Mosaic decorative film as well as preparation method and application thereof in furniture

Abstract

The invention relates to a mosaic decorative film as well as a preparation method and application thereof in furniture, and belongs to the technical field of decorative films. The mosaic decorative film comprises a base layer, a printing layer, mosaic dots, a bonding layer and a protective film layer, wherein the bonding layer is formed by curing an acrylic resin adhesive; the protective film layer is a PVA (polyvinyl alcohol) film modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals. The main functional layer of the mosaic decorative film is the protective film layer, and the phosphorylated cellulose nanofibers and the deacetylated chitin nanocrystals are attached to the PVA film through electrostatic complexation, so that the mosaic decorative film has good water resistance, fire resistance, wear resistance, adhesive property and mechanical strength, has good practicability, and is suitable for being used in the field of decoration. The film can be used as a protective film for furniture and provides protection for the furniture.

Description

Technical Field

[0001] The invention relates to the technical field of decorative films, and in particular to a mosaic decorative film and a preparation method thereof and application thereof in furniture. Background Art

[0002] Although decorative film paper has many advantages, such as beautiful appearance, excellent surface properties, low price, high temperature resistance and pollution and corrosion resistance, it also has some problems during use. For example, the brittleness of melamine-impregnated film paper increases after drying, which limits its use on special-shaped surfaces.

[0003] In order to improve the bonding strength between the decorative film and the substrate, acrylic resin is added as an adhesive. Because of its corrosion resistance, alkali resistance, fire resistance, and low odor, it has good potential as an adhesive. However, its use is often limited due to its poor surface wear resistance, low transmittance and short life. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a mosaic decorative film and a preparation method thereof and application in furniture, which has good water resistance and flame retardancy, good bonding performance with the base layer, and can improve its wear resistance and mechanical strength.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a mosaic decorative film, comprising a base layer, a printing layer, mosaic dots, an adhesive layer, and a protective film layer; wherein the adhesive layer is formed by curing an acrylic resin adhesive;

[0007] The protective film layer is a PVA film modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals, and the preparation method thereof comprises the following steps:

[0008] S1, mixing the phosphorylated cellulose nanofibers and the deacetylated chitin nanocrystals to form a suspension;

[0009] S1, mixing the phosphorylated cellulose nanofibers and the deacetylated chitosan nanocrystals to form a suspension; the mass ratio of the phosphorylated cellulose nanofibers to the deacetylated chitosan nanocrystals in the suspension is (30-70): (30-70)

[0010] S2, mixing the suspension with the PVA solution, adding ferric chloride, stirring, and obtaining a mixed slurry, wherein the mass ratio of the suspension to the PVA is (9-11):1; the mass ratio of the ferric chloride to the PVA is 1:(5-20);

[0011] S3, spreading the mixed slurry evenly, and then drying it to obtain the phosphorylated cellulose nanofiber and deacetylated chitin nanocrystal modified PVA film.

[0012] The protective film layer of the present invention is a PVA film modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals. PVA is a polymer rich in hydroxyl groups. These hydroxyl groups can form hydrogen bonds with a variety of substances, thereby facilitating the attachment of nanocrystals. Phosphorylated cellulose nanofibers carry a negative charge. This is because during the phosphorylation process, the hydroxyl groups on the surface of the cellulose nanofibers are replaced by phosphate groups, and the formed phosphate groups carry a negative charge. The presence of this negative charge can improve the thermal stability and flame retardant properties of the material, because the phosphate groups can release water molecules at high temperatures, thereby playing a role in cooling and isolating oxygen; deacetylated chitin nanocrystals carry a positive charge. This is because during the deacetylation process, the acetyl groups in the chitin molecules are removed, exposing more amino groups (-NH2), which are easily protonated in aqueous solution to form positively charged ammonium ions (-NH3 + ), the presence of this positive charge makes the deacetylated chitin nanocrystals show good dispersibility and stability in aqueous solution. When these two oppositely charged nanomaterials form stable aggregates in the solution through electrostatic complexation, the aggregates can then form stable attachments on the PVA surface. This electrostatic complexation enhances the interfacial interaction between the nanomaterials and PVA, which helps to improve the overall performance of the membrane.

[0013] The addition of phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals can reduce the porosity of the PVA membrane and improve its water barrier properties. Due to the high specific surface area and high porosity of phosphorylated cellulose nanofibers, they form a barrier in the PVA matrix to reduce the penetration of water; at the same time, the high crystallinity and rigidity of deacetylated chitin nanocrystals also help to improve the waterproof performance of the membrane.

[0014] The introduction of phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals can improve the thermal stability and flame retardant effect of the modified PVA film. The phosphate group decomposes at high temperature to produce phosphoric acid, which is an effective flame retardant that can form a protective layer on the surface of the material to isolate oxygen and heat; while the deacetylated chitin nanocrystals contain amino groups, which can capture free radicals during combustion and slow down the combustion reaction.

[0015] In the process of preparing the modified PVA film, ferric chloride is added as a complexing agent, which can form a complex with the hydroxyl groups on the PVA molecular chain, which helps to improve the water resistance of the PVA film. This complexation can enhance the interaction between PVA molecules and reduce the swelling degree of the film in water, thereby improving its waterproof performance. 3+The ions also form complexes with the phosphate groups in phosphorylated cellulose nanofibers, enhancing the aggregation and cross-linking of the materials. 3+ Ions can also complex with the amino groups in deacetylated chitin nanocrystals, combining with the amino groups through covalent bonds or ionic bonds to construct a stable strong cross-linked network structure to improve the compactness of the molecular chain arrangement, thereby improving the water resistance, barrier properties and mechanical properties of the protective film.

[0016] The present invention uses acrylic resin adhesive to bond the protective film layer to the mosaic dots. The hydroxyl (-OH) and carboxyl (-COOH) groups in the acrylic resin adhesive can react with the phosphate groups (-PO4 2- ) to form hydrogen bonds, thereby enhancing the bonding strength between the adhesive and the protective film layer. The amino groups of deacetylated chitin nanocrystals form positively charged ammonium ions (-NH3 + ) can generate electrostatic attraction with the negatively charged groups in the acrylic adhesive, thereby improving the bonding performance. Therefore, the bonding strength between the protective film layer and the substrate is improved, which can effectively prevent the protective film layer from warping during use and extend its service life.

[0017] Specifically, the mass ratio of phosphorylated cellulose nanofibers to deacetylated chitosan nanocrystals in the suspension may be 30:70, 40:60, 50:50, 60:40 and 70:30, more preferably 50:50.

[0018] Preferably, the mass concentration of the suspension is 0.5-1 wt%.

[0019] Specifically, the mass ratio of ferric chloride to PVA is 1: (5-20). If the ferric chloride content is too low, the cross-linking network strength is poor, and the water resistance and mechanical properties will be affected. If the ferric chloride content is too high, a large amount of Fe 3+ Under the action of PVA hydroxyl group, it is reduced to Fe 2+ At the same time, the hydroxyl groups in the PVA molecules are oxidized to form carbonyl groups, and double bonds are generated due to enol interconversion. This causes the oxidized polymer to become darker in color, less soluble, and precipitate from the aqueous solution, thus affecting the performance of the protective film layer.

[0020] Specifically, the method for preparing the phosphorylated cellulose nanofibers comprises the following steps:

[0021] The wood pulp fiber is immersed in a phosphorylation solution to carry out a phosphorylation reaction to obtain a mixed slurry; the mixed slurry is then dried to obtain a mixture, and the mixture is then subjected to a heat curing treatment to obtain a phosphorylated fiber; the phosphorylated fiber is added into water and mixed to prepare a dispersion, the pH value is adjusted to 9-10, and an ultrasonic treatment is carried out, and finally the dispersion is centrifuged to take out a supernatant, which is the phosphorylated cellulose nanofiber; wherein the phosphorylation solution contains a mixture of ammonium dihydrogen phosphate and urea in a molar ratio of 1: (4-7), the mass ratio of the phosphorylation solution to the wood pulp fiber is (5-6): 1, and the mass concentration of the phosphorylation solution is 20-30wt%.

[0022] Preferably, the phosphorylation reaction is carried out at a temperature of 70 to 80° C. for 10 to 40 minutes; and the thermal curing is carried out at a temperature of 100 to 110° C. for 10 to 30 minutes.

[0023] Specifically, the method for preparing the deacetylated chitin nanocrystals comprises the following steps:

[0024] Chitosan is mixed with sodium hydroxide solution, and sodium borohydride is added to carry out deacylation reaction. Then the reactant is collected and centrifuged, and the solid is washed to neutrality and dried to obtain the acetylated chitosan nanocrystals, wherein the mass ratio of chitosan, sodium hydroxide and sodium borohydride is 1 (10-12) (0.02-0.04).

[0025] Preferably, the deacylation reaction is carried out at a temperature of 85 to 95° C. and for a time of 1 to 4 hours.

[0026] Preferably, the thickness of the base layer is 1 to 2 mm.

[0027] Preferably, the thickness of the adhesive layer is 0.1-0.5 mm.

[0028] Preferably, the thickness of the protective film layer is 1 to 2 mm.

[0029] Preferably, the base layer is at least one of PVC, PP and PE.

[0030] In a second aspect, the present invention provides a method for preparing the mosaic decorative film, comprising the following steps:

[0031] (1) A printing layer is fixedly connected to the surface of the base layer, and a printing process is performed on the surface of the printing layer to obtain evenly distributed mosaic dots;

[0032] (2) Adhesive the mosaic dots to the protective layer using an acrylic resin adhesive, and then heat-press and cure the mosaic dots to form a bonding layer between the mosaic dots and the protective layer, thereby obtaining the mosaic decorative film.

[0033] Preferably, in step (2), the amount of acrylic resin adhesive added is 90 to 150 g / m 2 The hot pressing temperature is 120-160°C, the time is 1-3 minutes, and the pressure is 0.4-1 MPa.

[0034] In a third aspect, the present invention provides an application of the mosaic decorative film in the preparation of furniture. Specifically, the mosaic decorative film can be covered on the surface of furniture. In addition to providing the decorative effect of the mosaic, it can also provide the furniture with waterproofness, fire resistance, and wear resistance. Moreover, it has good adhesion to the surface of the furniture and strong durability.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The main functional layer of the mosaic decorative film of the present invention is a protective film layer, which is made of a PVA film modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals. The phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals are attached to the PVA film by electrostatic complexation, which reduces the porosity of the PVA film and improves its water barrier performance. Since the phosphorylated cellulose nanofibers have a high specific surface area and high porosity, they form a barrier in the PVA matrix to reduce the penetration of water. At the same time, the high crystallinity and rigidity of the deacetylated chitin nanocrystals also help to improve the waterproof performance of the film. The phosphoric acid group in the phosphorylated cellulose nanofibers decomposes at high temperature to produce phosphoric acid, which can form a protective layer on the surface of the material to isolate oxygen and heat, thereby playing a flame retardant role. The deacetylated chitin nanocrystals contain amino groups, which can capture free radicals during the combustion process and slow down the combustion reaction. Therefore, the mosaic decorative film of the present invention has good waterproofness, fire resistance, wear resistance, bonding performance and mechanical strength, has good practicality, and can be used as a protective film for furniture to provide protection for furniture.

[0037] (2) The present invention uses acrylic resin adhesive to bond the protective film layer to the mosaic dots. The phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals can react with the acrylic resin to improve the bonding performance. Therefore, the bonding strength between the protective film layer and the substrate is improved, which can effectively prevent the protective film layer from warping during use and extend its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of the mosaic decorative film of the present invention;

[0039] Figure 2 This is a physical picture of the mosaic decorative film of the present invention;

[0040] Figure 1 Middle: 1. Base layer; 2. Printing layer; 3. Mosaic dots; 4. Adhesive layer; 5. Protective film layer. DETAILED DESCRIPTION

[0041] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0042] The sources of materials, reagents and equipment used in the following examples and comparative examples are as follows:

[0043] PET film: The manufacturer is Dongguan Hongmei New Materials Co., Ltd., China, and the model is transparent PET film;

[0044] Polyvinyl alcohol (PVA): manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., China, brand name is P434375, average M w 146000-186000, 87-89% hydrolyzed;

[0045] Wood pulp fiber: the manufacturer is Shijiazhuang Xinyuan Cellulose Co., Ltd., China;

[0046] Chitosan: The manufacturer is Shanghai Yuanye Biotechnology Co., Ltd., China, brand number S11065;

[0047] Sodium borohydride: The manufacturer is Xiongda Chemical Co., Ltd., Maoming City, China;

[0048] Acrylic resin adhesive:

[0049] A. The manufacturer is Shanghai Weikai Optoelectronic New Materials Co., Ltd., China, and the brand is SA850;

[0050] B. The manufacturer is British Permabond, the brand is TA430;

[0051] Abrasion tester: The manufacturer is Shanghai Tianchen Modern Environmental Technology Co., Ltd., China, and the brand is JM-V;

[0052] Limiting oxygen index instrument, manufactured by Dynisco, USA, brand LOI;

[0053] Contact angle measuring instrument: manufacturer is German KRUSS company, brand DSA25;

[0054] Unless otherwise specified, other materials, reagents, equipment, etc. used in the examples and comparative examples can be obtained from commercial sources.

[0055] Example 1

[0056] A mosaic decorative film, such as Figure 1As shown, it includes a base layer 1, a printing layer 2, mosaic dots 3, an adhesive layer 4, and a protective film layer 5; wherein the base layer 1 is a PET film, the thickness of the base layer 1 is 1 mm, the thickness of the printing layer 2 is 0.25 mm, the thickness of the mosaic dots is 0.25 mm, the thickness of the adhesive layer 4 is 0.2 mm, the thickness of the protective film layer 5 is 1.3 mm, and the adhesive layer 4 is formed by curing an acrylic resin adhesive A;

[0057] The protective film layer 5 is a PVA film modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals, and its preparation method comprises the following steps:

[0058] S1, mixing the phosphorylated cellulose nanofibers and the deacetylated chitosan nanocrystals to form a suspension; wherein the mass ratio of the phosphorylated cellulose nanofibers to the deacetylated chitosan nanocrystals in the suspension is 50:50, and the mass concentration of the suspension is 0.5%;

[0059] S2, 5g PVA was mixed with 50mL deionized water to prepare a PVA solution, 50g of the suspension was mixed with the PVA solution, and 0.75g of ferric chloride was added and stirred to obtain a mixed slurry;

[0060] S3, spreading the mixed slurry evenly, and then drying it to obtain the phosphorylated cellulose nanofiber and deacetylated chitin nanocrystal modified PVA film;

[0061] Specifically, the method for preparing the phosphorylated cellulose nanofibers comprises the following steps:

[0062] 10g of wood pulp fiber is immersed in a phosphorylation solution of 5 times its mass, and a phosphorylation reaction is carried out at 75°C for 20 minutes to obtain a mixed slurry; the mixed slurry is then dried to obtain a mixture, and the mixture is heat-cured at 110°C for 20 minutes to obtain phosphorylated fiber; the phosphorylated fiber is added into water and mixed to prepare a dispersion, the pH is adjusted to 9, and ultrasonic treatment is carried out, and finally the dispersion is centrifuged to take out the supernatant, which is the phosphorylated cellulose nanofiber; wherein the mass concentration of the phosphorylation solution is 25%, and the phosphorylation solution contains a mixture of diammonium phosphate and urea in a molar ratio of 1:5.3.

[0063] Specifically, the method for preparing the deacetylated chitin nanocrystals comprises the following steps:

[0064] 11 g of sodium hydroxide was dissolved in 25 mL of water, and 1 g of chitosan was added and mixed, and then 0.03 g of sodium borohydride was added to carry out deacylation reaction at 90° C. for 3 h, and then the reactants were collected and centrifuged, and the solids were washed to neutrality and dried to obtain the acetylated chitosan nanocrystals.

[0065] The method for preparing a mosaic decorative film comprises the following steps:

[0066] (1) a printing layer 2 is fixedly connected to the surface of the base layer 1, and a printing process is performed on the surface of the printing layer 2 to obtain evenly distributed mosaic dots 3;

[0067] (2) Adhesive the mosaic dots 3 to the protective layer with acrylic resin, and then heat-press and cure them to form an adhesive layer 4 between the mosaic dots 3 and the protective layer, thereby obtaining the mosaic decorative film. The amount of acrylic resin adhesive added is 100 g / m 2 The hot pressing temperature is 130°C, the time is 2 min, and the pressure is 0.5 MPa.

[0068] Example 2

[0069] A mosaic decorative film, such as Figure 1 As shown, it includes a base layer 1, a printing layer 2, mosaic dots 3, an adhesive layer 4, and a protective film layer 5; wherein the base layer 1 is a PET film, the thickness of the base layer 1 is 1 mm, the thickness of the printing layer 2 is 0.25 mm, the thickness of the mosaic dots is 0.25 mm, the thickness of the adhesive layer 4 is 0.2 mm, the thickness of the protective film layer 5 is 1.3 mm, and the adhesive layer 4 is formed by curing an acrylic resin adhesive B;

[0070] The protective film layer 5 is a PVA film modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals, and its preparation method comprises the following steps:

[0071] S1, mixing the phosphorylated cellulose nanofibers and the deacetylated chitosan nanocrystals to form a suspension; wherein the mass ratio of the phosphorylated cellulose nanofibers to the deacetylated chitosan nanocrystals in the suspension is 50:50, and the mass concentration of the suspension is 0.5wt%;

[0072] S2, 5g PVA was mixed with 50mL deionized water to prepare a PVA solution, 45g of the suspension was mixed with the PVA solution, and 0.75g of ferric chloride was added and stirred to obtain a mixed slurry;

[0073] S3, spreading the mixed slurry evenly, and then drying it to obtain the phosphorylated cellulose nanofiber and deacetylated chitin nanocrystal modified PVA film;

[0074] Specifically, the method for preparing the phosphorylated cellulose nanofibers comprises the following steps:

[0075] 10g of wood pulp fiber is immersed in a phosphorylation solution of 5 times its mass, and a phosphorylation reaction is carried out at 70°C for 40 minutes to obtain a mixed slurry; the mixed slurry is then dried to obtain a mixture, and the mixture is heat-cured at 100°C for 30 minutes to obtain phosphorylated fiber; the phosphorylated fiber is added into water and mixed to prepare a dispersion, the pH is adjusted to 9, and ultrasonic treatment is carried out, and finally the dispersion is centrifuged to take out the supernatant, which is the phosphorylated cellulose nanofiber; wherein the mass concentration of the phosphorylation solution is 25%, and the phosphorylation solution contains diammonium phosphate and urea in a molar ratio of 1:4.

[0076] Specifically, the method for preparing the deacetylated chitin nanocrystals comprises the following steps:

[0077] 10 g of sodium hydroxide was dissolved in 25 mL of water, and 1 g of chitosan was added and mixed, and then 0.02 g of sodium borohydride was added to carry out deacylation reaction at 85° C. for 4 h, and then the reactants were collected and centrifuged, and the solids were washed to neutrality and dried to obtain the acetylated chitosan nanocrystals.

[0078] The method for preparing a mosaic decorative film comprises the following steps:

[0079] (1) a printing layer 2 is fixedly connected to the surface of the base layer 1, and a printing process is performed on the surface of the printing layer 2 to obtain evenly distributed mosaic dots 3;

[0080] (2) Adhesive the mosaic dots 3 to the protective layer using acrylic resin, and then heat-press and cure them to form an adhesive layer 4 between the mosaic dots 3 and the protective layer, thereby obtaining the mosaic decorative film. The amount of acrylic resin adhesive added is 90 g / m 2 The hot pressing temperature is 120°C, the time is 3 minutes, and the pressure is 0.4 MPa.

[0081] Example 3

[0082] A mosaic decorative film, such as Figure 1 As shown, it includes a base layer 1, a printing layer 2, mosaic dots 3, an adhesive layer 4, and a protective film layer 5; wherein the base layer 1 is a PET film, the thickness of the base layer 1 is 1 mm, the thickness of the printing layer 2 is 0.25 mm, the thickness of the mosaic dots is 0.25 mm, the thickness of the adhesive layer 4 is 0.2 mm, the thickness of the protective film layer 5 is 1.3 mm, and the adhesive layer 4 is formed by curing an acrylic resin adhesive B;

[0083] The protective film layer 5 is a PVA film modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals, and its preparation method comprises the following steps:

[0084] S1, mixing the phosphorylated cellulose nanofibers and the deacetylated chitosan nanocrystals to form a suspension; wherein the mass ratio of the phosphorylated cellulose nanofibers to the deacetylated chitosan nanocrystals in the suspension is 50:50, and the mass concentration of the suspension is 1 wt%;

[0085] S2, 5g PVA was mixed with 50mL deionized water to prepare a PVA solution, 55g of the suspension was mixed with the PVA solution, and 0.75g of ferric chloride was added and stirred to obtain a mixed slurry;

[0086] S3, spreading the mixed slurry evenly, and then drying it to obtain the phosphorylated cellulose nanofiber and deacetylated chitin nanocrystal modified PVA film;

[0087] Specifically, the method for preparing the phosphorylated cellulose nanofibers comprises the following steps:

[0088] 10g of wood pulp fiber is soaked in a phosphorylation solution of 6 times its mass, and a phosphorylation reaction is carried out at 80°C for 10 minutes to obtain a mixed slurry; the mixed slurry is then dried to obtain a mixture, and the mixture is heat-cured at 110°C for 10 minutes to obtain phosphorylated fiber; the phosphorylated fiber is added into water and mixed to prepare a dispersion, the pH is adjusted to 10, and ultrasonic treatment is carried out, and finally the dispersion is centrifuged to take out the supernatant, which is the phosphorylated cellulose nanofiber; wherein the mass concentration of the phosphorylation solution is 25%, and the phosphorylation solution contains diammonium phosphate and urea in a molar ratio of 1:7.

[0089] Specifically, the method for preparing the deacetylated chitin nanocrystals comprises the following steps:

[0090] 12 g of sodium hydroxide was dissolved in 25 mL of water, and 1 g of chitosan was added and mixed, and then 0.04 g of sodium borohydride was added to carry out deacylation reaction at 95° C. for 1 hour, and then the reactants were collected and centrifuged, and the solids were washed to neutrality and dried to obtain the acetylated chitosan nanocrystals.

[0091] The method for preparing a mosaic decorative film comprises the following steps:

[0092] (1) a printing layer 2 is fixedly connected to the surface of the base layer 1, and a printing process is performed on the surface of the printing layer 2 to obtain evenly distributed mosaic dots 3;

[0093] (2) Adhesive the mosaic dots 3 to the protective layer with acrylic resin, and then heat-press and cure them to form an adhesive layer 4 between the mosaic dots 3 and the protective layer, thereby obtaining the mosaic decorative film. The amount of acrylic resin adhesive added is 150 g / m 2The hot pressing temperature is 160°C, the time is 3 min, and the pressure is 1 MPa.

[0094] Embodiments 4 to 7

[0095] The difference between Examples 4 to 7 and Example 1 is that the mass ratios of phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals in the suspension are 30:70, 40:60, 60:40 and 70:30, respectively.

[0096] Embodiments 8 to 10

[0097] The difference between Examples 8 to 10 and Example 1 is that in step S2 of the method for preparing phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals modified PVA film, the added amounts of ferric chloride are 0.25 g, 0.50 g and 1 g, respectively.

[0098] Comparative Example 1

[0099] The difference between Comparative Example 1 and Example 1 is that the PVA film of Comparative Example 1 is not modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals.

[0100] Comparative Example 2

[0101] The difference between Comparative Example 2 and Example 1 is that the protective film layer 5 of Comparative Example 2 is a PVA film modified with phosphorylated cellulose nanofibers, that is, it is not modified with deacetylated chitin nanocrystals.

[0102] Comparative Example 3

[0103] The difference between Comparative Example 3 and Example 1 is that the protective film layer 5 of Comparative Example 3 is a PVA film modified with deacetylated chitin nanocrystals, that is, it is not modified with phosphorylated cellulose nanofibers.

[0104] Comparative Example 4

[0105] The difference between Comparative Example 4 and Example 1 is that no ferric chloride is added in the preparation method of the phosphorylated cellulose nanofibers and the deacetylated chitin nanocrystals modified PVA film.

[0106] Comparative Example 5

[0107] The difference between Comparative Example 5 and Example 1 is that 1.5 g of ferric chloride is added in step S2 of the method for preparing the phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals modified PVA film.

[0108] Performance Testing

[0109] The mosaic decorative films of Examples 1 to 10 and Comparative Examples 1 to 5 were respectively made into samples with a length of 80 mm, a width of 6.5 mm and a thickness of 3 mm, and a blank control group, i.e. a PET film of the same size, was set up. A total of 16 groups of samples were tested as follows:

[0110] 1. Limiting oxygen index (LOI) test: The LOI value of each group of samples was tested using a limiting oxygen index instrument according to GB / T 2406.2-2009 “Determination of Combustion Behavior of Plastics by Oxygen Index Law”, as shown in Table 1.

[0111] 2. Abrasion resistance test: The abrasion tester was used according to GB / T 1768-2006 "Determination of abrasion resistance of paints and varnishes - Rotating rubber grinding wheel method". The turntable speed was 70 rpm, the counterweight was 250 g, and the abrasion tester grinding wheel specifications were The number of turns was set to 100 and the mass wear was recorded. See Table 1 for details.

[0112] 3. Water resistance test: The contact angle of each group was tested at ambient temperature using a contact angle meter using a 5 μL water droplet. Each sample was tested three times and the average value was taken. See Table 1 for details.

[0113] 4. Mechanical strength test: The tensile strength and elongation at break of each group of samples were tested using a tensile testing machine according to GBT 1040.3-2006 “Test of tensile properties of plastics”. The specimen was type I and the test speed was 500 mm / min. Each sample was tested 3 times and the average value was taken. See Table 1 for details.

[0114] Table 1 Data of each group of samples

[0115]

[0116] It can be seen from Table 1 that, compared with the blank control group and comparative example 1, the mosaic decorative films of Examples 1 to 10 all have fire resistance, water resistance, wear resistance and mechanical properties.

[0117] Examples 1 and 4 to 7 are to explore the effect of the mass ratio of phosphorylated cellulose nanofibers and deacetylated chitosan nanocrystals on the performance of the decorative film. The best effect can be obtained when the mass ratio of phosphorylated cellulose nanofibers and deacetylated chitosan nanocrystals in the suspension is 50:50. This is because the positive and negative charges carried by the two are just in a state of complex equilibrium, so they can stably adhere to PVA, thereby improving the fire resistance, water resistance, wear resistance and mechanical properties.

[0118] Examples 1 and 8 to 10 and comparative examples 4 to 5 are used to explore the effect of the amount of ferric chloride added to the modified PVA film on the product performance. If 0 g of ferric chloride is added, the cross-linking network strength is poor and all properties will be affected. If the ferric chloride content is higher than 1 g, that is, the mass ratio of ferric chloride to PVA is greater than 1:5, a large amount of Fe 3+ Under the action of PVA hydroxyl group, it is reduced to Fe 2+ At the same time, the hydroxyl groups in the PVA molecules are oxidized to form carbonyl groups, and double bonds are generated due to the enol interconversion reaction. This causes the oxidized polymer to become darker in color, reduce its solubility, and precipitate from the aqueous solution, thereby affecting the performance of the protective film layer 5. Therefore, limiting the mass ratio of ferric chloride to PVA to within the range of 1: (5-20) can make the protective film layer 5 have good fire resistance, water resistance, wear resistance and mechanical properties.

[0119] After comparing Example 1 with Comparative Examples 1 to 3, it was found that only one type of fiber was modified in Comparative Examples 2-3 respectively, and the water resistance and fire resistance of the decorative films were greatly reduced, indicating that the phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals can synergistically improve the thermal stability, flame retardant effect, waterproof performance and mechanical properties of the modified PVA film.

[0120] In summary, the mosaic decorative film of the present invention has good waterproofness, fire resistance, wear resistance, bonding performance and mechanical strength, and has good practicality, such as Figure 2 As shown, the mosaic decorative film can be used as a protective film for furniture to provide protection for the furniture.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A mosaic decorative film, characterized in that: It includes a base layer, a printing layer, mosaic dots, an adhesive layer, and a protective film layer; wherein the adhesive layer is formed by curing an acrylic resin adhesive; The protective film layer is a PVA film modified by phosphorylated cellulose nanofibers and deacetylated chitin nanocrystals, and the preparation method thereof comprises the following steps: S1, mixing the phosphorylated cellulose nanofibers and the deacetylated chitosan nanocrystals to form a suspension; the mass ratio of the phosphorylated cellulose nanofibers to the deacetylated chitosan nanocrystals in the suspension is (30-70): (30-70); S2, mixing the suspension with the PVA solution, adding ferric chloride, stirring, and obtaining a mixed slurry, wherein the mass ratio of the suspension to the PVA is (9-11):1; the mass ratio of the ferric chloride to the PVA is 1:(5-20); S3, spreading the mixed slurry evenly, and then drying it to obtain the phosphorylated cellulose nanofiber and deacetylated chitin nanocrystal modified PVA film.

2. The mosaic decorative film according to claim 1, characterized in that: The mass concentration of the suspension is 0.5-1 wt %.

3. The mosaic decorative film according to claim 1, characterized in that: The method for preparing the phosphorylated cellulose nanofibers comprises the following steps: The wood pulp fiber is immersed in a phosphorylation solution to carry out a phosphorylation reaction to obtain a mixed slurry; the mixed slurry is then dried to obtain a mixture, and the mixture is then subjected to a heat curing treatment to obtain phosphorylated fibers; the phosphorylated fibers are added into water and mixed to prepare a dispersion, the pH value is adjusted to 9-10, and ultrasonic treatment is carried out, and finally the dispersion is centrifuged to take out a supernatant, which is the phosphorylated cellulose nanofiber; wherein the phosphorylation solution contains a mixture of ammonium dihydrogen phosphate and urea in a molar ratio of 1:(4-7); and the mass ratio of the phosphorylation solution to the wood pulp fiber is (5-6):

1.

4. The mosaic decorative film according to claim 3, characterized in that: The temperature of the phosphorylation reaction is 70-80° C., and the time is 10-40 minutes; the temperature of the thermal curing is 100-110° C., and the time is 10-30 minutes.

5. The mosaic decorative film according to claim 1, characterized in that: The method for preparing the deacetylated chitin nanocrystals comprises the following steps: Chitosan is mixed with sodium hydroxide solution, sodium borohydride is added to carry out deacylation reaction, and then the reactant is collected and centrifuged, the solid is washed to neutrality, and dried to obtain the acetylated chitosan nanocrystals; wherein the mass ratio of chitosan, sodium hydroxide and sodium borohydride is 1 (10-12) (0.02-0.04).

6. The mosaic decorative film according to claim 5, characterized in that: The temperature of the deacylation reaction is 85-95° C. and the time is 1-4 hours.

7. The mosaic decorative film according to claim 1, characterized in that: The mosaic decorative film is selected from at least one of (I) to (III): (I) The thickness of the base layer is 1 to 2 mm; (II) the thickness of the adhesive layer is 0.1 to 0.5 mm; (III) The thickness of the protective film layer is 1 to 2 mm.

8. The method for preparing a mosaic decorative film according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) a printing layer is fixedly connected to the surface of the base layer, and a printing process is performed on the surface of the printing layer to obtain evenly distributed mosaic dots; (2) Adhesive the mosaic dots to the protective layer using an acrylic resin adhesive, and then heat-press and cure them to form a bonding layer between the mosaic dots and the protective layer, thereby obtaining the mosaic decorative film.

9. The method for preparing a mosaic decorative film according to claim 8, characterized in that: In the step (2), the amount of acrylic resin adhesive added is 90 to 150 g / m 2 The hot pressing temperature is 120-160°C, the time is 1-3 minutes, and the pressure is 0.4-1 MPa.

10. Use of the mosaic decorative film according to any one of claims 1 to 7 in the preparation of furniture.

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