Glass fiber reinforced polyurethane plate as well as preparation method and application thereof

Abstract

The invention relates to the technical field of composite board preparation, in particular to a glass fiber reinforced polyurethane board as well as a preparation method and application thereof. The N layers of glass fiber felts are averagely impregnated in the polyurethane stock solution through two impregnation boxes, and impregnated glass fiber felts are obtained; spreading flame retardant powder on one surface of the impregnated glass fiber felt to obtain the impregnated glass fiber felt with the surface containing a flame retardant; and carrying out hot-pressing curing treatment on the glass fiber felt to obtain the glass fiber reinforced polyurethane plate. According to the preparation method provided by the invention, the content of glass fibers in the board is increased, the board has flame retardance, and the bending strength, bending modulus and nail-holding power of the board are also improved.

Description

Technical Field

[0001] The invention relates to the technical field of composite plate preparation, and in particular to a glass fiber reinforced polyurethane plate and a preparation method and application thereof. Background Art

[0002] Composite materials have received extensive attention due to their excellent performance, and each material plays its unique advantages in composite materials. Glass fiber reinforced polyurethane composite board is an important composite material that combines the advantages of glass fiber and polyurethane stock solution. It has the characteristics of high strength, good rigidity, corrosion resistance, good weather resistance, non-absorbent, anti-corrosion and antibacterial. This material is widely used in the fields of construction, transportation, aerospace, etc. The existing preparation method of glass fiber reinforced polyurethane composite board is mainly to stack multiple layers of continuous glass fiber or glass fiber felt, impregnate the polyurethane stock solution in turn through the dipping box, and then enter the compounding machine for hot pressing and curing to obtain a layered glass fiber reinforced polyurethane sheet with uniform and alternating distribution.

[0003] Although the existing glass fiber reinforced polyurethane composite board preparation method can obtain good performance, there are still some problems in practical application. First, in the existing method, the glass fiber content is relatively low (20-40%), the production cost is high, and it is difficult to make the surface completely flame retardant.

[0004] Therefore, increasing the glass fiber content and flame retardancy is an urgent problem to be solved in this type of automotive composite materials. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a glass fiber reinforced polyurethane board and its preparation method and application. The preparation method provided by the present invention not only increases the content of glass fiber in the board and also has flame retardancy, but also improves the bending strength, bending modulus and nail holding force of the board.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a glass fiber reinforced polyurethane plate, comprising the following steps:

[0008] 1) N layers of short-cut stitched glass fiber mats are equally divided into two groups, laid out in sequence, and impregnated with polyurethane stock solution through two dipping boxes respectively to obtain impregnated glass fiber mats;

[0009] The components of the polyurethane stock solution include material A and material B, the components of material A are 4110 polyether, water, silicone oil surfactant and polymerization inhibitor, and the mass ratio of 4110 polyether, water, silicone oil surfactant and polymerization inhibitor is 100:0.3:2.5:0.1;

[0010] The B material is 44V20 isocyanate;

[0011] The mass ratio of material A to material B is 1:1-1.3;

[0012] The N layers are more than 2 layers;

[0013] The surface density of the short-cut stitched glass fiber mat is 100-600 g / m 2 , door width is 0.6-1.25m;

[0014] 2) Sprinkling a flame retardant on one surface of the impregnated glass fiber felt obtained in step 1) to obtain a glass fiber felt having a flame retardant on its surface;

[0015] 3) subjecting the glass fiber felt with the flame retardant on the surface obtained in step 2) to a hot pressing curing treatment to obtain a glass fiber reinforced polyurethane sheet.

[0016] Preferably, in step 1), the speed at which the glass fiber felt passes through the dipping box is 0.3-0.6 m / min.

[0017] Preferably, in step 1), the total injection flow rate of the polyurethane stock solution injected into the dipping box is 1.2 to 4.2 kg / min;

[0018] The polyurethane stock solution is injected from the upper and lower surfaces of the dipping box through 4 to 16 injection ports at the same time.

[0019] Preferably, the amount of flame retardant sprinkled in step 2) is 200-300 g / m 2 .

[0020] Preferably, the flame retardant comprises aluminum hydroxide and / or magnesium hydroxide.

[0021] Preferably, the conditions of the hot pressing treatment in step 3) include: a temperature of 50 to 80° C., a speed of 0.3 to 0.6 m / min, a pressure of more than 2 MPa, and a gap controlled at 8 to 30 mm.

[0022] The present invention also provides a glass fiber reinforced polyurethane plate prepared by the preparation method described in the above technical solution, wherein the mass percentage of glass fiber in the glass fiber reinforced polyurethane plate is 50-70%, the thickness is 8-30mm, and the density is 500-1000kg / m 3 .

[0023] The present invention also provides the use of the glass fiber reinforced polyurethane sheet described in the above technical solution in improving the bending strength and bending modulus of the sheet.

[0024] The present invention also provides the use of the glass fiber reinforced polyurethane sheet described in the above technical solution in improving the nail holding force of the sheet.

[0025] The present invention can reduce the resistance of polyurethane stock solution to impregnate glass fiber felt by separate impregnation compared with dipping in a single dipping box, so that less polyurethane stock solution can be used to impregnate the same amount of glass fiber felt, thereby achieving the purpose of increasing the glass fiber content in the board.

[0026] Beneficial effects of the present invention:

[0027] 1. Use two dipping boxes to separately impregnate the glass fiber felt. Compared with a single dipping box, the polyurethane solution penetrates into relatively fewer reinforcement layers, reducing the resistance of the solution to penetration and flow between the reinforcement layers, making it easier to ensure that the polyurethane solution and the glass fiber felt are fully impregnated, which is beneficial to increase the content of the glass fiber felt in the board and also improve the strength and rigidity of the board.

[0028] 2. Adding inhibitor to the polyurethane stock solution can delay the speed of the stock solution, thereby increasing the impregnation time of the glass fiber and the polyurethane stock solution, which is beneficial to the full penetration of the stock solution into the glass fiber felt or glass fiber cloth, and prevents the stock solution from reacting before entering the main machine so that the thickness of the board cannot be accurately controlled.

[0029] 3. A flame retardant layer of magnesium hydroxide or aluminum hydroxide powder is sprinkled on the upper surface of the board. No adhesive is needed to be added during the preparation process. It can be directly cured as a whole during the hot pressing process, making the board surface non-flammable. In addition, because there is flame retardant powder on the surface, it plays a role similar to a release agent. In this way, the upper surface of the press no longer needs to be separated from the board by using a release cloth or spraying a release agent. The resulting board is suitable for use as a car body board or floor and other related fields with high requirements for surface flame retardancy.

[0030] 4. In order to improve the curing speed or production efficiency, the temperature of the crawler press can be adjusted appropriately to take into account the impregnation effect of the front process and the curing speed of the back process in the board production process.

[0031] In summary, compared with the prior art, the glass fiber reinforced polyurethane sheet of the present technical solution not only has high strength and good single-sided flame retardant effect, but also can significantly reduce the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0033] Figure 1 The glass fiber reinforced polyurethane sheet structure of the present invention;

[0034] Figure 2 This is a schematic diagram of the preparation process of the glass fiber reinforced polyurethane sheet of the present invention;

[0035] Figure 3 This is a schematic diagram of the two dipping boxes of the present invention injecting polyurethane glue simultaneously from top to bottom.

[0036] In the figure, 1. glass fiber stitched felt or glass fiber woven cloth, 2. glue dipping box, 3. glue injection port, 4. powder spreading machine, 5. crawler press, 6. flame retardant glass fiber reinforced polyurethane sheet, 7. flame retardant powder, 8. polyurethane foam. DETAILED DESCRIPTION

[0037] The present invention provides a method for preparing a glass fiber reinforced polyurethane plate, comprising the following steps:

[0038] 1) N layers of short-cut stitched glass fiber mats are equally divided into two groups, laid out in sequence, and impregnated with polyurethane stock solution through two dipping boxes respectively to obtain impregnated glass fiber mats;

[0039] The components of the polyurethane stock solution include material A and material B, the components of material A are 4110 polyether, water, silicone oil surfactant and polymerization inhibitor, and the mass ratio of 4110 polyether, water, silicone oil surfactant and polymerization inhibitor is 100:0.3:2.5:0.1;

[0040] The B material is 44V20 isocyanate;

[0041] The mass ratio of material A to material B is 1:1-1.3;

[0042] The N layers are more than 2 layers;

[0043] The surface density of the short-cut stitched glass fiber mat is 100-600 g / m 2 , door width is 0.6~1.25m;

[0044] 2) Sprinkling a flame retardant on one surface of the impregnated glass fiber felt obtained in step 1) to obtain a glass fiber felt having a flame retardant on its surface;

[0045] 3) subjecting the glass fiber felt with the flame retardant on the surface obtained in step 2) to a hot pressing curing treatment to obtain a glass fiber reinforced polyurethane sheet.

[0046] The present invention divides N layers of short-cut slit glass fiber felt into two groups, lays them in sequence, and then impregnates them with polyurethane stock solution (liquid) through two dipping boxes to obtain impregnated glass fiber felt; the components of the polyurethane stock solution include A material and B material, the components of the A material are 4110 polyether, water, silicone oil surfactant and polymerization inhibitor, and the mass ratio of the 4110 polyether, water, silicone oil surfactant and polymerization inhibitor is 100:0.3:2.5:0.1; the B material is 44V20 isocyanate; the mass ratio of the A material to the B material is 1:1-1.3; the N layers are more than 2 layers; the surface density of the short-cut slit glass fiber felt is 100-600g / m 2, the width is 0.6-1.25m. The present invention has no special limitation on the preparation method of the polyurethane stock solution, and the raw materials can be evenly mixed. The present invention has no special limitation on the source of the short-cut and sewed glass fiber mat, and conventional commercial products can be used, such as those purchased from Zhejiang Weitong Composite Materials Co., Ltd. The present invention has no special limitation on the source of the polyurethane stock solution, and conventional commercial products can be used, such as 44V20 isocyanate purchased from Covestro Polymers (China) Co., Ltd. and 4110 polyether purchased from Wanhua Chemical Group Co., Ltd., and the silicone oil surfactant brand is B8870 of Evonik Industries AG (Evonik) of Germany. In a specific embodiment of the present invention, the N is preferably 18, 20 and 30. In the present invention, the surface density of the short-cut and sewed glass fiber mat is preferably 300g / m 2 . In the present invention, the polyurethane stock solution preferably contains a polymerization inhibitor, and the mass percentage is preferably 0.2-1%. The present invention has no special limitation on the source of the polymerization inhibitor, and conventional commercially available products can be used, such as the YC-02 brand polymerization inhibitor of Guangzhou Yourun Synthetic Materials Co., Ltd. In the present invention, the polymerization inhibitor slows down the starting speed of the polyurethane stock solution, so that it has enough time to be fully and evenly impregnated with the glass fiber felt or glass fiber cloth, and prevents the stock solution from reacting before entering the host so that the thickness of the board cannot be accurately controlled.

[0047] In the present invention, a flame retardant is sprinkled on one surface of the obtained impregnated glass fiber mat (single surface) to obtain a glass fiber mat containing a flame retardant on the surface. In the present invention, the amount of the flame retardant sprinkled is preferably 200 to 300 g / m 2 In the present invention, the flame retardant preferably includes aluminum hydroxide and / or magnesium hydroxide.

[0048] The present invention performs a hot-pressing curing treatment on the obtained glass fiber felt containing a flame retardant on the surface to obtain a glass fiber reinforced polyurethane sheet. In the present invention, since the flame retardant is sprinkled on one side, the obtained glass fiber reinforced polyurethane sheet has a single-sided flame retardant effect. In the present invention, the conditions for the hot-pressing curing treatment preferably include: a temperature of 50 to 80°C, a speed of 0.3 to 0.6 m / min, a pressure of ≥2 MPa, and a gap control of 8 to 30 mm. In the present invention, the temperature of the hot-pressing treatment is more preferably 70°C. In the present invention, the speed of the hot-pressing treatment is more preferably 0.5 m / min. In the present invention, the gap control of the hot-pressing treatment is more preferably 15 mm.

[0049] The present invention provides a glass fiber reinforced polyurethane plate prepared by the preparation method described in the above technical solution, wherein the mass percentage of glass fiber in the glass fiber reinforced polyurethane plate is 50-70%, the thickness is 8-30mm, and the density is 500-1000kg / m 3 .

[0050] The present invention also provides the use of the glass fiber reinforced polyurethane sheet described in the above technical solution in improving the bending strength and bending modulus of the sheet.

[0051] The present invention also provides the use of the glass fiber reinforced polyurethane sheet described in the above technical solution in improving the nail holding force of the sheet.

[0052] In order to further illustrate the present invention, the present invention is described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0053] Example 1

[0054] A method for preparing a glass fiber reinforced polyurethane sheet, comprising the following steps:

[0055] The surface density of each layer of chopped and stitched fiberglass mat is 300g / m 2 , the width is 1.2m, 18 layers of short-cut slit-woven fiberglass mat are equally divided into 2 groups, laid out in sequence and passed through 2 dipping boxes respectively, and every 9 layers of short-cut slit-woven fiberglass mat pass through 1 dipping box to be impregnated with polyurethane stock solution;

[0056] The components of the polyurethane stock solution are material A and material B, wherein the components of material A are 4110 polyether, water, silicone oil surfactant and inhibitor, with a mass ratio of 100:0.3:2.5:0.1, and material B is 44V20 isocyanate, and the mass ratio of material A to material B is 1:1.2;

[0057] 4110 polyether was purchased from Wanhua Chemical Group Co., Ltd., 44V20 isocyanate was purchased from Covestro Polymer (China) Co., Ltd., silicone oil surfactant brand B8870 from Evonik Industries AG (Germany), and polymerization inhibitor was purchased from Guangzhou Yourun Synthetic Materials Co., Ltd. with brand YC-02 polymerization inhibitor;

[0058] The total injection flow rate of the polyurethane stock solution into the dipping box is 2.3kg / min, and the polyurethane stock solution is injected from the upper and lower sides of the dipping box through 8 injection ports at the same time;

[0059] Then sprinkle 200g / m2 on one surface. 2 The magnesium hydroxide powder and the impregnated glass fiber felt were sent to a crawler press at 70°C for hot pressing and curing treatment at a speed of 0.5m / min, a gap of 15mm, and a pressure of 2MPa to obtain a high-strength, single-sided flame-retardant glass fiber reinforced polyurethane sheet with a density of 620kg / m 3 The mass percentage of glass fiber felt is 60% and the thickness is 15mm.

[0060] Example 2

[0061] A method for preparing a glass fiber reinforced polyurethane sheet, comprising the following steps:

[0062] The surface density of each layer of chopped and stitched fiberglass mat is 200g / m 2 , the width is 1.2m, 30 layers of short-cut slit-woven glass fiber mats are equally divided into 2 groups, and after being laid out in sequence, they are passed through 2 dipping boxes respectively, and every 15 layers of short-cut slit-woven glass fiber mats are passed through 1 dipping box to be impregnated with polyurethane stock solution; the polyurethane stock solution is the same as that in Example 1;

[0063] The total injection flow rate of the polyurethane stock solution into the dipping box is 4.2kg / min, and the polyurethane stock solution is injected from the upper and lower sides of the dipping box through 8 injection ports at the same time;

[0064] Then sprinkle 300g / m 2 The aluminum hydroxide powder and the impregnated glass fiber felt are sent to a crawler press at 80°C for hot pressing at a speed of 0.6m / min, a gap of 12mm, and a pressure of 2MPa to obtain a high-strength, single-sided flame-retardant glass fiber reinforced polyurethane sheet with a density of about 1000kg / m 3 The mass percentage of glass fiber felt is 50% and the thickness is 12mm.

[0065] Example 3

[0066] A method for preparing a glass fiber reinforced polyurethane sheet, comprising the following steps:

[0067] The surface density of each layer of chopped and stitched fiberglass mat is 400g / m 2 , the width is 1.2m, 20 layers of short-cut slit-woven glass fiber mats are equally divided into 2 groups, and after being laid out in sequence, they are passed through 2 dipping boxes respectively, and every 10 layers of short-cut slit-woven glass fiber mats are impregnated with polyurethane stock solution through 1 dipping box; the polyurethane stock solution is the same as that in Example 1;

[0068] The total injection flow rate of the polyurethane stock solution into the dipping box is 1.2kg / min, and the polyurethane stock solution is injected from the upper and lower sides of the dipping box through 8 injection ports at the same time;

[0069] Then sprinkle 200g / m2 on one surface. 2 The aluminum hydroxide powder and the impregnated glass fiber felt were sent to a crawler press at 50°C for hot pressing at a speed of 0.3m / min, a gap of 20mm, and a pressure of 2MPa to obtain a high-strength, single-sided flame-retardant glass fiber reinforced polyurethane sheet with a density of 570kg / m 3 The mass percentage of glass fiber felt is about 70% and the thickness is 20mm.

[0070] Comparative Example 1

[0071] A method for preparing a glass fiber reinforced polyurethane sheet, comprising the following steps:

[0072] The surface density of each layer of chopped and stitched fiberglass mat is 300g / m 2, the width is 1.2m, 18 layers of short-cut slit-woven glass fiber mats are equally divided into 2 groups, and after being laid out in sequence, they are passed through 2 dipping boxes respectively, and every 9 layers of short-cut slit-woven glass fiber mats are impregnated with polyurethane stock solution through 1 dipping box; the polyurethane stock solution is the same as that in Example 1;

[0073] The total injection flow rate of the polyurethane stock solution into the dipping box is 2.3kg / min, and the polyurethane stock solution is injected from the upper and lower sides of the dipping box through 8 injection ports at the same time;

[0074] The impregnated glass fiber felt was sent to a crawler press at 70°C for hot pressing at a speed of 0.5m / min, a gap of 15mm, and a pressure of 2MPa to obtain a glass fiber reinforced polyurethane sheet with a density of 615kg / m 3 The mass percentage of glass fiber felt is about 60% and the thickness is 15mm.

[0075] Comparative Example 2

[0076] A method for preparing a high-strength flame-retardant glass fiber reinforced polyurethane sheet, comprising the following steps:

[0077] The surface density of each layer of chopped and stitched fiberglass mat is 200g / m 2 , the width is 1.2m, 30 layers of short-cut stitched glass fiber mat are impregnated with polyurethane stock solution through only one dipping box (same as in Example 1), the total injection flow rate of the polyurethane stock solution into the dipping box is 4.2kg / min, and the polyurethane stock solution is injected from the upper and lower surfaces of the dipping box through 8 injection ports at the same time;

[0078] Then sprinkle 300g / m 2 The aluminum hydroxide powder and the impregnated glass fiber felt were sent to a crawler press at 80°C for hot pressing at a speed of 0.6m / min, a gap of 12mm, and a pressure of 2MPa to obtain a high-strength, single-sided flame-retardant glass fiber reinforced polyurethane sheet with a density of 985kg / m 3 The mass percentage of glass fiber felt is about 50% and the thickness is 12mm.

[0079] Table 1 Test results of the plates prepared in Examples 1 to 3 and Comparative Examples 1 to 2

[0080] <![CDATA[Density kg / m 3 > Bending strength MPa Flexural modulus MPa Nail holding force N / mm Flame retardant Example 1 620 41 2425 80 Non-combustible surface Example 2 1000 79 4328 118 Non-combustible surface Example 3 570 45 2768 94 Non-combustible surface Comparative Example 1 615 40 2208 78 The surface is not flame retardant Comparative Example 2 985 65 3885 108 Non-combustible surface

[0081] Note: The test standard for flexural strength and flexural modulus is ASTMD790, and the test standard for nail holding force is GB 17657-2022.

[0082] It is not difficult to find from the above embodiments and comparative test results that the flame retardant effect of the board surface sprinkled with flame retardant powder is very good, and the board surface without flame retardant powder is not flame retardant; for the same percentage of glass fiber, using 2 dipping boxes to impregnate the polyurethane stock solution can improve the impregnation effect of the glass fiber felt, which can improve the strength and nail holding force of the board.

[0083] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a glass fiber reinforced polyurethane sheet, characterized in that: The following steps are involved: 1) N layers of short-cut stitched glass fiber mats are equally divided into two groups, laid out in sequence, and impregnated with polyurethane stock solution through two dipping boxes respectively to obtain impregnated glass fiber mats; The components of the polyurethane stock solution include material A and material B, the components of material A are 4110 polyether, water, silicone oil surfactant and polymerization inhibitor, and the mass ratio of 4110 polyether, water, silicone oil surfactant and polymerization inhibitor is 100:0.3:2.5:0.1; The B material is 44V20 isocyanate; The mass ratio of material A to material B is 1:1-1.3; The N layers are more than 2 layers; The surface density of the short-cut stitched glass fiber mat is 100-600 g / m 2 , door width is 0.6~1.25m; 2) Sprinkling a flame retardant on one surface of the impregnated glass fiber felt obtained in step 1) to obtain a glass fiber felt having a flame retardant on its surface; 3) subjecting the glass fiber felt with the flame retardant on the surface obtained in step 2) to a hot pressing curing treatment to obtain a glass fiber reinforced polyurethane sheet.

2. The preparation method according to claim 1, characterized in that: The speed at which the short-cut stitched glass fiber mat passes through the dipping box in step 1) is 0.3-0.6 m / min.

3. The preparation method according to claim 1, characterized in that: In the step 1), the total injection flow rate of the polyurethane stock solution into the dipping box is 1.2 to 4.2 kg / min; The polyurethane stock solution is injected from the upper and lower surfaces of the dipping box through 4 to 16 injection ports at the same time.

4. The preparation method according to claim 1, characterized in that: The amount of flame retardant sprinkled in step 2) is 200-300 g / m 2 .

5. The preparation method according to claim 1 or 4, characterized in that: The flame retardant includes aluminum hydroxide and / or magnesium hydroxide.

6. The preparation method according to claim 1, characterized in that: The conditions of the hot pressing curing treatment in step 3) include: a temperature of 50 to 80° C., a speed of 0.3 to 0.6 m / min, a pressure of more than 2 MPa, and a gap controlled at 8 to 30 mm.

7. A glass fiber reinforced polyurethane sheet prepared by the preparation method according to any one of claims 1 to 6, wherein the mass percentage of glass fiber in the glass fiber reinforced polyurethane sheet is 50-70%, the thickness is 8-30 mm, and the density is 500-1000 kg / m 3 .

8. Use of the glass fiber reinforced polyurethane sheet according to claim 7 in improving the bending strength and bending modulus of the sheet.

9. Use of the glass fiber reinforced polyurethane sheet as claimed in claim 7 to improve the nail holding force of the sheet.

Images