Low-density high-strength all-water-blown polyurethane material and preparation method thereof

Abstract

The invention provides a low-density high-strength all-water-blown polyurethane material and a preparation method thereof, and belongs to the technical field of polyurethane materials. By adding a certain amount of foamable beads, all-water foaming of polyurethane is enhanced, the strength of the prepared polyurethane material is greatly improved while low density is kept, and the problem that low density and strength cannot be achieved at the same time is solved. Besides, the low-density and high-strength all-water-foamed polyurethane material can be used for preparing materials used in the fields of furniture, transportation, refrigeration and heat preservation, building construction and the like, and the preparation method is green and environmentally friendly and has wide application prospects. The density of the prepared low-density high-strength all-water-foamed polyurethane material is as low as 10 kg / m < 3 >, the 10% deformation compression strength can reach 400 kPa or above, and the foaming ratio is 100 times or above.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane materials, and in particular to a low-density and high-strength all-water foamed polyurethane material and a preparation method thereof. Background Art

[0002] Polyurethane foam is made by polymerization of isocyanate and hydroxyl compounds. It can be divided into two categories according to its hardness: soft and hard, of which soft is the main variety. Generally speaking, it has excellent elasticity, softness, elongation and compression strength; good chemical stability, resistance to many solvents and oils; excellent wear resistance, 20 times greater than natural sponge; and excellent processability, thermal insulation, adhesion and other properties. It is a cushioning material with excellent performance.

[0003] As the concept of green environmental protection has gained popularity, all-water foaming technology has gradually become a research hotspot for polyurethane foam materials. All-water foaming is the reaction of water and isocyanate to generate carbon dioxide gas, which makes the viscoelastic foam material expand, foam, and solidify to obtain various polyurethane foam plastics. All-water foaming controls the density of the foam by the amount of water. When the foam density is low, a large amount of water is required to produce enough CO2, so that the foam will become brittle due to too many urea groups, thereby limiting the lower limit of the foam density. In order to maintain good stability, the foam material obtained by all-water foaming must have a density of more than 40kg / m3, and the amount of water added is generally less than 4% of the mass of the polyether. If the density is reduced by increasing the amount of water alone, the physical properties of the foam will deteriorate seriously. Generally speaking, the more water is used, the easier it is for the foam to burn, the stiffer it is, and the lower its strength and other mechanical properties. Summary of the invention

[0004] The purpose of the present invention is to provide a low-density and high-strength all-water foamed polyurethane material and a preparation method thereof. The low-density and high-strength all-water foamed polyurethane material provided by the present invention has both low density and high strength, and meets the high performance requirements of the low-density and high-strength all-water foamed polyurethane material.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a low-density and high-strength all-water foamed polyurethane material, which is prepared by comprising the following component raw materials in parts by weight: 17.0-55.0 parts of polyol, 0.8-25.0 parts of water, 0.07-8.0 parts of amine catalysts, 0.06-5.0 parts of organotin catalysts, 0.06-5.0 parts of foam stabilizers, 45.0-85.0 parts of isocyanates and 3.0-35.0 parts of foamable beads.

[0007] Preferably, the low-density and high-strength all-water foamed polyurethane material is prepared from raw materials including the following components in parts by weight: 30 to 40 parts of polyol, 3.0 to 10.0 parts of water, 0.5 to 3.0 parts of amine catalyst, 0.3 to 1.5 parts of organotin catalyst, 0.3 to 1.5 parts of foam stabilizer, 60.0 to 70.0 parts of isocyanate, and 10.0 to 25.0 parts of foamable beads.

[0008] Preferably, the polyol is a polyether polyol.

[0009] Preferably, the isocyanate is one or more of diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and isophorone diisocyanate.

[0010] Preferably, the amine catalyst is triethylenediamine; and the organotin catalyst is stannous octoate.

[0011] Preferably, the expandable beads are one or more of expandable polypropylene beads EPP, expandable polystyrene beads EPS or expandable polylactic acid beads EPLA.

[0012] The present invention also provides a method for preparing the low-density and high-strength all-water foamed polyurethane material described in the above technical solution, comprising the following steps:

[0013] (1) mixing a polyol, water, an amine catalyst, an organotin catalyst, a foam stabilizer and expandable beads, and performing a first stirring to obtain a mixture;

[0014] (2) adding isocyanate to the mixture obtained in step (1), and performing a second stirring to obtain a first intermediate;

[0015] (3) pouring the first intermediate obtained in step (2) into a mold and sequentially performing foaming and curing to obtain a low-density and high-strength all-water foamed polyurethane material.

[0016] Preferably, the rotation speed of the first stirring in step (1) is 500 to 2000 r / min, and the time of the first stirring is 30 to 120 s.

[0017] Preferably, the rotation speed of the second stirring in step (2) is 500 to 2000 r / min, and the time of the second stirring is 10 to 30 s.

[0018] Preferably, in the step (4), the foaming time is 0.5 to 2 minutes, the curing time is 5 to 20 minutes, and the curing temperature is room temperature.

[0019] The present invention provides a low-density and high-strength all-water foamed polyurethane material. By adding a certain amount of foamable beads, the all-water foaming of polyurethane is enhanced. While maintaining the low density, the strength of the prepared all-water foamed polyurethane material is greatly improved, which overcomes the problem that low density and strength cannot be achieved at the same time. In addition, the low-density and high-strength all-water foamed polyurethane material of the present invention can be used to prepare materials used in the fields of furniture, transportation, refrigeration and heat preservation, construction, etc., and its preparation method is green and environmentally friendly, and has broad application prospects. The results of the embodiment show that the low-density and high-strength all-water foamed polyurethane material prepared in Examples 1 to 5 of the present invention has a density of 400 kPa or more with a 10% deformation compression strength, and a foaming ratio of more than 100 times. While having a low density, its compression strength is much higher than that of Comparative Example 1 and Comparative Example 2. The polyurethane material prepared by the present invention has the advantages of both low density and high strength, and the preparation method is environmentally friendly, and can be used in industrial applications of polyurethane foam products. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a physical picture of the low-density and high-strength all-water foamed polyurethane material prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0021] The present invention provides a low-density and high-strength all-water foamed polyurethane material, which is prepared by the following component raw materials in parts by weight: The present invention provides a low-density and high-strength all-water foamed polyurethane material, which is prepared by the following component raw materials in parts by weight: 17.0 to 55.0 parts of polyol, 0.8 to 25.0 parts of water, 0.07 to 8.0 parts of amine catalysts, 0.06 to 5.0 parts of organotin catalysts, 0.06 to 5.0 parts of foam stabilizers, 45.0 to 85.0 parts of isocyanates, and 3.0 to 35.0 parts of foamable beads.

[0022] In the present invention, the low-density and high-strength all-water foamed polyurethane material is preferably prepared from raw materials comprising the following components in parts by weight: 30 to 40 parts of polyol, 3.0 to 10.0 parts of water, 0.5 to 3.0 parts of amine catalyst, 0.3 to 1.5 parts of organic tin catalyst, 0.3 to 1.5 parts of foam stabilizer, 60.0 to 70.0 parts of isocyanate, and 10.0 to 25.0 parts of foamable beads.

[0023] In the present invention, the polyol is preferably a polyether polyol. In the present invention, the polyether polyol is more preferably composed of a low molecular weight polyoxyethylene ether triol (referred to as polyol-A) having a number average molecular weight of 100 to 1000 g / mol and a high molecular weight polyoxyethylene ether triol (polyol-B) having a number average molecular weight of 1000 to 10000 g / mol. In the present invention, the mass ratio of the polyol-A to the polyol-B is preferably (1 to 6): (4 to 9), more preferably (2 to 4): (5 to 8). The present invention controls the type, composition and relative molecular weight of the polyether polyol within the above range to improve the dispersion stability and uniformity of the raw materials including the foaming beads in the all-water foamed polyurethane material, which is beneficial to reduce the density of the all-water foamed polyurethane material and improve its strength.

[0024] In the present invention, the isocyanate is preferably one or more of diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and isophorone diisocyanate. In the present invention, carbon dioxide gas generated by the reaction of water and isocyanate is preferably used as a foaming agent.

[0025] In the present invention, the amine catalyst is preferably triethylenediamine. In the present invention, the organotin catalyst is preferably stannous octoate. In the present invention, the foam stabilizer is preferably a silicon surfactant containing a Si-C structure, more preferably silicone oil.

[0026] In the present invention, the expandable beads are preferably one or more of expandable polypropylene beads (EPP), expandable polystyrene beads (EPS) or expandable polylactic acid beads (EPLA). The present invention uses the expandable beads of the above materials as modified raw materials, while maintaining a low density, greatly improving the strength of the prepared polyurethane material.

[0027] The present invention also provides a method for preparing the low-density and high-strength all-water foamed polyurethane material described in the above technical solution, comprising the following steps:

[0028] (1) mixing a polyol, water, an amine catalyst, an organotin catalyst, a foam stabilizer and expandable beads, and performing a first stirring to obtain a mixture;

[0029] (2) adding isocyanate to the mixture obtained in step (1), and performing a second stirring to obtain a first intermediate;

[0030] (3) pouring the first intermediate obtained in step (2) into a mold and sequentially performing foaming and curing to obtain a low-density and high-strength all-water foamed polyurethane material.

[0031] In the present invention, the first stirring speed is preferably 500-2000 r / min, more preferably 800-1500 r / min; the first stirring time is preferably 30-120 s, more preferably 50-100 s. The present invention controls the first stirring speed and time within the above range to promote uniform mixing of the components, thereby improving the comprehensive performance of the prepared polyurethane material.

[0032] In the present invention, the second stirring speed is preferably 500-1000 r / min, more preferably 600-800 r / min; the second stirring time is preferably 10-30 s, more preferably 15-25 s. The present invention controls the second stirring speed and time within the above range to promote uniform mixing of the components and improve the strength performance of the prepared polyurethane material.

[0033] In the present invention, the foaming time is preferably 0.5 to 2 minutes, more preferably 0.7 to 1.5 minutes. In the present invention, the curing time is preferably 5 to 20 minutes, more preferably 8 to 15 minutes; and the curing temperature is preferably room temperature.

[0034] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1

[0036] A low-density and high-strength all-water foamed polyurethane material is prepared from the following component raw materials in parts by weight: 35 parts of a polyol consisting of a polyol-A with a number average molecular weight of 500 g / mol and a polyol-B with a number average molecular weight of 5000 g / mol in a mass ratio of 4:6, 5.0 parts of water, 2.0 parts of an amine catalyst triethylenediamine, 0.8 parts of an organic tin catalyst stannous octoate, 0.8 parts of a foam stabilizer silicone oil, 65 parts of diphenylmethane diisocyanate (isocyanate), and 20 parts of EPP;

[0037] The preparation method of the above-mentioned low-density and high-strength all-water foamed polyurethane material comprises the following steps:

[0038] (1) mixing a polyol, water, an amine catalyst, an organotin catalyst, a foam stabilizer and foamable beads, and performing a first stirring at 1000 r / min for 80 seconds to obtain a mixture;

[0039] (2) adding isocyanate to the mixture obtained in step (1), and stirring for a second time at 600 r / min for 20 seconds to obtain a first intermediate;

[0040] (3) Pour the first intermediate obtained in step (2) into a mold, foam it for 1 minute, and then cure it at room temperature for 10 minutes to obtain a low-density and high-strength all-water foamed polyurethane material.

[0041] Example 2

[0042] A low-density and high-strength all-water foamed polyurethane material is prepared from the following component raw materials in parts by weight: 35 parts of a polyol consisting of a polyol-A with a number average molecular weight of 500 g / mol and a polyol-B with a number average molecular weight of 5000 g / mol in a mass ratio of 3:7, 5.0 parts of water, 2.0 parts of an amine catalyst triethylenediamine, 0.8 parts of an organic tin catalyst stannous octoate, 0.8 parts of a foam stabilizer silicone oil, 65 parts of toluene diisocyanate (isocyanate), and 15 parts of EPS;

[0043] The low-density and high-strength all-water foamed polyurethane material was prepared in the same manner as in Example 1.

[0044] Figure 1 This is a physical picture of the low-density and high-strength all-water foamed polyurethane material prepared in Example 2 of the present invention. Figure 1 It can be seen that the low-density and high-strength all-water foamed polyurethane material prepared in Example 2 has a dense appearance and is foamed evenly.

[0045] A low-density and high-strength all-water foamed polyurethane material was prepared according to the same composition and method as in Example 2, except that the amount of EPS added was 25 parts.

[0046] Example 4

[0047] A low-density and high-strength all-water foamed polyurethane material was prepared according to the same composition method as in Example 2. The difference from Example 2 is that the mass ratio of polyol-A to polyol-B is 2:8.

[0048] Example 5

[0049] A low-density and high-strength all-water foamed polyurethane material was prepared according to the same composition method as in Example 2, except that the added amount of toluene diisocyanate was 75 parts.

[0050] Comparative Example 1

[0051] A fully water-foamed polyurethane material was prepared according to the same composition and method as in Example 2, except that the amount of EPS added was 0 parts.

[0052] The performance of the low-density and high-strength all-water foamed polyurethane materials prepared in Examples 1 to 5 and the all-water foamed polyurethane material prepared in Comparative Example 1 was tested, and the results are shown in Table 1 below.

[0053] Table 1 Performance test results statistics

[0054]

[0055] As shown in Table 1, the density of the low-density and high-strength all-water foamed polyurethane material prepared in Example 2 of the present invention is 9.63 kg / m 3 The 10% deformation compression strength can reach 516.7 kPa. While having low density, its compression strength is much higher than 307.3 kPa of Comparative Example 1. The polyurethane material prepared by the present invention has the advantages of low density and high strength, and the preparation method is environmentally friendly and can be used in industrial applications of polyurethane foam products.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A low-density, high-strength, all-water foamed polyurethane material, characterized in that: The raw materials including the following components in parts by weight are prepared: 17.0-55.0 parts of polyol, 0.8-25.0 parts of water, 0.07-8.0 parts of amine catalyst, 0.06-5.0 parts of organic tin catalyst, 0.06-5.0 parts of foam stabilizer, 45.0-85.0 parts of isocyanate and 3.0-35.0 parts of foamable beads.

2. The low-density and high-strength all-water foamed polyurethane material according to claim 1, characterized in that: The raw materials including the following components in parts by weight are prepared: 20.0-50.0 parts of polyol, 1.0-20.0 parts of water, 0.2-3.0 parts of amine catalyst, 0.1-3.0 parts of organic tin catalyst, 0.1-3.0 parts of foam stabilizer, 50.0-80.0 parts of isocyanate and 5.0-30.0 parts of foamable beads.

3. The low-density and high-strength all-water foamed polyurethane material according to claim 1, characterized in that: The polyol is a polyether polyol.

4. The low-density and high-strength all-water foamed polyurethane material according to claim 1, characterized in that: The isocyanate is one or more of diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and isophorone diisocyanate.

5. The low-density and high-strength all-water foamed polyurethane material according to claim 1, characterized in that: The amine catalyst is triethylenediamine; the organotin catalyst is stannous octoate.

6. The low-density and high-strength all-water foamed polyurethane material according to claim 1, characterized in that: The expandable beads are one or more of expandable polypropylene beads EPP, expandable polystyrene beads EPS or expandable polylactic acid beads EPLA.

7. A method for preparing a low-density, high-strength all-water foamed polyurethane material according to any one of claims 1 to 6, characterized in that: The steps include: (1) mixing a polyol, water, an amine catalyst, an organotin catalyst, a foam stabilizer and expandable beads, and performing a first stirring to obtain a mixture; (2) adding isocyanate to the mixture obtained in step (1), and performing a second stirring to obtain a first intermediate; (3) pouring the first intermediate obtained in step (2) into a mold and sequentially performing foaming and curing to obtain a low-density and high-strength all-water foamed polyurethane material.

8. The preparation method according to claim 7, characterized in that: The rotation speed of the first stirring in the step (1) is 500 to 2000 r / min, and the time of the first stirring is 30 to 120 s.

9. The preparation method according to claim 7, characterized in that: The rotation speed of the second stirring in the step (2) is 500 to 2000 r / min, and the time of the second stirring is 10 to 30 s.

10. The preparation method according to claim 7, characterized in that: In the step (4), the foaming time is 0.5 to 2 minutes, the curing time is 5 to 20 minutes, and the curing temperature is room temperature.

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