NL2028877A

NL2028877A - Composite retention aid, preparation method and application thereof

Info

Publication number: NL2028877A
Application number: NL2028877A
Authority: NL
Inventors: Tong Jun; Chen Jiujiu
Original assignee: Hangzhou Jiuxu New Material Tech Co Ltd
Priority date: 2020-12-09
Filing date: 2021-07-29
Publication date: 2022-07-08
Also published as: CN112575612A; NL2028877B1; CN112575612B

Abstract

Disclosed are a composite retention aid and a preparation method thereof, comprising the following raw materials in parts by weight: 6—8 parts of high whiteness clay mineral, 0.3—0.6 part of sodium carbonate or lithium carbonate, O.5—l.5 parts of anionic polyacrylamide with high ionicity and low molecular weight, and 1—3 parts of magnesium silicate or aluminum silicate. The advantages of said composite retention aid are: the concentration of white water is reduced, the wet—end system is stabilized, retention is improved and the amount of pulp and costs are reduced. Drainage improvement is beneficial to increase speed. and. save steam. consumption. and. energy. Uniformity improvement is beneficial to improve paper quality and printing performance of paper. Adsorption and inhibition of stickies are conducive to improving the cleanliness of wet— end, clean production, environmental protection, extending the life cycle of consumables such as forming nets, and improving the stability of machine operation.

Description

COMPOSITE RETENTION AID, PREPARATION METHOD AND APPLICATION THEREOF TECHNICAL FIELD

[01] The present application belongs to the field of decorative base paper, in particular to a composite retention aid and a preparation method and application thereof.

BACKGROUND ART

[02] Decorative base paper is an essential material for many building material products in modern life, such as low pressure boards, high pressure boards, fire-proof boards, floors, etc. used in furniture and cabinets which is placed under the surface of product structure, and mainly plays a decorative role in providing patterns and a covering role in preventing the seepage of the underlying glue. Therefore, the paper is required to have good hiding power, impregnation, and printing performance. With the continuous improvement of the residential environment and working environment, the amount of decorative base paper is increasing, the quality is continuously improved, the color varieties are becoming increasingly rich, and the requirements are increasing. The main process for the production of decorative base paper is to use high-quality wood pulp fiber and titanium dioxide as the main filler. Titanium dioxide is delicate and wear-resistant, traditional 2b wet strength agents are mainly used for retention and drainage aid. The first pass retention rate is low, the uniformity is poor, and the dehydration speed is slow; and in the production process, it is easy to produce flocculation of titanium dioxide and fiber, which affects the product uniformity and covering rate, thereby causing poor printing properties and leakage of underlying glue. There are problems such as large fluctuations in process adjustment and poor stability in production.

SUMMARY

[03] Aiming at the problems in the prior art, the present disclosure provides a composite retention aid used for decorative base paper.

[04] A composite retention aid comprising the following raw materials in parts by weight: 6-8 parts of high whiteness clay mineral (diatomite or bentonite), 0.3-0.6 part of sodium carbonate or lithium carbonate, 0.5-1.5 parts of anionic polyacrylamide with high ionicity and low molecular weight (molecular weight of less than or equal to 6 million), and 1-3 parts of magnesium silicate or aluminum silicate.

[05] After using a composite retention aid, the stability of the production process is improved, the retention rate is good, the production cost is reduced, the product uniformity is good, the surface is smooth, and it has good absorption and adaptability. The print chromaticity is uniform, the stripes are clear, the color is bright, and the glue is not easy to penetrate.

[06] Preferably, the composite retention aid is prepared by the following raw materials in parts by weight: €.5 parts of high whiteness clay mineral (diatomite or bentonite), 0.5 part of sodium carbonate or lithium carbonate, 1 part of anionic polyacrylamide with high ionicity and low molecular weight, and 2 parts of magnesium silicate or aluminum silicate.

[07] Preferably, the composite retention aid is prepared by the following raw materials in parts by weight: 6.5 parts of high whiteness clay mineral (diatomite or bentonite), 0.5 part of lithium carbonate, 1 part of anionic polyacrylamide with high ionicity and low molecular weight, and 2 parts of magnesium silicate.

[08] Preferably, the high whiteness clay mineral is diatomite or bentonite, and the molecular weight of anionic polyacrylamide with high ionicity and low molecular weight is less than or equal to 6 million.

[09] The present disclosure is described in detail below:

[10] The present disclosure selects a clay mineral with high whiteness, high interlayer charge density and exchangeable charges as the main raw material. After purification, 1, grafting hydrophilic anionic polyacrylamide with high ionicity and low molecular weight; 2, performing interlayer charge exchange by monovalent ions Na and Li with smaller ionic radius to free up charge capacity; 3, adding magnesium silicate and aluminum silicate with many micropores to increase cavities. The composite retention aid obtained in this way has a large interlayer spacing, strong charge balance ability, many micropores, and strong adsorption capacity. These characteristics can meet the requirements of wet-end forming and charge balance in the special paper making process.

[11] Clay minerals (such as diatomite or bentonite) often undergo isomorphous substitution during the formation process, and there are excess negative charges between the crystal structure layers, which can maintain electrical neutrality by electrostatically adsorbing cations (positive charges in the wet strength agent). In addition, by utilizing the clay mineral with high surface area, the huge surface area is accompanied by a huge surface energy, which has great adsorption capacity, and is an ideal aid that adsorbs fine fibers and titanium dioxide. The surface of natural clays is subjected to treatment and micro- organification to make it hydrophilic and lipophilic, effectively improving its performance.

[12] The decorative retention aid for the decorative base paper of the present application has been specially treated to increase the interlayer spacing, increase the specific surface area, and have more micropores. It has a good effect on the adsorption of titanium dioxide in the decorative base paper, which is mainly achieved by the following two aspects:

[13] 1. The specific surface area of the clay mineral is increased by filling and exchanging of a large number of low-valent cations, thereby forming a good adsorption effect on the particles.

[14] 2, The clay is grafted with organic groups by organic modification of the surface of clay minerals, which has a good homosexual adsorption effect on the organic impurities in the pulp fiber, such as organic stickies, effectively reducing the viscosity of the pulp, reducing the sticking of the net and the roller, and achieving the purpose of cleaning the paper machine.

[15] 3. Adding silica-rich magnesium silicate and aluminum silicate, the porous surface makes 1t more capable of adsorption and exchange, which is conducive to paper forming and dehydration, and uniformity improvement of finished paper, and it 1s very beneficial to the glue dipping and printing of the subsequent processes of finished paper.

[16] The products of composite retention aids have five functions

[17] 1, Working together with wet strength agents to form a particle retention and drainage system, which can improve the first-pass retention rate, effectively take away the fine fibers and fillers in the white water, avoid the vicious cycle of the system, reduce the sewage treatment load and sludge production volume, and reduce environmental protection pressure.

[18] 2. Adding composite retention aids can increase the ash content of the paper, increase the retention of fillers and reduce the cost of pulp consumption per ton.

[19] 3. Adding composite retention aids can improve the printing performance of paper because of its strong adsorption.

[20] 4, In the production process, the composite retention rate is sufficiently combined with the wet strength agent to increase the wet strength of paper; drainage improves the extruding dryness of the paper, so that the performance of the paper machine is improved to a certain extent, and the electrical and steam consumption of the paper machine is reduced, which further increases the speed of the paper machine and the output of the paper machine, and ensures a stable increase in the operation efficiency of the paper machine.

[21] 5, Adding composite retention aids can achieve clean 5 production and service life extending of consumables such as forming nets.

[22] The composite retention aid for decorative base paper of the patent application is a product specially researched and developed based on the production characteristics of decorative base paper which is sensitive to the charge requirements of wet-end system. It solves the problems of low retention rate of titanium dioxide in the production of decorative base paper, unclean system, and poor production stability; and it is very suitable for the production of decorative base paper.

[23] The advantages of the composite retention aid of the present disclosure are as follows:

[24] The concentration of white water is reduced, the wet- end system is stabilized, retention is improved and the amount of pulp and costs are reduced.

[25] Drainage improvement 1s beneficial to increase speed and save steam consumption and energy.

[26] Uniformity improvement is beneficial to improve paper quality and printing performance of paper.

[27] Adsorption and inhibition of stickies are conducive to improving the cleanliness of wet-end, clean production, environmental protection, extending the life cycle of consumables such as forming nets, and improving the stability of machine operation.

[28] 1, Formula example

[29] Formula example 1:

[30] 6.0 parts of the purified bentonite

[31] 0.5 part of Na:C0:

[32] 1 part of anionic polyacrylamide with high ionicity and low molecular weight

[33] 2 parts of magnesium silicate

[34] Ratio of purified bentonite, Na,COs, anionic polyacrylamide with high ionicity and low molecular weight and magnesium silicate is 6.0: 0.5: 1: 2.

[35] Formula example 2:

[36] 7 parts of the purified diatomite

[37] 0.3 part of LizCOs

[38] 0.5 part of anionic polyacrylamide with high ionicity and low molecular weight

[39] 1 part of magnesium silicate

[40] Ratio of purified diatomite, Li:CO3, anionic polyacrylamide with high ionicity and low molecular weight and magnesium silicate is 7: 0.3: 0.5: 1.

[41] Formula example 3:

[42] 8 parts of the purified diatomite

[43] 0.6 part of Na:C03

[44] 1.5 parts of anionic polyacrylamide with high ionicity and low molecular weight

[45] 3 parts of aluminum silicate

[46] Formula example 4:

[47] 8 parts of the purified bentonite

[48] 0.4 part of Na:CO03

[49] 1 part of anionic polyacrylamide with high ionicity and low molecular weight

[50] 3 parts of aluminum silicate

[51] Formula example 5:

[52] 6.5 parts of the purified bentonite

[53] 0.5 part of Li:COs3

[54] 1 part of anionic polyacrylamide with high ionicity and low molecular weight

[55] 2 parts of magnesium silicate

BRIEF DESCRIPTION OF THE DRAWINGS

[56] FIG.1 is a flow chart of the preparation of a composite retention aid.

[57] FIG.2 is a comparison experiment diagram of water filterability;

:

[58] FIG.3 is a comparison experiment diagram of the retention effect;

[59] FIG.4 is a comparison experiment diagram of gas permeability of finished paper.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[60] The following is a further explanation of this application:

[61] Example 1

[62] A composite retention aid was prepared by the following steps: step 1): the bentonite was pulverized and screened with a 60-mesh sieve; pulping was carried out according to the ratio of bentonite to water of 2:8 (parts by weight). After soaking for 2 h, the resulting slurry was screened with an 80-mesh sieve, and impurities were discarded. After sedimentation, the slurry was dried to obtain purified bentonite for use;

[63] Step 2): 0.5 part of Na:CO3 was added to 6.0 parts of purified bentonite, and extruded twice by a double-roller; then 1.0 part of anionic polyacrylamide with high ionicity and low molecular weight (molecular weight of 4 million) and

2.0 parts of magnesium silicate were added for compounding to obtain the semi-finished products; and

[64] Step 3): The semi-finished products after compounding were screened with a 325-mesh sieve, to obtain a composite retention aid.

[65] Example 2

[66] A composite retention aid was prepared by the following steps: step 1): the diatomite was pulverized and screened with a 60-mesh sieve; pulping was carried out according to the ratio of diatomite to water of 2:8 (parts by weight). After soaking for 2 h, the resulting slurry was screened with an 80-mesh sieve, and impurities were discarded. After sedimentation, the slurry was dried to obtain purified diatomite for use;

[67] Step 2): 0.3 part of Li:CO3 was added to 7 parts of purified diatomite, and extruded twice by a double-roller;

then 0.5 part of anionic polyacrylamide with high ionicity and low molecular weight (molecular weight of 5 million) and 1 part of magnesium silicate were added for compounding to obtain the semi-finished products; and

[68] Step 3): The semi-finished products after compounding were screened with a 325-mesh sieve, to obtain a composite retention aid.

[69] Example 3

[70] A composite retention aid was prepared by the following steps: step 1): the diatomite was pulverized and screened with a 60-mesh sieve; pulping was carried out according to the ratio of diatomite to water of 2:8 (parts by weight). After soaking for 2 h, the resulting slurry was screened with an 80-mesh sieve, and impurities were discarded. After sedimentation, the slurry was dried to obtain purified diatomite for use;

[71] Step 2): 0.6 part of Na:CO; was added to 8 parts of purified diatomite, and extruded twice by a double-roller; then 1.5 parts of anionic polyacrylamide with high ionicity and low molecular weight (molecular weight of 3 million) and 3 parts of magnesium silicate were added for compounding to obtain the semi-finished products; and

[72] Step 3): The semi-finished products after compounding were screened with a 325-mesh sieve, to obtain a composite retention aid.

[73] Example 4

[74] A composite retention aid was prepared by the following steps: step 1): the bentonite was pulverized and screened with a 60-mesh sieve; pulping was carried out according to the ratio of bentonite to water of 2:8 (parts by weight). After scaking for 2 h, the resulting slurry was screened with an 80-mesh sieve, and impurities were discarded. After sedimentation, the slurry was dried to obtain purified bentonite for use;

[75] Step 2): 0.4 part of Na:CO0:3 was added to 8 parts of purified bentonite, and extruded twice by a double-roller; then 1 part of anionic polyacrylamide with high ionicity and low molecular weight (molecular weight of & million) and 3 parts of aluminum silicate were added for compounding to obtain the semi-finished products; and

[76] Step 3): The semi-finished products after compounding were screened with a 325-mesh sieve, to obtain a composite retention aid.

[77] Example 5

[78] A composite retention aid was prepared by the following steps: step 1): the bentonite was pulverized and screened with a 60-mesh sieve; pulping was carried out according to the ratio of bentonite to water of 2:8 (parts by weight). After scaking for 2 h, the resulting slurry was screened with an 80-mesh sieve, and impurities were discarded. After sedimentation, the slurry was dried to obtain purified bentonite for use;

[79] Step 2): 0.5 part of Li:CO3 was added to 6.5 parts of purified bentonite, and extruded twice by a double-roller; then 1 part of anionic polyacrylamide with high ionicity and low molecular weight (molecular weight of 5 million) and 2 parts of magnesium silicate were added for compounding to obtain the semi-finished products; and

[80] Step 3): The semi-finished products after compounding were screened with a 325-mesh sieve, to obtain a composite retention aid.

[81] The composite retention aids of the above-described embodiments were applied to the manufacturing of the decorative base paper, it was found that after adding the composite retention aids, good results were achieved in terms of drainability, retention effectiveness and air permeability of finished paper:

[82] The composite retention aid prepared in Example 5 of the present disclosure was applied to decorative base paper for performance experiments, and the results are as follows:

[83] 2, Comparison of product performance data

[84] (1) Comparison of drainability, shown in FIG.Z2;

[85] It can be seen from FIG.2 that during the preparation of the decorative base paper, without adding composite retention aid, the volume of steam per ton of paper is 2.3.

After adding composite retention aid, the volume of steam per ton of paper decreases, and as the amount of composite retention aid increases, it decreases until it stays the same; It can be seen form FIG.2 that in the process of preparing decorative base paper, the amount of steam per ton of paper can be saved by 0.3-0.5 ton.

[86] Therefore, during the preparation of the decorative base paper, the addition of composite retention aids can improve the drainage effectiveness and reduce steam consumption.

[87] (2) Comparison of retention effectiveness, shown in FIG.3

[88] The first-pass retention rate: without adding composite retention aid, first-pass retention rate is 60%.

[89] Using a composite retention aid, the first-pass retention rate is increased.

[290] It can be seen from FIG.3 that during the preparation of the decorative base paper, without adding composite retention aid, and the first-pass retention rate is 60%, and with the addition of the composite retention aid, the first- pass retention rate is increased to 80%. Therefore, adding a composite retention aid during the preparation process of the decorative base paper, 1t can improve the first-pass retention rate, reduce the concentration of white water, stabilize the wet-end system, reduce the amount of pulp and titanium dioxide, and reduce the cost.

[91] (3) Air permeability of finished paper is shown in FIG.4.

[92] It can be seen from FIG.4 that as shown in Line 1, the air permeability of finished paper prepared without adding the composite retention aid is 22; and the gas permeability of finished paper prepared by adding a composite retention aid (Line 2 in FIG. 4 is the test result of finished paper prepared by adding 5kg of composite retention aid) is 18; it can be seen that after adding a composite retention aid, the gas permeability of finished paper is decreased, the quality of finished paper is increased, and the glue dipping and printing performance of paper are improved.

Claims

CONCLUSIONS

A composite retention aid comprising the following raw materials by weight: 6-8 parts high white clay mineral, 0.3-0.6 parts sodium carbonate or lithium carbonate, 0.5-1.5 parts high ionic low molecular weight anionic polyacrylamide, and 1-3 parts of magnesium silicate or aluminum silicate.

The composite retention aid of claim 1, wherein it is prepared from the following raw materials in parts by weight: 6.5 parts high white clay mineral, 0.5 parts sodium carbonate or lithium carbonate, 1 part high ionic anionic polyacrylamide and low molecular weight, and 2 parts magnesium silicate or aluminum silicate.

The composite retention aid of claim 1, wherein the high white clay mineral is diatomite or bentonite, and the molecular weight of the high ionic, low molecular weight anionic polyacrylamide is less than or equal to 6 million.

A method for preparing the composite retention aid according to claim 1 or 2 or 3, comprising the following steps: Step 1): pulverizing the clay materials and sieving, pulverizing according to the weight ratio thereof to water of 2:8 into a slurry, subjecting the slurry to sieving, sedimentation, and drying to obtain a purified clay mineral;

Step 2): adding the purified clay mineral to sodium carbonate or lithium carbonate, extruding it twice by means of a double roller, and then adding the anionic low molecular weight polyacrylamide, magnesium silicate or aluminum silicate for compounding, and then crushing and screening to obtain a composite retention aid.

Use of the composite retention aid according to claim 1 or 2 or 3, in the preparation of decorative base paper.

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