WO2020159050A1 - Low emissivity glass - Google Patents

Abstract

The present invention relates to low emissivity glass in which a glass substrate, a first dielectric layer, a first metal protective layer, an infrared reflective metal layer, a second metal protective layer, a second dielectric layer and an overcoat layer are sequentially laminated. An a* value is -4 to 1, and a b* value is -15 or lower. The width ratio of the first metal protective layer and second metal protective layer is 1:0.5 to 0.6.

Description

Low-emission glass

The present invention relates to a low-emissivity glass exhibiting excellent durability and a strong blue surface.

Low-emission glass deposits a metal with high reflectivity in the infrared region, such as silver (Ag), in transparent glass, while maintaining the transparency of the glass, blocking indoor heat from being leaked to the outside in winter and entering the room in summer. It means a functional building material that reflects radiant heat. Low-emission glass has been used only for non-residential buildings with a large glass construction area, but recently, as the need for energy saving increases, cases applied to residential buildings are increasing, and the demand for low-emission glass with the appropriate characteristics is increasing.

In particular, in the case of low-emissive glass used in non-residential buildings, high insulation and shielding performance and excellent appearance are preferentially required instead of high visible light transmittance, whereas low-visibility glass used in residential buildings prefers high visible light transmittance for visibility. Is required. In addition, compared to the low-emission glass used in non-residential buildings, the glass used in residential buildings has a high amount of usage, and thus it is necessary to secure excellent durability at a level that can be distributed in many places.

On the other hand, the structure of the low-emission glass manufactured by the sputtering method includes an infrared reflective metal layer, and it is common to have a dielectric layer on the upper and lower metal layers to protect the infrared reflective metal layer. However, when the dielectric layer is deposited on the infrared reflective metal layer, since the metal is used as a target raw material in an oxygen or nitrogen atmosphere, the infrared reflective metal layer is oxidized or nitrided by oxygen or nitrogen injected into the chamber, thereby interlayering between the infrared reflective metal layer and the dielectric layer. There is a problem that the boundary becomes ambiguous. In addition, due to the ambiguity of the interlayer boundary as described above, there is a problem in that the emissivity value of the manufactured glass is increased and the properties of the low-emission glass are lost.

As an alternative to this, U.S. Patent No. 6,804,048 (Patent Document 1) includes a first undercoating layer comprising a dielectric material, an infrared reflecting layer, and a second undercoating layer comprising a dielectric material. Low-emission glass is disclosed. However, the low-emission glass of Patent Document 1 has a weak chemical durability, and thus the coating film is easily damaged, and thus has a disadvantage that blurring (haze) occurs in the coating film during the heat treatment or bending process.

In addition, Korean Patent No. 215,380 (Patent Document 2) includes a transparent non-metallic substrate, an anti-reflective base film containing zinc-tin oxide, a metallic film containing silver (Ag) and reflecting infrared rays, and zinc oxide. Disclosed is a coated product that reduces the blurring effect during heat treatment, including a crystalline metal contact film portion. However, the coated product of Patent Document 2 may have a problem that the metallic film is damaged when the coating film is exposed to the outside for a long time due to the weak durability of the zinc oxide of the coating layer located above and below the metallic film.

Therefore, there is a need for research and development on low-emission glass having excellent chemical and mechanical durability and excellent visible light transmittance.

Accordingly, the present invention is to provide a low-emission glass having a strong blue surface, excellent chemical and mechanical durability, and low emissivity.

The present invention includes a form in which a glass substrate, a first dielectric layer, a first metal protective layer, an infrared reflective metal layer, a second metal protective layer, a second dielectric layer, and an overcoat layer are sequentially stacked, and a* value is -4 to 1 , B* value is -15 or less, and the first metal protection layer and the second metal protection layer provide a low-emission glass having a thickness ratio of 1: 0.5 to 0.6.

The low-emission glass according to the present invention has a strong blue surface, excellent chemical and mechanical durability both before and after heat treatment, and low emissivity. Due to this, the low-emission glass is suitable as a building material for residential and non-residential buildings.

Hereinafter, the present invention will be described in detail.

In the present invention, the'a* value' and'b* value' of the glass are glass measured according to the KS L 2514 standard using a D65 standard light source in a wavelength range of 380 to 780 nm based on the average thickness of the glass substrate 6 mm. It means the a* value and b* value of the surface.

The low-emission glass according to the present invention includes a form in which a glass substrate, a first dielectric layer, a first metal protective layer, an infrared reflective metal layer, a second metal protective layer, a second dielectric layer, and an overcoat layer are sequentially stacked, and a* value This -4 to 1, b* value is -15 or less, and the first metal protective layer and the second metal protective layer have a thickness ratio of 1: 0.5 to 0.6.

Glass substrate

As the glass substrate, conventional glass such as soda-lime glass, which is used for construction or automobiles, can be used.

Further, as the glass substrate, glass having an appropriate thickness may be used according to the purpose of use. For example, a transparent soda-lime glass having an average thickness of 2 to 12 mm or 5 to 6 mm may be used as the glass substrate.

First dielectric layer and second dielectric layer

Each of the first dielectric layer and the second dielectric layer serves to protect the infrared reflective metal layer from ions or oxygen during heat treatment and to control the optical properties of the manufactured glass.

The first dielectric layer and the second dielectric layer may each include one or more selected from the group consisting of nitride and nitride oxide. Specifically, the first dielectric layer and the second dielectric layer may each include silicon-containing nitride. More specifically, the first dielectric layer and the second dielectric layer may each include SiAlN _x or Si _y N _z , where x is an integer from 1 to 3, y is 2 or 3, and z is 3 or It can be 4.

Each of the first dielectric layer and the second dielectric layer may have a refractive index of 1.8 to 2.5, and an absorption coefficient of 0.1 or less. Specifically, each of the first dielectric layer and the second dielectric layer may have a refractive index of 1.8 to 2.2 and an absorption coefficient of 0 to 0.1. When the refractive index and the absorption coefficient of each of the first dielectric layer and the second dielectric layer are within the above ranges, it is possible to prevent a problem that the visible light transmittance of the manufactured glass is reduced.

In addition, each of the first dielectric layer and the second dielectric layer may have an average thickness of 50 to 70 nm. When the average thickness of each of the first dielectric layer and the second dielectric layer is within the above range, it is possible to prevent a problem of a decrease in durability of the manufactured glass and a decrease in blue of the surface color.

First metal protective layer and second metal protective layer

The first metal protective layer and the second metal protective layer improve the adhesion between the infrared reflective metal layer and the dielectric layer, and serve to prevent the movement of Na and oxygen (O ₂ ) diffused in the glass during heat treatment and the infrared reflective metal layer. It plays a role in helping fusion of the infrared reflecting metal to enable stable behavior even at high heat treatment temperatures, and absorbing oxygen (O ₂ ) penetrating the infrared reflecting metal layer helps to maintain the low emission performance of the glass.

Each of the first metal protection layer and the second metal protection layer may include one or more selected from the group consisting of nickel (Ni), chromium (Cr), and nickel (Ni)-chromium (Cr) alloys. Specifically, each of the first metal protection layer and the second metal protection layer may include a nickel (Ni)-chromium (Cr) alloy. In this case, the nickel (Ni)-chromium (Cr) alloy may include 75 to 85% by weight of nickel and 15 to 25% by weight of chromium based on the total weight of the alloy.

In addition, each of the first metal protection layer and the second metal protection layer may have an average thickness of 4 to 20 nm. Specifically, each of the first metal protective layer and the second metal protective layer may have an average thickness of 4 to 10 nm. When the average thickness of each of the first metal protective layer and the second metal protective layer is within the above range, the durability and/or visible light transmittance of the manufactured glass is reduced, and the problem of increased fogging of the coating film after heat treatment and bending is prevented. can do.

The first metal protective layer and the second metal protective layer have a thickness ratio of 1: 0.5 to 0.6. When the thickness ratio of the first metal protective layer and the second metal protective layer is within the above range, it is possible to prevent a problem in which durability of the manufactured glass is lowered and a problem in which the blue color of the glass surface is reduced. In particular, the thickness ratio of the first metal protective layer and the second metal protective layer must be maintained within the above range so that the manufactured glass may have an appropriate absorption rate.

Infrared reflective metal layer

The infrared reflective metal layer serves to provide high shielding performance of the glass manufactured by selectively reflecting the sun's radiation and at the same time to realize low emission.

The infrared reflective metal layer may include a metal having excellent conductivity, and may include, for example, one or more metals selected from the group consisting of gold, silver, platinum, aluminum and copper. Specifically, the infrared reflective metal layer may include silver (Ag). More specifically, the infrared reflective metal layer may be made of silver.

In addition, the average thickness of the infrared reflective metal layer may be 10 to 15 nm. When the thickness of the infrared reflecting metal layer is within the above range, the problem of insufficient formation of the low-emission performance of the manufactured glass because the formation of the infrared reflecting metal layer is not normally performed, and the problem of a decrease in the blue color of the glass surface due to a high reflectance of the manufactured glass. Can be prevented.

Overcoat layer

The overcoat layer serves to protect the second dielectric layer and the infrared reflective metal layer.

The overcoat layer may include a material having high mechanical strength, low surface roughness, and high visible light transmittance. For example, the overcoat layer may include silicon (Si), niobium (Nb), titanium (Ti), zirconium (Zr), tantalum (Ta), or alloys, oxides, nitrides, or nitrides thereof. Specifically, the overcoat layer may include zirconium-containing oxide or nitride, or titanium-containing oxide or nitride. In this case, the titanium-containing nitroxide may be, for example, TiO _x N _y , where x and y may be a molar ratio of 100:0 to 75:25 based on 100 mol% of x and y in total.

In addition, the average thickness of the overcoat layer may be 2 to 15 nm. When the average thickness of the overcoat layer is within the above range, it is possible to prevent a problem that durability of the manufactured glass is lowered, and a problem that fogging occurs after heat treatment of the manufactured glass.

The low-emission glass according to the present invention has an a* value of -4 to 1, and a b* value of -15 or less. Specifically, the low-emission glass may have an a* value of -3 to 1 and a b* value of -30 to -18.

In addition, the low-emissivity glass may have an emissivity of 0.2 or less, or 0.1 or less. Emissivity is the ratio of energy that re-radiates after absorbing external light energy or re-radiates when surface reflection occurs. The maximum value is 1, and the smaller the value, the greater the ratio of energy to re-radiate or re-radiate. it means.

The low-emission glass according to the present invention as described above has a strong blue surface, and has excellent chemical and mechanical durability both before and after heat treatment. Due to this, the low-emission glass is suitable as a building material for residential and non-residential buildings.

The low-emission glass according to the present invention can be manufactured using a vacuum sputtering method as a thin film forming method for forming each layer. That is, the method for manufacturing low-emission glass according to the present invention may include forming each layer by sputtering deposition.

Hereinafter, the present invention will be described in more detail through examples. However, these examples are only for the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

[Example]

Examples 1 to 11 and Comparative Examples 1 to 13. Preparation of low-emission glass

The thickness of each layer was adjusted and laminated as described in Tables 1 and 2. Specifically, the first dielectric layer was coated on a 6 mm thick transparent glass substrate using a SiAl Rotary target under a nitrogen and argon atmosphere. Subsequently, a first metal protective layer was coated on the first dielectric layer using an NiCr Planar target in an argon atmosphere, and an infrared reflective metal layer was coated on the first metal protective layer using an Ag Planar target under an argon atmosphere. Thereafter, a second metal protective layer was coated on the infrared reflective metal layer using a NiCr Planar target in an argon atmosphere. Thereafter, a second dielectric layer is coated on the second metal protective layer using a SiAl Rotary target under a nitrogen and argon atmosphere, and finally, an overcoat layer is coated on the second dielectric layer using a Zr Rotary target under an argon and nitrogen atmosphere. Low-emission glass was prepared.

(Thickness nm)	Overcoat layer	Second dielectric layer	Second metal protective layer	Infrared reflective metal layer	First metal protective layer	First dielectric layer
Example 1	7	60	4	12	8	60
Example 2	7	60	4.8	12	8	60
Example 3	7	60	5	12	10	60
Example 4	7	60	6	12	10	60
Example 5	10	60	4	12	7	60
Example 6	7	65	4	10	6.7	55
Example 7	8	50	4.4	11	8	50
Example 8	8	70	4.4	14	8	70
Example 9	2	60	4.4	11	8	60
Example 10	8	60	4.4	12	8	60
Example 11	15	60	4.4	13	8	60

(Thickness nm)	Overcoat layer	Second dielectric layer	Second metal protective layer	Infrared reflective metal layer	First metal protective layer	First dielectric layer
Comparative Example 1	7	60	1.4	12	3	60
Comparative Example 2	7	60	1.9	12	3	60
Comparative Example 3	7	60	3	12	3	60
Comparative Example 4	7	40	6	12	10	40
Comparative Example 5	7	45	6	12	10	45
Comparative Example 6	7	48	6	12	10	48
Comparative Example 7	7	72	6	12	10	72
Comparative Example 8	7	75	6	12	10	75
Comparative Example 9	7	80	6	12	10	80
Comparative Example 10	0	60	6	12	12	60
Comparative Example 11	One	60	6	12	14	60
Comparative Example 12	16	60	9	12	20	60
Comparative Example 13	18	60	15	12	20	60

Test Example: Evaluation of glass properties

The properties of the low-emission glass prepared in Examples 1 to 11 and Comparative Examples 1 to 13 were measured in the following manner, and the results are shown in Table 3.

Specifically, the low-emission glass prepared in Examples and Comparative Examples was heat treated at 650° C. for 5 minutes, quenched, and properties were evaluated.

(1) color of the glass surface

Using the D65 standard light source in the wavelength range of 380 to 780 nm, the 10° reflection color of the glass surface was measured according to the KS L 2514 standard.

(2) sheet resistance

The sheet resistance was measured using a surface resistance meter (non-contact sheet resistance meter, manufactured by SURAGUS). The sheet resistance of glass is a value measured by a silver (Ag) layer, which is an infrared reflecting metal layer, for a solar heat ray, and is one of evaluation properties that can measure performance as a low-emission glass even after heat treatment.

(3) Scratch resistance

After spraying distilled water mixed with quartz powder on the coated surface of the manufactured glass, the nylon brush with a thickness of 0.5 mm was moved 200 times horizontally to the coated surface of the glass, and then the number of scratches generated on the coated surface was measured to improve the scratch resistance. Was evaluated.

Specifically, when there are no scratches, there are no scratches of grade 1, width of 1 mm or more, and less than 5 scratches of grade 2, grade 2, width of 1 mm or more, and scratches of width of 1 mm or less are generated by 5 or more. 3 grades, 1 or 2 thick scratches with a width of 1 mm or more were created, 4 grades with 3 or more thick scratches with a width of 1 mm or more, 5 grades, and 6 with a coating film peeled off the glass substrate .

(4) Moisture resistance

After the prepared low-emission glass was stored at 30°C and 80% relative humidity for 7 days, the moisture resistance was evaluated by measuring the number of pinholes generated on the surface of the overcoat layer.

(5) Haze

Haze was evaluated by observing the degree of blurring of the surface of the overcoat layer after heat treatment of the prepared low-emission glass.

(6) Emissivity

The emissivity was calculated based on the KS L 2525 standard after measuring the reflection spectrum of the infrared wavelength region (2,500 to 25,000 nm) using FT-IR after heat treatment of the low-emission glass.

(7) Visible light transmittance

The visible light transmittance was measured using a spectrophotometer (Spectrophotometer, Rambda950, manufactured by Perkinelmer) after heat treatment of the low-emission glass, and the transmission spectrum of the visible light wavelength range (380 to 780 nm) was calculated using the KS L 2514 standard.

division	Color of the glass surface				Sheet resistance (Ω/sq)	Scratch resistance	Moisture resistance (number of pinholes)	Hayes	Emissivity	Visible light transmittance (%)
	Y	L	a*	b*
Example 1	15.8	46.7	-0.2	-20.5	7	Level 2	none	none	0.081	54.8
Example 2	17.6	49.0	-0.9	-20.1	7	Level 2	none	none	0.081	53
Example 3	18.0	49.5	-1.1	-20.0	7	Level 2	none	none	0.081	51
Example 4	20.4	52.3	-1.8	-19.8	7	Level 2	none	none	0.081	47
Example 5	15.3	46.0	-0.7	-22.5	7	Level 2	none	none	0.081	54.3
Example 6	14.7	45.2	-0.2	-21	8	Level 2	none	none	0.095	56
Example 7	15.6	46.4	0.0	-20.5	7.5	Level 2	none	none	0.088	54.8
Example 8	18.0	49.5	-1.2	-20.7	6	Level 2	none	none	0.068	51
Example 9	13.8	43.9	-0.4	-20.0	7.5	Level 2	none	none	0.088	56.5
Example 10	15.6	46.5	-1.3	-20.0	7	Level 2	none	none	0.081	54
Example 11	19.2	50.9	-2.9	-19.7	6.5	Level 2	none	none	0.075	50.1
Comparative Example 1	11.8	40.9	3.1	-18.8	7	Grade 6	10 things	Occur	0.081	57.5
Comparative Example 2	13.0	43	2.2	-20.5	7	Grade 5	5	Occur	0.081	57.3
Comparative Example 3	15.5	46.3	1.1	-21.3	7	Level 3	Three	Fine occurrence	0.081	55.1
Comparative Example 4	16.6	47.8	1.4	-0.5	7	Level 3	none	Occur	0.081	54.6
Comparative Example 5	17.5	48.9	0.9	-5.0	7	Level 3	none	Occur	0.081	53.4
Comparative Example 6	18.4	50.0	0.5	-7.8	7	Level 3	none	Occur	0.081	52.4
Comparative Example 7	35.4	66.1	-7.8	-10.3	7	Level 2	none	Occur	0.081	40.1
Comparative Example 8	38.6	68.4	-8.6	-7.4	7	Level 2	none	Occur	0.081	38.3
Comparative Example 9	42.1	70.9	-8.9	-3.1	7	Level 2	none	Occur	0.081	35.8
Comparative Example 10	24.6	56.7	-2.5	-14.2	7	Grade 5	10 things	Occur	0.081	46.2
Comparative Example 11	25.1	57.2	-2.8	-14.7	7	Grade 5	10 things	Occur	0.081	46.1
Comparative Example 12	14	44.4	1.5	-14.2	7	Level 2	none	Occur	0.081	56.7
Comparative Example 13	17.5	49	1.2	-8.3	7	Level 2	none	Occur	0.081	42.3

As shown in Table 3, the low-emission glass of Examples 1 to 11 has a low sheet resistance of 9 Ω/sq or less even after heat treatment, has excellent durability such as moisture resistance and scratch resistance, and causes haze of the coating film due to heat treatment Without, the color of the glass surface was strong blue, and showed a high visible light transmittance of 47% or more.

On the other hand, Comparative Examples 1 to 3 in which the thicknesses of the first metal protective layer and the second metal protective layer were thin were insufficient in moisture resistance and haze occurred in the coating film after heat treatment. Particularly, in Comparative Examples 1 and 12 in which the thickness ratio between the first metal protective layer and the second metal protective layer was less than 0.5, a* value of the glass surface was greater than 1.1 and there was a problem in that the red color increased. In addition, Comparative Examples 2, 3 and 13 in which the thickness ratio exceeded 0.6 did not show a strong blue color. In addition, in Comparative Examples 4 to 9 in which the first dielectric layer and/or the second dielectric layer were thin or thick, there was a problem in that the strong blue color was reduced because the b* value of the glass surface was greater than -11. Further, in Comparative Examples 10 to 13 in which the overcoat layer was thin or thick, haze was generated after heat treatment, and thus the durability was insufficient. Particularly, in Comparative Examples 10 and 11 with or without an overcoat layer, scratch resistance and moisture resistance after heat treatment were remarkably insufficient.

Claims (4)

1. A glass substrate, a first dielectric layer, a first metal protective layer, an infrared reflective metal layer, a second metal protective layer, a second dielectric layer and an overcoat layer are sequentially stacked.

   Low-emission glass, wherein a* value is -4 to 1, b* value is -15 or less, and the first metal protective layer and the second metal protective layer have a thickness ratio of 1: 0.5 to 0.6.
2. The method according to claim 1,

   The first dielectric layer has an average thickness of 50 to 70 nm,

   The first metal protective layer has an average thickness of 4 to 20 nm,

   The infrared reflective metal layer has an average thickness of 10 to 15 nm,

   The second metal protective layer has an average thickness of 4 to 20 nm,

   The second dielectric layer has an average thickness of 50 to 70 nm,

   The overcoat layer has an average thickness of 2 to 15 nm, low-emission glass.
3. The method according to claim 1,

   The first dielectric layer and the second dielectric layer each include at least one selected from the group consisting of nitride and nitride oxide, the refractive index is 1.8 to 2.5, the absorption coefficient is 0.1 or less, low-emission glass.
4. The method according to claim 1,

   The first metal protective layer and the second metal protective layer each include at least one selected from the group consisting of nickel, chromium, and nickel-chromium alloys, low-emission glass.