CN105200846A - Calcium silicate filled release body paper and preparation method thereof - Google Patents

Abstract

The invention relates to calcium silicate filled release body paper and a preparation method thereof. The preparation method includes the steps that raw material pulp, calcium silicate filler and auxiliary materials are mixed and pulped, and mixed pulp is obtained; the calcium silicate filled release body paper is obtained sequentially through the technological steps of net part dewatering, paper making, pre-drying, surface sizing, after-drying and calendaring finishing. According to the preparation method, calcium silicate extracted from coal ash solid waste residues is used for replacing non-renewable calcium carbonate to serve as the filler, raw materials are rich in source and cheap, comprehensive utilization of solid waste is achieved, the environment is protected, fiber raw materials are saved, and the product quality of the release body paper can be greatly improved. The calcium silicate filled release body paper prepared through the preparation method has the advantages of being good in strength, high in stiffness and smooth and fine in surface compared with calcium carbonate filled release body paper.

Description

Calcium silicate filled release base paper and preparation method thereof

technical field

The invention relates to a calcium silicate filled release base paper and a preparation method thereof, belonging to the technical field of papermaking.

Background technique

Release paper, also known as anti-adhesive paper, silicone oil paper, release paper usually has a double-layer structure: the first layer is the release base paper as the base material, and the second layer is the release coating. The general manufacturing method of release paper is to pretreat the surface of the release base paper and apply a layer of primer, then apply a release agent and cure it into a release coating, and finally make a release paper.

Release base paper is an important paper-based material for the preparation of release paper. It has been widely used in light chemical industry, home appliances, maternal and child health care products, etc., such as self-adhesive label backing paper, self-adhesive decorative film backing paper, artificial leather backing paper, self-adhesive Carpet tiles, sound-absorbing materials, insulating materials, etc., the current release paper is increasing at an annual growth rate of 8-10%.

As the base material of the release paper, the release base paper largely determines the quality of the final product; the release base paper requires high strength, good shape stability, good stiffness, no lint and powder loss, and a certain smoothness ( Front side), no holes, hard blocks, air spots and dead folds are allowed, and the post-processing composite is good. At present, in the production process of release base paper, bleached kraft wood pulp and bleached straw pulp are usually used as the main fiber raw materials. The pulp is filled with calcium carbonate and neutrally sized with alkyl ketene dimer (AKD). Different grades of release base paper can be obtained after decoration treatment. In order to improve the smoothness and fineness of the surface of the release base paper, improve the shape stability, and reduce the production cost, adding calcium carbonate to the pulp is one of the important processes in the production of the release base paper. However, the addition of calcium carbonate in the production of release base paper will cause a series of problems, such as low fiber retention rate, high concentration of white water under the wire, large loss of paper strength, easy lint and powder loss, poor stiffness, and impact on paper machine equipment. High wear and tear. On the other hand, the raw material resources of calcium carbonate are limited, and it is used to fill the release paper, which also makes it difficult to control the production cost.

How to find a material with rich sources and low cost as a filler, and at the same time improve the product quality of release base paper has always been an urgent problem to be solved.

Contents of the invention

The main technical problem to be solved by the present invention is to provide a preparation method of calcium silicate filled release base paper, using calcium silicate instead of non-renewable calcium carbonate as filler, which can not only protect the environment, save fiber raw materials, but also greatly Improve the product quality of release base paper.

The invention also provides the calcium silicate filled release base paper prepared by the preparation method.

The invention provides a preparation method of calcium silicate filled release base paper, comprising the following steps:

1) Mix and beat the raw material slurry, calcium silicate filler and auxiliary materials to prepare a mixed slurry; wherein, the average particle size of the calcium silicate is 20-40um, whiteness ≥ 85% ISO, 10% suspension The pH value of the product is 8.0-9.5; the amount of calcium silicate relative to the dry raw material slurry is: 10-30%;

2) The mixed pulp is sequentially dehydrated, pressed, and pre-dried in the wire section, and then enters the surface sizing treatment process to obtain a paper sheet after the surface sizing treatment;

3) The paper sheet after the surface sizing treatment is subjected to post-drying and calendering finishing steps in order to obtain calcium silicate filled release base paper.

The calcium silicate used in the preparation method of the release base paper provided by the present invention is based on the research that the inventor selects calcium silicate and calcium carbonate respectively as various properties of the filler: in the release base paper production, calcium carbonate is used as a filler and will cause retention. Low rate, high concentration of white water under the wire, large loss of paper strength, easy lint and powder loss, poor stiffness, high wear on paper machine equipment, etc. Calcium silicate is a kind of paper with good dispersibility, low true density Stable porous mineral material, the research of the present invention found that the release base paper produced by using calcium silicate as filler has high retention rate, good sheet strength, high bulk, low quantification of paper, and is more conducive to ensuring paper calendering Good finishing, smooth and delicate surface, and calcium silicate can be extracted from fly ash solid waste, used to produce high value-added products such as release base paper, and can realize the comprehensive utilization of solid waste.

In the process of preparing calcium silicate plus filling release base paper in the present invention, the fiber raw materials that can be selected for the raw material slurry include bleached kraft softwood pulp and bleached kraft hardwood pulp, Italian APMP pulp and bleached kraft reed pulp. At least one formed mixture.

In a specific embodiment of the present invention, the weight ratio of the fiber raw materials is as follows: bleached kraft softwood pulp, bleached kraft hardwood pulp, Italian APMP pulp and bleached kraft reed pulp (5-50): (0- 95):(0-40):(0-40).

Further, the degree of beating used as a fiber raw material in the raw material slurry is: bleached kraft softwood pulp 45-55 ° SR; bleached kraft hardwood pulp 35-40 ° SR; Italian APMP pulp 50-60 ° SR; bleached Kraft reed pulp 35-40°SR is more conducive to improving the quality and performance of release base paper.

In the present invention, the auxiliary materials may include two or more of sizing agent, cationic starch, retention aid, bentonite and brightener. The inventor's research found that using more than two kinds of auxiliary materials is beneficial to improve the fiber retention rate.

In a specific embodiment of the present invention, the amount of control auxiliary materials relative to the dry raw material slurry is: 0.1-0.3% of sizing agent, 0.6-1.2% of cationic starch, 0.05-0.1% of retention aid, 0.2-0.5% of bentonite %, brightener 0.2-0.6%.

Further, the sizing agent may be alkyl ketene dimer (AKD) and/or alkenyl succinic anhydride (ASA). In a specific embodiment of the present invention, alkenyl succinic anhydride (ASA) or alkyl ketene dimer (AKD) is selected as the sizing agent, which is difficult to stay on the fiber when used alone, and cationic starch can be added to Improves retention of sizing agent on fibers. In addition, cationic starch and sizing agent act synergistically to improve paper strength while increasing sizing efficiency.

Further, the retention aid in the auxiliary agent can be selected from cationic polyacrylamide (CPAM) and/or anionic polyacrylamide (APAM). Cationic polyacrylamide can be used alone as a retention agent, and can also form a particle retention system with bentonite; in addition, because anionic polyacrylamide itself has a negative charge, it can play a strong retention effect when it forms a composite system with some cationic compounds. Therefore, cationic polyacrylamide and anionic polyacrylamide can also form a two-component retention system.

Further, bentonite may be modified bentonite.

In the present invention, the surface sizing treatment uses a surface sizing solution composed of starch derivatives and a synthetic styrene-acrylic sizing reinforcing agent; wherein each component of the surface sizing solution is by weight relative to the dry paper sheet: starch Derivatives 2.0-5.0%; synthetic styrene-acrylic sizing enhancer 0.2-0.3%.

Further, the starch derivative may be oxidized starch or enzyme-converted starch.

Further, the solid content of the surface sizing solution is between 8.0-12.0%.

In a specific embodiment of the present invention, the calendering finishing conditions are: temperature 60-130° C., pressure 80-120 kN/m.

In the method for preparing calcium silicate filled release base paper of the present invention, calcium silicate is used to replace non-renewable calcium carbonate as a filler, and calcium silicate filler and auxiliary materials are added to the raw material slurry for mixing and beating to make a mixed slurry; Wherein, the average particle size of the calcium silicate is 20-40um, the whiteness is ≥85% ISO, and the pH value of the 10% suspension is 8.0-9.5; the amount of calcium silicate relative to the dry mixed raw material slurry is: 10 -30%; the mixed pulp is sequentially dehydrated, pressed, and pre-dried in the wire section, and then enters the surface sizing treatment process to obtain a paper sheet after surface sizing treatment; followed by post-drying and calendering finishing processes in sequence to obtain Calcium silicate filled release base paper.

The present invention also provides the release base paper filled with calcium silicate prepared by the preparation method. Compared with the release base paper filled with calcium carbonate, it has the advantages of high retention rate, good sheet strength, high bulk, and Low weight, good calendering finish, smooth and delicate surface, low wear and so on.

The calcium silicate filled release base paper prepared by this preparation method can have the following indicators: quantitative 60-120g/m ² , opacity ≥ 90%, smoothness ≥ 40s, transverse stretch rate ≤ 2.5%, broken long roll The longitudinal length of the web is ≥4000m, the surface absorption weight (Cobb value) is 20-30g/m ² , the water content is 4-6%, and the ash content is 10-28%.

The present invention has following beneficial effects:

In the method for preparing calcium silicate plus filled release base paper, the present invention can use calcium silicate extracted from fly ash solid waste residue to replace non-renewable calcium carbonate as filler. Comprehensive utilization can also protect the environment, save fiber raw materials, and greatly improve the product quality of release base paper.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than Full examples. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

The calcium silicate used is extracted from high-alumina fly ash waste slag, the average particle size measured by laser particle size method is 20um, the whiteness is 92% ISO, and the pH value of 10% suspension is 8.0-9.5. Add 8.0 tons of clean water into a stirred stainless steel container with a volume ^of 10m3, slowly add 2.0 tons of calcium silicate at a stirring speed of 800 rpm, and disperse for 30 minutes to obtain a calcium silicate filler suspension with stable performance. spare;

Blend the bleached kraft softwood pulp with a beating degree of 50-55°SR and the bleached kraft hardwood pulp with a beating degree of 35-40°SR at a weight ratio of 30:70, and add calcium silicate fillers in turn for suspension liquid (120kg/ton of pulp for absolute drying), AKD sizing agent (2kg/ton of pulp), cationic starch (8kg/ton of pulp), PAM (0.5kg/ton of pulp), modified bentonite (2kg / ton of pulp) and an appropriate amount of whitening agent are mixed to make a mixed pulp, and papermaking is carried out on the Internet; double-sided dehydration is carried out through a double-wire paper machine, and the wet paper sheet enters a shoe press, and after pre-drying treatment, surface sizing treatment is performed. , the surface sizing solution is composed of enzyme-converted starch and synthetic styrene-acrylic surface sizing agent, with a solid content of 10%, the sizing amount of enzyme-converted starch is controlled to 25-30kg/ton of paper, and the amount of synthetic styrene-acrylic surface sizing agent is 2-3kg/ tons of paper. After the surface sizing, the wet paper sheets are subjected to post-drying treatment. After the post-drying treatment, the paper sheets with a dryness of 92-94% enter the calendering zone for finishing treatment. The calendering temperature is controlled at 120°C, and the calendering pressure is controlled at 90kN/m; after calendering, the paper is coiled and slit; the calcium silicate filled release base paper can be obtained, and its detection indicators: quantitative 70g/m ² , opacity ≥ 90%, smoothness ≥ 40s, transverse expansion rate ≤ 2.5%, broken long web longitudinal ≥ 4000m, surface absorption weight ≤ 30g/m ² , moisture 4-6%, ash 10-12%.

Example 2:

The average particle diameter of the calcium silicate used is 30um measured by the laser particle size method, the whiteness is 90% ISO, and the pH value of the 10% suspension is 8.0-9.5.

Add 8.0 tons of clean water into a stirred stainless steel container with a volume ^of 10m3, slowly add 2.0 tons of calcium silicate at a stirring speed of 800 rpm, and disperse for 30 minutes to obtain a calcium silicate filler suspension with stable performance. spare;

Blend the bleached kraft softwood pulp with a beating degree of 50-55°SR and the bleached kraft hardwood pulp with a beating degree of 35-40°SR at a weight ratio of 15:85, and add calcium silicate fillers in turn for suspension Liquid (absolute dry dosage is 220kg/ton of pulp), AKD sizing agent (dosage of 2kg/ton of pulp), cationic starch (dosage of 8kg/ton of pulp), PAM (dosage of 0.5kg/ton of pulp), modified bentonite (dosage of 2kg / ton of pulp) and an appropriate amount of whitening agent are mixed to prepare a mixed pulp, which is copied on the Internet; double-sided dehydration is carried out through a double-wire paper machine, and the wet paper is pressed and pre-dried. After the surface sizing treatment, the surface is applied to the surface. The glue solution is composed of enzyme-converted starch and synthetic styrene-acrylic surface sizing agent, with a solid content of 12%. The amount of enzymatically-converted starch gluing is controlled at 25-30kg/paper, and the amount of synthetic styrene-acrylic surface sizing agent is 2-3kg/paper. After the surface sizing, the wet paper sheets are subjected to post-drying treatment. After the post-drying treatment, the paper sheets with a dryness of 92-94% enter the calendering zone for finishing treatment. The calendering temperature is controlled at 120°C, and the calendering pressure is controlled at 90kN/m; after calendering, the paper is coiled and slit; the calcium silicate filled release base paper can be obtained, and its testing indicators: quantitative 90g/m ² , opacity ≥ 90%, smoothness ≥ 40s, transverse stretch rate ≤2.5%, broken long web lengthwise ≥4000m, surface absorption weight ≤30g/m ² , moisture content 4-6%, ash content 18-20%.

Example 3:

The average particle diameter of the calcium silicate used is 40um measured by the laser particle size method, the whiteness is 89% ISO, and the pH value of the 10% suspension is 8.0-9.5.

Add 8.0 tons of clean water into a stainless steel container with a volume ^of 10m3 and stir, slowly add 2.0 tons of calcium silicate at a stirring speed of 800 rpm, and disperse for 30 minutes to obtain a calcium silicate filler suspension with stable performance. ;

Bleached kraft softwood pulp with a beating degree of 50-55°SR, Italian APMP pulp with a beating degree of 50-60°SR, and bleached kraft reed pulp with a beating degree of 35-40°SR in a weight ratio of 30:35:35 Ratio to mix slurry, and add calcium silicate filler suspension (amount of 300kg/ton of pulp), AKD sizing agent (amount of 2.5kg/ton of pulp), cationic starch (amount of 10kg/ton of pulp), PAM (amount of 0.6kg / ton of pulp), modified bentonite (amount of 3kg/ton of pulp), and an appropriate amount of light yellow dye are mixed to prepare a mixed slurry, which is then copied on the Internet; double-sided dehydration is carried out through a double-wire paper machine, and the wet paper is pressed into the press and pre-dried. Finally, carry out surface sizing treatment, the surface sizing solution is composed of enzyme-converted starch and synthetic styrene-acrylic surface sizing agent, with a solid content of 12%. Dosage 2-3kg/paper. After the surface sizing, the wet paper sheets are subjected to post-drying treatment. After the post-drying treatment, the paper sheets with a dryness of 92-94% enter the calendering zone for finishing treatment. The calendering temperature is controlled at 120°C, and the calendering pressure is controlled at 100kN/m; after calendering, the paper is coiled and cut; the yellow calcium silicate filled release base paper can be obtained, and its detection index: quantitative 100g/m ² , opacity ≥ 90%, smooth Length ≥ 40s, transverse expansion rate ≤ 2.5%, broken long web length ≥ 4000m, surface absorption weight ≤ 30g/m ² , moisture 4-6%, ash 26-28%.

comparative example

Calcium carbonate is used as a filler to make release base paper. The average particle size of the calcium carbonate used is 15um measured by laser particle size method, the whiteness is 90% ISO, and the pH value of 10% suspension is 8.0-9.5.

Bleached kraft softwood pulp with a beating degree of 50-55°SR, Italian APMP pulp with a beating degree of 50-60°SR, and bleached kraft reed pulp with a beating degree of 35-40°SR in a weight ratio of 30:35:35 Ratio to mix the pulp, and add in turn a calcium carbonate filler with a solid content of 30% (dry dosage 350kg/ton pulp), AKD sizing agent (consumption 2.5kg/ton pulp), cationic starch (consumption 10kg/ton pulp), PAM (amount of 0.6kg/ton of pulp), modified bentonite (amount of 3kg/ton of pulp), and an appropriate amount of bright yellow dye are mixed to prepare a mixed slurry, which is then copied on the Internet; double-sided dehydration is carried out through a double-wire paper machine, and the wet paper is fed into the pulp. Pressing, after pre-drying treatment, surface sizing treatment, the surface sizing liquid is composed of enzyme-converted starch and synthetic styrene-acrylic surface sizing agent, with a solid content of 12%, and the sizing amount of enzyme-converted starch is controlled to 30-40kg/paper, synthetic The amount of styrene-acrylic surface sizing agent is 2-3kg/paper. After the surface sizing, the wet paper sheets are subjected to post-drying treatment. After the post-drying treatment, the paper sheets with a dryness of 92-94% enter the calendering zone for finishing treatment. The calendering temperature is controlled at 120°C, and the calendering pressure is controlled at 100kN/m; after calendering, the paper is coiled and slit; the yellow calcium carbonate filled release base paper is obtained, and its testing indicators: quantitative 100g/m ² , opacity ≥ 86%, smoothness ≥ 35s , transverse expansion rate ≤ 2.5%, broken long web longitudinal ≥ 3800m, surface absorption weight ≤ 30g/m ² , moisture 4-6%, ash 26-28%.

The inventor compared Example 3 and the comparative example, and the comparative data are shown in Table 1.

Table 1 Embodiment 3 and comparative example release base paper product comparison table

Comparison item Example 3 comparative example Opacity ≥90% ≥86% smoothness ≥40s ≥35s Break Long Web Portrait ≥4000m ≥3800m

From the results in Table 1, it can be known that the calcium silicate filled release base paper prepared by the present invention is compared with the calcium carbonate filled release base paper. advantage.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (12)

1. calcium silicates adds the preparation method filling out neutral sizing, and described method comprises:

1) raw material slurry is carried out mixing with calcium silicate filling material and auxiliary material pull an oar, be mixed with mixed slurry; Wherein, the average grain diameter of described calcium silicates is 20-40um, whiteness >=85%ISO, and the pH value of 10% suspension is 8.0-9.5; Calcium silicates relative to the consumption of raw material slurry described in over dry is: 10-30%;

2) by described mixed slurry successively through wet end dehydration, squeezing, front drying, enter top sizing treatment process, obtain the page after top sizing process;

3) described page after top sizing process, order carries out rear drying, press polish ornamenting operation, obtains calcium silicates and adds and fill out neutral sizing.

2. calcium silicates according to claim 1 adds the preparation method filling out neutral sizing, it is characterized in that, described raw material slurry comprises bleached sulphate softwood pulp and BRATSK, Italian APMP starch and the mixture of at least one fibrous raw material in bleached sulfate reed pulp; The weight ratio of described fibrous raw material is as follows: bleached sulphate softwood pulp: BRATSK: Italian APMP slurry: bleached sulfate reed pulp is (5-50): (0-95): (0-40): (0-40).

3. calcium silicates according to claim 2 adds the preparation method filling out neutral sizing, it is characterized in that, in described raw material slurry, the beating degree of each fibrous raw material is: bleached sulphate softwood pulp 45-55 ° of SR; BRATSK 35-40 ° SR; Italy APMP starches 50-60 ° of SR; Bleached sulfate reed pulp 35-40 ° SR.

4. calcium silicates according to claim 1 adds the preparation method filling out neutral sizing, it is characterized in that, it is two or more that described auxiliary material comprises in sizing agent, cationic starch, retention agent, bentonite and brightening agent.

5. calcium silicates according to claim 4 adds the preparation method filling out neutral sizing, it is characterized in that, controlling described auxiliary material relative to the consumption of raw material slurry described in over dry is: sizing agent 0.1-0.3%, cationic starch 0.6-1.2%, retention agent 0.05-0.1%, bentonite 0.2-0.5%, brightening agent 0.2-0.6%.

6. the calcium silicates according to claim 4 or 5 adds the preparation method filling out neutral sizing, it is characterized in that, described sizing agent is selected from alkyl ketene dimer and/or alkenyl succinic anhydride.

7. the calcium silicates according to claim 4 or 5 adds the preparation method filling out neutral sizing, it is characterized in that, described retention agent is cationic polyacrylamide and/or anionic polyacrylamide.

8. calcium silicates according to claim 1 adds the preparation method filling out neutral sizing, it is characterized in that, described top sizing process uses the surface size be made up of starch derivatives and synthetic styrene-acrylic gluing reinforcing agent; The each component of wherein said surface size is relative to over dry page by weight: starch derivatives 2.0-5.0%; Synthetic styrene-acrylic gluing reinforcing agent 0.2-0.3%.

9. calcium silicates according to claim 8 adds the preparation method filling out neutral sizing, it is characterized in that, described starch derivatives is oxidized starch or enzyme converted starch.

10. calcium silicates according to claim 8 or claim 9 adds the preparation method filling out neutral sizing, and it is characterized in that, the solid content of described surface size is 8.0-12.0%.

11. calcium silicates according to claim 1 add the preparation method filling out neutral sizing, it is characterized in that, described press polish ornamenting condition: temperature 60-130 DEG C, pressure 80-120kN/m.

12. 1 kinds of calcium silicates prepared according to method described in any one of claim 1-11 add fills out neutral sizing.