WO2019154251A1

WO2019154251A1 - Composite printing paper film for environmentally friendly pasting transfer direct-printing patterned paper and preparation method therefor

Info

Publication number: WO2019154251A1
Application number: PCT/CN2019/074118
Authority: WO
Inventors: 郑少华; 邹卫红; 郑乃玮
Original assignee: 佛山荷韵特种材料有限公司
Priority date: 2018-02-09
Filing date: 2019-01-31
Publication date: 2019-08-15
Also published as: CN108274914A; CN108274914B

Abstract

Disclosed are a composite printing paper film (10) for an environmentally friendly pasting transfer direct-printing patterned paper, and a preparation method therefor. The composite printing paper film is a composite material composed of a composite base paper (1) having a water transfer property and a printing film layer (2) capable of easily pasting a pattern. One side of the printing film layer is bonded to the composite base paper, and the other side of the printing film layer is used for printing a pattern, with the surface tension of the printing surface of the printing paper film being 32-38 dynes. After the composite material is immersed in water, the printing film layer can be separated from the composite base paper. By means of a special resin selection and a special formula combination in conjunction with a pre-resin coating process, this composite printing paper film and the preparation method therefor change the material used for conventional patterned papers and the configuration of a printing layer, eliminate a solvent-type cover glue layer used in the process of producing patterned papers, resulting in reduced emissions and in same being environmentally friendly, reduce the production time, significantly reduce costs, and improve the fineness of printing.

Description

Composite printing paper film for environmentally-friendly paste transfer direct printing paper and preparation method thereof

Technical field

The invention relates to the field of water transfer printing flower paper, in particular to a composite printing paper film for environment-friendly paste transfer direct printing paper and a preparation method thereof.

Background technique

Water transfer printing process, the principle is to first print the pattern on the bottom paper, then apply a layer of flexible coating film on the surface of the printed paper with a printed pattern to make a water transfer decal, then put the water transfer decal Soaking in water, dissolving the water sol of the water transfer decal paper in water, separating the patterned flexible coating film from the base paper, and transferring the patterned flexible coating film to the surface of the substrate to complete the water transfer printing.

The existing water transfer printing paper is realized by completely and conveniently transferring the printing pattern from the printing paper after soaking the water, by applying a flexible coating on the printing pattern, that is, transferring It is a flexible coating film to which a printed pattern is attached. As shown in FIG. 1, the conventional water transfer decal paper includes a water transfer transfer paper 1, and a printing layer 2 printed on one or more printing surfaces of the water transfer transfer paper 1 is provided on The flexible coating film 3 on the printed layer 2.

However, due to its special physical property requirements, the flexible coating film 3 can only be printed on the pattern by screen printing using an acrylic resin coating material. These kinds of resin coatings are currently solvent-based coatings. The production and use process will produce a large amount of organic solvent waste gas. In addition, most of the domestic water transfer printing enterprises are small-scale companies, and basically do not have sufficient effective treatment of these organic The ability of solvent exhaust gases has also led the industry to become a heavily polluting industry. The application of the screen printing method to form the coating film requires a long drying and drying time, thereby greatly reducing the production efficiency and increasing the cost.

Summary of the invention

The technical problem to be solved by the present invention is to provide a composite printing paper film special for environmentally-friendly paste transfer direct printing paper and a preparation method thereof, which change the setting mode of the printing layer, reduce the solvent-type cover rubber layer, and reduce emissions. Environmental protection, reducing the printing of paper and paper, and significantly reducing costs.

The technical problem to be solved by the invention is also to provide a composite printing paper film special for environmentally-friendly paste transfer direct printing paper and a preparation method thereof, which are not deformed by moisture absorption, have high printing exquisiteness, and the printing layer is easy to transfer.

In order to achieve the above technical effects, the present invention provides a composite printing paper film for environmentally-friendly adhesive transfer printing paper, which is a composite of at least one composite paper having water transfer property and at least one printed film layer which can be easily decaled. material;

After the composite material is immersed in water, the printed film layer can be detached from the composite base paper;

One side of the printed film layer is bonded to the composite base paper, and is a non-printing surface;

The other side of the printed film layer is used for printing a pattern, which is a printing surface;

The surface of the printed surface of the printed paper film has a surface tension of 32-38 dyne such that the release force between the printed paper film and the printed layer is less than the release force between the printed layer and the surface of the target printed article.

As an improvement of the above scheme, the printing film layer is produced by a plastic resin extrusion coating process.

As an improvement of the above solution, the raw material of the printing film layer is selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, POE, ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyurethane, ABS, EPDM copolymer. One or several of the resins.

As a modification of the above scheme, the raw material of the printing film layer has a tensile strength of 4 to 12 MPa.

As an improvement of the above solution, the raw material of the printing film layer further includes an auxiliary agent, and the auxiliary agent is one or more of an anti-blocking agent, a slip agent, and a silicone-based surface tension adjusting aid.

As a modification of the above scheme, the printed film layer has a thickness of 8 to 40 μm.

As an improvement of the above solution, the composite base paper comprises:

Special paper for water transfer printing paper;

a bottom layer connected to the special paper for water transfer printing paper;

a core layer connected to the underlayer;

a skin layer joined to the core layer, the skin layer being bonded to the printed film layer.

As a modification of the above scheme, the composite base paper has a basis weight of 40 to 130 g/m ² .

As a modification of the above scheme, the bottom layer is formed by coating a first coating material which is a coating made of kaolin/calcium carbonate, a synthetic latex and an auxiliary agent;

The core layer is formed by coating a second coating material, which is a modified starch boiled solution, or a solution prepared by digesting starch and water-soluble raw material;

The skin layer is formed by coating a third coating which is a modified starch boiling solution.

As a modification of the above solution, the coating amount of the bottom layer of the composite base paper is 10-20 g/m ² ;

The coating amount of the core layer of the composite base paper is 3-7 g/m ² ;

The coating amount of the surface layer of the composite base paper is ² to 5 g/m ² .

As an improvement of the above scheme, the printed surface of the printed paper film is previously subjected to corona treatment to achieve a desired surface tension.

Correspondingly, the present invention also provides a preparation method of a composite printing paper film for environmentally-friendly paste transfer direct printing paper, comprising:

(1) preparing a composite base paper;

(2) The printed film layer is prepared by extrusion coating plastic resin on the composite base paper, and then subjected to trimming, surface corona treatment, winding, cutting, and packaging into a finished printed paper film.

As an improvement of the above scheme, the step (1) includes:

Providing a special paper for water transfer printing paper;

Coating a coating made of kaolin/calcium carbonate, synthetic latex and auxiliary agent on the surface of the base paper and drying to form a bottom layer;

On the surface of the bottom layer, coating a solution of the modified starch boiled solution, or the modified starch and the water-soluble raw material, and drying to form a core layer;

On the surface of the core layer, the modified starch boiled solution is coated and dried to form a surface layer.

The implementation of the invention has the following beneficial effects:

1. The present invention provides a composite printing paper film for environmentally-friendly paste transfer printing paper, comprising a composite base paper and a printing film layer, wherein the printing film layer is used for printing a pattern. The invention changes the printing mode of the existing water transfer printing paper printing layer, and directly prints the pattern on the printing film layer instead of the water transfer printing paper. The printed paper film is used as the printing substrate, and because the printing surface has extremely high smoothness and extremely low roughness, and the plastic film has excellent dimensional stability, it is not as easy to absorb moisture as the paper material, so it is deformed. The printing exquisiteness of the invention is far superior to that of traditional flower paper.

2. The invention replaces the acrylic resin coating with a plastic resin film layer, because the physical properties of the latter vary greatly with climate temperature and storage time, while the former has excellent physical property stability, and thus greatly improved. The quality of printed paper.

Third, the use of the printing paper film of the invention to produce water transfer printing paper eliminates the process of printing the cover glue which is necessary in the traditional flower paper printing process, so the invention can greatly reduce the solvent discharge in the printing process, save energy and reduce emissions, and improve Productivity.

4. Compared with the traditional flower paper made by water transfer printing paper and cover glue, the new material and new structure paper also have a stronger cost competitive advantage, and the cost will be reduced by more than 40%.

DRAWINGS

1 is a schematic structural view of a conventional water transfer decal;

2 is a schematic structural view of a composite printing paper film for environmentally-friendly paste transfer direct printing paper according to the present invention;

Figure 3 is a schematic structural view of the composite liner shown in Figure 2;

Fig. 4 is a schematic view showing the structure of the environmentally friendly paste transfer straight printing paper of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the drawings and specific embodiments.

As shown in FIG. 2, the present invention provides a composite printing paper film 10 for environmentally-friendly paste transfer printing paper, comprising:

Composite base paper 1;

a printing film layer 2 disposed on the composite backing paper 1, one side of the printing film layer 2 is connected to the composite backing paper 1, is a non-printing surface 2A;

The other side of the printed film layer 2 is used for printing a pattern, which is a printing surface 2B.

The composite printed paper film is a composite material composed of at least one composite backing paper 1 having water transfer properties and at least one printed film layer 2 which can be easily decaled. After the composite material is immersed in water, the printed film layer 2 can be detached from the composite backing paper 1.

The present invention changes the printing method of the conventional water transfer printing paper printing layer, and directly prints the pattern on the printing paper film 2 instead of the water transfer backing paper. The printed paper film 2B is used as a printing printing surface, and the invention has extremely high smoothness and extremely low roughness, and the plastic film has excellent dimensional stability, and is not easily deformed by moisture like paper. The print is much more beautiful than traditional paper. Moreover, by using the printed paper film of the invention to produce flower paper, the printed film layer serves as a substrate and transfer substrate, and the traditional cover layer is not required, so the invention can greatly reduce the solvent discharge in the printing process, and save energy. row. In addition, compared with the traditional flower paper made by water transfer printing paper and cover rubber, the new material and new structural paper also have a stronger cost competitive advantage, and the cost will be reduced by more than 40%.

The flower paper of the novel structure of the invention can be used in the subsequent decal application, and the printing film layer can be printed while the flower paper is immersed in water and then the printed film layer with the printing layer is separated. Paste on the surface of the object. After the applique is dried or dried, the transferred film can be peeled off from the printed layer easily, completely and without damaging the printed image. For this reason, how to realize the printing film layer can be easily peeled off completely without damaging the printing pattern, which is a technical difficulty realized by the present invention.

For this reason, the printed film layer of the printed paper film needs to be specially formulated and subjected to appropriate corona treatment so that it has good printing property and the release force from the printing layer is lower than that of printing. The release force between the layer and the surface of the object is such that the printed film layer can be easily peeled off intact. However, if the release force is too low, the printed layer will be detached from the film prematurely before or during the pasting process, which will result in the transfer layer failing, and the release force is too low, and the printed paper film surface does not have good printability. The pattern is difficult to print on the printed paper film in a complete and beautiful manner, which may result in failure to use it properly.

In order to overcome the two mutual factors of the peelability of the printed paper film and the printability, the surface tension of the printed surface 2B of the printed paper film should be controlled to 32-38 dynes. When the surface tension is more than 32 dynes, the printed surface of the printed paper film has good printability. However, in order to be able to remove the printed film after decaling without damaging the printed pattern, the surface tension of the surface should be less than 38 dynes. If the surface tension of the printed surface 2B of the printed paper film is less than 32 dynes, the printed surface of the printed paper film does not have good printability, and printing is difficult; if the surface tension of the printed surface 2B of the printed paper film is greater than 38 dynes, the printed film The layer will be difficult to peel off from the surface of the printed layer.

Preferably, the surface tension of the printing surface 2B of the printed paper film is 32-37 dynes. More preferably, the surface tension of the printing surface 2B of the printed paper film is 32-36 dynes.

In the preparation of a printed paper film, the printed paper film is produced by a plastic resin extrusion coating process.

Laminating refers to a process in which a plastic extruder is used to plasticize and melt a plastic resin, and then a resin in a flowing state is poured onto a substrate through a narrow slit die of a T-die to form a composite material structure.

In order to achieve a surface tension of the printed paper film of 32-38 dynes, it can be achieved by the selection of the coating material, the compounding aid, and the appropriate corona treatment of the printing surface.

Specifically, the raw material of the printing film layer is selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, POE, ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyurethane, ABS, and ethylene propylene diene copolymer resin. One or several. The surface tension of the above resin is adjustable within 32-38 dyne, which satisfies the requirements of the present invention. The raw material of the printed film layer may further include an auxiliary agent to be used in combination with the resin raw material. The auxiliary agent is one or more of an anti-blocking agent, a slip agent, and a silicone-based surface tension adjusting aid.

As a preferred raw material formulation of the present invention, the raw material formulation of the printed film layer is any of the following:

(1) a polyethylene resin having a tensile strength of 4 to 12 MPa;

(2) an ethylene-vinyl acetate copolymer resin, a release agent and a slip agent having a tensile strength of 4 to 12 MPa, and an anti-adhesive agent and a slip agent are added in an amount of 0.1 to 10% of the ethylene-vinyl acetate copolymer resin;

(3) a polyethylene and POE mixed resin having a tensile strength of 4 to 12 MPa, wherein the POE is used in a proportion of 20 to 30%, and the polyethylene is used in a proportion of 70 to 80%;

(4) A mixed resin of an ethylene-propylene copolymer resin and a POE having a tensile strength of 4 to 12 MPa, wherein the POE is used in a proportion of 20 to 30%, and the ethylene-propylene copolymer resin is used in an amount of 70 to 80%.

(5) An ethylene-propylene copolymer resin having a tensile strength of 4 to 12 MPa, wherein the ethylene content is 5 to 10%.

The above formula can achieve a surface tension of 32-38 dyne on the printing surface 2B of the printed paper film, and the printed film layer has a lower tensile strength and has better decal working performance.

In order to satisfy the decalization performance of the printed film layer transferred from the flower paper during the decaling process, the film material of the printed film layer needs to have a lower tensile strength, and the tensile strength of the raw material of the printed film layer is set in the present invention. It is 4-12 MPa, which is one of the key technical difficulties in realizing the products of the present invention. Generally, the tensile strength of the plastic resin is relatively large, and a conventional plastic resin is used. The printed film layer cannot have good stretchability, and the decal operation performance is poor, and the requirements of containers of various shapes cannot be satisfied. The thickness of the printed film layer is set to 8 to 40 μm. The above-mentioned printing film layer of tensile strength and thickness is convenient for decaling and strong in practical use.

Preferably, the printed film layer has a tensile strength of 5 to 10 MPa, and the printed film layer has a thickness of 10 to 30 μm. More preferably, the printed film layer has a tensile strength of 7 to 9 MPa, and the printed film layer has a thickness of 15 to 25 μm.

In order to achieve a surface tension of the printed paper film surface of 32-38 dynes, the present invention can also be adjusted by subjecting the printed surface of the printed paper film to corona treatment.

It should be noted that the present invention can also achieve a surface tension of 32-38 dynes by the printing surface of the printed paper film by other technical means, and the embodiment thereof is not limited to the embodiment of the present invention.

Further, referring to Figure 3, the composite backing paper of the present invention comprises:

Water transfer printing paper special base paper 1;

a bottom layer 11 connected to the water transfer printing paper special backing paper;

a core layer 12 connected to the bottom layer 11;

The surface layer 13 is connected to the core layer 12, and the surface layer 13 is connected to the printed film layer.

Specifically, the bottom layer 11 is formed by coating a first coating material, which is a coating made of kaolin/calcium carbonate, a synthetic latex and an auxiliary agent, and the coating amount of the bottom layer 11 is 10-20 g/ m ² , its role is to form a relatively smooth surface on the surface of the base paper through the coating.

The core layer 12 is formed by coating a second coating material, which is a modified starch boiled solution, or a solution of modified starch and water-soluble raw material, and the coating amount of the core layer is 3-7 g. /m ² , its role is to form a smooth coating with fast water absorption.

The surface layer 13 is formed by coating a third coating material, which is a modified starch boiled solution, and the surface layer is coated in an amount of 2-5 g/m ^{2 to} form a fast water-soluble coating layer. .

The composite base paper of the present invention can be printed thinner than the normal water transfer printing paper because it is printed after being combined with the printed film layer. The basis weight of the normal water transfer printing paper is generally 135 to 190 g/m ² , and the basis weight of the composite base paper of the present invention is 40 to 130 g/m ² .

(1) preparing a composite base paper;

Step (1) includes:

Providing a special paper for water transfer printing paper;

Correspondingly, referring to FIG. 4, the invention also discloses an environmentally-friendly paste transfer straight printing paper, comprising: the composite printing paper film of any one of the above, and the printing layer 3 disposed on the printing surface thereof.

As a more preferred embodiment of the flower paper, the flower paper further includes: an adhesive layer 4 provided on the printing layer 3.

It should be noted that the composite printing paper film in the flower paper is the same as described above, and will not be described herein.

The invention is further illustrated below in conjunction with specific embodiments.

Example 1

(1) providing a water transfer performance composite base paper having a basis weight of 130 g/m ² ;

(2) Forming a printed film layer by extruding a polyethylene film on a composite base paper, and forming a printed film layer having a thickness of 15 μm, which is then trimmed, wound, and cut, and packaged into a finished printing paper. membrane.

Example 2

(1) preparing a composite base paper having a basis weight of 100 g/m ² , comprising:

Providing a special paper for water transfer printing paper;

Coating a coating made of kaolin, synthetic latex, paint auxiliaries on the surface of the base paper and drying, and coating amount is 10 g/m ² to form a bottom layer;

Coating the modified starch boiled solution on the surface of the bottom layer and drying, and coating amount is 3 g/m ² to form a core layer;

On the surface of the core layer, a modified starch boiled solution was applied and dried, and the coating amount was 2 g/m ² to form a surface layer.

(2) Forming a printed film layer by extruding a polyethylene film on a composite base paper, and forming a printed film layer having a thickness of 15 μm, which is trimmed, corona treated, wound, and cut, and packaged as Finished printed paper film.

Example 3

(1) preparing a composite base paper having a basis weight of 120 g/m ² , comprising:

Providing a special paper for water transfer printing paper;

Applying a coating made of calcium carbonate, synthetic latex, paint auxiliaries to the surface of the base paper and drying, and coating amount is 15 g/m ² to form a bottom layer;

Coating a modified solution of modified starch and sodium alginate in a surface of the bottom layer and drying, and coating amount is 5 g/m ² to form a core layer;

On the surface of the core layer, a modified starch boiled solution was applied and dried, and the coating amount was 3 g/m ² to form a surface layer.

(2) Forming a printed film layer by extrusion-leaching ethylene-vinyl acetate copolymer resin with anti-adhesive aid and smoothing aid on the composite base paper, and the thickness of the printed film formed by the coating is 20 micrometers. Edge, winding, cutting, packaging into finished printed paper film.

Example 4

(1) preparing a composite base paper having a basis weight of 80 g/m ² , comprising:

Providing a special paper for water transfer printing paper;

Applying a coating made of calcium carbonate, a synthetic latex, a coating aid to the surface of the base paper and drying, and coating a coating amount of 10 g/m ² to form a bottom layer;

Coating the modified starch boiled solution on the surface of the bottom layer and drying, and coating amount is 6 g/m ² to form a core layer;

On the surface of the core layer, the modified starch boiled solution is coated and dried, and the coating amount is 4 g/m ² to form a surface layer.

(2) by using a synthetic resin (PEE used in a ratio of 25%) on a composite base paper by extrusion, a printed film layer is formed, and the thickness of the printed film formed by the coating is 15 μm. , corona treatment, winding, cutting, packaging into a finished printed paper film.

Example 5

(1) A composite base paper having a basis weight of 60 g/m ² , comprising:

Providing a water transfer transfer paper;

Coating a modified solution of the modified starch and sodium alginate in a surface of the bottom layer and drying the coating solution in an amount of 3 g/m ² to form a core layer;

On the surface of the core layer, the modified starch boiled solution is coated and dried, and the coating amount is 3 g/m ² to form a surface layer.

(2) Forming a printed film layer by extrusion coating a mixed resin of ethylene-propylene copolymer resin and POE on a composite base paper (the POE content is about 25%), and forming a printed film layer having a thickness of 15 μm. After trimming, corona treatment, winding, cutting, packaging into a finished printed paper film.

Example 6

(1) preparing a composite base paper having a basis weight of 90 g/m ² , comprising:

Providing a special transfer paper for water transfer printing;

Coating a coating made of kaolin, synthetic latex, and coating auxiliary agent on the surface of the base paper and drying, and coating amount is 12 g/m ² to form a bottom layer;

On the surface of the core layer, the modified starch boiled solution is coated and dried, and the coating amount is 5 g/m ² to form a surface layer.

(2) Forming a printed film layer by extrusion-leaching an ethylene-propylene copolymer resin (having an ethylene content of 5 to 10%) on a composite base paper, and forming a printed film layer having a thickness of 10 μm, trimmed, Corona treatment, winding, cutting, packaging into finished printed paper film.

Example 7

The composite printed paper film of Example 1, a printed layer provided on the composite printed paper film, and an adhesive layer provided on the printed layer.

Example 8

The composite printed paper film of Example 2, a printed layer provided on the composite printed paper film, and an adhesive layer provided on the printed layer.

Example 9

The composite printed paper film of Example 3, a printed layer provided on the composite printed paper film, and an adhesive layer provided on the printed layer.

Example 10

The composite printed paper film of Example 4, a printed layer provided on the composite printed paper film, and an adhesive layer provided on the printed layer.

Example 11

The composite printed paper film of Example 5, a printed layer provided on the composite printed paper film, and an adhesive layer provided on the printed layer.

Example 12

The composite printed paper film of Example 6, a printed layer provided on the composite printed paper film, and an adhesive layer provided on the printed layer.

The composite printed paper films of Examples 1-6 were tested by techniques, and the results are shown in Table 1:

As can be seen from Table 1, the printed film of the present invention can be easily and quickly peeled off within 120 seconds after immersion in water. The surface of the printing surface of the composite printing paper film of the invention has a surface tension of between 32 and 38 dynes, the printing pattern can be transferred 100%, and the printing film layer can be conveniently printed from the printing without being completely damaged. Peel off the layer.

The flower papers of Examples 7-12 were technically tested, and the special resin selection and formula combination of the present invention was compared with the existing flower paper preparation, and the silk of the flower paper printing process was replaced by the pre-resin coating method. The screen printing is coated with cover glue, which reduces the organic solvent discharge in the production process of the paper by more than 40%, and can significantly improve the production efficiency and reduce the cost due to the reduction of the material cost and the reduction of the process of printing the cover glue.

Moreover, the printing surface of the present invention has extremely high smoothness and extremely low roughness (Ra < 0.02 μm), while the printing surface of the existing flower paper has a roughness Ra > 1 μm. In addition, the printed paper film has excellent dimensional stability and is not as easy to absorb moisture as the paper material, so the printing exquisiteness of the present invention will be far from the traditional flower paper.

The above is a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It is the scope of protection of the present invention.

Claims

The invention relates to a composite printing paper film for environmentally-friendly adhesive transfer printing paper, which is characterized in that it is a composite material composed of at least one composite bottom paper having water transfer property and at least one printed film layer which can be easily decaled;

After the composite material is immersed in water, the printed film layer can be detached from the composite base paper;

One side of the printed film layer is bonded to the composite base paper, and is a non-printing surface;

The other side of the printed film layer is used for printing a pattern, which is a printing surface;

The surface of the printed surface of the printed paper film has a surface tension of 32-38 dyne such that the release force between the printed paper film and the printed layer is less than the release force between the printed layer and the surface of the target printed article.
The composite printing paper film for environment-friendly adhesive transfer printing paper according to claim 1, wherein the printing film layer is obtained by a plastic resin extrusion coating process.
The composite printing paper film for environmentally-friendly adhesive transfer printing paper according to claim 2, wherein the printing film layer is made of polyethylene, polypropylene, polyvinyl chloride, POE, ethylene-vinyl acetate copolymer. One or more of polyvinyl alcohol, polyurethane, ABS, and ethylene propylene diene copolymer resin.
The composite printing paper film for environmentally-friendly adhesive transfer printing paper according to claim 3, wherein the raw material of the printing film layer has a tensile strength of 4 to 12 MPa.
The composite printing paper film for environment-friendly adhesive transfer printing paper according to claim 3 or 4, wherein the raw material of the printing film layer further comprises an auxiliary agent, and the auxiliary agent is an anti-blocking agent and a slip agent. One or more of silicone surface tension adjusting aids.
The composite printing paper film for environmentally-friendly adhesive transfer printing paper according to claim 1, wherein the printing film layer has a thickness of 8 to 40 μm.
The composite printed paper film for environmentally-friendly adhesive transfer printing paper according to claim 1, wherein the composite base paper comprises:

Special paper for water transfer printing paper;

a bottom layer connected to the special paper for water transfer printing paper;

a core layer connected to the underlayer;

a skin layer joined to the core layer, the skin layer being bonded to the printed film layer.
The composite printed paper film for environmentally-friendly adhesive transfer printing paper according to claim 7, wherein the composite base paper has a basis weight of 40 to 130 g/m 2 .
The composite printing paper film for environmentally-friendly adhesive transfer printing paper according to claim 7, wherein the bottom layer is formed by coating a first coating material, which is kaolin/calcium carbonate, synthetic latex and a coating made of an auxiliary agent;

The core layer is formed by coating a second coating material, which is a modified starch boiled solution, or a solution prepared by digesting starch and water-soluble raw material;

The skin layer is formed by coating a third coating which is a modified starch boiling solution.
The composite printing paper film for environmentally-friendly adhesive transfer printing paper according to claim 7, wherein the coating amount of the bottom layer of the composite base paper is 10-20 g/m 2 ;

The coating amount of the core layer of the composite base paper is 3-7 g/m 2 ;

The coating amount of the surface layer of the composite base paper is 2 to 5 g/m 2 .
The composite printing paper film for environmentally-friendly adhesive transfer printing paper according to claim 1, wherein the printing surface of the printing paper film is subjected to corona treatment in advance to achieve a desired surface tension.
A method for preparing a composite printed paper film for environmentally-friendly adhesive transfer printing paper according to any one of claims 1 to 11, characterized in that it comprises:

(1) preparing a composite base paper;

(2) The printed film layer is prepared by extrusion coating plastic resin on the composite base paper, and then subjected to trimming, surface corona treatment, winding, cutting, and packaging into a finished printed paper film.
The method for preparing a composite printed paper film for environmentally-friendly paste transfer printing paper according to claim 12, wherein the step (1) comprises:

Providing a special paper for water transfer printing paper;

Coating a coating made of kaolin/calcium carbonate, synthetic latex and auxiliary agent on the surface of the base paper and drying to form a bottom layer;

On the surface of the bottom layer, coating a solution of the modified starch boiled solution, or the modified starch and the water-soluble raw material, and drying to form a core layer;

On the surface of the core layer, the modified starch boiled solution is coated and dried to form a surface layer.