KR20200097193A - Inorganic low viscosity aqueous adhesive coating composition and its use - Google Patents

Abstract

An embodiment of the present invention provides an inorganic aqueous heterogeneous bonding and coating material composition. The composition contains silicate and alkoxysilane. In addition, the inorganic aqueous adhesive coating composition may have excellent adhesion, corrosion prevention and waterproof functions.

Description

Inorganic low viscosity aqueous adhesive coating composition and its use

The present invention relates to a silicon oxide-based low-viscosity, quick-drying water-based adhesive coating agent, by curing the same and different materials such as styrofoam, polyurethane foam, polyurea foam, and wood at low temperature (100 ^o C or less) to adhere to steel plate, concrete, glass, etc. And it relates to a quick-drying aqueous flame retardant / waterproof functional adhesive coating agent to be coated.

In general, silicate materials such as sodium silicate and potassium silicate are well known as representative inorganic binders, and unlike organic adhesives obtained from petrochemicals, they have high thermal stability and are environmentally friendly, so they are widely used as heat, chemical, and waterproof coatings. In particular, liquid sodium silicate, as the amount of moisture decreases, increases the viscosity of the solution rapidly and has adhesive strength, so when applied to the surface to be bonded, it obtains a smooth film like glass and at the same time has an excellent effect as an adhesive. However, since the applied and dried silicate is easily re-dissolved in moisture or water in the atmosphere, its use is inevitably limited unless it undergoes an insolubilization process. The easiest way to insolubilize liquid sodium silicate is to remove crystal water from the inside by gradually heat-treating at a high temperature of 500℃ or higher, but it is also limited in use due to the stability of the object to be bonded and the limitation of the work environment. It is also a reality that it takes a lot. Therefore, attempts to solve these problems by proceeding the insolubilization reaction by adding an appropriate additive to the liquid sodium silicate are being continued.

In the insolubilization of liquid sodium silicate, not only the type of additive, but also the amount used must be carefully controlled. For example, in order to insolubilize silicate, there are many known methods of directly treating with acid or polyvalent metal ions (for example, Zn+2, Cu+2, etc.). In this case, the reaction proceeds too quickly and the monolayer ), or due to too rapid gelation, there is a problem that a crack occurs on the surface of the adhesive surface due to a rapid volume reduction of the silicate. In order to make an adhesive that does not generate cracks or micropores at room temperature and does not dissolve well in water, it is important to find a raw material that reacts slowly and progresses insolubilization.It is intended to ensure that each raw material has high adhesive strength as well as insolubility through complementary action. The establishment of the process is also an important factor. On the other hand, there is an example of developing an insoluble binder using a conventional liquid sodium silicate, examples of which include Korean Patent No. 10-0556902, Korean Patent Publication No. 10-2005-0056186, and Patent Publication 10-2005-0056185. In these conventional techniques, a high concentration of sulfuric acid, hydrochloric acid, phosphoric acid, and acetic acid are gradually reacted with liquid sodium silicate as a binder and grouting agent to make silicate, and trace amounts of calcium carbonate (CaCO3) and calcium nitrate (Ca(NO3)2) of 0.05 to 1.0% by weight. ), magnesium chloride (MgCl2), magnesium sulfate (MgSO4), and calcium hydroxide (Ca(OH)2) are added to prepare an insoluble binder.

However, in the conventional manufacturing method, since a high concentration of acid is used, even if a small amount of high concentration acid is added to the liquid sodium silicate in a rotating reactor, the liquid sodium silicate in contact with the acid rapidly gelled, making it very difficult to stir. It was confirmed that even if the mixture was added and stirred for 3 hours or more, the gelled silicate and sodium salt were not easily dissolved and remained in the form of a fine lump. These microscopic lumps can be a factor that lowers the adhesive strength, and it was confirmed that process management to control a certain viscosity as an adhesive is very difficult. Therefore, it is a reality that there are many difficulties in producing a so-called modified silicate that causes a complete insolubilization reaction with an acid.

In addition, there is a problem that it is difficult to expect the effect of expressing water resistance at room temperature because it has a property of having water resistance after heating and drying at 100°C or more, so there are restrictions in applying it to an adhesive for building materials that are commonly used. In addition, due to the decrease in the overall adhesive strength, it was possible to act as a binder, but it was insufficient to serve as an adhesive.

In the process of adding 0.05 to 1.0% by weight of alkaline earth metal to the first product produced in the above process, a delicate mixing process in which a trace amount of additive is added and uniformly mixed is added, resulting in inhomogeneity in the adhesive production process of the entire manufacturing process. There is a possibility, and it is expected that over time it will react with moisture in the air and cause whitening. Most importantly, it is judged that the insolubility test and mechanical strength test are not suitable for the use of the adhesive at room temperature in that the test is performed by mixing a binder, perlite, zeolite, and carbon, and heat treatment at a temperature of 100℃ or higher. .

In addition, Korean Patent Laid-Open Nos. 10-2006-0043360 and 10-2006-0092783 require properties such as water resistance, adhesion, sound absorption, heat insulation, shock absorption, ultra-lightweight, low cost, complete non-combustibility, and complete pollution-free. It relates to construction and industrial foam moldings used in various industrial fields, and describes the manufacture of inorganic binders used in the manufacture of foam moldings. In detail, in addition to hydrochloric acid, sulfuric acid, and phosphoric acid, in the liquid sodium silicate, potassium chloride, quicklime, as in Korean Patent Nos. 10-0556902, 10-2005-0056186, and 10-2005-0056185 mentioned above. , Acidic substances such as ammonium chloride, alcohol (potassium chloride, quicklime, and ammonium chloride are basic substances, so there was an error.) Aluminum chloride, sodium aluminate, arsenic chloride, sodium arsenite, arsenic chloride, chromium(III) chloride, sodium chromite , Zinc hydroxide, arsenic hydroxide, tin hydroxide, chromium (III) hydroxide, zinc acid, arsenic acid, ortho tartaric acid, or amphoteric hydroxide containing chromic acid, etc. are administered to incomplete gelation of sodium silicate to incomplete gelation silicic acid. Explains how to make sodium.

In this technology, if the amount of acid is increased to promote incomplete gelation excessively, the adhesion strength may increase, and if the amount of acid is decreased, the adhesion strength decreases. However, no method for coping with the increase in excessive viscosity that occurs when incomplete gelation is excessively promoted has not been described. In addition, there is no mention of the degree of insolubility during curing at room temperature, as in Korean Patent Registration Nos. 10-0556902, Patent Publication No. 10-2005-0056186, and Patent Publication No. 10-2005-0056185 mentioned above. It is difficult to grasp the physical properties of the binder because there is no mention of the mechanical strength of the foamed molded product made by rapid drying at a high temperature of 150°C to 600°C using the prepared binder.

The above patent data mainly relates to the function as a binder, not as an adhesive, and is characterized by having a relatively low adhesive strength.

Liquid sodium silicate is a transparent or translucent solution that exhibits viscous alkalinity, and the molar ratio of liquid sodium silicate specified in the Korean Industrial Standard (KS M 1415) is 1:2.064 to 4.300 for Na2O and SiO2, and has various compositions. Since this liquid sodium silicate has its own adhesive strength, it is used in various ways such as cement additives to improve adhesives or soft ground, but it is widely used because the manufacturing process is simpler than other adhesives, equipment is simple, and production cost is low. Has become. In particular, unlike organic adhesives in the manufacturing process, formaldehyde emitted from most organic adhesives does not cause pollution and liquid sodium silicate does not emit at all, thus attracting attention in terms of environmental friendliness. However, when liquid sodium silicate is used as an adhesive, sodium ions contained in sodium silicate easily react with moisture or water in the air to form a salt such as sodium hydroxide, so when it comes into contact with moisture or water, it dissolves and loosens. There is a problem that the strength is lowered and thus it cannot perform the role as an adhesive. Because of this problem, some are adding raw materials such as carbon, zeolite, ocher, and illite to liquid sodium silicate, but it is still difficult to prevent the dissolution of the underlying sodium salt as well as the price is higher than that of the existing organic adhesives or the adhesive strength is lower. This is the reality.

However, in the past, there was no low viscosity, high strength, low temperature (100 ^o C or less) curable flame retardant/waterproof/corrosion prevention adhesive coating based on water glass.

US Patent Publication No. 6,642,338 (2003.11.04) US Patent Publication No. 7,285,592 (2007.10.23) US Patent Publication US 6,777,549 (2004.08.17) Japanese Patent Publication JP 16,358,303 (2004.12.24) Japanese Patent Publication JP 4,248,457 (2009.01.23) Japanese Patent Publication JP 1,664,424 (2017.06.30) Japanese Patent Publication JP 6,048,913 (2016.12.02) Japanese Patent Publication JP 14,012,811 (2002.01.15) Japanese Patent Publication JP 14,146,260 (2002.05.22)

The present invention is to solve the problems of the prior art described above, the object of the present invention is excellent in adhesive performance, cured at a low temperature below 100 ^o C, high adhesive strength and simple manufacturing process, economically advantageous low temperature curing quick-drying adhesive It's about coatings.

As an embodiment, the contents of this disclosure describe an inorganic aqueous adhesive coating composition including a silicate including at least one metal component and an alkoxysilane.

Preferably, the alkoxy silane may be tetramethoxysilane and/or tetraethoxysilane.

More preferably, the metal component is sodium (Na), potassium (K), lithium (Li), calcium (Ca), magnesium (Mg), aluminum (Al), zinc (Zn), iron (Fe), and lead. It may be at least one selected from the group consisting of (Pb), copper (Cu), and titanium (Ti).

More preferably, the inorganic aqueous adhesive coating composition is zinc (Zn), aluminum (Al), alumina (Al2O3), zinc oxide (ZnO), magnesium oxide (MgO), silicon oxide (SiO2), borax (B2O3), At least selected from the group consisting of boron (B), boric acid (B(OH)3), boron carbide (B4C), boron nitride (BN), aluminum nitride (AlN), silicon nitride (SiN), and titanium dioxide (TiO2) particles. It may further include one particle.

Even more preferably, the coating target of the inorganic aqueous adhesive coating composition may include metals including iron, stainless steel, copper, aluminum and zinc, and alloys thereof and concrete, glass, gypsum board, wood, and styrofoam.

The inorganic aqueous adhesive coating composition as described above can be cured at low temperature by adhesive coating on metals, including iron, stainless steel, copper, aluminum and zinc, and alloys thereof and concrete, glass, gypsum board, wood, styrofoam, etc., It can have excellent adhesion, corrosion protection and waterproof function.

In addition, the coating composition containing the boron element may be used for shielding nuclear radiation such as neutron shielding.

(Drawing 1) Adhesion strength measurement specimen
(Drawing 2) Flame-retardant coating send position panel structure

Hereinafter, the present invention will be described with reference to the accompanying drawings 1 and 2. However, the present invention may be implemented in a number of different forms, and therefore is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

In addition, the water-based adhesive prepared by this disease can be used for coating, and can be used for adhesion of dissimilar metal materials, anti-corrosion coating and flame retardant, waterproofing, and corrosion resistance of concrete flooring.

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

Manufacturing Example 1

Each 10 g of 35 wt% potassium silicate (SiO ₂ : K ₂ O molar ratio 3.2 to 4.8) aqueous solution and 40 wt% sodium silicate (SiO ₂ : Na ₂ O molar ratio 2.0 to 4.1) in a 1 L round bottom 3-neck flask equipped with a reflux device : 90g ~ 90g: Mix in a ratio of 10g and add about 350ml~400ml of distilled water to make 9 20% by weight mixed silicate aqueous solution respectively, and alkoxysilane (tetramethoxysilane, tetraethoxysilane) 0.1g, 0.5 By adding g, 1g and 3g and reacting at 50 ^o C to 60 ^o C for about 1 hour, a total of 36 types of transparent low viscosity aqueous adhesive samples 1-1 to 9-4 were prepared. At this time, when the alkoxysilane is added in excess of 3 g, the viscosity increases a lot, and when it is too small, the functionality decreases. The viscosity was measured using a Brockfield viscometer (DV2TLV) and the results are shown in Table 1.

division Viscosity (cps) Tetramethoxysilane (_1) Tetraethoxysilane (_2) 1-1 200 190 1-2 220 210 1-3 240 220 1-4 750 720 2-1 190 190 2-2 210 220 2-3 230 230 2-4 720 700 3-1 160 160 3-2 180 180 3-3 230 230 3-4 690 680 4-1 120 120 4-2 180 190 4-3 210 210 4-4 680 660 5-1 100 100 5-2 160 160 5-3 190 180 5-4 640 620 6-1 90 90 6-2 130 130 6-3 170 170 6-4 560 560 7-1 80 80 7-2 120 120 7-3 180 180 7-4 620 600 8-1 80 80 8-2 110 110 8-3 170 170 8-4 590 570 9-1 60 60 9-2 100 100 9-3 150 150 9-4 520 500

In Table 1, a mixed silicate aqueous solution prepared by mixing an aqueous potassium silicate solution and an aqueous sodium silicate solution in a ratio of 10 g: 90 g is expressed as Preparation Example 1-# (where # means the serial number of each preparation example), and , A mixed silicate aqueous solution prepared by mixing an aqueous potassium silicate solution and an aqueous sodium silicate solution in a ratio of 20g: 80g was designated as Preparation Example 2-#, and a potassium silicate aqueous solution and sodium silicate aqueous solution were mixed in a ratio of 10g: The mixed silicate aqueous solution was designated as Preparation Example 9-#.

In addition, in Table 1, the addition of 0.1g, 0.5g, 1g, and 3g of tetramethoxysilane to Preparation Example 1-# is represented as Preparation Examples 1-1_1 to 1-4_1, respectively, and Preparation Example 1- The addition of 0.1g, 0.5g, 1g, and 3g of tetraethoxysilane to 1 will be described as Preparation Examples 1-1_2 to 1-4_2, respectively. That is, for example, 1 g of tetramethoxysilane was further added to the mixed silicate aqueous solution in which 35 wt% potassium silicate aqueous solution and 40 wt% sodium silicate aqueous solution were mixed in a ratio of 70 g: 30 g means Preparation Example 7-3_1, and , 1 g of tetraethoxysilane was further added to the mixed silicate aqueous solution in which the 35 wt% potassium silicate aqueous solution and the 40 wt% sodium silicate aqueous solution were mixed at a ratio of 70 g: 30 g means Preparation Example 7-3_2.

Example 1

Using 36 water-based adhesives prepared according to Preparation Example 1 and a comparative example (porous bond), steel plate-steel plate, steel plate-stainless steel (SUS304) plate, steel plate-concrete brick, steel plate-glass, steel plate-styrofoam, concrete-styrofoam, Steel plate-wood board, concrete brick-wood board, as shown in Fig. 1, prepared each specimen and bonded each material to determine the adhesive strength of 1-1-1 to 9-4-8 with a UTM (multi tester) for a total of 288 pieces. Eight types of Comparative Examples were measured and shown in Table 2. At this time, 0.1 ml of each adhesive was evenly applied to an adhesive area of 1 cm ² and then cured in an 80 ^o C oven for 30 minutes to adhere.

division
(Tetramethoxysilane) Bonding strength by bonding material (kgf/cm ² ) Iron plate-iron plate Steel plate-stainless steel (SUS304) plate Iron plate-concrete Iron plate-glass Steel plate-Styrofoam Iron plate-wood Concrete-Styrofoam Concrete-wood boards Comparative example <3 <3 <1 <3 <0.05 <1 <0.05 <1 1-1-1 300 350 150 300 0.2 < 300 0.2 < 5 < 1-2-1 450 450 200 400 0.2 < 450 0.2 < 5 < 1-3-1 600 800 300 600 < 0.2 < 800 0.2 < 5 < 1-4-1 800 850 600 600 < 0.2 < 1200 0.2 < 5 < 2-1-1 300 350 150 300 0.2 < 300 0.2 < 5 < 2-2-1 450 450 200 400 0.2 < 450 0.2 < 5 < 2-3-1 600 800 300 600 < 0.2 < 800 0.2 < 5 < 2-4-1 850 850 600 600 < 0.2 < 1200 0.2 < 5 < 3-1-1 300 350 150 300 0.2 < 300 0.2 < 5 < 3-2-1 450 450 200 400 0.2 < 450 0.2 < 5 < 3-3-1 600 800 300 600 < 0.2 < 800 0.2 < 5 < 3-4-1 900 850 700 600 < 0.2 < 1200 0.2 < 5 < 4-1-1 400 350 150 400 0.2 < 300 0.2 < 5 < 4-2-1 450 450 200 400 0.2 < 450 0.2 < 5 < 4-3-1 750 800 300 600 < 0.2 < 800 0.2 < 5 < 4-4-1 900 900 750 600 < 0.2 < 1200 0.2 < 5 < 5-1-1 450 500 300 300 0.2 < 300 0.2 < 5 < 5-2-1 550 550 450 450 0.2 < 450 0.2 < 5 < 5-3-1 1000 800 800 600 < 0.2 < 800 0.2 < 5 < 5-4-1 1200 1100 1000 600 < 0.2 < 1200 0.2 < 5 < 6-1-1 500 450 450 300 0.2 < 300 0.2 < 5 < 6-2-1 450 450 450 450 0.2 < 450 0.2 < 5 < 6-3-1 800 800 800 800 0.2 < 800 0.2 < 5 < 6-4-1 1200 1200 1200 1200 0.2 < 1200 0.2 < 5 < 7-1-1 300 300 300 300 0.2 < 300 0.2 < 5 < 7-2-1 450 450 450 450 0.2 < 450 0.2 < 5 < 7-3-1 800 800 800 800 0.2 < 800 0.2 < 5 < 7-4-1 1100 1200 1200 1200 0.2 < 1200 0.2 < 5 < 8-1-1 300 300 300 300 0.2 < 300 0.2 < 5 < 8-2-1 450 450 450 450 0.2 < 450 0.2 < 5 < 8-3-1 800 800 800 800 0.2 < 800 0.2 < 5 < 8-4-1 1100 1000 1300 1200 0.2 < 1200 0.2 < 5 < 9-1-1 400 400 450 300 0.2 < 300 0.2 < 5 < 9-2-1 450 450 450 450 0.2 < 450 0.2 < 5 < 9-3-1 800 800 800 600 < 0.2 < 800 0.2 < 5 < 9-4-1 1000 1100 1000 600 < 0.2 < 1200 0.2 < 5 <

-Styrofoam and plate are damaged.

division
(Tetraethoxysilane) Bonding strength by bonding material (kgf/cm ² ) Iron plate-iron plate Steel plate-stainless steel (SUS304) plate Iron plate-concrete Iron plate-glass Steel plate-Styrofoam Iron plate-wood Concrete-Styrofoam Concrete-wood boards Comparative example <3 <3 <1 <3 <0.05 <1 <0.05 <1 1-1-2 320 350 150 300 0.2 < 300 0.2 < 5 < 1-2-2 450 450 200 400 0.2 < 450 0.2 < 5 < 1-3-2 600 800 300 600 < 0.2 < 800 0.2 < 5 < 1-4-2 800 850 600 600 < 0.2 < 1200 0.2 < 5 < 2-1-2 300 350 150 300 0.2 < 300 0.2 < 5 < 2-2-2 450 450 200 400 0.2 < 450 0.2 < 5 < 2-3-2 600 800 300 600 < 0.2 < 800 0.2 < 5 < 2-4-2 800 850 600 600 < 0.2 < 1200 0.2 < 5 < 3-1-2 300 350 150 300 0.2 < 300 0.2 < 5 < 3-2-2 450 450 200 400 0.2 < 450 0.2 < 5 < 3-3-2 600 800 300 600 < 0.2 < 800 0.2 < 5 < 3-4-2 900 850 700 600 < 0.2 < 1200 0.2 < 5 < 4-1-2 400 350 150 400 0.2 < 300 0.2 < 5 < 4-2-2 450 450 200 400 0.2 < 450 0.2 < 5 < 4-3-2 750 800 300 600 < 0.2 < 800 0.2 < 5 < 4-4-2 900 850 800 600 < 0.2 < 1200 0.2 < 5 < 5-1-2 450 500 300 300 0.2 < 300 0.2 < 5 < 5-2-2 550 550 450 450 0.2 < 450 0.2 < 5 < 5-3-2 1000 800 800 600 < 0.2 < 800 0.2 < 5 < 5-4-2 1200 1100 1000 600 < 0.2 < 1200 0.2 < 5 < 6-1-2 500 450 450 300 0.2 < 300 0.2 < 5 < 6-2-2 450 450 450 450 0.2 < 450 0.2 < 5 < 6-3-2 800 800 800 800 0.2 < 800 0.2 < 5 < 6-4-2 1200 1200 1200 1200 0.2 < 1200 0.2 < 5 < 7-1-2 300 300 300 300 0.2 < 300 0.2 < 5 < 7-2-2 450 450 450 450 0.2 < 450 0.2 < 5 < 7-3-2 800 800 800 800 0.2 < 800 0.2 < 5 < 7-4-2 1100 1200 1200 1200 0.2 < 1200 0.2 < 5 < 8-1-2 300 300 300 300 0.2 < 300 0.2 < 5 < 8-2-2 450 450 450 450 0.2 < 450 0.2 < 5 < 8-3-2 800 800 800 800 0.2 < 800 0.2 < 5 < 8-4-2 1100 1000 1300 1200 0.2 < 1200 0.2 < 5 < 9-1-2 350 400 450 300 0.2 < 300 0.2 < 5 < 9-2-2 450 450 450 450 0.2 < 450 0.2 < 5 < 9-3-2 800 800 800 600 < 0.2 < 800 0.2 < 5 < 9-4-2 1000 1100 1000 600 < 0.2 < 1200 0.2 < 5 <

Example 2

Preparation Example 5-3 of the sample was used to apply styrofoam (950mm*2100mm*30mm(T)) to the entire surface of the styrofoam using a spray gun and adhered to both sides with colored steel sheets (1000mm*2100mm*0.5mm(T)) Then, it was cured at 50 ^o C for 3 hours to produce a sandwich panel, and the flame retardant properties were analyzed according to the Korean Industrial Standard KS F ISO 5660-1.

As a result of the analysis, it was analyzed as a semi-noncombustible material.

Example 3

Among the inorganic aqueous adhesive coating compositions prepared according to Preparation Example 1, Example 3 was prepared by dipping-coating a steel plate using Preparation Example 9-3_1 and then curing it in an oven at 80° C. for 30 minutes.

Thereafter, a neutral salt spray test was performed on the coated specimen prepared according to Example 3 through ASTM B 117 (KS D6502), and the measurement results are shown in Table 4 below.

division Neutral salt water test for coated specimens (ASTM B 117) Comparative example
(Iron specimen, 100×100×2T) -Elapsed time: 180hr elapsed
-Red rust was confirmed. Example 3
(Iron specimen, 100×100×2T) -Elapsed time: 1,200hr elapsed
-No red rust and deformation of the coating film were observed

At this time, the heavy water salt spray test (ASTM B 117 (KS D6502)) is in the salt state 4.5% to 5.5% by weight NaCl (3.5 to 7.5pH), salt water concentration 1.0255 to 1.0400, spray pressure 0.7 to 1.8 kg / cm, and It was carried out in the test conditions of a chamber temperature of 33 ℃ to 37 ℃.

Accordingly, it was confirmed that the inorganic aqueous adhesive coating composition did not cause red rust and deformation on the coated film even after a long time elapsed.

The scope of the present invention is indicated by the claims to be described later, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims (5)

Silicate containing at least one metal component; And
Inorganic aqueous adhesive coating composition comprising an alkoxy silane (Alkoxysilane).
The method according to claim 1,
The alkoxy silane is tetramethoxysilane and/or tetraethoxysilane.
The method according to claim 1,
The metal components are sodium (Na), potassium (K), lithium (Li), calcium (Ca), magnesium (Mg), aluminum (Al), zinc (Zn), iron (Fe), lead (Pb), and copper. (Cu), at least one inorganic-based aqueous corrosion protection coating composition selected from the group consisting of titanium (Ti).
The method of claim 1
Zinc (Zn), aluminum (Al), alumina (Al2O3), zinc oxide (ZnO), magnesium oxide (MgO), silicon oxide (SiO2), borax (B2O3), boron (B), boric acid (B) in aqueous adhesive coatings (OH)3), boron carbide (B4C), boron nitride (BN), aluminum nitride (AlN), silicon nitride (SiN), and titanium dioxide (TiO2) particles.
In claim 1
Materials for adhesion and coating are iron, stainless steel, copper, aluminum, zinc and their alloy materials, ceramic materials such as ceramics, marble, gypsum, concrete, and foam materials such as styrofoam and urethane foam.

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