Preparation method of regenerated composite keel FRP interlayer binder

Abstract

The invention relates to the technical field of binders, in particular to a preparation method of a regenerated composite keel FRP interlayer binder. Comprising the following steps: S1, providing formaldehyde and water, and dissolving the formaldehyde in the water to form a mixed solution; s2, urea is provided and added into the mixed solution, meanwhile, the mixed solution is heated to 85 DEG C, then heating is stopped, heat preservation is conducted, and the urea reacts with formaldehyde; s3, when the temperature of the mixed solution is reduced to 20 DEG C and the mixed solution is dispersed, providing melamine and adding the melamine into the mixed solution, so that the melamine, the urea and the formaldehyde are subjected to condensation polymerization in water, and heat is generated to raise the temperature of the mixed solution; and S4, carrying out heat preservation on the mixed solution for 30 minutes, and when the mixed solution is cooled to 50 DEG C, taking out the reacted compound from the water to form the binder. The invention has the beneficial effects that the paint has excellent water resistance and can be applied in a high-humidity environment. The plywood adopting the interlayer adhesive prepared by the invention can meet the requirement of the water resistance of a plywood second-class plate so as to meet the application of an artificial board product in a high-humidity construction environment.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives, in particular to a method for preparing an adhesive between layers of a regenerated composite keel FRP. Background Art

[0002] In my country's construction industry, bamboo or wooden formwork is widely used as a supporting structure in the process of cast-in-place concrete construction. They bear the weight of the formwork itself and the external construction load. Bamboo or wooden formwork is usually made of a multi-layer structure bonded by adhesives. The adhesives used in the common composite wood products on the market generally have a series of disadvantages, such as insufficient product durability, low bonding strength, poor corrosion resistance, and excessive release of harmful substances (especially formaldehyde).

[0003] Therefore, the present invention provides a method for preparing a regenerated composite keel FRP interlayer adhesive. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a method for preparing a regenerated composite keel FRP interlayer adhesive to solve the problems of insufficient durability, low bonding strength, poor corrosion resistance and excessive release of harmful substances of the existing adhesives.

[0005] The technical solution to achieve the above purpose is:

[0006] The present invention provides a method for preparing a regenerated composite keel FRP interlayer adhesive, which specifically comprises the following steps:

[0007] S1: providing formaldehyde and water, and dissolving the formaldehyde in the water to form a mixed solution;

[0008] S2: providing urea and adding the urea to the mixed solution, and heating the mixed solution to 85° C., then stopping the heating and keeping the mixed solution warm, so that the urea and formaldehyde react;

[0009] S3: When the temperature of the mixed solution is reduced to 20° C. and is in a dispersed state, melamine is provided and added to the mixed solution, so that the melamine reacts with urea and formaldehyde in water to generate heat to increase the temperature of the mixed solution;

[0010] S4: The mixed solution is then kept warm for 30 minutes. When the mixed solution is cooled to 50° C., the reacted compound is taken out from the water to form a binder.

[0011] Furthermore, the mass ratio of formaldehyde, urea and melamine is 60:20:3.

[0012] Further, after step S1, an acid solution is provided and added to the mixed solution to adjust the pH value of the mixed solution to 6.0;

[0013] After step S2, the acid solution is added to the mixed solution to adjust the pH value of the mixed solution to 4.8.

[0014] Furthermore, the acid solution is a formic acid solution with a mass fraction of 15%-25%.

[0015] Furthermore, the acid solution is an acetic acid solution with a mass fraction of 15%-25%.

[0016] Further, after step S3, an alkaline solution is provided and added to the mixed solution to adjust the pH value of the mixed solution to 7.5.

[0017] Furthermore, the alkaline solution is a sodium hydroxide solution with a mass fraction of 5%-15%.

[0018] Furthermore, the heating rate in step S2 is 1.3°C / min.

[0019] Furthermore, when the mixed solution is cooled in step S4, the mixed solution is in a room temperature environment.

[0020] Furthermore, in step S4, before cooling the mixed solution, an auxiliary agent and urea are provided and added to the mixed solution.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The interlayer adhesive of the present invention has excellent water resistance and can be used in high humidity environments. The plywood prepared with the interlayer adhesive of the present invention can meet the water resistance requirements of the second type of plywood, so as to meet the application requirements of artificial board products in high humidity construction environments.

[0023] Compared with traditional urea-formaldehyde resin, the interlayer adhesive of the present invention significantly reduces the curing temperature characteristics, that is, when the interlayer adhesive of the present invention is used to make plywood, the entire curing process can be successfully completed at a maximum temperature of only 85°C. This significant temperature reduction can not only effectively save energy consumption in actual production applications, but also greatly improve production efficiency, showing its superior technical advantages.

[0024] The interlayer adhesive of the present invention has a simple production and synthesis process, does not require overheating, and is safe to produce and easy to operate.

[0025] The interlayer adhesive of the present invention has higher adhesion than that of traditional urea-formaldehyde resin and is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a flow chart for preparing the FRP interlayer adhesive for the regenerated composite keel. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] See also Figure 1 The present invention provides a method for preparing a regenerated composite keel FRP interlayer adhesive, which solves the problems of insufficient durability, low bonding strength, poor corrosion resistance and excessive release of harmful substances in existing adhesives. The interlayer adhesive of the present invention has excellent water resistance and can be used in high humidity environments. The plywood prepared with the interlayer adhesive of the present invention can meet the water resistance requirements of the second type of plywood, so as to meet the application requirements of artificial board products in high humidity construction environments.

[0029] Compared with traditional urea-formaldehyde resin, the interlayer adhesive of the present invention significantly reduces the curing temperature characteristics, that is, when the interlayer adhesive of the present invention is used to make plywood, the entire curing process can be successfully completed at a maximum temperature of only 85°C. This significant temperature reduction can not only effectively save energy consumption in actual production applications, but also greatly improve production efficiency, showing its superior technical advantages.

[0030] The interlayer adhesive of the present invention has a simple production and synthesis process, does not require overheating, and is safe to produce and easy to operate.

[0031] The interlayer adhesive of the present invention has higher adhesion than that of traditional urea-formaldehyde resin and is more stable.

[0032] The preparation method of the regenerated composite keel FRP interlayer adhesive of the present invention is described below with reference to the accompanying drawings.

[0033] See also Figure 1 , shows the preparation flow chart of the FRP interlayer adhesive of the recycled composite keel of the present invention. Figure 1 , a preparation method of a recycled composite keel FRP interlayer adhesive of the present invention is described.

[0034] like Figure 1 As shown, a method for preparing a regenerated composite keel FRP interlayer adhesive of the present invention specifically comprises the following steps:

[0035] S1: providing formaldehyde and water, and dissolving the formaldehyde in the water to form a mixed solution;

[0036] S2: providing urea and adding the urea to the mixed solution, and heating the mixed solution to 85° C., then stopping the heating and keeping the mixed solution warm, so that the urea and formaldehyde react;

[0037] S3: When the temperature of the mixed solution is reduced to 20° C. and is in a dispersed state, melamine is provided and added to the mixed solution, so that the melamine reacts with urea and formaldehyde in water to generate heat to increase the temperature of the mixed solution;

[0038] S4: The mixed solution is then kept warm for 30 minutes. When the mixed solution is cooled to 50° C., the reacted compound is taken out from the water to form a binder.

[0039] Specifically, by adding formaldehyde, urea and melamine into water, the efficiency of the polycondensation reaction between the three is improved, and at the same time, the water absorbs the heat generated by the polycondensation reaction to prevent accidents during the reaction.

[0040] In a specific embodiment, the mass ratio of formaldehyde, urea and melamine is 60:20:3.

[0041] In one specific embodiment, the molar ratio of formaldehyde to urea is 0.53.

[0042] In one embodiment, after step S1, an acid solution is provided and added to the mixed solution to adjust the pH value of the mixed solution to 6.0;

[0043] After step S2, the acid solution is added to the mixed solution to adjust the pH value of the mixed solution to 4.8.

[0044] In a specific embodiment, the acid solution is a formic acid solution with a mass fraction of 15%-25%.

[0045] In a specific embodiment, the acid solution is an acetic acid solution with a mass fraction of 15%-25%.

[0046] In one embodiment, after step S3, an alkaline solution is provided and added to the mixed solution to adjust the pH value of the mixed solution to 7.5.

[0047] In a specific embodiment, the alkaline solution is a sodium hydroxide solution with a mass fraction of 5%-15%.

[0048] In one specific embodiment, the heating rate in step S2 is 1.3° C. / min.

[0049] In a specific embodiment, when the mixed solution is cooled in step S4, the mixed solution is in a room temperature environment.

[0050] In a preferred embodiment, the room temperature is 25°C.

[0051] In a specific embodiment, in step S4, before cooling the mixed solution, an auxiliary agent and urea are provided and added to the mixed solution.

[0052] The present invention is described in detail above in conjunction with the embodiments of the accompanying drawings. A person skilled in the art can make various variations of the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation of the present invention, and the scope of protection of the present invention shall be defined by the scope of the attached claims.

Claims

1. A method for preparing a regenerated composite keel FRP interlayer adhesive, characterized in that: The specific steps include: S1: providing formaldehyde and water, and dissolving the formaldehyde in the water to form a mixed solution; S2: providing urea and adding the urea to the mixed solution, and heating the mixed solution to 85° C., then stopping the heating and keeping the mixed solution warm, so that the urea and formaldehyde react; S3: When the temperature of the mixed solution is reduced to 20° C. and is in a dispersed state, melamine is provided and added to the mixed solution, so that the melamine reacts with urea and formaldehyde in water to generate heat to increase the temperature of the mixed solution; S4: The mixed solution is then kept warm for 30 minutes. When the mixed solution is cooled to 50° C., the reacted compound is taken out from the water to form a binder.

2. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 1, characterized in that: The mass ratio of formaldehyde, urea and melamine is 60:20:

3.

3. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 1, characterized in that: After step S1, an acid solution is provided and added to the mixed solution to adjust the pH value of the mixed solution to 6.0; After step S2, the acid solution is added to the mixed solution to adjust the pH value of the mixed solution to 4.

8.

4. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 3, characterized in that: The acid solution is a formic acid solution with a mass fraction of 15%-25%.

5. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 3, characterized in that: The acid solution is an acetic acid solution with a mass fraction of 15%-25%.

6. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 1, characterized in that: After step S3, an alkaline solution is provided and added to the mixed solution to adjust the pH value of the mixed solution to 7.

5.

7. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 6, characterized in that: The alkaline solution is a sodium hydroxide solution with a mass fraction of 5%-15%.

8. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 1, characterized in that: The heating rate in step S2 is 1.3°C / min.

9. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 1, characterized in that: When the mixed solution is cooled in step S4, the mixed solution is in a room temperature environment.

10. The method for preparing a regenerated composite keel FRP interlayer adhesive according to claim 1, characterized in that: In step S4, before cooling the mixed solution, an auxiliary agent and urea are provided and added to the mixed solution.

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