Titanium white paper and preparation method and application thereof

Abstract

The application provides titanium white paper and a preparation method and application thereof, the titanium white paper comprises, from top to bottom, a surface coating resin layer, a first amino resin layer, a covering layer, white paper, a second amino resin layer and a back coating resin layer; the covering layer contains the following components: acrylic dispersion resin, acrylic emulsion, polyurethane emulsion, opaque acrylic ester copolymer and titanium white powder; the first amino resin layer and the second amino resin layer independently contain the following components respectively: urea-formaldehyde resin, triamine resin, opaque acrylic ester copolymer and titanium white powder; the opaque acrylic ester copolymer has a hollow structure. The application forms a three-dimensional covering by using the amino resin layer and the covering layer, so that ideal covering power and full whiteness are achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of decorative paper, and particularly relates to titanium white paper and a preparation method and application thereof. BACKGROUND

[0002] The decorative base paper, also known as titanium white paper, is an industrial special paper processed by a special process with high-quality wood pulp and titanium dioxide pigment as main raw materials. After printing and impregnation of resin such as melamine, it is mainly used for the surface layer paper, surface layer paper and bottom layer paper of the surface layer paper of the fiberboard, particle board and other man-made boards. When used in combination with other colors, it gives people a natural and generous feeling.

[0003] The production of the decorative base paper is divided into plain base paper and printed base paper according to the application, and is mainly divided into white paper and colored paper according to the color. The white paper including the paper with almost white color is the mainstream product of the decorative paper. In this type of paper, a large amount of titanium white powder (about 35% on average, and even up to 45%) must be added to ensure the color of the white paper, avoid the phenomenon of showing the bottom, and prevent the color of the man-made board from interfering with the surface color of the decorative board.

[0004] One of the existing technologies is to coat the titanium white paste on the low-basis-weight base paper by printing, and the other is to add a certain amount of titanium white powder in the impregnation water or surface coating glue, so as to increase the hiding power. However, simply adding titanium white powder will accelerate the solidification of the glue to a certain extent (the amount of titanium white powder added is 13% of the glue), which will cause the crosslinking between the glue molecules, increase the viscosity of the glue, change the conventional 12s (four cups) to 20s (four cups), affect the penetration and coating of the glue, and thus affect the pressing effect. On the other hand, the solidification of the impregnation amino resin and the surface coating three-amine glue also affects the surface stain resistance. SUMMARY

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application provides a titanium white paper and a preparation method and application thereof.

[0006] According to a first aspect of the present application, a titanium white paper is provided, which comprises, from top to bottom, a surface coating resin layer, a first amino resin layer, a hiding layer, a white paper, a second amino resin layer and a back coating resin layer.

[0007] The hiding layer contains the following components: acrylic dispersion resin, acrylic emulsion, polyurethane emulsion, opaque acrylic ester copolymer and titanium white powder;

[0008] The first amino resin layer and the second amino resin layer independently contain the following components: urea-formaldehyde resin, triamine resin, opaque acrylic ester copolymer and titanium white powder;

[0009] The opaque acrylate copolymer has a hollow structure.

[0010] In some embodiments, the acrylic dispersion resin has a molecular weight of less than 10,000 and a solid content of 30-35%.

[0011] In some embodiments, the acrylic emulsion has a molecular weight of more than 100,000 and a solid content of 40-45%.

[0012] In some embodiments, the polyurethane emulsion has a molecular weight of 1,000-10,000 and / or a solid content of 30-35%.

[0013] In some embodiments, the opaque acrylate copolymer is an anionic copolymer and has a solid content of 29-31%.

[0014] In some embodiments, the titanium white has a particle size of 0.2-0.5 μm.

[0015] In some embodiments, the triamine resin has a molecular weight of 800-3,000.

[0016] In some embodiments, the covering layer is prepared from the following ingredients by mass parts: 1-2 parts of ethanolamine, 2-4 parts of acrylic dispersion resin, 18-22 parts of acrylic emulsion, 0.2-0.3 parts of silicone defoaming agent, 5-8 parts of polyurethane emulsion, 4-6 parts of opaque acrylate copolymer, 4-6 parts of titanium white, 0.1-0.3 parts of benzopropyl isothiazolinone, and 60-70 parts of water.

[0017] In some embodiments, the first and second amino resin layers are respectively independently prepared from the following ingredients by mass parts: 83-87 parts of urea-formaldehyde resin, 13-17 parts of triamine resin, 4-6 parts of opaque acrylate copolymer, 4-6 parts of titanium white, 0.2-0.3 parts of curing agent, 0.1-0.2 parts of penetrating agent, and 0.4-0.6 parts of dispersing agent.

[0018] In some embodiments, the curing agent is ammonium chloride; the penetrating agent is fatty alcohol polyoxyethylene ether; and the dispersing agent is at least one of polysiloxane or polyacrylic acid.

[0019] In some embodiments, the face-coating resin layer and the back-coating resin layer are respectively independently composed of triamine glue, and the triamine glue of the face-coating resin layer contains two-dimensional nano-kaolin.

[0020] In some embodiments, the raw materials for preparing the triamine glue include 37 wt% of formaldehyde solution 100 parts, water 60 parts, caprolactam 8 parts, and melamine 90 parts by mass.

[0021] In some embodiments, the triamine glue is prepared by mixing formaldehyde solution and water, adjusting the pH to 8.5-9.0 by adding caustic soda, then adding caprolactam and melamine, heating to 95℃ for 40-50 min, maintaining the temperature for 60 min, and then testing the water-soluble ratio. When the water-soluble ratio is 2.3-2.7, the temperature is lowered to 40-45℃, and the triamine glue is obtained.

[0022] In some embodiments, the triamine glue of the surface coating resin layer contains 1-2 wt% of two-dimensional nanometer kaolin. The two-dimensional nanometer kaolin has an average thickness of 20-50 nm and an average diameter of 300 nm, and has a synergistic effect with titanium white powder, which not only has the function of shielding ultraviolet rays, but also can improve the reflection of sunlight, increase the whiteness and gloss of the decorative base paper, and appropriately reduce the amount of titanium dioxide, thereby reducing the cost.

[0023] In some embodiments, the opaque acrylic ester copolymer is a hollow copolymer formed by styrene, butyl acrylate, and methacrylic acid; and / or, the particle size of the opaque acrylic ester copolymer is about 600 μm.

[0024] After the amino resin is cross-linked and cured, it forms a three-dimensional network structure with many voids, which can cause the surface of the film layer to have poor stain resistance. The opaque acrylic ester copolymer with the particle size can be well dispersed in the voids of the amino resin structure, thereby improving the stain resistance of the film layer.

[0025] In some embodiments, the thickness of the surface coating resin layer is 0.4-0.6 mm.

[0026] In some embodiments, the thickness of the first amino resin layer is 0.2-0.3 mm.

[0027] In some embodiments, the thickness of the second amino resin layer is 0.2-0.3 mm.

[0028] In some embodiments, the thickness of the covering layer is 0.2-0.3 mm.

[0029] In some embodiments, the white paper has a grammage of 70-80 g / m 2 .

[0030] In some embodiments, the thickness of the back coating resin layer is 0.3-0.5 mm.

[0031] According to a second aspect of the present application, a method for preparing the titanium white paper as described in the first aspect of the present application is provided, comprising the following steps:

[0032] S1: coating one side of the white paper with a diluent, drying to obtain a cover layer;

[0033] S2: immersing the white paper with the cover layer in an amino resin, and drying to form an amino resin layer on each side of the white paper;

[0034] S3: roll coating triamine glue on the two amino resin layers respectively, and drying to obtain the titanium white paper.

[0035] In some embodiments, in step S1, the viscosity of the diluent is 14-16 s (four-cup coating), the pH of the diluent is between 7-8, and the solid content of the diluent is 20-25%. The diluent is coated on one side of the white paper by a printing machine to play a role of the first cover layer.

[0036] In some embodiments, in step S1, the coating amount of the diluent is 2-4 g / m 2 .

[0037] In some embodiments, in step S2, the viscosity of the amino resin is 12-14 s (four-cup coating), the pH of the amino resin is between 7-8, and the solid content of the amino resin is 45-50%. The amino resin enters the inside and surface layer of the paper by immersion to play a role of the second cover layer.

[0038] In some embodiments, in step S2, the sizing amount of the amino resin is 50-60 g / m 2 .

[0039] In some embodiments, in step S2, the drying is performed in a five-section oven, and the temperatures are set as 130℃, 140℃, 150℃, 150℃, and 130℃ in sequence. After drying, the volatile matter of the white paper is about 7%.

[0040] In some embodiments, in step S3, the sizing amount of the triamine glue is 15-18 g / m 2 .

[0041] The present application also provides an artificial board comprising the titanium white paper as described in the first aspect of the present application.

[0042] According to an embodiment of the present application, at least the following beneficial effects are achieved:

[0043] (1) The white paper itself has insufficient hiding power and whiteness. The present application firstly prints and coats a covering layer on the white paper, and the covering layer contains titanium white and an opaque acrylic ester copolymer. The opaque acrylic ester copolymer has a hollow structure, and air is introduced after water is dried. The light is scattered when it enters, and the light cannot pass through, thereby achieving the purpose of covering. The hiding power can be improved to the effect achieved by adding an excessive amount of titanium white alone by using the synergistic effect of titanium white and the opaque acrylic ester copolymer.

[0044] (2) The present application uses amino resin to form a three-dimensional covering with the covering layer, thereby achieving the most ideal hiding power and full whiteness. The titanium white and the opaque acrylic ester copolymer in the covering layer form the first layer of covering, and the amino resin forms the second layer of covering. Both layers of covering contain titanium white and the opaque acrylic ester copolymer, which have a covering effect, and are better than a single layer in terms of hiding power and full whiteness. BRIEF DESCRIPTION OF DRAWINGS

[0045] The present application will be further described below in combination with the drawings and examples, in which:

[0046] Figure 1 The structure diagram of the titanium white paper of Example 1 of the present application.

[0047] Reference signs:

[0048] 101, top coating resin layer; 102, first amino resin layer; 103, covering layer; 104, white paper; 105, second amino resin layer; 106, back coating resin layer. DETAILED DESCRIPTION

[0049] The concept and technical effects of the present application will be described below in combination with examples, so as to fully understand the purpose, features and effects of the present application.

[0050] The titanium white mentioned below is purchased from Chengdu Zhengqi New Material Co., Ltd., and the opaque acrylic ester copolymer ROSF-HE380 is purchased from Foshan Rosof Technology Co., Ltd. The remaining raw materials not specifically described are all conventional commercially available products; and the process steps or preparation methods not specifically mentioned are known to those skilled in the art.

[0051] Table 1: Raw material composition of titanium white paper of Examples 1-2 and Comparative Examples 1-4 (by mass)

[0052]

[0053]

[0054] Example 1-2 and Comparative Example 1-3, the raw materials shown in Table 1 were weighed and titanium white paper was prepared according to the following steps:

[0055] (1) Preparation of the covering layer:

[0056] The water, monoethanolamine, acrylic dispersion resin, acrylic emulsion, silicone defoaming agent, polyurethane emulsion, benzyl isothiazolinone, opaque acrylic ester copolymer and titanium dioxide shown in Table 1 were weighed and mixed uniformly in a reaction kettle to obtain a printing diluent. The printing diluent was coated on the front side of the white paper with a grammage of 75 g / m 2 by a printing machine, and the coating amount was 4 g / m 2 by dry weight. After drying, the covering layer was formed.

[0057] (2) Preparation of the first and second amino resin layers:

[0058] The urea-formaldehyde resin, triamine resin, opaque acrylic ester copolymer, titanium dioxide, curing agent, penetrant and dispersant shown in Table 1 were weighed and mixed uniformly in a reaction kettle to obtain a first amino resin. The white paper after forming the covering layer was immersed in the first amino resin, and after drying, the first and second amino resin layers were formed on the front and back sides of the white paper, respectively, with a glue application amount of 55 g / m 2 by dry glue. Drying was carried out in a five-section oven with the temperature set at 130°C, 140°C, 150°C, 150°C and 130°C, respectively. After drying, the volatile matter of the white paper was about 7%.

[0059] (3) Triamine glue was roll-coated on the first and second amino resin layers, respectively, with a glue application amount of 15 g / m 2 by dry glue, and after drying, the titanium white paper was obtained.

[0060] Among them, the titanium white paper prepared in Example 1, as shown in Figure 1 , from top to bottom are the top coating resin layer 101, the first amino resin layer 102, the covering layer 103, the white paper 104, the second amino resin layer 105 and the back coating resin layer 106. Among them, the thickness of the top coating resin layer 101 is 0.5 mm, the thickness of the first and second amino resin layers 102 and 105 is 0.3 mm, the thickness of the covering layer 103 is 0.3 mm, and the thickness of the back coating resin layer 106 is 0.5 mm.

[0061] Comparative Example 4

[0062] A method for preparing titanium white paper, which is different from Example 1 in that the preparation and coating of the printing diluent are not performed, and titanium dioxide is additionally added to the raw materials for preparing the first amino resin. The specific process is as follows:

[0063] (1) Preparation of the first and second amino resin layers:

[0064] The urea-formaldehyde resin, triamine resin, opaque acrylic ester copolymer, titanium white, curing agent, penetrating agent and dispersing agent were weighed according to the mass parts shown in Table 1, mixed uniformly in a reaction kettle to obtain a first amino resin. The white paper was immersed in the first amino resin, and after drying, the first and second amino resin layers were formed on the front and back surfaces of the white paper, respectively. The coating amount was 55 g / m 2 . The drying was performed in a five-section oven, and the temperatures were set at 130°C, 140°C, 150°C, 150°C and 130°C, respectively. After drying, the volatile matter of the white paper was about 7%.

[0065] (2) The triamine glue was roll-coated on the first and second amino resin layers, respectively, and the coating amount of the triamine glue was 15 g / m 2 . After drying, the titanium white paper was obtained.

[0066] The titanium white paper prepared in Comparative Example 4 had, from top to bottom, a surface coating resin layer, a first amino resin layer, a white paper, a second amino resin layer and a back coating resin layer.

[0067] Test Example

[0068] Table 2 is a data recording table for the pressing test of the titanium white paper prepared in Examples 1-2 and Comparative Examples 1-4.

[0069] Table 2 Pressing test data table of titanium white paper

[0070]

[0071] In the above data, the whiteness was tested according to GB / T 7974-2002; the opacity was tested according to GB / T 1543-2005; and the stain resistance was tested according to GB / T 17657-2013. As can be seen from Table 2, the whiteness, opacity (hiding power) and stain resistance of the titanium white paper of Example 1 and Example 2 are all superior to those of Comparative Examples 1-4. Among them, in the preparation process of the covering layer and the amino resin layer of Comparative Example 1, the titanium white powder is replaced with an equal amount of opaque acrylic ester copolymer; in the preparation process of the covering layer and the amino resin layer of Comparative Example 2, the opaque acrylic ester copolymer is replaced with an equal amount of titanium white powder, and the whiteness, hiding power and stain resistance of the titanium white paper prepared by the two are all inferior to those of Example 1, proving that the titanium white powder and the opaque acrylic ester copolymer have a synergistic effect, and the effect is better than that of any single component when the total content is the same; the amino resin layer of Comparative Example 3 does not contain titanium white powder, while the covering layer is additionally added with the corresponding titanium white powder; the titanium white paper of Comparative Example 4 has no covering layer, and the amino resin layer is additionally added with the corresponding titanium white powder, and the performance of the titanium white paper prepared by the two is also inferior to that of Example 1, indicating that the covering layer and the amino resin layer of Example 1, which contain titanium white powder and opaque acrylic ester copolymer having a covering effect, form a three-dimensional covering, and the hiding power and whiteness are better than those of a single layer.

[0072] The above describes the embodiments of the present application in detail in combination with the test data, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A titanium white paper, characterized in that, The face coating resin layer, the first amino resin layer, the covering layer, the white paper, the second amino resin layer and the back coating resin layer are sequentially arranged from top to bottom. The covering layer comprises the following components: acrylic dispersion resin, acrylic emulsion, polyurethane emulsion, opaque acrylic ester copolymer and titanium white powder. The first amino resin layer and the second amino resin layer independently comprise the following components: urea-formaldehyde resin, triamine resin, opaque acrylic ester copolymer and titanium white powder. The opaque acrylic ester copolymer has a hollow structure. The covering layer is prepared from the following raw materials in parts by mass: monoethanolamine 1-2 parts, acrylic dispersion resin 2-4 parts, acrylic emulsion 18-22 parts, silicone defoaming agent 0.2-0.3 parts, polyurethane emulsion 5-8 parts, opaque acrylic ester copolymer 4-6 parts, titanium white powder 4-6 parts, benzopropyl isothiazolinone 0.1-0.3 parts and water 60-70 parts. The first amino resin layer and the second amino resin layer are independently prepared from the following raw materials in parts by mass: urea-formaldehyde resin 83-87 parts, triamine resin 13-17 parts, opaque acrylic ester copolymer 4-6 parts, titanium white powder 4-6 parts, curing agent 0.2-0.3 parts, penetrating agent 0.1-0.2 parts and dispersing agent 0.4-0.6 parts.

2. The titanium white paper according to claim 1, characterized in that, The face coating resin layer and the back coating resin layer are independently composed of triamine glue, and the triamine glue of the face coating resin layer comprises two-dimensional nano kaolin.

3. The titanium white paper according to claim 1, characterized in that, The opaque acrylic ester copolymer is a hollow copolymer prepared from styrene, butyl acrylate and methacrylic acid; and / or the particle size of the opaque acrylic ester copolymer is 600 μm.

4. The method of producing titanium white paper according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: S1: coating one side of the white paper with a layer of diluent, drying to obtain a covering layer; S2: immersing the white paper with the covering layer in amino resin, and drying to form two layers of amino resin layers on the two sides of the white paper; S3: roll coating triamine glue on the two layers of amino resin layers respectively, and drying to obtain titanium white paper.

5. The preparation method according to claim 4, characterized in that, In step S1, the diluent is applied in an amount of 2 to 4 g / m 2 .

6. The preparation method according to claim 4, characterized in that, In step S2, the sizing amount of the amino resin is 50 to 60 g / m 2 .

7. The preparation method according to claim 4, characterized in that, In step S3, the sizing amount of the triamine glue is 15-18 g / m 2 .

8. A wood-based panel, characterized in that The titanium white paper comprises the titanium white paper according to any one of claims 1-4. The titanium white paper comprises the titanium white paper according to any one of claims 1-4.

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