TWI541191B - Aluminum phosphate gel and method of manufacturing the same - Google Patents

Description

Aluminum phosphate gel and manufacturing method thereof

The present invention relates to an aluminum phosphate gel and a method for producing the same, and more particularly to an aluminum phosphate gel which does not contain chloride ions (Cl ^- ) or nitrates (NO ₃ ^- ) and a method for producing the same.

Aluminum phosphate gel can be used as an adhesive or heat-dissipating coating. In the past, aluminum phosphate gel was prepared by dissolving aluminum chloride in phosphoric acid or dissolving alumina in nitric acid and redissolving it in phosphoric acid. The Cl ^- or NO ₃ ^- contained in the gel volatilizes during the heating process and corrodes the equipment, and is detrimental to the human body and the environment.

For example, U.S. Patent Nos. 4,458,023, 4,542,118, 3,544,476, and Chinese Patent Publication No. 10250434B, each of which uses an inorganic acid containing a Cl ^- or NO ₃ ^- or a salt thereof to prepare an aluminum phosphate gel. Inorganic adhesives, or used in the manufacture of catalysts.

Further, generally, for a functional coating film on a steel sheet surface, for example, a heat-conductive steel sheet, an organic polymer is used as a binder. For example, U.S. Patent Publication No. 2010/0291379, No. 2010/0021726, Chinese Patent Publication No. 101573403A, and No. 101960049A, all of which are organic resins such as an acrylate resin or a polyurethane resin. As a main component of the heat-dissipating coating film, various additives are added thereto to achieve heat dissipation. Conductive, corrosion resistant and other functions. The disadvantage is that the heat resistance of the organic resin is poor, and it is easily deteriorated in an environment where high temperature is required for a long period of time, and the functions such as adhesion are lost, which is disadvantageous for a long-term high-temperature use environment.

Therefore, it is necessary to provide an aluminum phosphate gel and a method for producing the same, which does not contain components such as chloride ions and nitrates, and has good heat resistance and electrical conductivity to solve the problems of the conventional technology.

The main object of the present invention is to provide an aluminum phosphate gel and a method for producing the same, which does not contain a nitrate or chloride ion component, and therefore does not escape acid gas when heated, and requires high temperature operation for a long time. The equipment will not have an adverse effect.

A secondary object of the present invention is to provide an aluminum phosphate gel and a method for producing the same, which can form a stable gel state with a phosphate and an aluminum ion by using a chelating agent, and can further add a heat conductive particle to form an aqueous coating for use in a cold rolled steel sheet. On the galvanized steel sheet, a coating film having excellent heat resistance, electrical conductivity, heat dissipation and excellent adhesion is formed.

In order to achieve the above object, an embodiment of the present invention provides an aluminum phosphate gel formed by mixing an aqueous solution of aluminum monophosphate and an organic chelating agent, wherein the solid content of the aqueous solution of aluminum phosphate is 10~ 30 wt%, and the aluminum phosphate gel comprises a condensation polymer obtained by condensation polymerization of the organic chelating agent.

In one embodiment of the invention, the weight of the organic chelating agent is from 20 to 25 grams relative to 100 grams of the aqueous solution of aluminum phosphate.

In an embodiment of the invention, the phosphate (P-O in phosphoric acid) contained in the aqueous phosphoric acid and the organic chelating agent or the condensation polymer are bonded by hydrogen bonding.

In one embodiment of the invention, the aluminum ions (Al ³⁺ ) contained in the aqueous phosphoric acid solution, the P-OH, PO of the phosphoric acid, and the organic chelating agent coordinate to form an aluminum ion complex.

In one embodiment of the invention, the organic chelating agent is at least one selected from the group consisting of isopropanolamine, isobutanolamine, ethylene glycol amine, propanolamine, and diisopropanolamine.

In an embodiment of the invention, the aluminum phosphate gel further comprises carbon black, graphite or a mixture thereof.

In one embodiment of the invention, the carbon black has a particle size of less than 3 micrometers (μm).

In one embodiment of the invention, the graphite has a thickness of less than 0.15 millimeters (mm).

In an embodiment of the present invention, when the aluminum phosphate gel comprises a mixture of the carbon black and the graphite, the weight ratio of the carbon black to the graphite is carbon black: graphite = 100: 10 to 100, and the carbon black and The weight ratio of the mixture of graphite to the aqueous solution of aluminum phosphate is (carbon black + graphite): aqueous solution of aluminum phosphate = 2 to 10:100.

Another embodiment of the present invention provides a method for producing an aluminum phosphate gel, comprising the steps of: preparing an aqueous solution of aluminum monophosphate containing phosphate and aluminum ions; adding an organic chelating agent to the aqueous solution of aluminum phosphate until the acid and alkali The value is pH=4.0 to 8.5 to form a reaction solution; and the reaction solution is heated to 50 to 90 ° C for a predetermined period of time to obtain the above-mentioned aluminum phosphate gel.

In one embodiment of the present invention, the weight ratio of phosphorus to aluminum in the aqueous aluminum phosphate solution is phosphorus: aluminum = 2.5 to 4.0:1.

In one embodiment of the invention, the aqueous aluminum phosphate solution has a pH of <2.0.

In one embodiment of the invention, the phosphate is derived from phosphoric acid, aluminum dihydrogen phosphate or a mixture thereof.

In an embodiment of the invention, the aluminum ion is derived from at least one selected from the group consisting of aluminum metal, aluminum hydroxide, aluminum oxide, and aluminum dihydrogen phosphate.

In one embodiment of the invention, the weight of the organic chelating agent is from 20 to 25 grams relative to 100 grams of the aqueous solution of aluminum phosphate.

In an embodiment of the invention, the preset time is 1 to 6 hours.

In an embodiment of the invention, the aluminum phosphate gel is further baked at 100 to 150 ° C and dried to form a thermoplastic adhesive.

In one embodiment of the invention, the thermoplastic adhesive has a glass transition temperature of 70 to 80 °C.

1‧‧‧ Thermal coating

2‧‧‧High emissivity coating

3‧‧‧Blackbody furnace

4‧‧‧ test strips

A‧‧‧heat source temperature measurement point

Fig. 1 is a simplified schematic view of a device for measuring heat dissipation capability in an embodiment of the invention.

Fig. 2 is a view showing the glass transition temperature (Tg) of a thermoplastic adhesive according to an embodiment of the present invention by PERKIN-ELMER DSC (Differential Scanning Calorimetry).

The above and other objects, features and advantages of the present invention will become more <RTIgt; Furthermore, the directional terms mentioned in the present invention, such as upper, lower, top, bottom, front, rear, left, right, inner, outer, side, surrounding, central, horizontal, horizontal, vertical, longitudinal, axial, Radial, most The upper layer or the lowermost layer, etc., is only referring to the direction of the additional pattern. In addition, the singular forms "a", "the" For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof; "%" as referred to in the present specification means "percent by weight (wt%)" unless otherwise specified; For example, 10%~11% of A) include upper and lower limits (ie 10% ≦A≦11%) unless otherwise specified; if the value range does not define a lower limit (such as B below 0.2%, or 0.2) B) below B) means that the lower limit may be 0 (ie 0% ≦ B ≦ 0.2%); the proportional relationship of the "weight percentage" of each component may also be replaced by the proportional relationship of "parts by weight". The above terms are used to illustrate and understand the present invention and are not intended to limit the invention.

An embodiment of the present invention provides an aluminum phosphate gel formed by mixing an aqueous solution of aluminum monophosphate and an organic chelating agent, wherein the aqueous solution of the aluminum phosphate has a solid content of 10 to 30% by weight, and the aluminum phosphate gel comprises the aluminum phosphate gel. A condensation polymer formed by condensation polymerization of an organic chelating agent.

In one embodiment, the phosphate in the aqueous solution of aluminum phosphate and the organic chelating agent or the condensation polymer are hydrogen-bonded; the aluminum ion can coordinate with the organic chelating agent to form an aluminum metal. Compound. The organic chelating agent may, for example, be an organic alcohol amine compound, and may be at least one selected from the group consisting of isopropanolamine, isobutanolamine, ethylene glycol amine, propanolamine, and diisopropanolamine.

In an embodiment, the aluminum phosphate gel may further comprise other additives, such as a thermally conductive material, a conductive material or a humectant, according to actual use requirements. Preferably, the aluminum phosphate gel is used as a main component (or a matrix), and further comprises carbon black, graphite or a mixture thereof. The carbon black has a particle size of less than 3 micrometers (μm) and the graphite has a thickness of less than 0.15 millimeters (mm). this The aluminum phosphate gel can be used as an aqueous coating and has good heat resistance, heat dissipation and electrical conductivity. When the aluminum phosphate gel comprises a mixture of the carbon black and the graphite, the weight ratio of the carbon black to the graphite is carbon black: graphite = 100: 10 to 100, and the mixture of the carbon black and the graphite and the aluminum phosphate The weight ratio of the aqueous solution is (carbon black + graphite): aqueous aluminum phosphate solution = 2 to 10: 100, for example, 3.5 g of carbon black and 0.5 g of graphite are added together in 100 g of an aqueous solution of aluminum phosphate, but are not limited thereto.

Furthermore, another embodiment of the present invention provides a method for producing an aluminum phosphate gel, which mainly comprises the steps of: (S1) preparing an aqueous solution of aluminum monophosphate containing phosphate and aluminum ions; and (S2) adding an organic chelating agent. Up to the aluminum phosphate aqueous solution until the pH value of the aqueous aluminum phosphate solution is 4.0 to 8.5 to form a reaction solution; and (S3) heating the reaction solution to 50 to 90 ° C for a predetermined time to obtain The above aluminum phosphate gel. The details of the implementation of the above-described steps of the embodiment and the principles thereof will be described in detail below.

The method for producing an aluminum phosphate gel according to the above embodiment of the present invention is first: (S1) preparing an aqueous solution of aluminum monophosphate containing phosphate and aluminum ions. In this step, the aluminum phosphate aqueous solution contains phosphorus to aluminum in a weight ratio of phosphorus: aluminum = 2.5 to 4.0: 1, and may be, for example, 2.5, 3.0, 3.5 or 4 phosphorus: 1 aluminum. The pH of the aqueous aluminum phosphate solution formed is preferably pH < 2.0. Further, the phosphate may be provided by phosphoric acid, aluminum dihydrogen phosphate or a mixture thereof. The aluminum ion may be provided by an aluminum metal or an inorganic salt not containing chloride ions or nitrates, such as at least one of aluminum hydroxide, aluminum oxide, and aluminum dihydrogen phosphate. The solid content of the aqueous aluminum phosphate solution was measured to be 10 to 30% by weight by heating at 150 ° C for 30 minutes.

The method for producing an aluminum phosphate gel according to the above embodiment of the present invention is followed by: (S2) adding an organic chelating agent to the aqueous aluminum phosphate solution until the pH of the aqueous aluminum phosphate solution is pH=4.0 to 8.5 to form a reaction. Solution. The weight added by the organic chelating agent in this step The organic chelating agent may be added to the aqueous aluminum phosphate solution in an amount of, for example, 100 g of the aqueous aluminum phosphate solution in an amount of 20 to 25 g with respect to 100 g of the aqueous aluminum phosphate solution, but is not limited thereto.

The automatic carbon dioxide absorption method of the above embodiment of the present invention is finally: (S3) heating the reaction solution to 50 to 90 ° C for a predetermined period of time to obtain the above aluminum phosphate gel. In this step, the preset time is 1 to 6 hours, and the reaction solution is heated to promote a small amount of condensation polymerization of the alcoholamine and PO-Al (aluminum phosphate), so that the reaction solution is formed to be viscous and transparent. The aluminum phosphate gel.

In addition to the steps included in the above embodiments, the aluminum phosphate gel formed in the step (S3) may be further baked at 100 to 150 ° C, and dried to form a thermoplastic adhesive. The thermoplastic adhesive has a glass transition temperature of 70 to 80 °C.

In order to verify the heat dissipation capability of the aluminum phosphate gel provided by the present invention, please refer to the following experimental description and its test results.

Production of aluminum phosphate gel: First, prepare an aqueous solution of aluminum phosphate, the weight ratio of phosphorus / aluminum (P / Al) is controlled at 2.5 / 1.0 ~ 4.0 / 1.0, wherein phosphorus can be derived from phosphoric acid, aluminum dihydrogen phosphate; aluminum from aluminum metal, The solid content of aluminum hydroxide, aluminum oxide or aluminum dihydrogen phosphate, which is formulated into an aqueous solution, is heated at 150 ° C for 30 minutes and tested to be 10 to 30% by weight. Next, the aqueous phosphoric acid solution is stirred and isopropanolamine, isobutanolamine, ethylene glycol amine, propanolamine, diisopropanolamine are added in an amount, and the organic alcohol amine can adjust the pH of the solution from pH<2.0. To 4.0~8.5, the hydrogen bond or ionic bond is formed by the NH, OH group and the P-OH, PO of the phosphoric acid and the Al ⁺³ and Al-OH groups of the aluminum salt, so as to be stably dispersed in the aqueous solution, avoiding the acidity and alkalinity. The increase in the formation of aluminum hydroxide or aluminum dihydrogen phosphate precipitation. Then, the solution is heated at 50 to 90 ° C for 1 to 6 hours to promote further condensation polymerization of the organic alcohol amine and PO-Al into a viscous and transparent gelatinous product, which is an aluminum phosphate gel.

The above aluminum phosphate gel can be directly used as a main component of the heat-dissipating coating, or can be baked and dried at 100 to 150 ° C to become a thermoplastic adhesive. The glass transition temperature (Tg) of the adhesive is PERKIN-ELMER DSC (Differential scanning). Calorimetry, differential scanning calorimeter) can be found to be about 70~80 °C after testing, as shown in Figure 2.

Aluminum phosphate gel is applied to the test of heat-dissipating steel sheet: 10~30wt% of the above-mentioned aluminum phosphate gel is used as the main component of the coating, and its pH is controlled at pH=5.0~8.0, and carbon black with particle diameter less than 3.0μm is added. The graphite having a thickness of less than 0.15 mm has a weight ratio of graphite to carbon black of 10 to 100/100, and the weight ratio of (carbon black + graphite) / 20 wt% aqueous aluminum phosphate solution is 2.0 to 10.0/100.0. In addition, the coating must be added with an appropriate amount of humectant to control the surface tension ≦ 55 dyne / cm. Please refer to Table 1, the test piece number used in the test of the present invention, the type of steel sheet, and the composition ratio of the aluminum phosphate gel in the coating.

For example, the number CSC uses (0.5g graphite + 3.5g carbon black) / 100g (15wt% aluminum phosphate aqueous solution), pH=5.5 aluminum phosphate gel coating, baked at 280 ° C for 45 seconds, the film thickness after drying It is 1 to 5 μm, for example, 2.0 μm. The number of CSC galvanized steel sheets and galvanized steel sheets, anti-fingerprint steel sheets and Posco steel products were measured separately according to the heat dissipation capacity shown in Fig. 1. The scattering effects and related properties were recorded under Table 2, where ΔT is the temperature difference of the temperature measured by the numbered test piece at point A with respect to the galvanized steel sheet, and the larger the ΔT, the better the heat dissipation effect. As shown in Fig. 1, the black body furnace 3 provides radiant heating to each test piece 4, and the test piece 4 has a high emissivity (ε = 0.9) coating 2 on the side close to the black body furnace 3 and a heat dissipating coating on the other side. Membrane 1. Replacing contact heating with radiant heating eliminates measurement errors caused by contact thermal resistance and heat source instability. Point A is the heat source temperature measurement point.

As can be seen from Table 2, the numbered CSC galvanized steel sheet has the best heat dissipation effect. At the same heat source temperature measurement point A, the CSC galvanized steel sheet temperature is 77.9 ° C, and the Posco steel mill product is 80.9. °C, while the general galvanized steel sheet (no coating) is 89.4 °C. Compared with the two, CSC galvanized steel sheet decreased by 11.5 ° C, Posco steel products decreased by 8.5 ° C, so CSC improved the heat dissipation of galvanized steel sheet is significantly better than Posco steel products.

In addition, the results of measuring the thermal emissivity coefficient by the thermal radiation tester are shown in Table 2. The emissivity coefficient of the numbered CSC galvanized steel sheet is 0.90, which is higher than that of the Posco steel mill product (0.65) and the general anti-fingerprint steel sheet (0.26). Galvanized steel sheet (<0.1). The heat resistance test was carried out by placing each number of steel sheets in an oven at 300 ° C for 7 days. After taking out, place a square on the steel sheet, each interval of about 1 mm, a total of 100 grids, and then peeling off with 3M tape. The result is CSC. The galvanized steel sheet did not peel off, and the Posco steel mill product was partially peeled off. The conductivity test is based on the Japanese Mitsubishi Chemical Loresta GP MCT-600 desktop low-impedance meter, and the surface resistance is measured. The measurement results can pass <10 ^-1 Ω using the numbered steel sheets of the aluminum phosphate gel of the present invention. test.

Compared with the prior art, the embodiment of the present invention forms an aluminum phosphate gel which is free from chloride ions or nitrate and has stable properties by using an aqueous solution of aluminum phosphate containing phosphate and aluminum ions and an organic chelating agent, and the gel can be added. Appropriate amount of carbon black, graphite, wetting agent, used for special inorganic coatings and adhesives, no organic resin, can form heat-dissipating coating film on galvanized steel sheet or cold-rolled steel sheet. After the coating film is placed in an oven at 300 ° C for 168 hours, Still able to maintain good heat dissipation, conductivity, adhesion and other properties.

The present invention has been disclosed in its preferred embodiments, and is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

Claims (14)

An aluminum phosphate gel formed by mixing an aqueous solution of aluminum monophosphate and an organic chelating agent, wherein the solid content of the aqueous aluminum phosphate solution is heated at 150 ° C for 30 minutes to 10 to 30 wt %, and the aluminum phosphate gel comprises the a condensation polymer polymerized by an organic chelating agent, wherein the aluminum phosphate aqueous solution contains phosphorus to aluminum in a weight ratio of phosphorus: aluminum = 2.5 to 4.0:1, and the organic chelating agent is selected from isopropanolamine and isobutylene. At least one of a group consisting of an alcohol amine, an ethylene glycol amine, a propanolamine, and a diisopropanolamine, and the weight of the organic chelating agent is 20 to 25 grams with respect to 100 grams of the aqueous aluminum phosphate solution. The aluminum phosphate gel according to claim 1, wherein the phosphate contained in the aqueous aluminum phosphate solution and the organic chelating agent or the condensation polymer are bonded by hydrogen bonding. The aluminum phosphate gel according to claim 1, wherein the aluminum ion contained in the aqueous aluminum phosphate solution, the P-OH of the phosphoric acid, the P-O, and the organic chelating agent coordinate to form an aluminum ion complex. The aluminum phosphate gel of claim 1, wherein the aluminum phosphate gel further comprises carbon black, graphite or a mixture thereof. The aluminum phosphate gel of claim 4, wherein the carbon black has a particle size of less than 3 microns. The aluminum phosphate gel of claim 4, wherein the graphite has a thickness of less than 0.15 mm. The aluminum phosphate gel according to claim 4, wherein the aluminum phosphate gel comprises a mixture of the carbon black and the graphite, the weight of the carbon black and the graphite The amount ratio is carbon black: graphite = 100: 10 to 100, and the weight ratio of the mixture of carbon black and the graphite to the aqueous solution of aluminum phosphate is (carbon black + graphite): aqueous solution of aluminum phosphate = 2 to 10:100. A method for producing an aluminum phosphate gel, comprising the steps of: preparing an aqueous solution of aluminum monophosphate containing phosphate and aluminum ions; adding an organic chelating agent to the aqueous solution of aluminum phosphate until the pH value is 4.0 to 8.5, Forming a reaction solution; and heating the reaction solution to 50 to 90 ° C for a predetermined period of time to obtain the aluminum phosphate gel according to claim 1, wherein the aluminum phosphate aqueous solution contains phosphorus and aluminum The weight ratio is phosphorus: aluminum = 2.5~4.0:1, and the organic chelating agent is selected from the group consisting of isopropanolamine, isobutanolamine, ethylene glycol amine, propanolamine and diisopropanolamine. At least one, and the weight of the organic chelating agent is 20 to 25 grams relative to 100 grams of the aqueous solution of aluminum phosphate. The method for producing an aluminum phosphate gel according to claim 8, wherein the aqueous aluminum phosphate solution has a pH of <2.0. The method for producing an aluminum phosphate gel according to claim 8, wherein the phosphate is derived from phosphoric acid, aluminum dihydrogen phosphate or a mixture thereof. The method for producing an aluminum phosphate gel according to claim 8, wherein the aluminum ion is derived from at least one selected from the group consisting of aluminum metal, aluminum hydroxide, aluminum oxide, and aluminum dihydrogen phosphate. The method for producing an aluminum phosphate gel according to claim 8, wherein the preset time is 1 to 6 hours. A method for producing an aluminum phosphate gel according to claim 8 of the patent application, The aluminum phosphate gel is further baked at 100 to 150 ° C and dried to form a thermoplastic adhesive. The method for producing an aluminum phosphate gel according to claim 13, wherein the thermoplastic adhesive has a glass transition temperature of 70 to 80 °C.