Scratch-resistant grain lettering film and manufacturing method thereof
Technical Field
The invention relates to the field of TPU material application, in particular to a scratch-resistant grain lettering film made of a TPU material and a manufacturing method thereof.
Background
The grain lettering film is a heat transfer printing product, and its principle is that the transfer printing film with grain is directly contacted with printing stock, and the grain layer on the transfer printing film is transferred onto the printing stock by means of heating and pressurizing action of heat transfer printing equipment, and generally is formed from four portions of hot-melt adhesive layer, grain layer, resin forming layer and release film, in which the resin forming layer can be used for forming and protecting pattern of finished product after transfer printing, and mainly determines the performance and forming effect of product, and has the important action for quality of whole grain lettering film.
The existing grain lettering film is mostly made by adopting a PET film, a PVC film, a PC film and the like as release films and forming a resin molding layer, a grain layer and a hot melt adhesive layer through coating by a coating process. Due to the performance limitation of the colloid of the resin molding layer, the lettering film has the defects of poor molding, scratch resistance and the like, and can not meet the requirements of zipper films and some shoe and clothes products which need scratch resistance.
Patent document CN 102936476B discloses a method for manufacturing a thermal transfer adhesive film, which is equivalent to the method for manufacturing a lettering film in practical application, and improves a hot melt adhesive layer without improving a resin molding layer, so that the overall quality of the lettering film is not improved.
The TPU (thermoplastic polyurethane elastomer) is a thermoplastic elastomer, has the characteristics of wear resistance, high elasticity, good impact property and the like, but has the defects of low surface hardness and poor formability, and the TPU film is soft and is easily scratched by a strong external force.
ABS (acrylonitrile-butadiene-styrene) is a common thermoplastic resin with excellent performance and has the advantages of balanced mechanical properties, excellent processability, high surface hardness and the like.
Disclosure of Invention
Therefore, in order to solve the above problems, the present invention provides a scratch-resistant grain lettering film and a manufacturing method thereof, which solve the problem of poor scratch resistance of the grain lettering film in the prior art.
In order to achieve the purpose, the invention adopts the following technical scheme:
the scratch-resistant grain lettering film comprises, from bottom to top, a release film, a release layer, a resin molding layer, a grain layer and a hot melt adhesive layer in sequence, and is characterized in that the resin molding layer comprises, by weight, 60% -70% of TPU, 5% -15% of ABS, 10% -20% of sodium stearate modified wollastonite, 1% -5% of a compatilizer, 1% -5% of polysiloxane and 0% -2% of a flatting agent. Stearic acid modified wollastonite powder (calcium silicate), wherein a stearic acid end is well combined with ABS and TPU polar ends, and a wollastonite end forms a rigid filling core which is uniformly dispersed in a resin blend to form a stable structure, so that the surface hardness of the blended resin is obviously enhanced, and the scratch resistance is improved; the compatibilizer can act as a bridge for the calcium silicate to link with the TPU or ABS; the surface lubrication effect of the polysiloxane can reduce the surface friction coefficient so as to improve the surface scratch resistance of the material; leveling agents improve the flow properties of the blend.
The further improvement is that: the TPU is a polyester polyurethane elastomer, and the Shore A hardness of the TPU is 65-80; the wear resistance, tear resistance and tensile and tear strength of the polyester polyurethane are superior to those of polyether polyurethane.
The further improvement is that: the stearic acid modified wollastonite powder (calcium silicate) has an average particle size of 4-6 μm, has a large specific surface area, can be better combined with resin, and has better dispersibility.
The further improvement is that: the preparation method of the stearic acid modified wollastonite comprises the following steps: adding stearic acid accounting for 1.0-1.2% of the weight of the wollastonite powder, stirring at the speed of 900-1000r/min, at the temperature of 80-120 ℃ for 20-30min, cooling, and removing larger particles to obtain stearic acid modified wollastonite powder.
The further improvement is that: the compatilizer is ABS grafted maleic anhydride (ABS-G) or styrene-maleic anhydride copolymer (SMA) or methacrylic acid-butadiene-styrene (MBS), and the compatibility and the mechanical strength of the blending material are further improved.
The further improvement is that: the leveling agent is an acrylic leveling agent, and can improve the leveling effect, increase smoothness and improve the scratch resistance.
A novel scratch-resistant grain lettering film manufacturing method comprises the following steps:
1) preparing a release film (commonly used PET, PVC, PC and the like);
2) coating a layer of silicone oil on the release film to serve as a release layer, wherein the release layer is used for enabling the release film to be easily separated from the resin forming layer in the use process of the lettering film;
3) coating the resin molding layer material of the invention on the release layer by using an extrusion coating method; the resin forming layer determines the forming effect and the scratch resistance of the scratch-resistant grain lettering film;
4) printing a line layer on the resin molding layer;
5) coating hot melt adhesive on the grain layer to form a hot melt adhesive layer, and manufacturing a scratch-resistant grain lettering film; the hot melt adhesive layer has higher adhesive force with the surface of the printing stock, so that the grain layer is firmly combined with the surface of the printing stock, and the hot melt adhesive layer must be matched with a printing material and selected according to different printing stocks.
The further improvement is that; the thickness of the release film is 5c-10 c.
The further improvement is that: the resin molding layer adopts an extrusion coating process, a double screw is used in an extrusion stage, the temperature of each section of an extruder is 180-240 ℃, and the rotating speed of the screw is 200-400 r/min; coating the wet film with the thickness of 20c-30c, drying in a 12-section oven at 60-115 ℃ at the speed of 75-100 m/min.
The further improvement is that: and heating and drying the scratch-resistant grain lettering film at the temperature of 80-100 ℃ for 5-8 minutes to ensure that the surface of the scratch-resistant grain lettering film is dry by touch, so that the viscosity is reduced.
By adopting the technical scheme, the invention has the beneficial effects that:
1. the ABS added in the formula of the resin molding layer has the advantage of higher surface hardness, and the scratch resistance and the moldability of the resin molding layer are improved while the texture of TPU is maintained.
2. The structure formed by using the sodium stearate modified wollastonite as the filler is stable, and the surface scratch resistance of the TPU base material is obviously improved.
3. The compatilizer ABS is grafted with maleic anhydride (ABS-G) or styrene-maleic anhydride copolymer (SMA) or methacrylic acid-butadiene-styrene (MBS), so that the compatibility of TPU and ABS and the mechanical strength of a mixed material are improved, and the scratch resistance of a resin molding layer is further improved.
4. The polysiloxane has a surface lubricating effect, and can reduce the surface friction coefficient so as to further improve the scratch resistance of the resin molding layer.
5. The acrylic leveling agent can improve the leveling effect, increase the smoothness, improve the scratch resistance and further improve the scratch resistance of the resin molding layer.
6. By adopting the extrusion coating process, the coating has good uniformity and can obtain a coating with ideal thickness.
7. The grain lettering film manufactured by the method has clear grains, retains the advantage of good hand feeling of TPU, improves the scratch resistance, and has wide market value and social value particularly in the zipper film industry and the shoe and clothes industry.
Drawings
FIG. 1 is a view showing the structure of a scratch-resistant type grain marking film of example 1 of the present invention.
FIG. 2 is a production flow chart of example 1 of the present invention.
Detailed Description
The following detailed description will be provided for the embodiments of the present invention with reference to specific embodiments, so that how to apply the technical means to solve the technical problems and achieve the technical effects can be fully understood and implemented.
Unless otherwise indicated, the technical means employed in the examples are conventional means well known to those skilled in the art, and the reagents and products employed are commercially available.
Example 1
The utility model provides a scratch-resistant type line membrane of carving characters, as shown in figure 1, from bottom to top in proper order for PET to leave type membrane 1, silicon oil from type layer 2, resin shaping layer 3, line layer 4, hot melt adhesive layer 5, resin shaping layer raw materials component is polyester TPU60 KG, ABS15KG, stearic acid modified wollastonite powder 20KG (average particle diameter 4 mu m-6 mu m), ABS-G3 KG, polysiloxane 1KG, acrylic acid flatting agent 1 KG.
The preparation method of the stearic acid modified wollastonite powder comprises the following steps: adding 0.25KG stearic acid into wollastonite powder 25KG with average particle size of 4-6 microns, stirring at 900r/min and 80 ℃ for 20min, cooling to room temperature, and removing larger particles to obtain stearic acid modified wollastonite powder.
Referring to fig. 2, the method for preparing the scratch-resistant grain lettering film comprises the following steps:
coating a layer of silicone oil on a PET release film 1 with the width of 1000mm and the thickness of 10c to form a release layer 2; fully mixing the raw material components of the resin molding layer to obtain a mixture, feeding the mixture into a double-screw extruder, fully fusing the materials under the shearing, mixing and conveying of a screw to form coating liquid, and extruding the coating liquid from a gap of an extrusion nozzle under the conditions that the temperature of each section of the double-screw extruder is 180-200 ℃ and the rotating speed of the screw is 400 r/min; coating the extrusion coating liquid on a release layer 2 to form a resin forming layer 3, wherein the thickness of a coated wet film is 20c, the speed of the coating is 75m/min, the section of an oven is 12, and the drying temperature is 115 ℃; printing a grain layer 4 on the resin molding layer 3; and (3) coating a hot melt adhesive film 5 on the grain layer 4, heating and drying for 5 minutes at 100 ℃ to ensure that the surface of the grain layer is dry by touch, and reducing the viscosity to prepare the scratch-resistant grain lettering film.
Example 2
The utility model provides a resistant type line membrane of carving characters, is PET from type membrane, silicone oil from type layer, resin shaping layer, line layer, hot melt adhesive layer by supreme down in proper order, resin shaping layer raw materials component is polyester TPU60 KG, ABS5KG, stearic acid modified wollastonite powder 10KG, ABS-G1 KG, polysiloxane 1KG, acrylic acid flatting agent 5 KG.
The preparation method of the stearic acid modified wollastonite powder comprises the following steps: adding 15KG of wollastonite powder with the average particle size of 4-6 microns into stearic acid, stirring at the speed of 1000r/min and the temperature of 120 ℃ for 30min, cooling to room temperature, and removing larger particles to obtain stearic acid modified wollastonite powder.
The preparation method of the scratch-resistant grain lettering film comprises the following steps:
coating a layer of silicone oil on a PET release film with the width of 1000mm and the thickness of 5c to serve as a release layer; fully mixing the raw material components of the resin molding layer to obtain a mixture, feeding the mixture into a double-screw extruder, fully fusing the materials under the shearing, mixing and conveying of a screw to form coating liquid, and extruding the coating liquid from a gap of an extrusion nozzle under the conditions that the temperature of each section of the double-screw extruder is 220-240 ℃ and the rotating speed of the screw is 200 r/min; coating the extrusion coating liquid on a release layer to form a resin forming layer, wherein the thickness of a coated wet film is 30c, the speed is 100m/min, the section of an oven is 12, and the drying temperature is 60 ℃; printing a grain layer on the resin molding layer; and coating a hot-melt adhesive film on the grain layer, heating and drying for 8 minutes at 80 ℃ to ensure that the surface of the grain layer is dry by touch, and reducing the viscosity to prepare the scratch-resistant grain lettering film.
Example 3
The utility model provides a resistant scratch type line membrane of carving characters, is PET from type membrane, silicone oil from type layer, resin shaping layer, line layer, hot melt adhesive layer by supreme down in proper order, resin shaping layer raw materials component is polyester TPU 70KG, ABS10KG, stearic acid modified wollastonite powder 10KG, ABS-G5 KG, polysiloxane 4.9KG, acrylic acid flatting agent 0.1 KG.
The preparation method comprises the following steps:
coating a layer of silicone oil on a PET release film with the width of 1000mm and the thickness of 7.5c to serve as a release layer; fully mixing the raw material components of the resin molding layer to obtain a mixture, feeding the mixture into a double-screw extruder, fully fusing the materials under the shearing, mixing and conveying of a screw to form coating liquid, and extruding the coating liquid from a gap of an extrusion nozzle under the conditions that the temperature of each section of the double-screw extruder is 200-220 ℃ and the rotating speed of the screw is 300 r/min; coating the extrusion coating liquid on a release layer to form a resin forming layer, wherein the thickness of a coated wet film is 25c, the speed is 90m/min, the section of an oven is 12, and the drying temperature is 80 ℃; printing a grain layer on the resin molding layer; and coating a hot-melt adhesive film on the grain layer, heating and drying for 6 minutes at 90 ℃ to ensure that the surface of the grain layer is dry by touch, and reducing the viscosity to prepare the scratch-resistant grain lettering film.
Experimental example: performance testing
The scratch-resistant grain lettering films of examples 1-3 and the grain lettering film finished products (PE material 4, PVC material 5 and PU material 6) purchased in the market are transferred onto the clothing cloth according to the heat transfer printing temperature of 150 ℃, the time of 10s and the pressure of 6KG to respectively manufacture heat transfer printing finished products 1-6, and the conventional pencil hardness test and the GB/T8629 fabric washing standard water washing resistance test are carried out, and the results are shown in the first table:
watch 1
The experimental results show that the pencil hardness of the examples 1-3 is higher than that of the market products 4-6, the washing resistance experiment has no degumming, and the example 1 with higher ABS and other additives has higher scratch resistance, so that the scratch-resistant grain lettering film disclosed by the invention has higher scratch resistance and can better meet the application requirements of zippers and shoes and clothes under the condition of meeting basic requirements.
While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.