KR102028349B1 - Heat-isolating paint with high performance - Google Patents

Abstract

A heat insulation paint with high performance of the present invention comprises: (i) 28-52 wt% of an acrylic copolymer emulsion; (ii) 8-14 wt% of a core-shell opaque acrylic copolymer; (iii) 12-18 wt% of titanium dioxide having near-infrared reflectance greater than or equal to 50%; (iv) 8-12 wt% of an extender pigment; (v) 4-8 wt% of a hollow polymer bead; (vi) 12-14 wt% of deionized water; and (vii) 4-6 wt% of an additive. The heat insulation paint with high performance of the present invention includes a hollow polymer bead with improved near-infrared reflection efficiency instead of an inorganic hollow bead included in a conventional heat insulation paint, and a core-shell opaque acrylic copolymer having a much higher light reflectance than an aqueous polymer included in a conventional heat insulation paint, thereby having further improved sunlight reflection efficiency, insulation performance, and weather resistance compared to a conventional heat insulation paint. Therefore, the present invention realizes an effect of reducing energy management costs and carbon dioxide generation when painted on an inner wall, an outer wall or the like of a building.

Description

Heat-isolating paint with high performance

 The present invention relates to a high-performance heat shielding coating, and more particularly, to a heat shielding coating having excellent solar reflection efficiency, heat insulation performance, and weather resistance.

Due to meteorological changes caused by global warming, Korea is expected to increase the temperature by 1.1 ℃ ~ 1.5 ℃ by 2020, and the number of heat waves caused by subtropical heat has increased by 7.2 times in 2020 ~ 2049 from 9 days in 2009. is estimated to be 23 days tropical night also in the reference 4, 2009 2020-2049 1.5 times 20.6 and so on prolonged days overall, the temperature and the energy consumption due to the increase in summer cooling operation rate increased from sitjeom being elevated the CO ₂ generated according burden There is an urgent need to establish countermeasures against this rising prospect.

As a solution for this, one of the technologies for suppressing solar radiation on rooftops, walls and non-permeable surfaces of urban buildings during summer is actively introducing technologies for suppressing solar radiation generation on buildings and urban non-permeable surfaces by thermal paint construction. It is also well known.

Principle of solar radiation suppression of heat shield paint reflects near-infrared rays, which converts about 52% of sunlight into radiant heat, so that the heat shield paint cannot be converted into radiant heat and at the same time, some formed heat is transferred to the building and non-transmissive surface of the object. It is to insulate the hollow beads (Hollowed Beads) in which the excellent air insulation function that can suppress the (Hollowed Beads) is built into the paint coating (Orientation).

Therefore, it can be seen that the thermal paint performance depends on the effective use of a material having a high near infrared reflectance in the 780 nm to 2500 nm region of the solar wavelength, and at the same time selecting hollow beads having better thermal insulation. have.

In general, titanium dioxide (TiO ₂ ), which has the highest whiteness, is the material that most reflects sunlight, but since it mainly represents reflectance in the visible region, as shown in FIG. 4, the near infrared reflectance value is almost 1. Only about 46%, which is the level of 2, can exhibit radiant heat suppression efficiency.

In addition, many thermal paint research-designers have introduced technologies to improve thermal insulation performance by combining materials with high light reflectance in the visible region, such as Mica, glass beads, alumina, etc., which have high light reflectivity. The technique is considered to have technical limitations in improving the performance of the fundamental thermal barrier paint because of its low reflectance in the near infrared region, which is actually converted to radiant heat.

In Korean Patent Laid-Open Publication No. 10-1998-068912 as a heat shielding paint, (ii) 15 to 30% by weight of porous inorganic material and (i) 1.5 to 5.0% by weight of titanium dioxide, which is thermal insulation pigment, The heat shield paint is made, and in Korean Patent No. 10-1291894, (5) 5 to 10% by weight of heat shield pigments, such as antimony oxide, (ii) 10 to 20% by weight of inorganic fine particle hollow beads, (i) acrylic resin A heat shield paint containing 60 to 75% by weight and 5 to 10% by weight of an additive is disclosed.

However, the conventional heat shielding paints have a problem of poor solar reflectance, heat insulation performance, and weather resistance due to low near infrared reflectance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat shield coating having excellent solar reflection efficiency, heat insulation performance, and weather resistance at the same time by including a polymer hollow bead having excellent near infrared reflection efficiency and a core-shell opaque acrylic copolymer having excellent light reflectance.

In order to achieve such a problem, in the present invention, the heat-shielding paint is (28) to 52% by weight of the acrylic copolymer emulsion, (ii) 8 to 14% by weight of the core-shell opaque acrylic copolymer, and (i) the near infrared reflectance is 50%. Titanium dioxide 12 to 18% by weight, (ⅳ) sieving pigments 8 to 12% by weight (i) 4 to 8% by weight polymer hollow beads, (i) 12 to 14% by weight of deionized water and (ⅶ) additives It consists of 6 weight%.

The present invention includes a polymer hollow bead with improved near-infrared reflection efficiency instead of a hollow hollow bead included in a conventional heat shield coating, and at the same time, a core-shell opaque acrylic having a much higher light reflectance than an aqueous polymer included in a conventional heat shield paint. It includes a copolymer and has a solar reflection efficiency, heat insulation performance, and weather resistance significantly improved than conventional heat shield paints.

Therefore, when the present invention is coated on the inner wall or outer wall of the building, the effect of reducing energy management cost and carbon dioxide generation is realized.

1 is a photograph of a polymer hollow bead constituting the present invention.
2 is a schematic cross-sectional view of a polymer hollow bead constituting the present invention.
Figure 3 is a graph of the solar (solar) reflectance comparison according to the type of hollow bead (30% by weight) contained in the heat shield paint.
4 is a graph showing solar radiation (solar light) reflectance of titanium dioxide and calcium carbonate according to wavelengths;
Figure 5 is a thermal image comparison picture of the exterior of the building coated with the conventional heat shield paint and the present invention heat shield paint, respectively.
Figure 6 is a thermal image comparison of the interior of the building, respectively, the conventional heat shield paint and the present invention heat shield paint.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

The thermal barrier paint according to the present invention is 28 to 52% by weight of acrylic copolymer emulsion (Acrylic Copolymer emulsion), 8 to 14% by weight of Core-Shell Opaque Acryl Copolymer, titanium dioxide having near infrared reflectance of 50% or more. (High NIR Titanium Dioxide) 12-18% by weight, sieving pigment 8-12% by weight, polymer hollow beads (4-8% by weight), DI water 12-14% by weight and additives 4 It consists of -6 weight.

The acrylic copolymer emulsion may be an acrylic resin having good weather resistance as an exterior coating, an acrylic fluorine copolymer resin, an acrylic urethane copolymer resin, or an acrylic melamine copolymer resin, and the type thereof is not particularly specified. When the amount used is adjusted to 28 to 52% by weight so that the total weight with the newly introduced core-shell opaque acrylic copolymer of the present invention is 42 to 60% by weight, the adhesion, tensile strength and flexibility of the coating film Was the most suitable.

The core-shell opaque acrylic copolymer (Core-Shell Acryl Copolymer) is an organic polymer white pigment that has been developed and used as a plastic white pigment and can replace some inorganic titanium dioxide (TiO ₂ ). Resins.

The performance principle of these core-shell opaque acrylic copolymers as an organic polymer white pigment substitute is a resin synthesized by a core-shell emulsion process by enlarging the difference in refractive index between the core layer and the shell layer. When the ion exchange water contained in the core is dried out and dried, the dry coating film is formed, and due to the large refractive index difference between the core layer and the shell layer, the white light is generated based on light scattering due to the decrease in the light transmittance of the incident light.

In the present invention, the purpose of using the core-shell opaque acrylic copolymer as a constituent of the heat shielding paint is a resin used in the heat shielding paint of the prior art and the acrylic copolymer emulsions of the present invention, the dry coating film is mostly transparent coating film This is to solve the disadvantage that high transmittance of solar light causes negative adverse effects in terms of expression of solar reflection efficiency. By converting these transparent dry coatings into white dry coatings, the light reflection is dramatically increased and at the same time, it is discretized. To increase the light reflecting efficacy of titanium.

In the present invention, when the addition amount of the core-shell opaque acrylic co-polymer is more than 14% by weight, the dry coating film strength is weak, which is not preferable.

Titanium dioxide having a near infrared reflectance of 50% or more constituting the heat shielding coating of the present invention is titanium dioxide, which more precisely manages the crystal structure arrangement of the rutile crystal structure, and has a low reflectance in the near infrared region of 780 to 2500 nm. It is a 54.3% phosphor and is a special titanium dioxide with a near infrared reflectance higher than that of ordinary titanium dioxide, 46.0%.

In terms of the amount of use, while the amount of titanium dioxide used in the prior art is about 20% by weight, the present invention provides the synergistic effect of the core-shell opaque acrylic copolymer mentioned above and the excellent near infrared ray of the special titanium dioxide of the present invention. Due to the reflectance value, 12 to 18% by weight can express a sufficient effect.

The polymer hollow beads (Polymer Hollowed Beads) as shown in Fig. 1 are hollow beads of acrylonitrile-methyl methacrylate copolymer crosslinked shell (Sheath), discontinuous coating of calcium carbonate on the bead surface One specialty polymer is hollow beads.

Since the polymer hollow bead of the present invention has an average true specific gravity of 0.12, which is lower than that of the glass hollow beads of the prior art (usually 0.15 to 0.35), and is an organic material, the thermal conductivity is lower than that of the inorganic material. It exhibits (solar) reflectivity and, unlike inorganic hollow beads, is a flexible bead, which improves impact resistance, elasticity and flexibility.

As another feature, in the case of the conventional inorganic hollow beads, a coupling agent is required in order to solve the problem of weakening the inorganic-duration bond due to the lack of compatibility with the organic binder. Since the component is an acrylic copolymer, due to the excellent compatibility with the acrylic binder used in the polymer surface chemical properties, the bead suppression of the detachment of the hollow beads of the dry coating film is very excellent.

In the amount of the polymer hollow beads of the present invention, less than 4% by weight could not exhibit a sufficient insulating volume (Volume) in the coating film, when exceeding 8% by weight of the physical strength of the coating film due to excessive volume (Volume) It was unfavorable because it was damaged.

In the present invention, the extender pigment is a raw material used to improve the coating film strength and easy workability of the thermal barrier paint, and can be used calcium carbonate, barium sulfate, talc, silica powder, kaolin or a mixture thereof. It does not specify the kind in particular. In terms of the amount of use thereof, the above range was most appropriate in terms of the heat shield performance efficiency of the present invention.

In the present invention, the fluidity regulator, the leveling agent, the antifoaming agent, the cryoprotectant, and the like, which are used as additives used to control other viscosity and workability, may use any one of conventional industrially used materials. It doesn't specify that kind. However, it was optimal to express the performance of the present invention in the amount used in the above range.

Hereinafter, the present invention will be described in detail through Examples and Comparative Examples.

However, the protection scope of the present invention is not limited only to the following examples.

Example 1

450 g of acrylic copolymer emulsion (hereinafter referred to as "KJE-450") with a solid content of 49% and 38% of a core-shell opaque acrylic copolymer (hereinafter referred to as "koque-37") in a 2 liter stainless steel vessel (Vessel) 120 g, deionized water 60 g, and 3 g of a dispersant (hereinafter referred to as "AQ 380") were added thereto, followed by homogeneous stirring at 150 rpm for 5 minutes, followed by 90 g of calcium carbonate and 54.3% of near infrared reflectance. 140 g of titanium (hereinafter referred to as “High NIR TiO ₂ ”) was added while stirring at 150 rpm, and the stirring speed was increased to 800 rpm for 20 minutes. After stirring and dispersing, acrylonitrile coated with discontinuous calcium carbonate on the surface was added thereto. After adding 60 g of polymer hollow bead consisting of methyl methacrylate copolymer resin and 70 g of deionized water, stirring and dispersing at 600 rpm for 30 minutes, and adding 7 g of additive (fluidity regulator) to it and stirring at 600 rpm for 10 minutes. After drunk Extruded heat shield coating 1,000g was prepared.

The results of evaluating the various physical properties of the prepared thermal insulation paints are shown in Table 1.

Example 2

Except for changing the content of KJE-450 to 490g in Example 1, and changed the koque-37 content to 80g to prepare a heat-shielding coating 1,000g in the same process and composition as in Example 1.

The results of evaluating various physical properties of the prepared thermal insulation paints are shown in Table 1.

Comparative Example 1

Except for using koque-37 in Example 1, except that the content of KJE-45 was changed to 570g 1,000g of a heat-shielding coating was prepared in the same process and composition as in Example 1.

The results of evaluating various physical properties of the prepared thermal insulation paints are shown in Table 1.

Comparative Example 2

The same process as in Example 1 except that High NIR TiO ₂ was not added (used) in Example 1, but 140 g of TiO ₂ (Dupon R-902) manufactured by DuPont, USA was added instead. And 1,000 g of a heat shield paint was prepared as a composition.

The results of evaluating various physical properties of the prepared thermal insulation paints are shown in Table 1.

Comparative Example 3

In the same process and composition as in Example 1, except that the polymer hollow beads were not added (used) in Example 1, but 60 g of glass hollow beads (Micro Bubbles S35) made in 3M was used instead. 1,000 g of thermal insulation paint was prepared.

The results of evaluating various physical properties of the prepared thermal insulation paints are shown in Table 1.

Thermal coating property evaluation result division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Reflectance
(%) 300-780 nm 89.4 85.6 82.3 84.2 80.4 780-2500 nm 88.7 87.6 84.1 85.3 80.7 300-2500 nm 89.0 86.3 84.9 85.7 81.8 Corrected Reflectance (%) 93 92 90 91 89 Thermal Conductivity W / (m-K) 0.076 0.09 0.092 0.087 0.12 Near infrared reflectance (%) 88.7 87.6 84.1 85.3 80.7 Accelerated weathering (Xenon) near infrared reflectance (%) 600 hr 88.5 87.4 83.8 84.7 80.1 1200 hr 88.1 87.1 82.9 84.2 79.4 2500 hr 87.9 86.9 82.4 83.8 78.9

As can be seen from the performance evaluation results as described above, the near-infrared reflectivity of Example 1 and Example 2 of the present invention was 88.7%, 87.6% was confirmed to be very good compared to the reference, whereas the core-shell opaque acrylic of the present invention In Comparative Example 1 in which the copolymer Koque-37 was excluded, the near infrared reflectance was slightly lowered to 84.1%.

In addition, the near-infrared reflectivity of Comparative Example 3, which was replaced by glass hollow beads (Micro bubbles) instead of the polymer hollow beads of the present invention, was found to be 80.7%, which was much lowered, and the thermal conductivity was also significantly increased to 0.12 (W / mK). Insulation effect was found to be inferior to the polymer hollow bead value (0.076 ~ 0.09) of the present invention.

Based on the above performance evaluation, the general paint and the thermal insulation paint of the present invention were installed on the exterior of the gymnasium roof, and the temperature distribution was measured by the thermal imaging camera from 12:10 to 12:30 pm in the summer of August 2018. As a result, as shown in FIG. 5, the outside surface temperature of the general coating roof (Roof) is 91.1 ° C., whereas the temperature of the insulating coating surface of the present invention is about 40.8 ° C., indicating a temperature difference of about 50.3 ° C. At this time, the interior temperature measurement of the interior of the roof (Roof) as shown in Figure 6 the general coating surface inside temperature is 50.4 ℃ and the inner temperature of the heat shield coating surface of the present invention is about 43.3 ℃, room temperature of about 7.1 ℃ It was confirmed that there is a temperature reducing effect.

1: polymer component 2: surface coated calcium carbonate
3: glass hollow bead 4: ceramic hollow bead
5: polymer hollow bead 6: calcium carbonate hollow bead
7: binder without hollow beads
A: A thermal image photograph of a portion coated with the heat shield coating of the present invention.
B: The thermal image photograph of the part to which the conventional thermal insulation paint was coated.

Claims (5)

(Iii) 28 to 52 wt% of acrylic copolymer emulsion, (ii) 8 to 14 wt% of core-shell opaque acrylic copolymer, (iii) 12 to 18 wt% of titanium dioxide having near infrared reflectance of 50% or more, (iii) extender pigment 8-12 wt% (iii) 4-8 wt% of polymer hollow beads, (iv) 12-14 wt% of deionized water, and 4-6 wt% of (iv) additive. 2. The high performance heat-shielding coating according to claim 1, wherein the polymer hollow beads are made of acrylonitrile-methyl methacrylate copolymer resin in which calcium carbonate is discontinuously coated on the surface. The high-performance heat shielding coating according to claim 1, wherein the titanium dioxide having a near infrared reflectance of 50% or more is a rutile crystal structure. The high-performance heat shielding paint according to claim 1, wherein the extender pigment is one or a mixture of two or more selected from calcium carbonate, barium sulfate, talc, silica powder and kaolin. The high-performance heat shielding coating according to claim 1, wherein the additive is one or a mixture of two or more selected from a fluidity regulator, a dispersant, a leveling body, an antifoaming agent, and an antifreezing agent.

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