Flame retardant impregnated paper and production process thereof

Abstract

The present invention relates to the technical field of impregnated paper and proposes a flame-retardant impregnated paper and its production process. The flame-retardant impregnated paper comprises, from bottom to top, a base paper layer, a flame-retardant layer, and a protective layer. The flame-retardant layer comprises the following components in parts by weight: 20-30 parts of a first polyurethane-modified epoxy resin, 2-4 parts of a flame retardant, 1-2 parts of a plasticizer, 0.02-0.05 parts of a curing agent, and 1-2 parts of a dispersant. The protective layer comprises the following components in parts by weight: 20-30 parts of a second polyurethane-modified epoxy resin, 2-4 parts of zinc borate, 2-3 parts of a plasticizer, and 0.02-0.05 parts of a curing agent. The epoxy equivalent weight of the first polyurethane-modified epoxy resin is greater than that of the second polyurethane-modified epoxy resin. This technical solution solves the problem of poor flame retardancy in impregnated paper in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of impregnated paper, and in particular to flame-retardant impregnated paper and a production process thereof. Background Art

[0002] Impregnated paper, also known as impregnated paper, is made by impregnating specialized paper with resin and then drying it. It's widely used in veneer panels to improve their surface quality. However, as a flammable material, impregnated paper poses safety risks. Therefore, developing an impregnated paper with excellent flame retardancy not only extends its service life but also significantly reduces potential safety hazards and property damage. Summary of the Invention

[0003] The present invention provides a flame retardant impregnated paper and a production process thereof, which solves the problem of poor flame retardancy of impregnated paper in the related art.

[0004] The technical solutions of the present invention are as follows:

[0005] The present invention provides a flame retardant impregnated paper, which comprises, from bottom to top, a base paper layer, a flame retardant layer, and a protective layer;

[0006] The flame retardant layer comprises the following components in parts by weight: 20-30 parts of a first polyurethane modified epoxy resin, 2-4 parts of a flame retardant, 1-2 parts of a plasticizer, 0.02-0.05 parts of a curing agent, and 1-2 parts of a dispersant;

[0007] The protective layer comprises the following components in parts by weight: 20-30 parts of a second polyurethane-modified epoxy resin, 2-4 parts of zinc borate, 2-3 parts of a plasticizer, and 0.02-0.05 parts of a curing agent;

[0008] The epoxy equivalent of the first polyurethane-modified epoxy resin is greater than the epoxy equivalent of the second polyurethane-modified epoxy resin.

[0009] As a further technical solution, the epoxy equivalent of the first polyurethane-modified epoxy resin is 310-330 g / eq.

[0010] As a further technical solution, the epoxy equivalent of the second polyurethane-modified epoxy resin is 235~270g / eq.

[0011] As a further technical solution, the flame retardant has a core-shell structure, the shell layer components include ammonium polyphosphate, and the core layer components include zinc borate, calcium hydroxide and polyvinyl chloride.

[0012] As a further technical solution, the mass ratio of the ammonium polyphosphate, zinc borate and calcium hydroxide is 2:2~5:1; the mass ratio of the polyvinyl chloride and zinc borate is 2:1~2.

[0013] As a further technical solution, the method for preparing the flame retardant comprises the following steps:

[0014] A1. Mix zinc borate, calcium hydroxide and polyvinyl chloride and granulate to obtain a core layer of flame retardant;

[0015] A2, dispersing ammonium polyphosphate in a polyethylene glycol aqueous solution to obtain a flame retardant shell solution;

[0016] A3. Mixing the core layer solution of the flame retardant and the shell layer solution of the flame retardant, and drying them to obtain a flame retardant.

[0017] As a further technical solution, the curing agent is an amine curing agent; and the dispersant is one or more of BYK-191, BYK-161, and BYK-110.

[0018] As a further technical solution, the plasticizer is one of dioctyl phthalate and diisononyl phthalate.

[0019] As a further technical solution, in step A2, the mass fraction of the polyethylene glycol aqueous solution is 5% to 8%.

[0020] The present invention also provides a production process for the flame retardant impregnated paper, comprising the following steps:

[0021] S1, mixing the components of the flame retardant layer, coating the mixture on the upper surface of the base paper layer, and drying the mixture to obtain a first impregnated paper;

[0022] S2. Mix the components of the protective layer, apply the mixture to the upper surface of the first impregnated paper, and dry the mixture to obtain a flame-retardant impregnated paper.

[0023] As a further technical solution, the coating amount during coating is 10~15g / m 2 .

[0024] The working principle and beneficial effects of the present invention are:

[0025] 1. In the present invention, by using polyurethane-modified epoxy resins with different epoxy equivalents in the flame retardant layer and the protective layer, the dispersion of the flame retardant in the matrix and the interlayer bonding strength are improved, thereby significantly improving the flame retardant properties of the impregnated paper.

[0026] 2. In the present invention, when the epoxy equivalent of the polyurethane-modified epoxy resin in the flame-retardant layer is 310-330 g / eq. and the epoxy equivalent of the polyurethane-modified epoxy resin in the protective layer is 235-270 g / eq., the interlayer bonding degree and the dispersion of the flame retardant in the matrix are better, further improving the flame retardant properties of the impregnated paper.

[0027] 3. In the present invention, a core-shell structured flame retardant is prepared, wherein the shell component is ammonium polyphosphate, and the core component includes zinc borate, calcium hydroxide and polyvinyl chloride, which synergistically reduce the internal heat of the impregnated paper during combustion, thereby further improving the flame retardant properties of the impregnated paper. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0029] In the following examples and comparative examples, the epoxy equivalent weight of the polyurethane-modified epoxy resin DER852 is 310-330 g / eq.; the epoxy equivalent weight of the polyurethane-modified epoxy resin DER791 is 235-270 g / eq.; the epoxy equivalent weight of the polyurethane-modified epoxy resin DER858 is 380-420 g / eq.; the aromatic amine curing agent is M-60; the particle size of ammonium polyphosphate is 200 mesh and the molecular weight is 115.0; the particle size of zinc borate is 1500 mesh; the particle size of calcium hydroxide is 150 mesh; the model of polyvinyl chloride is S-800; and the weight-average molecular weight of polyethylene glycol is 3500-4400.

[0030] Example 1

[0031] A flame retardant impregnated paper, comprising, from bottom to top, a base paper layer, a flame retardant layer, and a protective layer;

[0032] The flame retardant layer includes the following components in parts by weight: 20 parts of polyurethane modified epoxy resin DER858, 1 part of ammonium polyphosphate, 0.5 parts of zinc borate, 0.5 parts of calcium hydroxide, 1 part of dioctyl phthalate, 0.02 parts of aromatic amine curing agent, and 1 part of dispersant BYK-191;

[0033] The protective layer comprises the following components in parts by weight: 20 parts of polyurethane modified epoxy resin DER858, 2 parts of zinc borate, 2 parts of dioctyl phthalate, and 0.02 parts of aromatic amine curing agent;

[0034] The production process of flame retardant impregnated paper includes the following steps:

[0035] S1, after mixing the components of the flame retardant layer, 2 coating the upper surface of the base paper layer and drying to obtain the first impregnated paper;

[0036] S2, after mixing the components of the protective layer, 2 The flame retardant impregnated paper is coated on the upper surface of the first impregnated paper and dried to obtain the flame retardant impregnated paper.

[0037] Example 2

[0038] A flame retardant impregnated paper, comprising, from bottom to top, a base paper layer, a flame retardant layer, and a protective layer;

[0039] The flame retardant layer includes the following components in parts by weight: 25 parts of polyurethane modified epoxy resin DER858, 1.5 parts of ammonium polyphosphate, 0.75 parts of zinc borate, 0.75 parts of calcium hydroxide, 1.5 parts of dioctyl phthalate, 0.04 parts of aromatic amine curing agent, and 1.5 parts of dispersant BYK-110;

[0040] The protective layer comprises the following components in parts by weight: 25 parts of polyurethane modified epoxy resin DER858, 3 parts of zinc borate, 2.5 parts of diisononyl phthalate, and 0.03 parts of aromatic amine curing agent;

[0041] The production process of flame retardant impregnated paper includes the following steps:

[0042] S1, after mixing the components of the flame retardant layer, 2 coating the upper surface of the base paper layer and drying to obtain the first impregnated paper;

[0043] S2, after mixing the components of the protective layer, 2 The flame retardant impregnated paper is coated on the upper surface of the first impregnated paper and dried to obtain the flame retardant impregnated paper.

[0044] Example 3

[0045] A flame retardant impregnated paper, comprising, from bottom to top, a base paper layer, a flame retardant layer, and a protective layer;

[0046] The flame retardant layer includes the following components in parts by weight: 30 parts of polyurethane modified epoxy resin DER858, 2 parts of ammonium polyphosphate, 1 part of zinc borate, 1 part of calcium hydroxide, 2 parts of diisononyl phthalate, 0.05 parts of aromatic amine curing agent, 1 part of dispersant BYK-191, and 1 part of dispersant BYK-161;

[0047] The protective layer comprises the following components in parts by weight: 30 parts of polyurethane modified epoxy resin DER858, 4 parts of zinc borate, 3 parts of diisononyl phthalate, and 0.05 parts of aromatic amine curing agent;

[0048] The production process of flame retardant impregnated paper includes the following steps:

[0049] S1, after mixing the components of the flame retardant layer, 2 coating the upper surface of the base paper layer and drying to obtain the first impregnated paper;

[0050] S2, after mixing the components of the protective layer,2 The flame retardant impregnated paper is coated on the upper surface of the first impregnated paper and dried to obtain the flame retardant impregnated paper.

[0051] Example 4

[0052] The only difference between this embodiment and embodiment 3 is that the component of the flame retardant layer, polyurethane modified epoxy resin DER858, is replaced with polyurethane modified epoxy resin DER791.

[0053] Example 5

[0054] The only difference between this embodiment and embodiment 3 is that the component of the protective layer, polyurethane-modified epoxy resin DER858, is replaced with polyurethane-modified epoxy resin DER852.

[0055] Example 6

[0056] The only difference between this embodiment and embodiment 3 is that the component of the protective layer, polyurethane-modified epoxy resin DER858, is replaced with polyurethane-modified epoxy resin DER791.

[0057] Example 7

[0058] The only difference between this embodiment and embodiment 6 is that the component of the flame retardant layer, polyurethane-modified epoxy resin DER858, is replaced with polyurethane-modified epoxy resin DER852.

[0059] Example 8

[0060] The only difference between this embodiment and embodiment 7 is that the ammonium polyphosphate, zinc borate and calcium hydroxide in the flame retardant layer are prepared into a core-shell structure flame retardant in which the shell layer component includes ammonium polyphosphate and the core layer component includes zinc borate, calcium hydroxide and polyvinyl chloride. The preparation method of the flame retardant comprises the following steps:

[0061] A1. Mix 1 part zinc borate, 1 part calcium hydroxide and 2 parts polyvinyl chloride and granulate to obtain a core layer of flame retardant;

[0062] A2. Disperse 2 parts of ammonium polyphosphate in a 5% by mass polyethylene glycol aqueous solution to obtain a flame retardant shell solution;

[0063] A3. Mixing the core layer solution of the flame retardant and the shell layer solution of the flame retardant, and drying them to obtain a flame retardant.

[0064] Example 9

[0065] The only difference between this embodiment and embodiment 8 is the preparation method of the flame retardant, which includes the following steps:

[0066] A1. Mix 2.8 parts of zinc borate, 0.4 parts of calcium hydroxide and 5.6 parts of polyvinyl chloride and granulate to obtain a core layer of flame retardant;

[0067] A2. Disperse 2.8 parts of ammonium polyphosphate in a 5% by mass polyethylene glycol aqueous solution to obtain a flame retardant shell solution;

[0068] A3. Mixing the core layer solution of the flame retardant and the shell layer solution of the flame retardant, and drying them to obtain a flame retardant.

[0069] Example 10

[0070] The only difference between this embodiment and embodiment 8 is the preparation method of the flame retardant, which includes the following steps:

[0071] A1. Mix 1.6 parts of zinc borate, 0.8 parts of calcium hydroxide and 3.2 parts of polyvinyl chloride and granulate to obtain a core layer of flame retardant;

[0072] A2. Disperse 1.6 parts of ammonium polyphosphate in a 5% by mass polyethylene glycol aqueous solution to obtain a flame retardant shell solution;

[0073] A3. Mixing the core layer solution of the flame retardant and the shell layer solution of the flame retardant, and drying them to obtain a flame retardant.

[0074] Example 11

[0075] The only difference between this embodiment and embodiment 8 is the preparation method of the flame retardant, which includes the following steps:

[0076] A1. Mix 2.5 parts of zinc borate, 0.5 parts of calcium hydroxide and 5 parts of polyvinyl chloride, and granulate to obtain a core layer of flame retardant;

[0077] A2. Disperse 1 part of ammonium polyphosphate in a 5% by mass polyethylene glycol aqueous solution to obtain a flame retardant shell solution;

[0078] A3. Mixing the core layer solution of the flame retardant and the shell layer solution of the flame retardant, and drying them to obtain a flame retardant.

[0079] Example 12

[0080] The only difference between this embodiment and embodiment 8 is the preparation method of the flame retardant, which includes the following steps:

[0081] A1. Mix 2.5 parts of zinc borate, 0.5 parts of calcium hydroxide and 2.5 parts of polyvinyl chloride and granulate to obtain a core layer of flame retardant;

[0082] A2. Disperse 1 part of ammonium polyphosphate in an 8% by mass polyethylene glycol aqueous solution to obtain a flame retardant shell solution;

[0083] A3. Mixing the core layer solution of the flame retardant and the shell layer solution of the flame retardant, and drying them to obtain a flame retardant.

[0084] Comparative Example 1

[0085] The only difference between this comparative example and Example 3 is that the flame retardant impregnated paper comprises, from bottom to top, a base paper layer and a protective layer;

[0086] The protective layer comprises the following components in parts by weight: 30 parts of polyurethane modified epoxy resin DER858, 4 parts of zinc borate, 3 parts of diisononyl phthalate, and 0.05 parts of aromatic amine curing agent;

[0087] The production process of flame retardant impregnated paper includes the following steps:

[0088] The components of the protective layer are mixed, coated on the upper surface of the base paper layer, and dried to obtain the flame retardant impregnated paper.

[0089] Comparative Example 2

[0090] The only difference between this comparative example and Example 3 is that the flame retardant impregnated paper comprises, from bottom to top, a base paper layer and a flame retardant layer;

[0091] The flame retardant layer includes the following components in parts by weight: 30 parts of polyurethane modified epoxy resin DER858, 2 parts of ammonium polyphosphate, 1 part of zinc borate, 1 part of calcium hydroxide, 2 parts of diisononyl phthalate, 0.05 parts of aromatic amine curing agent, 1 part of dispersant BYK-191, and 1 part of dispersant BYK-161;

[0092] The production process of flame retardant impregnated paper includes the following steps:

[0093] The components of the flame retardant layer are mixed, coated on the upper surface of the base paper layer, and dried to obtain the flame retardant impregnated paper.

[0094] The flame retardant impregnated papers prepared in Examples 1 to 12 and Comparative Examples 1 to 2 were tested for heat release rate according to the CAN ULC-S135 standard. The test results are shown in the following table:

[0095]

[0096] By comparing the data of Examples 1 to 12 and Comparative Examples 1 to 2, it was found that the heat release rate of the impregnated paper prepared in Examples 1 to 12 was lower than that in Comparative Examples 1 to 2, indicating that the flame retardant properties of the impregnated paper can be significantly improved by using polyurethane-modified epoxy resins with different epoxy equivalents in the flame retardant layer and the protective layer to improve the dispersion of the flame retardant in the matrix and the interlayer bonding strength.

[0097] By comparing the data of Examples 3 to 7, it was found that the heat release rate of the impregnated paper prepared in Example 7 was lower than that of Examples 3 to 6, indicating that when the epoxy equivalent of the polyurethane-modified epoxy resin in the flame-retardant layer was 310 to 330 g / eq. and the epoxy equivalent of the polyurethane-modified epoxy resin in the protective layer was 235 to 270 g / eq., the interlayer bonding degree and the dispersion of the flame retardant in the matrix were better, further improving the flame retardant properties of the impregnated paper.

[0098] By comparing the data of Examples 7 to 12, it was found that compared with Examples 7 to 9, the heat release rate of the impregnated paper prepared in Examples 10 to 12 was lower, indicating that the preparation of the core-shell structure flame retardant, the shell component ammonium polyphosphate, and the core layer components including zinc borate, calcium hydroxide and polyvinyl chloride synergistically reduced the internal heat of the impregnated paper during combustion, thereby further improving the flame retardant properties of the impregnated paper.

[0099] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A flame retardant impregnated paper, characterized in that: From bottom to top, it includes base paper layer, flame retardant layer and protective layer; The flame retardant layer comprises the following components in parts by weight: 20-30 parts of a first polyurethane modified epoxy resin, 2-4 parts of a flame retardant, 1-2 parts of a plasticizer, 0.02-0.05 parts of a curing agent, and 1-2 parts of a dispersant; The protective layer comprises the following components in parts by weight: 20-30 parts of a second polyurethane-modified epoxy resin, 2-4 parts of zinc borate, 2-3 parts of a plasticizer, and 0.02-0.05 parts of a curing agent; The epoxy equivalent of the first polyurethane-modified epoxy resin is greater than the epoxy equivalent of the second polyurethane-modified epoxy resin.

2. The flame retardant impregnated paper according to claim 1, characterized in that: The epoxy equivalent of the first polyurethane-modified epoxy resin is 310-330 g / eq.

3. The flame retardant impregnated paper according to claim 1, characterized in that: The epoxy equivalent of the second polyurethane-modified epoxy resin is 235-270 g / eq.

4. The flame retardant impregnated paper according to claim 1, characterized in that: The flame retardant has a core-shell structure, wherein the shell layer components include ammonium polyphosphate, and the core layer components include zinc borate, calcium hydroxide and polyvinyl chloride.

5. The flame retardant impregnated paper according to claim 4, characterized in that: The mass ratio of the ammonium polyphosphate, zinc borate and calcium hydroxide is 2:2-5:1; the mass ratio of the polyvinyl chloride and zinc borate is 2:1-2.

6. The flame retardant impregnated paper according to claim 4, characterized in that: The preparation method of the flame retardant comprises the following steps: A1. Mix zinc borate, calcium hydroxide and polyvinyl chloride and granulate to obtain a core layer of flame retardant; A2, dispersing ammonium polyphosphate in a polyethylene glycol aqueous solution to obtain a flame retardant shell solution; A3. Mixing the core layer solution of the flame retardant and the shell layer solution of the flame retardant, and drying them to obtain a flame retardant.

7. The flame retardant impregnated paper according to claim 1, characterized in that: The curing agent is an amine curing agent; the dispersant is one or more of BYK-191, BYK-161, and BYK-110.

8. The flame retardant impregnated paper according to claim 1, characterized in that: The plasticizer is one of dioctyl phthalate and diisononyl phthalate.

9. The flame retardant impregnated paper according to claim 6, characterized in that: In step A2, the mass fraction of the polyethylene glycol aqueous solution is 5% to 8%.

10. The process for producing flame retardant impregnated paper according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, mixing the components of the flame retardant layer, coating the mixture on the upper surface of the base paper layer, and drying the mixture to obtain a first impregnated paper; S2. Mix the components of the protective layer, apply the mixture to the upper surface of the first impregnated paper, and dry the mixture to obtain a flame-retardant impregnated paper.

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