KR20220067116A - Decorative Sheet Having Nano Cellulose - Google Patents

Abstract

The present invention relates to a decorative material including a base layer, a printing layer, and a transparent coating layer including nanocelluloses and a resin binder. The decorative material according to the present invention has an effect that the design of the printed layer is clear and can be observed without distortion, while the hardness of the surface is excellent.

Description

Decorative Material Containing Nano Cellulose {Decorative Sheet Having Nano Cellulose}

The present invention relates to a decorative material comprising a substrate layer, a printed layer, and a transparent coating layer comprising nano cellulose and a resin binder, and while improving the mechanical properties of the surface of the decorative material including nano cellulose, the image of the printed layer It relates to decorative materials that can be observed clearly.

Decorative materials refer to materials that can be used as various finishing materials on the inner walls of buildings, living accessories, and household items constituting living spaces.

In general, the decorative material has a structure of a laminate in which a base layer, a printing layer, and a surface coating layer are sequentially stacked in a height direction from the bottom surface. can

As the decorative material is used as a finishing material to protect various materials to be coated, it is easy to be exposed to repeated contact or strong impact on the surface of the decorative material. At this time, if the decorative material does not have sufficient hardness, scratches are formed on the surface, there is a problem that the appearance is damaged or the decorative material can be destroyed.

For the above reasons, the surface of the decorative material is configured to laminate a layer such as a surface coating layer, a transparent film layer, etc. on the surface of the printing layer.

Moreover, since the printing layer is configured to implement a design using inks of various colors and is not specially configured to prevent damage to the surface, without a coating layer or a transparent film layer on the surface, the appearance of the decorative material may be damaged due to damage to the printing layer. There are possible problems.

On the other hand, nano-cellulose refers to nano-structured cellulose, which is a light solid component that can be obtained through mechanical or chemical treatment on plant cell walls, has plastic-like properties, high transparency, renewability, biodegradability, and biodegradability. With its advantages such as stability, high thermal stability, and easy formability, it has recently been in the spotlight as a new material with eco-friendly manufacturing technology and high functionality.

Nanocellulose has high mechanical strength and can be processed into a film form, etc., and can be used for reinforcing materials for building materials and various molding materials. Accordingly, there is a problem in that the dispersibility to different materials is deteriorated.

In particular, there is a problem in that it cannot be dispersed in a hydrophobic polymer material, an aprotic organic solvent, or the like, and an aggregate is formed between the nano-cellulose particles.

Therefore, there is a need for research on a technique for using nano-cellulose having excellent mechanical properties to improve the mechanical properties of a decorative material and to facilitate the implementation of a printed layer.

Republic of Korea Patent No. 1677099 (2016.11.18) Chinese Patent Publication No. 2017-11292061 (2018.05.18)

Hubble et al. Nanocellulose in Thin Films, Coatings, and Plies for Packaging Applications: A Review. BioRes. 12(1), 2143-2233 (2017).

An object of the present invention is to provide a decorative material with improved surface hardness and improved mechanical properties.

An object of the present invention is to provide a decorative material including a transparent coating layer that can be observed without distortion while improving the hardness of the surface and the design of the printed layer is clear.

An object of the present invention is to provide a decorative material having improved dispersibility due to high hydrophilicity of nano-cellulose, in which nano-cellulose is uniformly dispersed in a transparent coating layer, thereby improving mechanical properties, such as surface hardness, on the entire surface of the decorative material.

Decorative material according to the present invention for solving the above problems,

It includes a substrate layer, a printing layer, and a transparent coating layer having nano cellulose and a resin binder.

In the present invention, the nano-cellulose may be one or more selected from the group consisting of cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs).

In the present invention, the nano-cellulose may be a cellulose nanocrystal.

In the present invention, the cellulose nanocrystals may have an average width of 5 to 30 nm (nanometers), and an average length of 80 to 1200 nm (nanometers).

In the present invention, the resin binder may include an acrylic resin, and the nano-cellulose may be included in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the resin binder.

In the present invention, the decorative material may have a surface abrasion resistance value of 500 to 1500 times.

In the present invention, the decorative material may have a Distinctness of Image of 75 or more.

The decorative material according to the present invention has the effect of improving the hardness of the decorative material surface and improving mechanical properties.

The present invention solves the problem of poor dispersibility due to high hydrophilicity on the particle surface of nano-cellulose, so that it is uniformly dispersed in the transparent coating layer, so that the effect of improving physical properties on the entire surface of the decorative material is excellent, and it has excellent processability.

The decorative material according to the present invention has an effect that the design of the printed layer is clear and can be observed without distortion while having excellent surface hardness.

An object of the present invention is to provide a decorative material having improved dispersibility due to high hydrophilicity of nano-cellulose, in which nano-cellulose is uniformly dispersed in a transparent coating layer, thereby improving mechanical properties, such as surface hardness, on the entire surface of the decorative material.

1 is a vertical cross-sectional schematic view of a decorative material according to an embodiment of the present invention;
2 is a TEM image of the decorative material of Comparative Example 6 (left) and Example 1 (right).

Hereinafter, each configuration of the present invention will be described in more detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out, but this is only an example, and the scope of the present invention is defined by the following contents Not limited.

The present invention relates to a decorative material having an effect of improving the mechanical properties of the decorative material while excellently realizing the inherent decorative properties of the decorative material by using an environmentally friendly and natural material useful for improving mechanical properties.

In particular, in order to utilize nano-cellulose, which is attracting attention as being effective in improving mechanical properties, aggregation of particles due to the inherent high hydrophilicity of nano-cellulose is improved so that it can be uniformly dispersed in the layer, thereby reducing processability and manufacturing efficiency. It is characterized in that it has excellent physical properties compared to the existing decorative materials without making it.

Hereinafter, the present invention will be described in more detail.

decorative material

The decorative material according to the present invention includes a base layer, a printing layer and a transparent coating layer, and the transparent coating layer includes nano cellulose.

In general, in decorative materials, the base layer is a layer forming the base of the decorative material, and constitutes a flat layer so that the design embodied in the printed layer can be displayed without deformation, and forms a feeling of thickness of the decorative material.

The decorative material according to the present invention may be used in various products such as wallpaper, flooring, interior film, exterior film, etc., and may further include an additional layer to provide functionality for each product.

The additional layer may be appropriately included for each function of wallpaper, flooring, etc., such as an adhesive layer, a reinforcing functional layer, a transparent film layer, a sound-absorbing layer, an impact mitigating layer, and an embossing layer, and it is limited to necessarily including one additional layer. and may be configured to include one or more layers.

The object to which the decorative material according to the present invention is applied can be utilized according to the characteristics of various products as described above. However, in the case of the decorative material according to the present invention, the transparent coating layer containing the naturally-derived nano cellulose is composed of the outermost surface of the decorative material, so that when applied to living spaces or household items, the harmfulness to people, animals, and plants is low, Even when discarded after use, it has excellent biodegradability compared to the case of using fillers made of plastic materials or reinforcing synthetic fibers.

1 is a vertical cross-sectional schematic view of a decorative material according to an embodiment of the present invention.

1, it can be seen that the decorative material according to an embodiment of the present invention has a structure in which a base layer 10, a printing layer 20, and a transparent coating layer 30 are sequentially stacked in the height direction from the bottom surface. have.

As described above, each decorative material may include an additional layer above and/or below each layer to provide additional functionality as it is used as a variety of products.

base layer

In the present invention, the base layer may be configured the same or similar to the base layer constituting the existing decorative material.

The base layer is a layer constituting the base of the decorative material, and may be configured to be flat so that the design to be displayed through the printing layer can be accurately realized, and configured to form a certain thickness, and configured to support the printing layer.

The base layer may be configured to further include components such as a plasticizer, a curing agent, and a filler based on the polymer component, and the constituents may be appropriately selected and added according to the physical properties to be imparted to the base layer.

The polymer constituting the base layer may include, for example, one or more selected from the group consisting of polyvinyl chloride, polyester, polyethylene terephthalate, polyethylene, polypropylene, polyvinylidene fluoride, and the like.

The polymer does not necessarily have to be a single component, and may be configured in various ways, such as using different polymers by blending them together.

The polymer may preferably be polyvinyl chloride.

The base layer is prepared in the form of a film by forming a composition in which various additional components are mixed based on the polyvinyl chloride polymer, and calendering it.

The thickness of the base layer may be 50 μm to 1000 μm (micrometer), preferably, 150 μm to 250 μm (micrometer). It is preferable that the base layer has a suitable supporting performance and is configured to have a thickness within the above range so that the decorative material satisfies the minimum durability.

print layer

In the present invention, one surface of the above-described base layer has a structure in which a printed layer is laminated.

The printed layer may be printed on the surface of the substrate layer by digital printing in terms of process efficiency.

The printed layer is a part for imparting decorative properties to the decorative material according to the present invention and improving the appearance, and may be configured in the same or similar manner as the existing decorative material.

The printed layer may be formed by drying after printing, or curing by thermal curing and/or photocuring after printing.

Specifically, the printing layer is formed using an ink composition, and the ink composition includes an acrylic resin, a pigment, and a photoinitiator.

The acrylic resin is a photocurable resin, and when light is irradiated to an ink composition including a photoinitiator, it is cured by a photocuring reaction triggered by the photoinitiator.

After the ink composition is printed on the surface of the base layer, the printed layer is cured by irradiating light having a wavelength of 200 nm to 400 nm (nanometers) to form a printed layer.

In order to improve the printability of the print layer, an undercoat (primer) coating may be performed on the surface of the substrate layer, which may be appropriately selected according to the characteristics of the substrate layer and the ink composition.

The printed layer may have a thickness of 30 μm to 150 μm (micrometers). If it is thicker than the thickness, there is a problem in that the flexibility of the decorative material is reduced, and if it is thinner than the thickness, there is a problem in that it is easily destroyed and the design of the printed layer may be damaged and deformed.

As the pigment included in the ink composition, various pigments such as inorganic pigments and organic pigments may be used. For example, inorganic pigments such as titanium oxide, iron oxide, alumina, talc, and calcium carbonate, and organic pigments such as azo pigments, phthalocyanine pigments and nitro pigments can be used.

transparent coating layer

In the present invention, the upper portion of the printed layer is provided with a transparent coating layer that prevents damage to the printed layer, can project the printed layer as it is, and protects the surface of the decorative material.

In particular, the decorative material according to the present invention is characterized in that it contains nano-cellulose, which is a naturally-derived new biophilic material capable of improving the mechanical properties of the material.

The transparent coating layer is preferably configured to be transparent so that the printing layer can be observed while satisfying certain surface properties.

The transparent coating layer is formed by applying a coating solution composition to the upper portion of the printing layer, drying or curing the coating solution composition, and the coating solution composition includes nano cellulose and a resin binder.

Nanocellulose is largely classified into cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs). In the case of cellulose nanofibers, it has a fiber shape, and in the case of cellulose nanocrystals, it has a rod shape.

The nano-cellulose added to the transparent coating layer may be one or more selected from the group consisting of cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs).

Although not necessarily limited to including only one component, preferably, it may include cellulose nanocrystals.

In general, in the case of using nano-cellulose in the form of fibers, the mechanical properties of the material itself are excellent compared to cellulose nanocrystals of the same concentration. However, when using nano-cellulose in the form of fibers, as shown in FIG. 2 (right), the tangled portion is stretched due to the hydrophilicity of the surface of the nano-cellulose, and there is a problem that the nano-cellulose is not uniformly dispersed in the coating layer, Accordingly, there may be a problem in that the mechanical properties of the coating layer are rather deteriorated.

Therefore, in the present invention, in consideration of the dispersibility of the nano-cellulose, by using the cellulose nanocrystal, the mechanical properties of the entire coating layer are improved.

Accordingly, in the present invention, while strengthening the mechanical properties of the surface of the decorative material using cellulose nanocrystals, the dispersibility is improved, and the processability of the cellulose nanocrystals for forming the transparent coating layer is improved, thereby improving the manufacturing efficiency of the decorative material, It was constructed so that nano-cellulose can be used for decoration.

The cellulose nanocrystals may have an average width of 5 to 30 nm (nanometers), and an average length of 80 to 1200 nm (nanometers). Preferably, the average length may be 150 nm to 300 nm (nanometers).

When the length is longer than the above length, it is difficult to uniformly disperse the cellulose nanocrystals in the coating solution composition, so that workability is lowered, and in some cases, there is a problem that the abrasion resistance and scratch resistance of the surface are rather lowered, and if it is shorter than the length, , there is a problem in that the effect of improving the surface hardness of the decorative material is reduced.

2 is a TEM image of a decorative material of a comparative example (left) and an example (right). Referring to FIG. 2, in the transparent coating layer on the surface of the decorative material according to Example (right), nano-cellulose particles are uniformly formed on the entire surface of the coating layer. On the other hand, it can be observed that nano-cellulose is entangled in the transparent coating layer on the surface of the decorative material according to the comparative example (left). Apart from its excellent mechanical properties, the mechanical properties of the transparent coating layer are rather deteriorated due to a decrease in dispersibility in the transparent coating layer.

On the other hand, the resin binder may be used to have transparency to be suitable for forming a transparent coating layer, and if it has transparency and has a characteristic of less distortion of the printed layer, it may be used without particular limitation.

Preferably, an acrylic resin can be used. In the case of using an acrylic resin, it is possible to form a transparent layer, and since the transparent coating layer can be formed through a photocuring reaction after the coating solution composition is applied, it is advantageous in terms of manufacturing efficiency.

More preferably, as the acrylic resin, a waterborne urethane acrylic resin may be used. When this is used, the compatibility with the nanocellulose having hydrophilicity is excellent, and there is an advantage in that the dispersibility of the nanocellulose can be further improved.

The acrylic resin may have a weight average molecular weight of 500 to 10000. Preferably, 1000 to 3000 can be used.

When the molecular weight is larger than the molecular weight, there is a problem that the curing of the coating layer is not properly made during the elapsed work, and when it is smaller than the molecular weight, there is a problem in that the elongation of the transparent coating layer is lowered.

The transparent coating layer may contain 0.5 to 10 parts by weight of the nano-cellulose based on 100 parts by weight of the acrylic resin. Preferably, it may be included in an amount of 1 to 6 parts by weight.

When added in excess than the above content, the projected printed layer is not clearly observed and there is a problem of reduced image quality. has a minor problem.

Accordingly, the decorative material including the transparent coating layer may have a Distinctness of Image (DOI) of 75 or more, preferably 85 or more.

Specifically, it is a unit that measures how clearly a reflected image appears on a reflective surface. In the present invention, the transparent coating layer has excellent transparency and clarity so that the design of the printed layer can be clearly implemented.

When the image quality is lower than the above numerical range, there is a problem in that the content of nano-cellulose is excessive or the transparency of the polymer itself is low.

The decorative material according to the present invention having a transparent coating layer containing nano-cellulose as described above may have a wear resistance value of 500 to 1500 times. Preferably, it may be 900 to 1100 times.

The surface hardness has a high value compared to the decorative material having a transparent coating layer that does not contain nano-cellulose, and when the surface hardness is lower than the numerical range, there is a problem that there is no significant difference compared to the existing decorative material, In order to configure higher than the numerical range, as the content of nano-cellulose must be excessive, there is a problem that cannot be easily manufactured due to problems such as difficulty in preparing a coating solution composition.

The transparent coating layer is a photocurable layer, similar to the printing layer, after applying the composition forming the transparent coating layer to the surface of the printing layer, it can be prepared by curing by irradiating ultraviolet rays with a wavelength of 200 to 400 nm (nanometers). have.

How to manufacture decorative materials

The decorative material according to the present invention may be manufactured in an in-line process similar to the conventional method of manufacturing the decorative material.

Specifically, forming the base layer, printing an ink composition on the surface of the base layer and curing it to form a printed layer, applying a coating solution composition to the surface of the print layer and curing it to form a transparent coating layer may include the step of

Each process may be configured to be sequentially stacked in one process line.

The step of forming the base layer may be a step of calendering and extruding the composition for forming the base layer and processing it into a film form, and the step of forming the print layer includes gravure printing, digital printing, It can be printed in the form of a design to be implemented on the decorative material by using various printing technologies such as screen printing. After printing, the ink composition is irradiated with light as described above and cured by a photocuring reaction to form a printed layer.

On the other hand, in the step of forming the transparent coating layer, the coating solution composition is applied on the top of the printing layer using various methods such as roll coating, knife coating, digital printing, gravure printing, etc., and then irradiated with light as described above. , is formed as a transparent coating layer by curing by a photocuring reaction.

By finally performing the step of forming the transparent coating layer, the mechanical properties of the decoration material are improved as the finished decoration material is provided with a transparent coating layer containing nano cellulose, and at the same time, the design of the printed layer as a transparent coating layer is vividly and without deformation. have the effect that

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out, but this is only an example, and the scope of the present invention is defined by the following contents Not limited.

[Production Example]

A decorative material was prepared based on the following Table 1.

The base layer was prepared by mixing a composition containing polyvinyl chloride, and then, a stretched polyvinyl chloride base layer in the form of a film having an average thickness of 200 μm by a calendering method.

UV curable ink was printed on one surface of the prepared base layer, and UV rays of 350 nm were irradiated at 1,200 mJ/cm 2 to form a printed layer.

After printing the composition for forming a transparent coating layer on the surface of the cured printing layer, ultraviolet rays having a wavelength of 200 to 400 nm were irradiated at 1,200 mJ/cm 2 to form a transparent coating layer.

(Unit: phr) Example comparative example Reference example One 2 3 4 5 6 One 2 3 4 5 6 7 8 base layer PVC 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 plasticizer 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 print layer acrylate
Suzy 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 pigment 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 photoinitiator 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 transparent coating layer acrylate
Suzy 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 CNCs Width: 20 nm, Length: 100 nm One 3 5 - - - - - - - - - - - unadded Width: 20 nm, Length: 200 nm - - - One 3 5 10 0.5 - - - - - - Width: 20 nm, Length: 50 nm - - - - - - - - One 3 5 - - - Width: 20 nm, Length: 2㎛ - - - - - - - - - - - One 3 5 photoinitiator 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

[Experimental example]

For the manufactured decorative material, the physical properties were evaluated as follows. The results of each physical property evaluation are shown in Table 2 below.

1. Measurement of surface abrasion resistance of decorative materials

For each decorative material specimen, the surface abrasion resistance was measured using a Taber Rotary Abraser (Taber 5155, Taber Industry).

- Wear wheel (CS-17, Taber Industry)

- load 1kg

- KSM ISO 9352, result evaluation method b

2. Measurement of surface scratch resistance of decorative materials

For each decorative material specimen, the surface scratch resistance was measured using a Pencil Hardness Tester (CT-PC2, Coretech).

- Load 0.5kg

- Angle 45˚

- KS M ISO15184, KS G 2603 (pencil)

- 9H (highest scratch resistance) ~ 9B (lowest scratch resistance)

3. Measurement of Distinctness of Image (DOI)

For each decorative material specimen, the DOI value was measured using a Goniophotometer (Rhopoint IQ, RHOPOINT Instruments).

- Resolution 0.1 / Reproducibility ±0.2 / Precision ±0.5

- Measuring range: 0-100

- STANDARD, ASTM D5767 (Measures the sharpness of reflected images)

4. Surface adhesion measurement

For each decorative material specimen, the surface of the coating layer was cross-cut by 10 horizontal and vertical lines at 1 mm intervals to form a total of 100 slices. Thereafter, the number of peeled fragments among 100 fragments was checked using the tape specified in the fragment topography to measure surface adhesion.

- ASTM D3359 Method B

- O: The number of detached fragments is less than 5

- △: The number of detached fragments is 5 or more but less than 15

- X: The number of detached fragments is 15 or more

division Example comparative example Reference example One 2 3 4 5 6 One 2 3 4 5 6 7 8 wear resistance
(CS-17, 1kg)
(unit: number of times) 1100 1150 1150 1150 1300 1250 850 1025 1050 1100 1000 1150 1350 1250 1050 scratch resistance F F F F H H HB F HB F HB F F F HB Seon Young-seong (DOI) 89.2 87.8 86.5 89 87.1 86.1 81.2 89.3 89.1 88.7 86.9 85.9 83.6 81.5 89.8 adherence O O O O O O △ O O O O O O △ O

The abrasion resistance value is to measure the mechanical properties of the surface of the decorative material, and refers to the number of times the wear wheel is applied until the transparent coating layer is damaged and removed and the printing layer starts to be damaged by repeatedly contacting the abrasive wheel to the surface of the decorative material.

Therefore, the higher the wear resistance value, the better the wear resistance.

Referring to Tables 1 and 2, in the case of the specimens of Examples, it can be confirmed that the wear resistance value has a value of 1100 or more. In the case of all Examples and Comparative Examples 4 and 6 to 8, it can be confirmed that the physical properties of the wear resistance of the surface were improved compared to the reference example in which CNCs were not added.

On the other hand, in the case of Comparative Example 1, even though the same CNCs as in Examples 1 to 3 were added, as the content of CNCs was excessive, it could be confirmed that the surface abrasion resistance of the decorative material was rather reduced.

As an excessive amount of CNCs is added, the CNCs are not uniformly dispersed in the coating solution for forming the transparent coating layer, so it is difficult to form a transparent coating layer of uniform thickness. appeared, and the abrasion resistance of the decorative material was lowered. For this reason, in the case of Comparative Example 1, the value of the image quality of the decorative material was the lowest.

On the other hand, in the case of Comparative Examples 3 to 5, in which the length of the CNCs is relatively short compared to the Examples, the wear resistance is lowered even as the content of the CNCs is increased, and it can be confirmed that the scratch resistance is also equal or lower. As the length of CNCs shortened, the surface area showing high hydrophilicity greatly increased, and as the surface area increased, agglomeration due to the hydrophilicity of CNCs appeared.

In particular, Comparative Examples 3 to 5, although the CNCs of the same content as Examples 1 to 6 were used, abrasion resistance was evaluated low, and scratch resistance was also evaluated low.

Referring to Comparative Examples 6 to 8, as compared to the reference example, the scratch resistance was confirmed to be at the same level as the example, but as the image quality of the decorative material was lowered, the image of the printed layer when the transparent coating layer was projected on the printed layer There is a problem that is distorted, there is a problem that the quality of the decorative material is lowered.

In particular, in the case of Comparative Example 8, there was a problem of poor adhesion of the transparent coating layer, there was a problem that the durability of the decoration material itself was lowered.

10: base layer, 20: printing layer, 30: transparent coating layer

Claims (7)

base layer; printed layer; and
Transparent coating layer having nano cellulose (Nano Celluloses) and a resin binder; A decorative material comprising. According to claim 1,
The nano-cellulose is cellulose nanofibers (Cellulose Nanofibers, CNFs) and cellulose nanocrystals (Cellulose Nanocrystals, CNCs) at least one decorative material selected from the group consisting of. According to claim 1,
The nano-cellulose is a decorative material that is a cellulose nanocrystal. 4. The method of claim 3,
The cellulose nanocrystal has an average width of 5 to 30 nm (nanometers), and an average length of 80 to 1200 nm (nanometers). According to claim 1,
The resin binder includes an acrylic resin,
The nano-cellulose is a decorative material that is included in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the resin binder. According to claim 1,
The decorative material has a surface abrasion resistance value of 500 to 1500 times. According to claim 1,
The decorative material is a decorative material having a Distinctness of Image of 75 or more.

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