insulating sheet

Info

Publication number: WO2004009357A1
Application number: PCT/JP2003/009235
Authority: WO
Inventors: Shigeru Aoki
Original assignee: Kimoto Co., Ltd.
Priority date: 2002-07-22
Filing date: 2003-07-22
Publication date: 2004-01-29
Also published as: AU2003252228A1; TW200403288A; JP4227100B2; JPWO2004009357A1

Abstract

A heat insulating sheet which comprises a heat insulating layer containing a urethane resin and a heat insulating pigment and, laminated thereon, a resin layer formed from a urethane resin, and has a tensile yield strength of 10 N/mm2 or less, preferably 5 N/mm2 or less. The heat insulating sheet can be used for suppressing the elevation of an inner temperature due to sun light and can be well pasted even on a curved face or the like; and since it uses no vinyl chloride resin as a base material, it is free from the generation of a toxic gas in incineration disposal and also from the bleeding of a plasticizer even after the use for a long period of time, and is less susceptible to the change due to the elapse of time.

Description

Heat shield sheet. Technical field

The present invention can be applied to roofs and outer walls of buildings, such as factories and houses, roofs and outer plates of vehicles such as containers and refrigerating vehicles, and roofs and outer walls of ships, plants, sheds, livestock bars, and the like. The present invention relates to a heat-shielding sheet that can suppress an increase in internal temperature caused by sunlight. Background art

Conventionally, transport vehicles such as containers and refrigeration vehicles have attached heat-insulating sheets to roofs and outer panels to suppress the rise in internal temperature caused by sunlight. As such a heat-insulating sheet, a heat-insulating sheet in which a heat-insulating pigment has been kneaded into a thermoplastic resin has conventionally been used. For example, Patent Documents 1 and 2 disclose a composition containing a specific heat-shielding pigment in a thermoplastic resin such as a vinyl chloride resin, a polyethylene resin, a polyester resin, or a (meth) acrylic resin. A product formed into a sheet has been proposed. Recently, a heat-shielding sheet in which a heat-shielding paint is applied on a base material such as plastic has been proposed. For example, Patent Literature 3, Patent Literature 4 and Patent Literature 5 disclose that a heat-shielding layer composed of a heat-shielding pigment and a binder is formed on a sheet or film of a vinyl chloride, polyolefin, polycarbonate, (meth) acrylic acid-based resin, or the like. Something has been proposed. These heat-insulating sheets are used by being adhered to an object to be shielded from outside (an adherend) via an adhesive layer or an adhesive layer.

Patent Document 1 JP-A-8-81567

Patent Document 2 JP 2002-12679 A

Patent Document 3 JP-A-10-250002

Patent Document 4 JP 2002-12683 A

Patent Document 5 JP 2001-270021 A Such a heat-shielding sheet is required to have sufficient heat-shielding properties and to follow the shape of the adherend, that is, to have flexibility. In particular, when the adherend has a curved surface, it is desirable to have a high elongation. However, when a large amount of heat-insulating pigment is contained in the heat-insulating sheet or the heat-insulating layer in order to obtain sufficient heat-insulating properties, there is a problem that the softness is impaired, the sticking becomes difficult, and the film is easily broken. For this reason, conventional heat-shielding sheets generally use a highly flexible vinyl chloride resin as a base material. However, there are the following problems with the heat-shielding sheet using the biel chloride-based resin.

First, vinyl chloride resin has a problem that it emits toxic gas during incineration. In the field of plastic materials, desalination has been promoted. In applications where high flexibility is required, such as when the adherend has a curved surface, it is necessary to add a large amount of a plasticizer to the vinyl chloride resin. If it is used, the plasticizer bleeds out on the surface, and if this causes cracks in the heat-shielding layer, there will be a ray problem.

Therefore, an object of the present invention is to provide a heat-shielding sheet that can be satisfactorily stuck even when an adherend has a curved surface or the like without using a vinyl chloride resin. Disclosure of the invention

A heat-insulating sheet of the present invention that solves the above object is characterized in that a heat-insulating layer containing a urethane-based resin and a heat-insulating pigment is laminated with a resin layer formed of a urethane-based resin. .

The resin layer made of a urethane resin has flexibility close to that of a vinyl chloride resin sheet, and can be further improved in flexibility by forming a multilayer structure in which this is laminated with a heat shield layer. In particular, the force required to start elongation (tensile yield strength) can be reduced. Thereby, it is possible to adhere with good workability when applying while stretching according to the shape of the adherend, and there is no breakage. Even if the flexibility of the heat shield layer itself is low, it can be adhered following the shape of the adherend. Furthermore, since no chlorinated butyl resin is used, there is no deterioration or cracking of the heat shield layer due to bleeding of the plasticizer, and there is no problem of environmental pollution at the time of disposal. In addition, by including the same resin as the urethane-based resin that constitutes the resin layer in the heat shield layer, the adhesiveness between the resin layer and the heat shield layer is improved, the flexibility is improved, and the resin is stretched at the time of application. Even so, the occurrence of cracks can be suppressed.

The heat-insulating sheet of the present invention has a tensile yield strength of preferably 1 O NZmm ² or less, preferably 5 N / mm ² or less, and more preferably 3.5 N / mm ² or less. By setting the tensile yield strength within the above range, it is possible to adhere while sticking to an adherend while easily stretching it according to its shape.

The term “tensile yield strength” is a value measured based on JIS K7113-1981 (Plastic tensile test method). Is defined as the tensile stress at the point “Tensile rupture strength” is the tensile stress at the moment when the test piece ruptures.

Further, the heat-shielding sheet of the present invention, in the above configuration, has an adhesive layer on a surface of the resin layer opposite to the surface having the heat-shielding layer.

The heat shield sheet of the present invention preferably has a solvent permeation prevention layer between the heat shield layer and the resin layer. The resin layer made of a urethane-based resin has a high solvent permeability, and by providing such a solvent permeation prevention layer, the solvent contained in the heat-shielding layer coating solution when the heat-shielding layer is formed by coating is formed. In addition, it is possible to prevent the residual solvent contained in the heat shield layer after the formation of the heat shield layer from reaching the adhesive layer through the resin layer, thereby reducing the adhesiveness.

When the heat-shielding sheet of the present invention has an adhesive layer, it is preferably formed by forming the adhesive layer on another base material and then laminating it on a resin layer. By laminating a preformed adhesive layer on the resin layer instead of forming the adhesive layer directly on the resin layer, the number of times that the resin layer and the heat shield layer are heated can be reduced, and the resin layer and Shrinkage of the heat shielding layer due to heat can be reduced. Further, the adhesive layer can be formed irrespective of whether the curing of the resin layer made of the urethane-based resin is completed, and the production becomes easy. Furthermore, since the penetration of the solvent of the adhesive layer coating solution into the resin layer can be prevented, the adhesive force over time due to the solvent penetrating into the resin layer does not easily decrease. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view showing an embodiment of the heat shield sheet of the present invention, wherein 11 is a heat shield layer, 12 is a resin layer, 13 is an adhesive layer, and 14 is a solvent permeation prevention layer. FIG. 2 is a cross-sectional view of a test device for evaluating thermal insulation. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the heat shield sheet of the present invention will be described in detail.

1 (a) to 1 (c) are views showing an embodiment of the heat shield sheet of the present invention. The heat-insulating sheet of the present invention has a heat-insulating layer 11 and a resin layer 12 made of urethane-based resin as basic components as shown in FIG. 1 (a). As shown in (b), the resin layer 12 has an adhesive layer 13 on the surface opposite to the surface on which the heat shielding layer 11 is formed. In another embodiment, as shown in FIG. 1C, a layer (solvent permeation preventing layer) 14 for preventing the permeation of a solvent is provided between the resin layer 12 and the heat shield layer 11. The adhesive layer 13 is provided with a separator 15 that can be peeled off.

The heat shield sheet of the present invention has a laminated structure in which a heat shield layer 11 and a resin layer 12 formed of a urethane-based resin are laminated, and has such a layer structure. Thereby, even when the adherend has a curved surface or the like, it can be stuck well. Hereinafter, the difference in performance between a sheet in which a heat-shielding pigment is kneaded (hereinafter, referred to as a kneaded sheet) and a heat-shielding sheet of the present invention in which a heat-shielding layer and a resin layer are laminated (hereinafter, referred to as a multilayer sheet) will be described. I do.

In general, the elongation rate of a sheet material is reduced by incorporating a heat-shielding pigment. Therefore, if the heat-insulating sheet is stretched by applying force until it breaks, the kneaded sheet containing the heat-insulating pigment uniformly throughout the sheet is more likely to have the heat-insulating pigment coated on the surface of the heat-insulating sheet. Elongates longer than multilayer sheets containing higher density. That is, the tensile elongation at break has a large value. On the other hand, as for the force required to start elongation (that is, tensile yield strength), a kneaded sheet containing a heat-shielding pigment in the entire heat-shielding layer requires a larger force than a multilayer sheet. This is probably because the multilayer sheet does not contain a heat-shielding pigment or the like that hinders the elongation of the resin layer, and thus can start to elongate with a weak force. At this time, the heat shield layer containing the heat shield pigment at a high density is laminated on the resin layer. Therefore, it is considered that the resin layer elongates with a relatively weak force following the elongation of the resin layer. When attaching a heat-shielding sheet to an adherend, particularly when following a curved surface, the tensile yield strength is important among the above properties. That is, even when the multilayer sheet having a low tensile yield strength is stretched by a relatively weak force, the resin layer follows the curved surface and extends, so that it can be easily attached to the adherend. In addition, the heat-shielding layer does not cause growth cracks as the resin layer grows.

According to a detailed study by the present inventors, when the tensile yield strength is 1 O NZmm ² or less, preferably 5 ΝΖηηιη ² or less, and more preferably 3.5 NZmm ² or less, It was found that the sheet could be pasted, and that the sheet did not return after pasting. The heat-shielding sheet having such characteristics can be constituted by forming a multilayer using a urethane-based resin as a non-PVC-based resin. Next, each layer constituting the heat shield sheet of the present invention will be described.

The urethane-based resin that constitutes the resin layer is obtained by crosslinking with a urethane-based resin base material and a curing agent such as polyisocyanate, and is structurally rich in elasticity, self-healing, tough, and wear-resistant. Are better. The properties of such a resin layer can be appropriately adjusted depending on the acid value, hydroxyl value and molecular weight of the urethane-based base material, the molecular structure of the polyisocyanate, the content of the disocyanate group, and the degree of polymerization thereof. . As long as the resin layer does not impair the function of the present invention, other resins, pigments, lubricants, coloring agents, antistatic agents, flame retardants, antibacterial agents, antifungal agents, ultraviolet absorbers, light stabilizers, Various additives such as an antioxidant, a leveling agent, a flow regulator, and an antifoaming agent can be contained.

The resin layer is formed as a coating liquid by mixing a urethane resin, other components added as needed, and a diluting solvent, and applying this coating liquid to a predetermined coating layer by a known coating method (for a heat shield layer, ), Dried and hardened by the heat of cascade. It is also possible to use a generally used urethane sheet as the resin layer.

The thickness of the lunar layer is preferably 20 μm or more, more preferably 50 μm or more, as a lower limit. The upper limit is preferably 300 im or less, more preferably 10 im or less. 0 z ^ m or less. By setting the thickness of the luster layer to 20 μππ or more, it is possible to prevent cracks and the like from occurring in the heat shield layer when the heat shield 1 "raw sheet is stretched to be attached to the adherend. By setting the thickness of the resin layer to 300 / zm or less, the shielding sheet can be stuck to the adherend with relatively low force.

It is preferable to use a resin layer having a tensile yield strength of 1 to 7 NZmm ² in consideration of the above-mentioned material and thickness, etc.!

The heat-shielding layer is a layer containing a heat-shielding pigment, for example, a binder containing a urethane-based resin and a heat-shielding pigment. Heat-shielding pigments are heat-insulating properties that make it difficult to transmit heat energy from sunlight, heat-reflective properties that reflect heat energy from sunlight without absorbing it, and long-wave that radiates the absorbed heat energy back to the outside as infrared rays. It refers to inorganic or organic pigments having radioactivity or the like, and known materials can be used. Specific examples include inorganic pigments such as ceramic, iron oxide, lead oxide, titanium oxide, talc, and barium sulfate, and organic pigments such as phthalocyanine pnoray and sinkaciared.One or more of these may be appropriately combined. Can be used. Among these, it is preferable to use ceramic fine particles having excellent heat insulating properties, heat reflectivity and long-wave radiation, particularly transparent hollow ceramic fine particles, and titanium oxide having excellent heat reflectivity and self-cleaning properties.

As a binder for binding the heat shielding pigment, a binder containing at least a urethane resin is used. As the urethane-based resin, the same urethane-based resin as used in the resin layer can be used. By including the urethane-based resin in the heat-shielding layer, it is possible to obtain a heat-insulating layer with good elongation and good scratch resistance. In addition, it has excellent adhesion to a resin layer composed of a urethane-based resin and does not delaminate.

The heat shield layer may be blended with another resin as a binder as long as the effect of the urethane resin is not impaired. Other resins include, for example, olefin-based resins such as polyethylene, polypropylene, ethylene-based copolymers, and propylene-based copolymers, acrylic resins such as (meth) acrylate copolymers, and polyester-based resins. Known resins can be used. The content of the urethane resin in one component of the binder in the heat shield layer is not particularly limited, but is preferably 20% by weight or more, more preferably 50% by weight or more, and further preferably 90% by weight or more. Thermal barrier By setting the content of the urethane resin in one binder component to 20% by weight or more, even when the shape of the adherend has a curved surface when formed into a heat-insulating sheet, the expansion of the resin layer described later can be achieved. Therefore, it is possible to prevent cracks in the heat shield layer.

The content of the heat-insulating pigment in the heat-insulating layer cannot be said unconditionally because it varies depending on the thickness of the heat-insulating layer, the intended effect of the heat-insulating property, etc., but the lower limit is preferably 10% by weight or more, more preferably 2% by weight or more. 0 weight ° / ₀ or more. The upper limit is 60 weight to prevent the heat-shielding layer from cracking when the heat-shielding sheet is stretched to be attached to the adherend. / ₀ or less, preferably about 40% by weight or less.

In addition, the heat-shielding layer may contain, in addition to the binder and the heat-shielding pigment, other components as long as the function of the present invention is not impaired, similarly to the resin layer. Such a heat-shielding layer is prepared by mixing a binder, a heat-shielding pigment, and other components and a diluting solvent added as necessary, to prepare a heat-shielding layer coating solution. By using a conventionally known coating method, for example, a bar coater, a die coater, a blade coater, a spin coater, a rhono recorder, a gravure coater, a flow coater, spraying, screen printing, etc. ) And dried and cured by caloric heat to form a heat shield layer. Further, as the heat shield layer, a sheet formed by kneading a heat shield pigment into a binder component containing at least a urethane-based resin may be used.

The thickness of the heat-insulating layer cannot be said unconditionally because it differs depending on the amount of the heat-insulating pigment to be added, the intended effect of the heat-insulating properties, etc., but when it is provided by a coating method, it is preferably 50 μΐη to 700 μm, preferably 1 μm. It is about 0 0 / zm to 500 μπι. If the thickness of the heat-shielding layer is less than 5, the content of the heat-insulating pigment is high to obtain sufficient heat-shielding properties, and cracks are easily formed when the heat-insulating layer is extended. The ratio of the thickness of the resin layer to the thickness of the heat-insulating layer varies depending on the thickness of the entire sheet and the desired heat-insulating properties, but the overall thickness is 200 / Xn! In the case of about 400 μπι, the ratio of the resin layer and the heat shielding layer is about 40:60 to: L 0:90. '

The adhesive layer is a layer for attaching the heat-shielding sheet of the present invention to an adherend, and is formed on the surface of the resin layer opposite to the surface on which the heat-shielding layer is formed. Adhesive constituting the adhesive layer Examples of the adhesive include commonly used acrylic adhesives, silicone adhesives, urethane adhesives, and rubber adhesives. Further, a sticking agent having performance such as antistatic property may be used.

The pressure-sensitive adhesive layer is generally formed by dissolving or dispersing the pressure-sensitive adhesive in a diluting solvent as necessary to form a coating solution, and applying and drying the coating solution by a conventionally known coating method. Since the thickness of the adhesive layer varies depending on the adherend, it cannot be said unconditionally.However, in consideration of sticking properties, the lower limit is 20 m or more, preferably 30 m or more, and the upper limit is 200 m. Hereinafter, it is desirable to set it to about 100 zm or less. .

The solvent permeation prevention layer prevents the solvent contained in the heat-shielding layer coating solution when forming the heat-shielding layer and the solvent component remaining in the heat-shielding layer from penetrating into the resin layer, reaching the adhesive layer and reducing the adhesiveness. This layer is provided between the heat shield layer and the resin layer.

As a material for forming the solvent permeation prevention layer, a luster having good flexibility and high solvent resistance is used. As such a gist, specifically, a polyamide-based resin, a urethane-ataryl-based resin, a modified polyester, and the like are preferable, and a polyamide-based resin is particularly preferable. The solvent permeation prevention layer preferably contains a small amount of a urethane-based resin in order to enhance the adhesion to the heat shielding layer and the resin layer. A water-based urethane acrylic resin is preferable as the urethane-based resin that improves the adhesiveness. In order to obtain a higher solvent permeation prevention effect, the amount of the urethane resin is preferably not more than 50 parts by weight based on 100 parts by weight of the polyamide resin.

The solvent permeation prevention layer can be formed by applying an aqueous coating solution to the resin layer. The thickness is related to the thickness of each element of the heat-insulating sheet, but is preferably about 1 μm to 20 m, more preferably about 1 μm to 10 m, in order to obtain the above effects. More preferably, it is about 1 xm to 5 / xm. Next, a method for manufacturing the heat shield sheet of the present invention having the above-described configuration will be described.

The heat-shielding layer Z resin layer (heat-shielding layer Z, solvent permeation prevention layer / resin layer), which is a basic configuration of the heat-shielding sheet of the present invention, can be formed by co-extrusion, dry lamination, or coating. . When applying, apply either the heat-shielding layer or the luster layer It can be formed by forming a substrate or a substrate provided as a coating layer on a separator or the like as a substrate and applying the other to the substrate. The adhesive layer may be formed before laminating the resin layer and the heat shielding layer, or may be formed after laminating. In particular, it is preferable that the adhesive layer formed by coating on a base material such as a separator is formed by attaching the adhesive layer to a resin layer. In this case, the number of repetitions of the coating and drying steps can be reduced, and shrinkage of the resin layer and the heat shield layer due to heat can be reduced. Further, the adhesive layer can be formed irrespective of the completion of the curing of the resin layer made of the urethane-based resin, and the production becomes easy.

One example of the production method is to apply a coating solution for the heat-shielding layer, which is prepared by mixing a binder, a heat-shielding pigment, other components added as necessary, and a diluting solvent, onto a separator by a conventionally known coating method. Then, it is dried and cured by heating to form a heat shield layer. Next, a urethane-based resin, other components added as necessary, and a diluting solvent are mixed on the heat shield layer to form a coating liquid, and the heat shield layer is coated on the heat shield layer by a conventionally known coating method as described above. Then, it is dried and cured by heating to form a resin layer. When a solvent permeation prevention layer is provided, after forming a heat shielding layer, an aqueous coating solution of a resin constituting the solvent permeation prevention layer is applied by a known coating method, dried, and then applied as above. Then, a resin layer is formed.

Further, a coating solution obtained by dissolving an adhesive in a diluting solvent is applied on the resin layer by a conventionally known application method and dried to form an adhesive layer, thereby obtaining the heat shield sheet of the present invention.

As another example, a commercially available urethane sheet may be used as a resin layer, a heat shield layer may be formed on one surface of the urethane sheet, and an adhesive layer may be formed on the other surface.

In addition, the manufacturing method described above (it is merely an example, and the manufacturing method of the heat insulating sheet of the present invention is not limited to these manufacturing methods. For example, a resin layer, an adhesive layer Instead of sequentially laminating the layers, the heat shielding layer, the resin layer, and the adhesive layer may be formed in any order.

The thus manufactured heat shield sheet of the present invention can be attached to a desired adherend via an adhesive layer. In this case, workability is good even when the adherend is a curved surface. Can be stuck. In addition, since no chlorinated vinyl resin to which a plasticizer is added is used, no toxic gas is generated during baking *, and no cracks or the like occur in the heat shield layer even when used for a long period of time. Example

Hereinafter, the present invention will be described in more detail based on examples. In this example, “parts” and “%” are based on weight unless otherwise specified.

[Example 1]

Apply a heat-shielding layer coating solution of the following formulation to a paper separator with a thickness of 100 μm (Binasheet 70S-218T: Fujimori Kogyo Co., Ltd.) and dry it at 90 ° C for 10 minutes to obtain a thickness of 200 μm. m heat barrier layer was formed. Next, a resin layer coating solution having the following formulation was applied onto the heat shield layer, and dried at 10 ° C. for 6 minutes to form a resin layer having a thickness of 80 μm. Thus, a heat shield sheet was obtained.

Next, an adhesive layer coating solution having the following formulation was applied to the same paper separator as above, and dried at 10 ° C. for 5 minutes to form an adhesive layer having a thickness of 60 m, thereby obtaining an adhesive sheet. The adhesive layer of this adhesive sheet and the resin layer of the above-mentioned heat-insulating sheet were laminated and left to cure in an environment of 60 ° C for 7 days to produce a heat-insulating sheet of Example 1. Thermal barrier pigment dispersion for thermal barrier coating solution of Example 1>

Heat shielding pigment (Titanium CR97: Ishihara Titanium Industry Co., Ltd.) 68 parts, methyl ethyl ketone 29 parts, dispersant (Disperbyk l61: Big Chemie Japan) 3 parts dispersing machine ) To obtain a 68% dispersion of the heat-shielding pigment (heat-shielding pigment dispersion (a)).

Thermal barrier coating solution of Example 1>

■ Heat-shielding pigment dispersion (a) 28 parts

-Acrylic urethane resin base (solid content 35%) 7 3 parts

(Neo Paint # 8500 Clear: Asia Industry Co., Ltd.)

• Polyisocyanate (solid content 53%) 24 parts (Curing agent for Neo Paint # 8500: Asia Industries Co., Ltd.)

• Acrylic urethane resin base agent (solid content 35%) 90 parts

(Neo Paint # 8500 Clear: Asia Industry Co., Ltd.)

• Polyisocyanate (solid content 53%) 30 parts

(Curing agent for NeoPaint # 8500: Asia Industries Co., Ltd.)

'' Ataryl adhesive (solid content 40%) 62 parts

(Nisset KP-2074: This Carbide Company)

• 1 part of polyisocyanate

(Nisset CK-117: Nippon Carbide Doe)

• 37 parts of ethyl acetate

[Example 2]

An 80 / zm-thick urethane sheet (Silk Mouth MT93: Okura Kogyo Co., Ltd.) was laminated with a resin layer composed of a force and an adhesive layer of an adhesive sheet produced in the same manner as in Example 1. Next, on the surface of the urethane sheet on which the adhesive layer is not laminated, a heat-shielding layer coating solution obtained by adding a urethane-based resin as a component of a binder to a commercially available heat-shielding paint containing 40% of a heat-shielding pigment. The following formula is applied), dried at 90 ° C for 10 minutes to form a heat-insulating layer of 20 μμηη, and left to cure at 60 ° C for 7 days to prepare the heat-insulating sheet of Example 2. did. Thermal barrier coating solution of Example 2>

-Commercial base material for heat-shielding paint (solid content 65%) 56 parts

(Miracunore S5007F: Nagashima Special Paint Co., Ltd.)

-19 parts of the above heat-insulating hardener for raw paint (solid content 60%)

(Mirakuru S ⁵ 00 ⁷ F curing agent: Nagashimatokushutoryo Co., Ltd.) • Acryl-based urethane resin base agent (solid content 35%) 18 parts

(Neo Paint # 8500 Clear: Asia Industry Co., Ltd.)

■ Polyisocyanate (solid content 53%) 6 parts

(Curing agent for Neo Paint # 8500: Asia Industries Co., Ltd.)

[Example 3]

A resin layer made of the same urethane sheet as in Example 2 and an adhesive layer of an adhesive sheet produced in the same manner as in Example 1 were laminated. Next, the surface towards the adhesive layer of the urethane sheet is not laminated, coated with a solvent permeation preventing layer coating solution having the following formulation, 1 1 0 ° and dried for 3 minutes in C, and solvent penetration thickness 3 _M m An prevention layer was formed. A heat-shielding layer was formed on the solvent permeation preventing layer in the same manner as in Example 2 and left to cure in an environment of 60 ° C. for 7 days to produce a heat-insulating sheet of Example 3. Example 3 solvent permeation prevention layer coating solution>

· Water-based urethane acrylic resin 8 parts

(Solid content 37%) (NeoRez R-9676: Avia)

'Polyamide 6/6, 6/6, 13 copolymer 1 2 parts

(Solid content 100%)

(Ultra Mound I C: BAS F Japan)

'' Meta-modified alcohol 5 6 parts

• Tap water 24 parts

[Comparative Example 1]

A heat-shielding layer coating solution having the following formulation was applied to the paper separator of Example 1 and dried at 90 ° C. for 10 minutes to form a heat-shielding layer having a thickness of 280 / X m. Next, the heat shield layer and the adhesive layer of the adhesive sheet of Example 1 were laminated, and left to cure in an environment of 60 ° C. for 7 days to produce a heat shield sheet of Comparative Example 1. <Coating solution for heat shield layer of Comparative Example 1>

• 33 parts of commercially available thermal barrier paint base (solid content: 65%)

(Miracool S5007F: Nagashima Special Paint Co., Ltd.)

• Hardening agent for thermal barrier paint (solid content 60%) 1 1 part

(Curing agent for Miracool S5007F: Nagashima Special Paint Co., Ltd.)

• Acrylic urethane resin base agent (solid content 35%) 42 parts

(Neo Paint # 8500 Clear: Asia Industry Co., Ltd.)

• Polyisocyanate (solid content 53%) 14 parts

(Curing agent for Neo Paint # 8500: Asia Industries Co., Ltd.)

[Comparative Example 2]

The heat-shielding sheet (ATTSU-9: RIKEN TECHNOS) composed of a vinyl chloride resin, a heat-shielding layer (thickness 220 / m) made of heat-shielding pigment, and an adhesive layer (thickness 110 μπι) was used as the heat-insulating property of Comparative Example 2. Sheet.

[Comparative Example 3]

A heat-shielding layer coating solution having the following formulation was applied to the paper separator of Example 1, and 90. C, dried for 10 minutes to form a 200 μm thick heat shield layer. Next, a resin layer coating solution having the following formulation was applied on the heat shield layer, and dried at 100 ° C. for 6 minutes to form a resin layer having a thickness of 80 m, thereby obtaining a heat shield sheet. Next, the resin layer of this heat-shielding sheet and the adhesive layer of the adhesive sheet of Example 1 were laminated and left to cure at 60 ° C. for 7 days to produce a heat-shielding sheet of Comparative Example 3. Thermal barrier coating solution of Comparative Example 3)

-28 parts of the heat-insulating pigment dispersion of Example 1 (a)

• Ataryl resin base (solid content 50%) 59 parts

(Ataridick A801-P: Dainippon Ink & Chemicals, Inc.)

• Polyisocyanate (solid content 75%) 12 parts

(Barnock DN-950: Dainippon Ink & Chemicals, Inc.) <Resin layer coating liquid of Comparative Example 3>

'Ataryl resin base (solid content 50%) 84 parts

(Ataridick A801-P: Dainippon Ink & Chemicals, Inc.)

'Polyisocyanate (solid content 75%) 16 parts

(Barnock DN-950: Dainippon Ink & Chemicals, Inc.)

The heat-shielding sheets obtained in the examples and comparative examples were evaluated for heat-shielding properties, sticking properties to adherends, and scratch-preventing properties. Further, the heat-shielding sheets of the examples were evaluated for adhesiveness. Table 1 shows the evaluation results.

(1) Evaluation of heat insulation

The heat-insulating sheets of Examples and Comparative Examples were attached to a 25/2 m-thick polyester film via an adhesive layer, cut into a size of 11 OmmX11 Omm, and used as test specimens. As shown, the heat insulation was evaluated using the test apparatus 25 as follows. The test piece 21 was fitted into the upper part of the test box 24 cut out to a size of 10 OmmX 100 mm so that the heat shield layer was on the upper side, and the incandescent lamp 22 provided above the test piece 21 was used. Then, the temperature was measured and recorded by a temperature sensor 23 installed on the back surface of the test piece 21.

Here, as the test box 24, a styrofoam box having a thickness of 3 Omm and dimensions of “length” × “width” × “height” = 25 Omm × 350 mm × 250 mm was used. The distance between the test piece 21 and the incandescent lamp 22 was 15 Omm. As the incandescent lamp 22, RF 100 V 18 OWHC (Toshiba Lighting & Technology Corporation) was used. As the temperature sensor 23, a thermo recorder RT-11 (Tabayspeck) was used. The test was conducted in a constant temperature and humidity room at 23 ° C and 50% RH without any wind.

The evaluation was performed when the temperature of the temperature sensor 23 was less than 50 ° C 30 minutes after the start of measurement. The sample was marked with “〇” and the sample with 50 ° C or higher was marked with “X”. At this time, the temperature on the irradiation surface side of the test piece 21 was about 80 ° C.

(2) Evaluation of stickability to adherend

The “tensile yield strength” of the heat-insulating sheets of Examples and Comparative Examples was measured using a tensile strength universal tensile tester (Tensilon HTM-100: Orientec) according to JIS K7113-1981. Test piece: No. 4 test piece, distance between grips: 10 Omm, width: 25.4 mm, pulling speed: speed F (50 mm: min ± 10%).

Evaluation, tensile what yield strength was 3. 5NZmm ² hereinafter referred to as "〇", those of 3. 5N Zmm ² to more than 1 ONZnrni ² hereinafter referred to as "△", those of more than 10 N / mm ² " X ”.

(3) Evaluation of scratch resistance

The heat-shielding sheets of Examples and Comparative Examples were stuck to a glass plate having a thickness of 2 mm via an adhesive layer, and a safia needle having a radius of 0.1 mm and a tip angle of 60 ° was vertically dropped thereon. Next, a weight was placed on the safia needle, the heat-insulating sheet was moved at a speed of 260 Omm / min, and the weight was evaluated when a scratch was confirmed with a 25x lens.

The evaluation was “〇” when the sample was not damaged at 600 g or less, and “X” was at 300 g or less.

(4) Evaluation of adhesiveness

Cut the heat shield sheet of the example into a size of 25 mm in width and 150 mm in length, paste it on SU, S 304 steel plate, leave it in an atmosphere of 23 ° C, 50% RH for 5 minutes, and peel off The film was peeled at a strength of 30 Omm / min and an angle of 180 °, and the adhesive strength was measured. Those with an adhesive force exceeding 800 g / 25 mm were marked with “〇”, and those with 800 g / 25 mm or less were marked with “△”. table 1

As is clear from Table 1, the heat-shielding sheet of the example has a lower tensile yield strength than the heat-shielding sheet of Comparative Example 12 and is relatively weaker than the heat-shielding sheet of Comparative Example 12 It was able to start stretching by force, and as a result, it exhibited excellent adhesion to adherends with curved surfaces. Further, the heat-shielding layer of the example contains a heat-shielding pigment which is an obstacle to elongation at a higher density than the heat-shielding layer of Comparative Example 12 and is applied with a relatively weak force. Elongation was obtained to the extent that it could be stuck to the body, and it could reasonably follow the elongation of the resin layer, without causing cracks in the heat shield layer.

On the other hand, in the heat-insulating sheet of Comparative Example 3 in which an acryl-based resin was used as a binder of the heat-shielding layer while an acryl-based resin was used instead of the urethane-based resin as the resin layer, it was comparatively difficult to stretch. It required a great deal of force, and when it was extended, it cracked the thermal barrier.

Further, in addition to the above-mentioned effects, the heat-insulating sheet of the example obtained an evaluation result that was superior to the heat-insulating sheet of the comparative example in terms of scratch resistance, and is suitable as a material to be attached to the outside of the adherend. It was shown.

Further, since the heat-shielding sheet of Example 3 is provided with a solvent-penetration preventing layer, the solvent of the heat-shielding-layer coating liquid when forming the heat-shielding layer and the residual ij remaining in the heat-shielding layer penetrate into the resin layer. However, since migration to the adhesive layer can be prevented, high adhesiveness could be maintained. As is clear from the above examples, according to the present invention, the urethane resin and the shielding Since the heat-shielding layer containing the thermal pigment and the resin layer formed from the polyurethane resin are laminated, a heat-shielding sheet that can be stuck well even when the adherend has a curved surface or the like is provided. can get. In addition, since the Shiridani vinyl resin to which a plasticizer is added is not used, no toxic gas is generated during incineration, and even if used for a long period of time, the heat shield layer may crack. A heat-insulating sheet free of heat is obtained.

Claims

The scope of the claims

1. A heat-insulating sheet comprising a heat-insulating layer containing a urethane-based resin and a heat-insulating pigment, and a resin layer formed of a urethane-based resin laminated.

2. The heat shield sheet according to claim 1, wherein the tensile yield strength is 10 NZmm ² or less.

3. The heat shield sheet according to claim 1, wherein an adhesive layer is provided on a surface of the luster layer opposite to a surface having the heat shield layer.

4. The heat shielding sheet according to claim 1, further comprising a solvent permeation prevention layer between the heat shielding layer and the resin layer.

5. The heat shielding sheet according to claim 4, wherein the solvent permeation prevention layer contains a polyamide resin.

6. The heat shielding sheet according to any one of claims 3 to 5, wherein the pressure-sensitive adhesive layer is laminated on the resin layer after being formed on another base material.