阅读说明：本技术 一种装饰原纸的制备方法 (Preparation method of decorative base paper ) 是由 周晓光 骆华英 丁威 黄学英 于振中 刘强利 于 2020-05-26 设计创作，主要内容包括：本发明公开了一种装饰原纸的制备方法,包括如下步骤：(1)打浆；(2)制备填料分散液；(3)制浆：将填料分散液与浆料混合,并加入阳离子松香胶、硫酸铝、PAM干强剂和脱气剂；(4)抄造；(5)压榨和前干燥；(6)涂布：涂布液以重量份计原料包括：30~50份填料,10~20份聚乙烯醇,5~10份阳离子淀粉,0.3~0.5份十二烷基二胺盐酸盐,0.1~0.3份消泡剂,0.1~0.3份甘油,70~80份水；其中填料为SrTiO<Sub>3</Sub>改性纳米TiO<Sub>2</Sub>；(7)干燥和压光。本发明采用SrTiO<Sub>3</Sub>改性纳米TiO<Sub>2</Sub>作为填料,在保证装饰原纸使用性能的同时,使填料具有对甲醛的光催化性能,降低浸胶后的甲醛释放量。(The invention discloses a preparation method of decorative base paper, which comprises the following steps: (1) pulping; (2) preparing a filler dispersion; (3) pulping: mixing the filler dispersion liquid with the slurry, and adding the cationic rosin size, aluminum sulfate, PAM dry strength agent and degassing agent; (4) manufacturing paper with pulp; (5) squeezing and pre-drying; (6) coating: the coating liquid comprises the following raw materials in parts by weight: 30-50 parts of filler, 10-20 parts of polyvinyl alcohol, 5-10 parts of cationic starch, 0.3-0.5 part of dodecyl diamine hydrochloride, 0.1-0.3 part of defoaming agent, 0.1-0.3 part of glycerol and 70-80 parts of water; wherein the filler is SrTiO 3 Modified nano TiO 2 (ii) a (7) Drying and calendering. The invention adopts SrTiO 3 Modified nano TiO 2 As the filler, the use performance of the decorative base paper is ensured, and meanwhile, the filler has the photocatalytic performance on formaldehyde, so that the formaldehyde emission after gum dipping is reduced.)

1. The preparation method of the decorative base paper is characterized by comprising the following steps:

(1) pulping: pulping and then preparing pulp to obtain pulp;

(2) preparing a filler dispersion liquid: adding the filler into a dodecyl diamine hydrochloride solution, and uniformly stirring to obtain a filler dispersion liquid;

(3) pulping: mixing the filler dispersion liquid with the slurry, adding the cationic rosin size, aluminum sulfate, PAM dry strength agent and degassing agent, and uniformly stirring to obtain mixed slurry;

(4) manufacturing paper: screening the mixed pulp on a net to make wet paper sheets;

(5) pressing and pre-drying: squeezing and pre-drying the wet paper sheet to obtain a pre-dried paper sheet;

(6) coating: coating the paper sheet after the previous drying with a coating liquid, wherein the coating liquid comprises the following raw materials in parts by weight: 30-50 parts of filler, 10-20 parts of polyvinyl alcohol, 5-10 parts of cationic starch, 0.3-0.5 part of dodecyl diamine hydrochloride, 0.1-0.3 part of defoaming agent, 0.1-0.3 part of glycerol and 70-80 parts of water; the filler in the step (2) and the step (6) is SrTiO₃Modified nano TiO₂；

(7) Drying and calendering: and drying and calendaring the coated paper to obtain the decorative base paper.

2. The method of claim 1, wherein the SrTiO is used in the steps (2) and (6)₃Modified nano TiO₂The preparation method of the filler comprises the following steps:

a) mixing TiCl₄Dripping the mixture into 30-36% hydrochloric acid to obtain TiCl₄Hydrochloric acid solution, TiCl₄The volume ratio of the hydrochloric acid to the hydrochloric acid is 1: (10-15);

b) mixing TiCl₄Hydrochloric acid solution and SrCl₂And AgNO₃Mixing the aqueous solutions of (a) to obtain a mixed solution, wherein TiCl is contained in the mixed solution₄、SrCl₂And AgNO₃In a molar ratio of 1: (0.8-0.9): (0.1 to 0.2);

c) mixing nanometer TiO₂Adding into the mixed solution, stirring to obtain dispersion, and adding into nanometer TiO₂With TiCl₄The molar ratio of (2-4): 1;

d) dropping NaOH and Na into the dispersion liquid under stirring₂CO₃The mixed precipitant is stirred to react for 30-60 min until the pH value is 9-9.5, and then the mixed precipitant is filtered, and the precipitate is treated by NaHCO with the pH value of 7-8₃Cleaning the solution and deionized water, drying at 60-70 ℃ to obtain a precursor, and adding NaOH and Na in the mixed precipitator₂CO₃The molar ratio of (2-3) to (1);

e) and calcining the precursor at 900-950 ℃ for 4-6 h to obtain the filler.

3. A decorative element according to claim 2The preparation method of the paper is characterized in that the nano TiO₂The particle size of (A) is 10 to 30 nm.

4. The process for preparing a decorative base paper according to claim 1 or 2, wherein the dodecyl diamine hydrochloride in steps (2) and (6) is prepared by: dissolving 1, 12-dodecyl diamine with 30-36% hydrochloric acid, adding excessive acetone for crystallization for 30-60 min, filtering, and drying a precipitate to obtain dodecyl diamine hydrochloride, wherein the mass-volume ratio of the 1, 12-dodecyl diamine to the hydrochloric acid is as follows: 1g (5-10 mL).

5. The preparation method of the decorative base paper as claimed in claim 1, wherein the pulp in the step (1) comprises 0-20% of bleached softwood pulp and 80-100% of bleached hardwood pulp, the pulp degree of the pulp is 40-45 ° SR, and the wet weight is 2.0-3.0 g.

6. The method for preparing decorative base paper according to claim 1, 2 or 3, wherein the mass concentration of the dodecyl diamine hydrochloride solution in the step (2) is 1-2%, and the mass ratio of the filler to the dodecyl diamine hydrochloride in the filler dispersion is (90-100): 5.

7. the method for preparing decorative base paper according to claim 1, wherein the filler dispersion added in step (3) has a filler content of 30 to 60kg per ton, a cationic rosin size of 15 to 25kg per ton, aluminum sulfate of 15 to 20kg per ton, a PAM dry strength agent of 10 to 20kg per ton, and a deaerator of 0.5 to 1.0kg per ton.

8. The method of claim 1, wherein the pressing step (5) comprises two pressing steps, the first pressing step is performed at a pressure of 0.4-0.5 MPa, and the second pressing step is performed at a pressure of 0.2-0.3 MPa.

9. The method of claim 1The preparation method of the decorative base paper is characterized in that the coating weight of the coating liquid in the step (6) is 3-5 g/m²。

Technical Field

The invention relates to the technical field of papermaking, in particular to a preparation method of decorative base paper.

Background

The decorative base paper is an industrial special paper processed by a special process, and is mainly used for surface layer paper, surface layer paper and bottom layer paper of artificial boards such as fiber boards, shaving boards and the like after being printed and impregnated by melamine resin. Therefore, the decorative base paper is named melamine paper after being dipped in glue in the artificial board industry, and various decorative materials made of artificial boards coated by the melamine paper have the excellent characteristics of heat insulation, flame retardance, no warping, no cracking, easy cleaning and the like, and are various in color and variety and wide in application.

Disclosure of Invention

The invention provides a preparation method of decorative base paper, aiming at overcoming the problems that in the prior art, when decorative base paper is dipped to produce decorative paper, glue mainly uses melamine formaldehyde resin formed by condensation polymerization of melamine and formaldehyde, so that decorative paper prepared by dipping the decorative base paper contains a certain amount of free formaldehyde, formaldehyde is continuously released in the using process, and the decorative base paper is harmful to human bodies under the conditions of home decoration and the like, and the preparation method of the decorative base paper is provided₃Modified nano TiO₂As the filler, the covering power and the absorption performance of the decorative base paper are ensured, and the filler has the photocatalytic performance on formaldehyde, so that the decorative base paper can be used for degrading formaldehyde in a photocatalytic manner, the formaldehyde release amount of the impregnated decorative paper is reduced, and the harm to a human body is reduced.

In order to achieve the purpose, the invention adopts the following technical scheme:

a preparation method of decorative base paper comprises the following steps:

(1) pulping: pulping and then preparing pulp to obtain pulp;

(2) preparing a filler dispersion liquid: adding the filler into a dodecyl diamine hydrochloride solution, and uniformly stirring to obtain a filler dispersion liquid;

(3) pulping: mixing the filler dispersion liquid with the slurry, adding the cationic rosin size, aluminum sulfate, PAM dry strength agent and degassing agent, and uniformly stirring to obtain mixed slurry;

(4) manufacturing paper: screening the mixed pulp on a net to make wet paper sheets;

(5) pressing and pre-drying: squeezing and pre-drying the wet paper sheet to obtain a pre-dried paper sheet;

(6) coating: is dried before being coated with coating liquidCoating the dried paper sheet, wherein the coating liquid comprises the following raw materials in parts by weight: 30-50 parts of filler, 10-20 parts of polyvinyl alcohol, 5-10 parts of cationic starch, 0.3-0.5 part of dodecyl diamine hydrochloride, 0.1-0.3 part of defoaming agent, 0.1-0.3 part of glycerol and 70-80 parts of water; the filler in the step (2) and the step (6) is SrTiO₃Modified nano TiO₂；

(7) Drying and calendering: and drying and calendaring the coated paper to obtain the decorative base paper.

In the invention, SrTiO is adopted₃Modified nano TiO₂Preparation of decorative base paper as filler, nano TiO₂The photocatalyst is a common photocatalyst, can catalyze water or oxygen in the air into photogenerated active groups with strong oxidizing capability such as hydroxyl radicals, superoxide anion radicals, active oxygen and the like, and the photogenerated active groups can oxidize reductive formaldehyde into carbon dioxide and water, so that the release amount of formaldehyde is reduced. But pure nano TiO₂The band gap of the catalyst is wide, the catalyst has catalytic activity only under the excitation of ultraviolet light, the requirement on the particle size of the catalyst is high, the application is limited, and the solar energy cannot be fully utilized to catalyze and degrade formaldehyde. And SrTiO₃The material is a photocatalytic material with a perovskite structure, the variable amplitude of the vacancy is large, and the band gap energy of the material can be adjusted through partial doping of an A site or a B site, so that the material has photocatalytic activity in a larger wavelength range. Thus, SrTiO is used in the present invention₃To nanometer TiO₂The modification can effectively increase the number of active sites on the surface of the catalyst, improve the photocatalytic efficiency, and enable the catalyst to have catalytic activity in a larger wavelength range by doping, so that the filler can effectively carry out photocatalytic degradation on formaldehyde contained in the decorative base paper after gum dipping under the action of sunlight, the release amount of the formaldehyde is reduced, and the preparation method is beneficial to human health.

And has a perovskite structure₃The lattice vibration can enable the solar cell to have good infrared radiation performance in a far infrared wave band, heat in sunlight can be dissipated in a heat radiation mode, and absorption of materials to the heat is reduced. Thus, SrTiO is used₃Modified nano TiO₂As the filler, a decorative base paper can be usedThe solar energy water heater has self-radiation cooling performance, and avoids the influence of overhigh temperature on materials and life of furniture, cabinets and the like under the irradiation of sunlight.

Meanwhile, the filler is added twice in the pulping process and the coating process, so that the decorative base paper has good covering power and good absorption performance on glue during gum dipping, and the phenomenon that the bonding force between fibers is reduced due to the addition of excessive filler in the pulping process, so that the paper strength is influenced, is avoided. And because the filler with good photocatalytic performance has small grain diameter and poor dispersibility, is easy to agglomerate in slurry and coating liquid, and influences the service performance of decorative base paper and the photocatalytic activity of the filler, the invention uses dodecyl diamine hydrochloride to carry out surface modification on the filler, and the-NH at two ends of the dodecyl diamine hydrochloride₃ ⁺Can be mixed with SrTiO in the filler₃And hydrogen bond action is formed, so that adjacent fillers can be connected through a fatty chain, the dispersion stability of the fillers is improved, and the influence of filler agglomeration on the performance of the decorative base paper is prevented.

Therefore, the decorative base paper prepared by the invention has high strength, good absorption performance and good use performance; the formaldehyde has photocatalytic degradation capability and good environmental protection performance; and the material has self-radiation cooling performance, and can protect materials such as furniture and the like.

Preferably, SrTiO described in steps (2) and (6)₃Modified nano TiO₂The preparation method of the filler comprises the following steps:

a) mixing TiCl₄Dripping the mixture into 30-36% hydrochloric acid to obtain TiCl₄Hydrochloric acid solution, TiCl₄The volume ratio of the hydrochloric acid to the hydrochloric acid is 1: (10-15); b) mixing TiCl₄Hydrochloric acid solution and SrCl₂And AgNO₃Mixing the aqueous solutions of (a) to obtain a mixed solution, wherein TiCl is contained in the mixed solution₄、SrCl₂And AgNO₃In a molar ratio of 1: (0.8-0.9): (0.1 to 0.2);

c) mixing nanometer TiO₂Adding into the mixed solution, stirring to obtain dispersion, and adding into nanometer TiO₂With TiCl₄The molar ratio of (2-4): 1;

d) dispersed downward under stirringDropping NaOH and Na into the solution₂CO₃The mixed precipitant is stirred to react for 30-60 min until the pH value is 9-9.5, and then the mixed precipitant is filtered, and the precipitate is treated by NaHCO with the pH value of 7-8₃Cleaning the solution and deionized water, drying at 60-70 ℃ to obtain a precursor, and adding NaOH and Na in the mixed precipitator₂CO₃The molar ratio of (2-3) to (1);

e) and calcining the precursor at 900-950 ℃ for 4-6 h to obtain the filler.

In the invention, Ag is adopted for SrTiO₃Doping and adding nano TiO₂The Ag doping can adjust the band gap energy of the Ag through coating modification, so that the filler has photocatalytic activity in a visible light range and can catalyze formaldehyde degradation under sunlight. And Ag doping can also improve SrTiO₃The crystal lattice vibration activity of the decorative base paper is improved, and the infrared radiation performance of the decorative base paper is improved, so that the self-radiation cooling performance of the decorative base paper is improved.

Preferably, the nano TiO₂The particle size of (A) is 10 to 30 nm.

Preferably, the preparation method of the dodecyl diamine hydrochloride in the steps (2) and (6) comprises the following steps: dissolving 1, 12-dodecyl diamine with 30-36% hydrochloric acid, adding excessive acetone for crystallization for 30-60 min, filtering, and drying a precipitate to obtain dodecyl diamine hydrochloride, wherein the mass-volume ratio of the 1, 12-dodecyl diamine to the hydrochloric acid is as follows: 1g (5-10 mL).

Preferably, the pulp in the step (1) comprises 0-20% of bleached softwood pulp and 80-100% of bleached hardwood pulp, the pulp size of the pulp is 40-45 DEG SR, and the wet weight is 2.0-3.0 g.

Preferably, the mass concentration of the dodecyl diamine hydrochloride solution in the step (2) is 1-2%, and the mass ratio of the filler to the dodecyl diamine hydrochloride in the filler dispersion is (90-100): 5.

preferably, the filler dispersion liquid added in the step (3) has a filler dosage of 30-60 kg per ton of paper, a cationic rosin size of 15-25 kg per ton of paper, aluminum sulfate of 15-20 kg per ton of paper, a PAM dry strength agent of 10-20 kg per ton of paper and a degassing agent of 0.5-1.0 kg per ton of paper.

Preferably, the squeezing in the step (5) adopts two squeezing steps, wherein the pressure of a first squeezing line is 0.4-0.5 Mpa, and the pressure of a second squeezing line is 0.2-0.3 Mpa.

Preferably, the coating amount of the coating liquid in the step (6) is 3 to 5g/m²。

Therefore, the invention has the following beneficial effects:

(1) the fillers are added twice in the pulping process and the coating process, so that the decorative base paper has good covering power and good absorption performance on glue during gum dipping, and the phenomenon that the bonding force between fibers is reduced due to the addition of excessive fillers in the pulping process, so that the strength of the paper is influenced is avoided;

(2) using SrTiO₃Modified nano TiO₂The filler is used for preparing the decorative base paper, so that the filler can effectively degrade formaldehyde contained in the decorative base paper after gum dipping under the action of sunlight, the release amount of the formaldehyde is reduced, and the decorative base paper is beneficial to human health;

(3) using SrTiO₃Modified nano TiO₂As the filler, the decorative base paper can also have self-radiation cooling performance, the absorption of the material to heat is effectively reduced, furniture is protected, and the influence of overhigh temperature under the irradiation of sunlight on the material and life is avoided.

Detailed Description

The invention is further described with reference to specific embodiments. The raw materials used in the present invention are not specified to be all commercially available or commonly used in the art, and the papermaking methods used in the present invention are all conventional in the art.