Environment-friendly fireproof flame-retardant paper and preparation method thereof

Abstract

The invention belongs to the technical field of environment-friendly paper materials, and provides environment-friendly fireproof flame-retardant paper and a preparation method thereof, and the environment-friendly fireproof flame-retardant paper is prepared from the following raw materials in parts by mass: 20-40 parts of alginate fiber, 50-80 parts of bamboo pulp fiber, 5-15 parts of a flame retardant, 2-5 parts of chitosan, 1-3 parts of nano silicon dioxide and 200-400 parts of water. The alginate fibers and the bamboo pulp fibers are used as main raw materials, and the phosphorus-nitrogen environment-friendly flame retardant and the modified magnesium hydroxide are compounded, so that the dual effects of natural flame retardance and chemical synergy are achieved; according to the invention, the flame retardant and the fibers are synchronously beaten, so that nonuniformity and agent waste caused by later-stage coating are avoided; the environment-friendly fireproof flame-retardant paper is prepared from environment-friendly materials, volatile organic compounds are not discharged in the whole process, the paper can be recycled and degraded, the binding force between modified magnesium hydroxide and fibers is high, and the physical performance of the paper can be further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmentally friendly paper materials, and in particular to environmentally friendly fire-retardant paper and a preparation method thereof. Background Art

[0002] Fireproof and flame-retardant paper is a special paper with fireproof and flame-retardant properties, which is widely used in packaging, construction, electronics and other fields. Traditional fireproof and flame-retardant paper usually uses halogen-containing (such as bromine, chlorine) or phosphate compounds (such as ammonium phosphate, borax, etc.). Although the flame retardant effect is good, it has the problems of poor environmental protection and easy residue. For example, when halogen flame retardants burn, they release toxic gases such as hydrogen chloride and hydrogen bromide, which seriously endanger human health and the environment. Although ceramic fiber paper is resistant to high temperatures, the raw material cost is high, the production energy consumption is large, and it is difficult to degrade after disposal, which does not meet environmental protection requirements; traditional plant fiber paper is impregnated or sprayed with flame retardants in the later stage. The process is complicated and may cause the mechanical properties of the paper to deteriorate. There is also the risk of chemical residues.

[0003] Therefore, developing a fire-retardant paper that is environmentally friendly, has good flame retardant effect and maintains good physical properties has become an urgent problem that the industry needs to solve. Summary of the Invention

[0004] The purpose of the present invention is to provide an environmentally friendly fireproof and flame-retardant paper and a preparation method thereof, to overcome the toxicity and environmental hazards of traditional chemical flame retardants, to achieve halogen-free and low-smoke flame-retardant paper, to optimize the process route, to reduce production energy consumption, and at the same time to ensure the mechanical strength and processing adaptability of the paper.

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

[0006] The present invention provides an environmentally friendly fireproof and flame-retardant paper, which is prepared from the following raw materials in parts by weight:

[0007] 20-40 parts of seaweed fiber, 50-80 parts of bamboo pulp fiber, 5-15 parts of flame retardant, 2-5 parts of chitosan, 1-3 parts of nano silicon dioxide and 200-400 parts of water.

[0008] Preferably, the flame retardant comprises ammonium polyphosphate and modified magnesium hydroxide;

[0009] The mass ratio of the ammonium polyphosphate to the modified magnesium hydroxide is 0.8-1:0.8-1.

[0010] Preferably, the modified magnesium hydroxide is magnesium hydroxide modified by a silane coupling agent, and the amount of the silane coupling agent added is 2 to 5% of the mass of the magnesium hydroxide;

[0011] The silane coupling agent is one or both of KH-550 and KH-560.

[0012] The present invention also provides a method for preparing environmentally friendly fire-retardant paper, comprising the following steps:

[0013] (1) mixing seaweed fiber, bamboo pulp fiber and water and beating the mixture to obtain slurry a;

[0014] (2) mixing slurry a with chitosan and nano-silica and continuing to beat to obtain slurry b;

[0015] (3) mixing the slurry b and the flame retardant, and adjusting the pH to obtain a slurry c;

[0016] (4) using an inclined wire paper machine to form the slurry c on the screen to form a wet paper sheet, and the wet paper sheet is sequentially dehydrated by pre-pressing and main pressing to obtain a semi-dry paper sheet;

[0017] (5) The semi-dried paper sheets are sequentially subjected to low-temperature drying and high-temperature drying to obtain the fire-proof and environmentally friendly flame-retardant paper.

[0018] Preferably, the beating speed in step (1) is 1200 to 1800 r / min, and the beating time is 25 to 35 min.

[0019] Preferably, the beating speed in step (2) is 1200-1800 r / min, and the beating time is 10-15 min.

[0020] Preferably, citric acid or sodium hydroxide is used to adjust the pH in step (3), and the pH is 6.5 to 7.0.

[0021] Preferably, the speed of surfing the Internet in step (4) is 10 to 15 m / min.

[0022] Preferably, the pre-pressing pressure in step (4) is 40-60 kPa, and the main pressing pressure is 180-220 kPa.

[0023] Preferably, the temperature of the low-temperature drying in step (5) is 80-100°C, and the temperature of the high-temperature drying is 120-140°C.

[0024] The present invention has the following beneficial effects:

[0025] (1) The present invention uses seaweed fiber and bamboo pulp fiber as main raw materials, compounded with phosphorus-nitrogen environmentally friendly flame retardants and modified magnesium hydroxide, to achieve the dual effects of natural flame retardancy and chemical synergy;

[0026] (2) The present invention simultaneously beats the flame retardant and the fiber to avoid unevenness and waste of reagents caused by later coating;

[0027] (3) The environmentally friendly fireproof and flame-retardant paper of the present invention is prepared using environmentally friendly materials, and no volatile organic compounds are emitted throughout the process. The paper is recyclable and degradable, and the modified magnesium hydroxide has a strong bonding force with the fiber, which can further improve the physical properties of the paper. DETAILED DESCRIPTION

[0028] The present invention provides an environmentally friendly fireproof and flame-retardant paper, which is prepared from the following raw materials in parts by weight:

[0029] 20-40 parts of seaweed fiber, 50-80 parts of bamboo pulp fiber, 5-15 parts of flame retardant, 2-5 parts of chitosan, 1-3 parts of nano silicon dioxide and 200-400 parts of water.

[0030] In the present invention, the mass fraction of the seaweed fiber is preferably 22 to 38 parts, more preferably 24 to 36 parts, and even more preferably 25 to 35 parts.

[0031] In the present invention, the weight percentage of the bamboo pulp fiber is preferably 53 to 77 parts, more preferably 56 to 74 parts, and even more preferably 60 to 70 parts.

[0032] In the present invention, the mass fraction of the flame retardant is preferably 6 to 14 parts, more preferably 7 to 13 parts, and even more preferably 8 to 12 parts.

[0033] In the present invention, the mass fraction of the chitosan is preferably 2.5 to 4.5 parts, more preferably 3 to 4 parts, and even more preferably 3.5 parts.

[0034] In the present invention, the mass fraction of the nano-silicon dioxide is preferably 1.2 to 2.8 parts, more preferably 1.4 to 2.6 parts, and even more preferably 1.6 to 2.8 parts.

[0035] In the present invention, the mass fraction of the water is preferably 220 to 380 parts, more preferably 240 to 360 parts, and even more preferably 260 to 340 parts.

[0036] In the present invention, the flame retardant preferably includes ammonium polyphosphate and modified magnesium hydroxide.

[0037] In the present invention, magnesium hydroxide is dispersed in ethanol, a silane coupling agent is added and mixed to react, and then the mixture is filtered and dried to obtain modified magnesium hydroxide.

[0038] In the present invention, the mass ratio of the ammonium polyphosphate to the modified magnesium hydroxide is preferably 0.8-1:0.8-1, more preferably 0.9-1:0.9-1, and even more preferably 1:1.

[0039] In the present invention, the modified magnesium hydroxide is magnesium hydroxide modified by a silane coupling agent, and the addition amount of the silane coupling agent is preferably 2-5% of the mass of the magnesium hydroxide, more preferably 2.5-4.5%, and even more preferably 3-4%.

[0040] In the present invention, the mass volume ratio of the magnesium hydroxide to ethanol is preferably 80-120 g:400-600 ml, more preferably 90-110 g:450-550 ml, and more preferably 100 g:500 ml.

[0041] In the present invention, the silane coupling agent is preferably one or both of KH-550 and KH-560.

[0042] In the present invention, the mixing temperature is preferably 50-60°C, more preferably 52-58°C, and even more preferably 54-56°C.

[0043] In the present invention, the mixing time is preferably 3 to 4.5 hours, more preferably 3.2 to 4.3 hours, and even more preferably 3.5 to 4 hours.

[0044] The present invention also provides a method for preparing environmentally friendly fire-retardant paper, comprising the following steps:

[0045] (1) mixing seaweed fiber, bamboo pulp fiber and water and beating the mixture to obtain slurry a;

[0046] (2) mixing slurry a with chitosan and nano-silica and continuing to beat to obtain slurry b;

[0047] (3) mixing the slurry b and the flame retardant, and adjusting the pH to obtain a slurry c;

[0048] (4) using an inclined wire paper machine to form the slurry c on the screen to form a wet paper sheet, and the wet paper sheet is sequentially dehydrated by pre-pressing and main pressing to obtain a semi-dry paper sheet;

[0049] (5) The semi-dried paper sheets are sequentially subjected to low-temperature drying and high-temperature drying to obtain the fire-proof and environmentally friendly flame-retardant paper.

[0050] In the present invention, the seaweed fiber is preferably pretreated: the seaweed fiber is cut into 5-10 mm segments and soaked in water for 20-24 hours to remove impurities and water-soluble salts.

[0051] In the present invention, the beating degree of the bamboo pulp fiber in step (1) is preferably controlled at 30-40°SR.

[0052] In the present invention, the beating speed in step (1) is preferably 1200 to 1800 r / min, more preferably 1300 to 1700 r / min, and even more preferably 1400 to 1600 r / min.

[0053] In the present invention, the beating time is preferably 25 to 35 minutes, more preferably 26 to 34 minutes, and even more preferably 27 to 33 minutes.

[0054] In the present invention, the beating speed in step (2) is 1200-1800 r / min, more preferably 1300-1700 r / min, and even more preferably 1400-1600 r / min.

[0055] In the present invention, the beating time is preferably 10 to 15 minutes, more preferably 11 to 14 minutes, and even more preferably 12 to 13 minutes.

[0056] In the present invention, citric acid or sodium hydroxide is used to adjust the pH in step (3), and the pH is preferably 6.5 to 7.0.

[0057] In the present invention, the speed of surfing in step (4) is preferably 10 to 15 m / min, more preferably 11 to 14 m / min, and even more preferably 12 to 13 m / min.

[0058] In the present invention, the pre-pressing pressure in step (4) is preferably 40 to 60 kPa, more preferably 42 to 58 kPa, and even more preferably 45 to 55 kPa.

[0059] In the present invention, the main pressing pressure is preferably 180 to 220 kPa, more preferably 185 to 215 kPa, and even more preferably 190 to 210 kPa.

[0060] In the present invention, the dryness of the semi-dry paper in step (4) is preferably 40-50%, more preferably 42-48%, and even more preferably 44-46%.

[0061] In the present invention, circulating hot air is introduced during the drying process in step (5), which can reduce energy consumption.

[0062] In the present invention, the temperature of the low-temperature drying in step (5) is preferably 80-100°C, more preferably 82-98°C, and even more preferably 85-95°C.

[0063] In the present invention, the dryness of the paper sheet after low-temperature drying is controlled between 80% and 85%.

[0064] In the present invention, the high-temperature drying temperature is preferably 120 to 140°C, more preferably 122 to 138°C, and even more preferably 125 to 135°C.

[0065] In the present invention, the dryness of the paper sheet after high-temperature drying is ≥93%.

[0066] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0067] Example 1

[0068] 30 parts by mass of seaweed fiber were cut into small segments of 8 mm, soaked in water for 24 h to remove impurities and water-soluble salts, and then mixed with 60 parts by mass of bamboo pulp fiber with a beating degree of 30°SR and 300 parts by mass of water, and beaten at a speed of 1500 r / min for 30 min to obtain slurry a. Keeping the speed unchanged, slurry a was mixed with 3 parts by mass of chitosan and 2 parts by mass of nano-silica and continued to be beaten for 12 min to obtain slurry b; slurry b was mixed with 5 parts by mass of ammonium polyphosphate and 5 parts by mass of modified magnesium hydroxide, stirred at a rate of 800 r / min for 20 min, and the pH was adjusted to 6.8 with citric acid to obtain slurry c. An inclined wire paper machine is used to put the slurry c on the wire at a speed of 12 m / min to form a wet paper sheet. The wet paper sheet is dehydrated in sequence by pre-pressing (pressure 50 kPa) and main pressing (pressure 200 kPa) to obtain a semi-dry paper sheet with a dryness of 45%. The wet paper sheet is then dried at a low temperature of 90°C and a high temperature of 130°C to obtain an environmentally friendly fire-retardant paper with a dryness of 95%.

[0069] Example 2

[0070] 20 parts by mass of seaweed fiber were cut into small segments of 5 mm, soaked in water for 20 hours to remove impurities and water-soluble salts, and then mixed with 50 parts by mass of bamboo pulp fiber with a beating degree of 30°SR and 200 parts by mass of water, and beaten at a speed of 1200 r / min for 25 minutes to obtain slurry a. Keeping the speed unchanged, slurry a was mixed with 2 parts by mass of chitosan and 1 part by mass of nano-silica and continued to be beaten for 10 minutes to obtain slurry b; slurry b was mixed with 2.5 parts by mass of ammonium polyphosphate and 2.5 parts by mass of modified magnesium hydroxide, stirred at a rate of 500 r / min for 10 minutes, and the pH was adjusted to 6.5 with citric acid to obtain slurry c. An inclined wire paper machine is used to put the slurry c on the wire at a speed of 10 m / min to form a wet paper sheet. The wet paper sheet is dehydrated in sequence by pre-pressing (pressure 50 kPa) and main pressing (pressure 200 kPa) to obtain a semi-dry paper sheet with a dryness of 42%. The wet paper sheet is then dried at a low temperature of 80°C and at a high temperature of 120°C to obtain an environmentally friendly fire-retardant paper with a dryness of 94%.

[0071] Example 3

[0072] 40 parts by mass of seaweed fiber were cut into small segments of 10 mm, soaked in water for 24 h to remove impurities and water-soluble salts, and then mixed with 80 parts by mass of bamboo pulp fiber with a beating degree of 40°SR and 400 parts by mass of water, and beaten at a speed of 1800 r / min for 35 min to obtain slurry a. Keeping the speed unchanged, slurry a was mixed with 5 parts by mass of chitosan and 3 parts by mass of nano-silica and continued to be beaten for 15 min to obtain slurry b; slurry b was mixed with 7.5 parts by mass of ammonium polyphosphate and 7.5 parts by mass of modified magnesium hydroxide, stirred at a rate of 800 r / min for 20 min, and the pH was adjusted to 7.0 with citric acid to obtain slurry c. A slant-wire paper machine is used to form the slurry c by putting it on the wire at a speed of 15 m / min to form wet paper sheets. The wet paper sheets are dehydrated in sequence by pre-pressing (pressure 50 kPa) and main pressing (pressure 200 kPa) to obtain semi-dry paper sheets with a dryness of 49%. The wet paper sheets are then dried at low temperature of 100°C and high temperature of 140°C to obtain environmentally friendly fire-retardant paper with a dryness of 98%.

[0073] As can be seen from the above examples, the present invention provides an environmentally friendly fireproof and flame-retardant paper and a preparation method thereof, which is prepared from the following raw materials in parts by weight: 20-40 parts seaweed fiber, 50-80 parts bamboo pulp fiber, 5-15 parts flame retardant, 2-5 parts chitosan, 1-3 parts nano-silicon dioxide, and 200-400 parts water. The present invention uses seaweed fiber and bamboo pulp fiber as the main raw materials, compounding a phosphorus-nitrogen environmentally friendly flame retardant and modified magnesium hydroxide to achieve the dual effects of natural flame retardancy and chemical synergy; the present invention simultaneously beats the flame retardant and fiber to avoid unevenness and waste of reagents caused by later coating; the environmentally friendly fireproof and flame-retardant paper of the present invention is prepared using environmentally friendly materials, has no volatile organic compound emissions throughout the process, and the paper is recyclable and degradable. The modified magnesium hydroxide has a strong bond with the fiber, which can further improve the physical properties of the paper.

[0074] 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 principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An environmentally friendly fire-retardant paper, characterized in that: The invention is prepared by comprising the following raw materials in parts by weight: 20-40 parts of seaweed fiber, 50-80 parts of bamboo pulp fiber, 5-15 parts of flame retardant, 2-5 parts of chitosan, 1-3 parts of nano silicon dioxide and 200-400 parts of water.

2. The environmentally friendly fire-retardant paper according to claim 1, characterized in that: The flame retardant includes ammonium polyphosphate and modified magnesium hydroxide; The mass ratio of the ammonium polyphosphate to the modified magnesium hydroxide is 0.8-1:0.8-1.

3. The environmentally friendly fire-retardant paper according to claim 2, characterized in that: The modified magnesium hydroxide is magnesium hydroxide modified by a silane coupling agent, and the amount of the silane coupling agent added is 2 to 5% of the mass of the magnesium hydroxide; The silane coupling agent is one or both of KH-550 and KH-560.

4. A method for preparing the environmentally friendly fire-retardant paper according to claims 1 to 3, characterized in that: The following steps are involved: (1) mixing seaweed fiber, bamboo pulp fiber and water and beating the mixture to obtain slurry a; (2) mixing slurry a with chitosan and nano-silica and continuing to beat to obtain slurry b; (3) mixing the slurry b and the flame retardant, and adjusting the pH to obtain a slurry c; (4) using an inclined wire paper machine to form the slurry c on the screen to form a wet paper sheet, and the wet paper sheet is sequentially dehydrated by pre-pressing and main pressing to obtain a semi-dry paper sheet; (5) The semi-dried paper sheets are sequentially subjected to low-temperature drying and high-temperature drying to obtain the fire-proof and environmentally friendly flame-retardant paper.

5. The preparation method according to claim 4, characterized in that The beating speed in the step (1) is 1200-1800 r / min, and the beating time is 25-35 min.

6. The preparation method according to claim 4, characterized in that The beating speed in the step (2) is 1200-1800 r / min, and the beating time is 10-15 min.

7. The preparation method according to claim 4, characterized in that In the step (3), citric acid or sodium hydroxide is used to adjust the pH, and the pH is 6.5 to 7.

0.

8. The preparation method according to claim 4, characterized in that The speed of surfing the Internet in step (4) is 10-15 m / min.

9. The preparation method according to claim 4, characterized in that The pre-pressing pressure in step (4) is 40-60 kPa, and the main pressing pressure is 180-220 kPa.

10. The preparation method according to claim 4, characterized in that The temperature of the low-temperature drying in step (5) is 80-100°C, and the temperature of the high-temperature drying is 120-140°C.