Formula and process for filling polyurethane material in pipeline

Abstract

The invention discloses a formula and a process for filling a pipeline with a polyurethane material, and aims to solve the technical problems that the strength, the thermal stability, the hardness, the elasticity and the compressive strength of the current polyurethane material in the use process are relatively general, the filling and curing speed is low, the polyurethane material can be cured by matching with high temperature, and the service life is relatively short. Comprising the following raw materials in percentage by weight: 40-60% of isocyanate; the mass part of the polyether polyol is 10%-30%; the mass part of the cross-linking agent is 3%-6%; the mass part of the catalyst is 1%-2%; 2%-5% by mass of a foam stabilizer; the mass part of the foaming agent is 5-18%; 3%-4% by mass of a flame retardant; and the mass part of the surfactant is 1%-2%. The chain extender can react with a functional group on a linear polymer chain, so that a molecular chain is prolonged, the mechanical property and the processing property of the polyurethane material are enhanced, the reaction speed is increased, and the strength and the thermal stability of the polyurethane material are improved.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline filling materials, and in particular to a formula and process for filling a polyurethane material in a pipeline. Background Art

[0002] Polyurethane insulated pipes are widely used in insulation and cold preservation projects of industrial pipelines such as centralized heating, refrigeration, oil and steam transportation due to their excellent insulation effect, simple construction, and obvious energy-saving and anti-corrosion effects. The basic structure of polyurethane insulated pipes includes an outer protective pipe, an inner steel pipe, and a polyurethane insulation layer between the inner steel pipe and the outer protective pipe. With the advancement of technologies such as heating pipe preparation and construction, and the sharp increase in heating area, there is a demand for insulated pipes with larger diameters. The preparation method of the insulation layer of the insulated pipe is generally to place the assembled pipe on a foaming platform, and to use a foaming gun to pour the foaming material into the gap between the outer protective pipe and the inner steel pipe to prepare the insulation layer of the insulated pipe.

[0003] In the process of realizing the invention, the inventor found that there are at least the following problems in the prior art that have not been solved: during use, the strength, thermal stability, hardness, elasticity and compressive strength of traditional polyurethane materials are relatively average, and the filling and curing speed is slow, high temperature is required for curing, and the service life is relatively short. Therefore, a new technical solution needs to be designed to solve it. Summary of the invention

[0004] The purpose of the present invention is to provide a formula and process for filling polyurethane materials in pipes to solve the technical problems that the strength, thermal stability, hardness, elasticity and compressive strength of current polyurethane materials are relatively average during use, the filling and curing speed is slow, high temperature is required for curing and the service life is relatively short.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a formula and process for filling a polyurethane material in a pipe, comprising the following raw materials and their weight fractions: 40%-60% by mass of isocyanate; 10%-30% by mass of polyether polyol; 3%-6% by mass of cross-linking agent; 1%-2% by mass of catalyst; 2%-5% by mass of foam stabilizer; 5%-18% by mass of blowing agent; 3%-4% by mass of flame retardant; 1%-2% by mass of surfactant; 2%-4% by mass of chain extender; and 4%-13% by mass of water.

[0006] As a preferred embodiment of the present invention, the formula of the polyurethane material filled in the pipe includes the following raw materials and their weight fractions: 45% by mass of isocyanate; 18% by mass of polyether polyol; 3% by mass of cross-linking agent; 1% by mass of catalyst; 2% by mass of foam stabilizer; 12% by mass of blowing agent; 3% by mass of flame retardant; 1% by mass of surfactant; 2% by mass of chain extender; and 13% by mass of water.

[0007] As a preferred embodiment of the present invention, the formula of the polyurethane material filled in the pipe includes the following raw materials and their weight fractions: 50% by mass of isocyanate; 20% by mass of polyether polyol; 3% by mass of cross-linking agent; 1% by mass of catalyst; 2% by mass of foam stabilizer; 12% by mass of blowing agent; 3% by mass of flame retardant; 1% by mass of surfactant; 2% by mass of chain extender; and 6% by mass of water.

[0008] As a preferred embodiment of the present invention, the method for preparing the polyurethane material filled in the pipeline comprises the following steps:

[0009] a. Weigh the above raw materials in parts by weight;

[0010] b. After step a is completed, the polyether polyol and the chain extender are added to the mixer and heated and mixed for a period of time, and then the isocyanate is added to the mixer and mixed to obtain a mixture A;

[0011] c. After step b is completed, the crosslinking agent, catalyst, foam stabilizer, flame retardant and surfactant are added to mixture A and heated and mixed to obtain mixture B;

[0012] d. After step c is completed, water and a foaming agent are added to mixture B and mixed to obtain a fluid polyurethane material.

[0013] As a preferred embodiment of the present invention, in the step b, the polyether polyol and the chain extender are added to a mixer and heated and mixed for a period of time, the temperature is heated to 70-80°C, and the mixing time is 15-20 minutes, and the isocyanate is added to the mixer and mixed, the mixing temperature is 65-75°C, and the mixing time is 20-25 minutes.

[0014] As a preferred embodiment of the present invention, in step c, the crosslinking agent, catalyst, foam stabilizer, flame retardant and surfactant are added to mixture A for heating and mixing, the mixing temperature is 70-75° C., and the mixing time is 25-30 min.

[0015] As a preferred embodiment of the present invention, in step d, water and a foaming agent are added to mixture B for mixing, the mixing temperature is 70-75° C., and the mixing time is 30-35 min.

[0016] As a preferred embodiment of the present invention, the pouring process of the polyurethane material filled in the pipeline, the pouring steps are as follows:

[0017] S1. First, an outer tube is placed outside the inner tube of the pipeline, and three connecting rods are welded at both ends to position the inner tube;

[0018] S2. Then seal one end of the inner tube and the outer tube, and then transfer the prepared fluid-like polyurethane material from the sealed barrel to the vacuum infusion equipment;

[0019] S3. The fluid polyurethane material is then filtered into a metering pump by a vacuum infusion device, driven by a pneumatic motor, and fed into the spray gun body. The compressed air regulator then brings the material into a mixing chamber for mixing;

[0020] S4. Finally, the material forms foam and is sprayed out through the nozzle so as to fill the gap between the inner tube and the outer tube of the pipeline.

[0021] As a preferred embodiment of the present invention, the catalyst used is divalent tin (Sn2+) and tetravalent tin (Sn4+); the flame retardant used is dimethyldiallyltriamine; and the surfactant used is an aqueous polyurethane surfactant.

[0022] As a preferred embodiment of the present invention, the chain extender is one or more of N-isopropylethylenediamine (IPEDA), triethylenetetramine (TETA) and diethylenetriamine (DETA).

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention uses a chain extender that can react with the functional groups on the linear polymer chain, thereby extending the molecular chain, enhancing the mechanical properties and process properties of the polyurethane material, and accelerating the reaction speed, thereby improving the strength and thermal stability of the polyurethane material;

[0025] Using divalent tin (Sn2+) and tetravalent tin (Sn4+) as catalysts can accelerate the curing speed of the polyurethane material after filling, and improve the hardness, elasticity and compressive strength of the polyurethane material after curing;

[0026] The addition of flame retardants and foam stabilizers can slow down the aging of polyurethane materials, effectively avoid large-scale burning of polyurethane materials, and extend the service life of polyurethane materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0028] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0030] The invention provides a technical solution: a formula and a process for filling a polyurethane material in a pipeline, comprising the following raw materials and their weight fractions: 40%-60% by mass of isocyanate; 10%-30% by mass of polyether polyol; 3%-6% by mass of a crosslinking agent; 1%-2% by mass of a catalyst; 2%-5% by mass of a foam stabilizer; 5%-18% by mass of a blowing agent; 3%-4% by mass of a flame retardant; 1%-2% by mass of a surfactant; 2%-4% by mass of a chain extender; and 4%-13% by mass of water.

[0031] Furthermore, the formula of the polyurethane material filled in the pipe includes the following raw materials and their weight fractions: 45% by mass of isocyanate; 18% by mass of polyether polyol; 3% by mass of cross-linking agent; 1% by mass of catalyst; 2% by mass of foam stabilizer; 12% by mass of blowing agent; 3% by mass of flame retardant; 1% by mass of surfactant; 2% by mass of chain extender; and 13% by mass of water.

[0032] Furthermore, the formula of the polyurethane material filled in the pipe includes the following raw materials and their weight fractions: 50% by mass of isocyanate; 20% by mass of polyether polyol; 3% by mass of cross-linking agent; 1% by mass of catalyst; 2% by mass of foam stabilizer; 12% by mass of blowing agent; 3% by mass of flame retardant; 1% by mass of surfactant; 2% by mass of chain extender; and 6% by mass of water.

[0033] Further, the manufacturing method of the polyurethane material filled in the pipeline, the manufacturing steps are as follows:

[0034] a. Weigh the above raw materials in parts by weight;

[0035] b. After step a is completed, the polyether polyol and the chain extender are added to the mixer and heated and mixed for a period of time, and then the isocyanate is added to the mixer and mixed to obtain a mixture A;

[0036] c. After step b is completed, the crosslinking agent, catalyst, foam stabilizer, flame retardant and surfactant are added to mixture A and heated and mixed to obtain mixture B;

[0037] d. After step c is completed, water and a foaming agent are added to mixture B and mixed to obtain a fluid polyurethane material.

[0038] Further, in step b, the polyether polyol and the chain extender are added to the mixer and heated and mixed for a period of time, the temperature is heated to 70-80°C, the mixing time is 15-20 minutes, and the isocyanate is added to the mixer and mixed, the mixing temperature is 65-75°C, and the mixing time is 20-25 minutes.

[0039] Furthermore, in step c, a crosslinking agent, a catalyst, a foam stabilizer, a flame retardant and a surfactant are added to the mixture A and heated and mixed. The mixing temperature is 70-75° C. and the mixing time is 25-30 minutes.

[0040] Furthermore, in step d, water and a foaming agent are added to the mixture B for mixing at a temperature of 70-75° C. for a mixing time of 30-35 min.

[0041] The filling process of the pipe filled with polyurethane material, the filling steps are as follows:

[0042] S1. First, an outer tube is placed outside the inner tube of the pipeline, and three connecting rods are welded at both ends to position the inner tube;

[0043] S2. Then seal one end of the inner tube and the outer tube, and then transfer the prepared fluid-like polyurethane material from the sealed barrel to the vacuum infusion equipment;

[0044] S3. The fluid polyurethane material is then filtered into a metering pump by a vacuum infusion device, driven by a pneumatic motor, and fed into the spray gun body. The compressed air regulator then brings the material into a mixing chamber for mixing;

[0045] S4. Finally, the material forms foam and is sprayed out through the nozzle so as to fill the gap between the inner tube and the outer tube of the pipeline.

[0046] The catalyst used is divalent tin (Sn2+) and tetravalent tin (Sn4+); the flame retardant used is dimethyldiallyltriamine; and the surfactant used is a water-based polyurethane surfactant.

[0047] The chain extender is one or more of N-isopropylethylenediamine (IPEDA), triethylenetetramine (TETA) and diethylenetriamine (DETA).

[0048] Embodiment 1

[0049] The formula of the polyurethane material for filling the pipe includes the following raw materials and their weight fractions: 45% by mass of isocyanate; 18% by mass of polyether polyol; 3% by mass of cross-linking agent; 1% by mass of catalyst; 2% by mass of foam stabilizer; 12% by mass of blowing agent; 3% by mass of flame retardant; 1% by mass of surfactant; 2% by mass of chain extender; and 13% by mass of water.

[0050] The production steps are as follows:

[0051] a. Weigh the above raw materials in parts by weight;

[0052] b. After step a is completed, the polyether polyol and the chain extender are added to the mixer and heated and mixed for a period of time, heated to a temperature of 70°C, and the mixing time is 15 minutes. Then, the isocyanate is added to the mixer and mixed at a temperature of 65°C and a mixing time of 20 minutes to obtain a mixture A;

[0053] c. After step b is completed, the crosslinking agent, catalyst, foam stabilizer, flame retardant and surfactant are added to the mixture A and heated and mixed. The mixing temperature is 73 ° C and the mixing time is 27 min to obtain a mixture B;

[0054] d. After step c is completed, water and a blowing agent are added to mixture B and mixed at a temperature of 73° C. for 35 min to obtain a fluid polyurethane material.

[0055] Embodiment 2

[0056] The formula of the polyurethane material for filling the pipe includes the following raw materials and their weight fractions: 50% by mass of isocyanate; 20% by mass of polyether polyol; 3% by mass of cross-linking agent; 1% by mass of catalyst; 2% by mass of foam stabilizer; 12% by mass of blowing agent; 3% by mass of flame retardant; 1% by mass of surfactant; 2% by mass of chain extender; and 6% by mass of water.

[0057] The production steps are as follows:

[0058] a. Weigh the above raw materials in parts by weight;

[0059] b. After step a is completed, the polyether polyol and the chain extender are added to the mixer and heated and mixed for a period of time, heated to a temperature of 70°C, and the mixing time is 15 minutes. Then, the isocyanate is added to the mixer and mixed at a temperature of 65°C and a mixing time of 20 minutes to obtain a mixture A;

[0060] c. After step b is completed, the crosslinking agent, catalyst, foam stabilizer, flame retardant and surfactant are added to the mixture A and heated and mixed. The mixing temperature is 73 ° C and the mixing time is 27 min to obtain a mixture B;

[0061] d. After step c is completed, water and a blowing agent are added to mixture B and mixed at a temperature of 73° C. for 35 min to obtain a fluid polyurethane material.

[0062] The data parameters of polyurethane materials used in traditional pipes are shown in Table 1:

[0063] Test items Curing speed Aging speed Thermal stability Compressive strength Parameters Slow piece Difference weak

[0064] Example 1 The data parameter table 2 of the polyurethane material filled in the pipe is as follows:

[0065] Test items Curing speed Aging speed Thermal stability Compressive strength Parameters Faster Slow generally Strong

[0066] Example 2 The data parameter table 3 of the polyurethane material filled in the pipe is as follows:

[0067] Test items Curing speed Aging speed Thermal stability Compressive strength Parameters quick slow excellent powerful

[0068] In summary, referring to the data comparison of Table 1, Table 2 and Table 3, it can be seen that the chain extender can react with the functional groups on the linear polymer chain to extend the molecular chain, enhance the mechanical properties and process properties of the polyurethane material, and accelerate the reaction speed, thereby improving the strength and thermal stability of the polyurethane material;

[0069] Using divalent tin (Sn2+) and tetravalent tin (Sn4+) as catalysts can accelerate the curing speed of the polyurethane material after filling, and improve the hardness, elasticity and compressive strength of the polyurethane material after curing;

[0070] The addition of flame retardants and foam stabilizers can slow down the aging of polyurethane materials, effectively avoid large-scale burning of polyurethane materials, and extend the service life of polyurethane materials.

[0071] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0072] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. The formula of the polyurethane material filled in the pipe is characterized by: The invention comprises the following raw materials and their weight fractions: 40%-60% by weight of isocyanate; 10%-30% by weight of polyether polyol; 3%-6% by weight of crosslinking agent; 1%-2% by weight of catalyst; 2%-5% by weight of foam stabilizer; 5%-18% by weight of blowing agent; 3%-4% by weight of flame retardant; 1%-2% by weight of surfactant; 2%-4% by weight of chain extender; and 4%-13% by weight of water.

2. The formula of the polyurethane material for filling the pipe according to claim 1, characterized in that: The invention comprises the following raw materials and their weight fractions: 45% by weight of isocyanate; 18% by weight of polyether polyol; 3% by weight of crosslinking agent; 1% by weight of catalyst; 2% by weight of foam stabilizer; 12% by weight of blowing agent; 3% by weight of flame retardant; 1% by weight of surfactant; 2% by weight of chain extender; and 13% by weight of water.

3. The formula of the polyurethane material for filling the pipe according to claim 1, characterized in that: The invention comprises the following raw materials and their weight fractions: 50% by weight of isocyanate; 20% by weight of polyether polyol; 3% by weight of crosslinking agent; 1% by weight of catalyst; 2% by weight of foam stabilizer; 12% by weight of blowing agent; 3% by weight of flame retardant; 1% by weight of surfactant; 2% by weight of chain extender; and 6% by weight of water.

4. The method for manufacturing a pipe filled with polyurethane material according to claim 1, characterized in that: The production steps are as follows: a. Weigh the above raw materials in parts by weight; b. After step a is completed, the polyether polyol and the chain extender are added to the mixer and heated and mixed for a period of time, and then the isocyanate is added to the mixer and mixed to obtain a mixture A; c. After step b is completed, the crosslinking agent, catalyst, foam stabilizer, flame retardant and surfactant are added to mixture A and heated and mixed to obtain mixture B; d. After step c is completed, water and a foaming agent are added to mixture B and mixed to obtain a fluid polyurethane material.

5. The method for manufacturing a pipe filled with polyurethane material according to claim 4, characterized in that: In the step b, polyether polyol and chain extender are added to a mixer and heated and mixed for a period of time, the temperature is heated to 70-80° C., and the mixing time is 15-20 minutes. Isocyanate is added to the mixer and mixed, the mixing temperature is 65-75° C., and the mixing time is 20-25 minutes.

6. The method for manufacturing a pipe filled with polyurethane material according to claim 4, characterized in that: In the step c, the crosslinking agent, catalyst, foam stabilizer, flame retardant and surfactant are added to the mixture A and heated and mixed. The mixing temperature is 70-75° C. and the mixing time is 25-30 minutes.

7. The method for manufacturing a pipe filled with polyurethane material according to claim 4, characterized in that: In the step d, water and a foaming agent are added to the mixture B for mixing at a temperature of 70-75° C. for 30-35 minutes.

8. The process for filling a pipe with polyurethane material according to claim 1, characterized in that: The perfusion steps are as follows: S1. First, an outer tube is placed outside the inner tube of the pipeline, and three connecting rods are welded at both ends to position the inner tube; S2. Then seal one end of the inner tube and the outer tube, and then transfer the prepared fluid-like polyurethane material from the sealed barrel to the vacuum infusion equipment; S3. The fluid polyurethane material is then filtered into a metering pump by a vacuum infusion device, driven by a pneumatic motor, and fed into the spray gun body. The compressed air regulator then brings the material into a mixing chamber for mixing; S4. Finally, the material forms foam and is sprayed out through the nozzle so as to fill the gap between the inner tube and the outer tube of the pipeline.

9. The formulation of the polyurethane material for filling the pipe according to claim 1, characterized in that: The catalyst is divalent tin (Sn2+) and tetravalent tin (Sn4+); the flame retardant is dimethyldiallyltriamine; and the surfactant is a water-based polyurethane surfactant.

10. The formula of the polyurethane material for filling the pipe according to claim 1, characterized in that: The chain extender is one or more of N-isopropylethylenediamine (IPEDA), triethylenetetramine (TETA) and diethylenetriamine (DETA).

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