Halogen-free flame-retardant paper for archives and integrated preparation method thereof

Abstract

This invention discloses a halogen-free flame-retardant paper for archival use and its integrated preparation method. Through in-situ synthesis of flame retardants, compound modification, pulp addition + impregnation composite papermaking, and continuous deep processing of archival supplies, a complete integrated production chain is achieved, from chemical raw materials to finished archival equipment. The paper produced by this invention is halogen-free and low-smoke, has an oxygen index ≥30%, is acid-free and aging-resistant, does not shed dust, does not yellow, and is self-extinguishing upon removal from flame. It is suitable for archival storage in archives, government agencies, and enterprises. The product is registered under the trademark "Ji Lu" and has advantages such as high safety, long lifespan, low cost, environmental stability, and high brand recognition, making it widely applicable in the field of archival equipment manufacturing.

Description

I. Technical Field This invention relates to the fields of special papermaking technology, flame retardant material technology, and archival equipment materials. Specifically, it relates to an acid-free and halogen-free flame retardant paper for archives and an integrated preparation method of its chemical raw materials, flame retardants, papermaking, and archival supplies. The products produced are branded under the Jilu brand. II. Background Technology Currently, archival paper generally suffers from problems such as flammability and poor safety. Traditional flame-retardant paper is mostly produced by simply adding purchased flame retardants or by surface coating, which has defects such as easy migration of flame retardants, powdering, yellowing, poor aging resistance, and significant decrease in strength. At the same time, the production process is decentralized, making it impossible to achieve continuous and integrated production from chemical raw materials to finished archival supplies, resulting in high costs, poor quality stability, and great difficulty in environmental protection and safety management.

[0001] To address the aforementioned shortcomings, this invention provides a complete production chain integrating flame retardant synthesis, modification, pulping, impregnation and papermaking, and finished file box processing. This achieves a comprehensive performance improvement in file paper, including high flame retardancy, acid-free properties, durability, environmental friendliness, and low cost. The products are uniformly labeled with the Jilu trademark, forming a branded and standardized production process. III. Summary of the Invention 1. Purpose of the invention We provide a halogen-free, low-smoke, non-toxic, acid-free, and long-lasting flame-retardant paper for archives, and a set of industrially feasible integrated chemical-paper-archives preparation methods. The product is branded as Jilu and supplied to archives systems nationwide.

[0002] 2. Technical Solution (1) Raw material composition (by weight) 1. Pulp Components - Softwood pulp: 40-60 parts - Bamboo pulp or cotton pulp: 20-40 parts - Freeze degree controlled at: 35~45°SR 2. Composite flame retardant components - Ammonium polyphosphate (APP type II): 50 parts - Melamine: 25 parts - Pentaerythritol: 10 parts - Aluminum hydroxide: 8 parts - Zinc borate: 5 parts - Silane coupling agent KH-550: 2 parts 3. Papermaking additives components - Dispersant (sodium polyacrylate): 1.0 to 2.0 parts - Wet strength agent (PAE): 2.0–3.0 parts - Thickener (CMC): 0.5–1.0 parts - Retention aid (cationic starch): 1.0–1.5 parts - pH adjuster: Apply an appropriate amount to maintain the system pH between 7.0 and 8.5. (2) Integrated preparation method 1. In-situ synthesis and modification of flame retardants Phosphoric acid and urea were added to a reaction vessel at a molar ratio of 1:1.8; the temperature was raised to 160-180℃ and the reaction was maintained for 2.5-3 hours; after cooling, the mixture was pulverized to a finer mesh than 200 mesh to obtain ammonium polyphosphate intermediate; melamine, pentaerythritol, aluminum hydroxide, zinc borate and silane coupling agent KH-550 were added; the mixture was stirred and modified at 55-65℃ for 40 minutes to obtain composite flame retardant powder.

[0003] 2. Preparation of flame retardant liquid Composite flame retardant powder: 35 parts Deionized water: 60 parts Dispersant: 1.5 parts Thickener: 1.0 part Wet strength agent: 2.5 parts Stir at high speed for 60 minutes to prepare a flame retardant liquid with a solid content of 35% to 40%.

[0004] 3. In-pulp additive + impregnation composite papermaking process The pulp is de-beaten to 35-45°SR; flame retardant and retention aid are added and mixed thoroughly; the pulp is formed on the wire section and dewatered by pressing; it is then impregnated in the impregnation tank for 5-8 seconds; the pressure of the press rolls is controlled at 0.3-0.5 MPa; the pulp is dried in sections at a temperature of 110-130°C; and finally calendered, spun, and cut to obtain Jilu brand flame retardant base paper.

[0005] 4. Integrated deep processing of archival supplies Flame-retardant base paper is directly fed to the printing, die-cutting, and box-gluing production lines; finished products such as Jilu brand file boxes, file bags, scientific and technological file boxes, and personnel file boxes are made; realizing the integrated production of the entire chain from chemical raw materials to flame retardants to flame-retardant paper to archival supplies.

[0006] 5. Beneficial effects 6. The flame retardant is synthesized, compounded, and modified in situ in an integrated manner, without powdering, migration, or yellowing.

[0007] 7. The process of adding ingredients into the slurry and impregnating it results in uniform flame retardancy and high strength.

[0008] 8. Halogen-free phosphorus and nitrogen system, oxygen index (LOI) ≥ 30%, flame retardant rating B1, self-extinguishing upon removal of flame, and non-dripping.

[0009] 9. Acid-free pH 7.0–8.5, meeting the requirements for long-term preservation of archives.

[0010] 10. The entire supply chain from chemical processing to papermaking to archival supplies is under automated control, reducing production costs by 20% to 35% and ensuring stable quality.

[0011] 11. All products use the Jilu brand for easy market identification, quality traceability, and brand protection. IV. Detailed Implementation Example 1 - Softwood pulp: 50 parts - Bamboo pulp: 30 servings - Flame retardant synthesis temperature: 170℃ - Modification temperature: 60℃ - Flame retardant liquid-solid content: 37% - Soaking time: 6s - Drying temperature: 120℃ - Production speed: 20m / min - Brand logo: Jilu Performance results: Oxygen Index (LOI): 32% Flame retardant rating: GB 8624 B1 pH: 7.8 Halogen-free, low-smoke, non-toxic, self-extinguishing when removed from flame, and drip-free, it is suitable for long-term preservation of archives and is a high-end flame-retardant archive paper under the Jilu brand.

Claims

1. An integrated preparation method for halogen-free flame-retardant paper for archival use, characterized in that, Includes the following steps: (1) Ammonium polyphosphate is synthesized from phosphoric acid and urea as raw materials, and then compounded with melamine, pentaerythritol, aluminum hydroxide, zinc borate and silane coupling agent, and then modified by heating to obtain a composite flame retardant; (2) Prepare a flame retardant liquid by mixing the composite flame retardant with water, dispersant, wet strength agent and thickener; (3) After pulping, the pulp is mixed with flame retardant liquid, and then formed by pulp addition + impregnation composite process, dried, calendered and slit to obtain flame retardant paper; (4) Flame-retardant paper is directly used for printing, die-cutting, and gluing to form Jilu brand file boxes or file bags.

2. The method according to claim 1, characterized in that, The synthesis temperature of ammonium polyphosphate is 160–180℃, and the reaction time is 2.5–3 h; the modification temperature of the flame retardant is 55–65℃, and the time is 40 min.

3. The method according to claim 1, characterized in that, The flame retardant liquid-solid content is 35%–40%, the impregnation time is 5–8 seconds, and the drying temperature is 110–130°C.

4. The method according to claim 1, characterized in that, The pulp consists of 40-60 parts softwood pulp and 20-40 parts bamboo or cotton pulp, with a freeness of 35-45°SR and a pH of 7.0-8.

5.

5. A halogen-free flame-retardant paper for archival use, characterized in that, Prepared by any of the methods in claims 1 to 4, with an oxygen index (LOI) ≥ 30%, a flame retardant rating of B1, and being halogen-free, low-smoke, non-toxic, and acid-free, it is suitable for long-term preservation of archives. The product brand is Jilu.

6. An integrated production system for chemical, papermaking, and archival supplies, characterized in that, The system includes, in sequence, a flame retardant synthesis and modification unit, a pulping unit, an impregnation and papermaking unit, a drying and calendering unit, and a printing, die-cutting, and file box forming unit, achieving continuous closed-loop production and ultimately producing Jilu brand file storage equipment.