CN110172306A - A kind of carve characters pre-coating film and preparation process for in-mould injection - Google Patents

Abstract

The invention discloses a lettering pre-coating film for in-mold injection molding, which comprises a film substrate with a UV-cured anti-friction coating on the surface, a vacuum aluminized layer, an adhesive coating for ABS or PC, and a tackifier layer, the upper and lower surfaces of the vacuum aluminized layer are respectively provided with an upper primer for enhancing the bonding force of the surface coating of the vacuum aluminized layer and a lower primer for enhancing the bonding force with ABS or PC adhesive coating layer; also includes preparation process; the present invention carries out double-sided coating resin on the upper and lower surfaces of the vacuum aluminized layer, strengthens the binding force between each layer such as the upper primer layer and the lower primer layer, and the lower surface of the aluminum plated layer Coating adhesive coating and adhesion-promoting layer on the primer layer improves the peeling force after bonding with ABS or PC resin, and facilitates the accurate realization of in-mold injection molding operation. The pre-coating film is a surface with pre-coating effect. It is suitable for packaging products of ABS or PC and other injection molding resins in the mold injection molding process.

Description

A lettering pre-coating film for in-mold injection molding and its preparation process

technical field

The embodiments of the present invention relate to the technical field of packaging for home appliances, daily chemicals, electronics, automobiles, etc., and specifically relate to a lettering pre-coating film for in-mold injection molding and a preparation process.

Background technique

The original definition of the pre-coated film used in the packaging market refers to the pre-coated plastic film with hot melt adhesive and rewinding on the extrusion laminating machine or coating machine. It is a packaging product that is rewound on the film for the manufacturer to choose, and then laminated with the paper printed matter.

Lamination is a processing technology that coats plastic film with an adhesive, heats and presses paper prints to form a paper-plastic product. Transparent plastic film, the surface is smoother and brighter, thereby improving the gloss and fastness of printed matter, the graphic color is more vivid, full of three-dimensional effect, and at the same time, it also plays the role of waterproof, antifouling, wear resistance, folding resistance, chemical corrosion resistance, etc. .

Existing pre-coating films for in-mold injection usually only include one layer of polyurethane base structure, single-sheet operation, color silk screen printing, and metal ink silk screen printing to imitate electroplating. The structure is simple, so the efficiency is extremely low and the cost is high. It is understood that for high-end products in the IMD industry, which involve product manufacturing processes such as primer coating, hot-melt adhesive coating, coating, high-temperature barrier, and pre-coating film production, due to the cross-industry technical processes involved between enterprises, the industry's internal Due to the confidentiality of the involved technical processes, it is impossible to integrate some technical processes belonging to various industries. Therefore, the performance of the pre-coated film used in the in-mold injection molding industry produced by a single preparation process often cannot meet the use requirements. For example, in the process of in-mold injection molding, the IMD pre-coating film mainly based on silk screen printing technology cannot guarantee good adhesion with resins used in in-mold injection molding such as ABS and PC due to backward technology, surface bubbles and poor viscosity. The low peeling force between the aluminum layer and the color printing ink leads to the inability to meet the requirements for the use of in-mold injection products, and the aluminum layer falls off at high temperature, discolors, and the temperature resistance is insufficient to deform, resulting in poor appearance of the product.

Contents of the invention

For this reason, the embodiment of the present invention provides a lettering pre-coating film for in-mold injection molding and a preparation process, through double-sided coating on the aluminum-plated surface, vacuum coating, coating adhesive for ABS or PC injection bonding, increasing The combination of multiple processes such as adhesive layer solves the problem of the single pre-coating film preparation process in the existing in-mold injection molding technology, resulting in single-function pre-coating film products, narrow product application range, and ABS or PC resin when used for in-mold injection molding. Problems such as poor bonding effect, air bubbles, discoloration of aluminum plating layer at high temperature and fading of color printing. At the same time, it also replaces the low-efficiency operation of silk screen printing.

In order to achieve the above purpose, embodiments of the present invention provide the following technical solutions:

A lettering pre-coating film for in-mold injection molding, comprising a film base material, a vacuum aluminized layer, an ABS adhesive coating and an adhesion-promoting layer arranged in sequence, and the upper and lower surfaces of the vacuum aluminized layer are respectively provided with a useful An upper primer coat and a lower primer coat for enhancing the bonding force of the surface coating of the vacuum aluminized layer.

The embodiment of the present invention is also characterized in that the upper primer layer and the lower primer layer are respectively polymethyl methacrylate and polyurethane resin.

The embodiment of the present invention is also characterized in that a pre-coating film is provided between the undercoat layer and the ABS adhesive coating, and the pre-coating film is polyurethane hot-melt adhesive resin.

The embodiment of the present invention is also characterized in that the adhesion-promoting layer is specifically acrylic resin.

In addition, the present invention also provides a preparation process for lettering precoating film for in-mold injection, comprising the following steps:

Step 100, coating a layer of polymethyl methacrylate resin on the inner layer of the film substrate as an enhanced aluminized coating before aluminizing;

Step 200, vacuum aluminizing once to obtain biaxially oriented polypropylene aluminized film;

Step 300, coating the surface of the biaxially stretched polypropylene aluminized film with an upper primer layer and a lower primer layer to enhance the coating adhesion of the film surface;

Step 400, coating a hot-melt pre-coating film on the surface of the lower primer layer once, and coating an ABS adhesive coating and an adhesion-promoting layer on the surface of the hot-melt adhesive pre-coating film in sequence;

Step 500, bonding and covering under heat and pressure after sequential coating to form an integrated structure.

The embodiment of the present invention is also characterized in that, in step 100, the film substrate has a width of 1250 mm and a thickness of 25 μm.

The embodiment of the present invention is also characterized in that, in step 300, the dry weight of the upper primer layer and the lower primer layer are both 0.07 g/m ² , and the thickness is 0.02-0.04 μm.

The embodiment of the present invention is also characterized in that, in step 400, the preparation method of the hot melt adhesive pre-coating film is specifically:

Coat the hot-melt adhesive resin with a coating machine or a dry compound machine, and the coating thickness of the hot-melt adhesive resin is 3-5 μm;

The coated hot-melt adhesive resin and tackifying layer are coated on the base material through a screen roll, then dried in an oven at 85-90°C, cooled in a cooling roll, and then wound up.

The embodiment of the present invention is also characterized in that the dry weight of the hot melt adhesive resin is 5-8 g/m ² .

Embodiments of the present invention have the following advantages:

The present invention double-coats the resin on the upper and lower surfaces of the vacuum aluminized layer, enhances the bonding force between the layers such as the upper and lower undercoats, and coats and cements the lower undercoat on the aluminized surface. Additive coating and adhesion-promoting layer, which improves the peeling force after bonding with ABS or PC resin, and facilitates accurate in-mold injection molding operations. The pre-coating film is a surface with a pre-coating effect, suitable for injection molding such as ABS or PC. Packaging products of resin in-mold injection molding process.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that are required in the description of the embodiments or the prior art. Apparently, the drawings in the following description are only exemplary, and those skilled in the art can also obtain other implementation drawings according to the provided drawings without creative work.

The structures, proportions, sizes, etc. shown in this manual are only used to cooperate with the content disclosed in the manual, so that people familiar with this technology can understand and read, and are not used to limit the conditions for the implementation of the present invention, so there is no technical In the substantive meaning above, any modification of structure, change of proportional relationship or adjustment of size shall still fall within the scope of the technical content disclosed in the present invention without affecting the functions and objectives of the present invention. within the range that can be covered.

Fig. 1 is a structural representation of the present invention;

Fig. 2 is a schematic diagram of the preparation process of the present invention.

In the figure: 1-film base material; 2-upper primer layer; 3-vacuum aluminized layer; 4-lower primer layer; 5-adhesive coating; 6-adhesion-promoting layer.

Detailed ways

The implementation mode of the present invention is illustrated by specific specific examples below, and those who are familiar with this technology can easily understand other advantages and effects of the present invention from the contents disclosed in this description. Obviously, the described embodiments are a part of the present invention. , but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Fig. 1, a kind of continuous coating method that the present invention provides has the peeling force between polyester film and aluminum-plated layer, and increases the peeling force between aluminum-plated layer and ABS or PC injection molded part, is used for The pre-coated film of in-mold injection, including the film base material 1, the vacuum aluminized layer 3, the adhesive coating 5 and the adhesion-promoting layer 6 for ABS or PC, which are arranged in sequence, have a UV curing friction-resistant coating on the surface. The upper and lower surfaces of the vacuum aluminized layer 3 are respectively provided with an upper primer layer 2 for enhancing the surface coating bonding force of the vacuum aluminized layer 3 and a lower primer layer for enhancing the bonding force with ABS or PC adhesive coating 5 4.

The film substrate 1 is specifically any one of BOPET, BOPA, PC, and BOPP films. Described upper base coat 2 is one or more in polyurethane resin, copolyester, acrylate ester resin, and described lower base coat 4 is one or more in acrylic acid, alkane resin, so The above-mentioned adhesive coating 5 is aimed at improving the hot-melt adhesive coating for ABS or PC injection molding resin bonding. The adhesion-promoting layer 6 is specifically one or more of acrylate resin, modified polyester polyol mixture, and modified isocyanate adduct.

Wherein, the adhesive coating 5 is to bond ABS or PC resin after chemical reaction occurs under high temperature conditions during the in-mold injection molding process; the surface of the adhesive coating 5 is coated with acrylate, modified polyester polyol mixture 1. One or more of the adducts of modified isocyanates are used as the adhesion-promoting layer 6 to increase the initial peeling force of the product.

The film substrate 1 with the UV-cured anti-friction coating on the surface preferably has a width of 500-1800 mm and a thickness of 15-100 μm. In step 100 and step 300, the dry weight of the upper primer layer 2 and the lower primer layer 4 is preferably 0.01-0.5 g/m2, and the thickness is preferably 0.01-0.1 μm.

In addition, based on the above structure, the preparation process of the present invention is different from the common pre-coating film prepared by extrusion compounding process, and the present invention adopts various coating adhesive processes to produce. As shown in Figure 2, the preparation process specifically includes the following steps:

Step 100, coating one or more of polyurethane, copolyester, and acrylic resin on the inner layer of the film base material with a UV-cured friction-resistant coating on the surface to increase the surface coating of the vacuum aluminized layer Adhesive top coat;

Step 200, vacuum aluminizing once to obtain an aluminized thin film;

Step 300, coating one or more of acrylic and alkane resins on the surface of the aluminum-plated film with a UV-cured friction-resistant coating on the surface, as a base for increasing the bonding force between the aluminum-plated surface and the adhesive resin coating;

Step 400, coating an adhesive layer and a tackifier layer for injection molding of ABS or PC resin on the surface of the lower primer layer;

Step 500, after rewinding and slitting, place the die-cut product in a mold, inject ABS or PC resin into the mold, bond and cover under heat and pressure to form an integrated structure.

In the above-mentioned in-mold injection molding process, a double-sided coating process is used on the aluminum-plated surface to become a link layer between layers, which is a new method for making pre-coated films for in-mold injection molding.

For ABS or PC resin type injection molding pre-coating film in the mold, adopting the method of coating the adhesion-promoting layer can improve the peeling force of bonding with ABS or PC resin. The present invention coats the surface of the hot-melt adhesive layer with the tackifying layer, which is A process design to increase initial adhesion.

Wherein, in step 400, the preparation method of the pre-coating film for in-mold injection molding of ABS or PC resin is specifically:

Use a coating machine or a dry laminating machine to apply the coating solution of the adhesive and the adhesion-promoting layer on the aluminum-coated film sequentially through the mesh roll, dry it in the oven at 85-90°C, and then pass it through the cooling roller to cool down and collect it. roll. The thickness of the adhesive coating was 5 μm.

In the preparation process of the polyurethane hot-melt adhesive resin pre-coating film, a coating process or a dry compound machine is used and combined with on-line corona treatment. It is a special hot-melt adhesive coating method by using dry compound machine and hot-melt adhesive coating process, combined with online corona treatment, and the adjustment and cooperation of film material parameters made in each process link. The 100# and 60# mesh rolls used in the present invention are coated with hot-melt adhesive resin for bonding in ABS injection molding process, and utilize dry compound machine to make hot-melt adhesive pre-coating film. Another new method for making films for inner injection molding.

Among them, the pre-coated film used for ABS or PC resin in-mold injection has no benzene additives in the process of production and processing, and the total amount of solvent residue is ≤5.0mg/m ² , which complies with GB/T10004-2008 Plastic composite film and bag for packaging Benzene solvents are not allowed to be detected in the national standards for dry compounding and extrusion compounding.

In above-mentioned technical scheme of the present invention, comprise the feature of following four aspects:

Feature 1: The upper and lower surfaces of the aluminized layer are coated with an undercoat to enhance bonding force.

The first process is to use the laser engraving process to make the screen roll, that is, the above-mentioned screen roll base material, and coat the polyurethane resin on the surface of the transparent BOPET base material once, which is used as an enhanced aluminized coating before aluminizing. Floor.

The second process is to coat one or more of polyurethane, copolyester, and acrylic resin on the surface of the transparent film substrate once, which is used as the top coating of the reinforced aluminized coating before aluminizing, and then Vacuum aluminum plating becomes aluminized film.

The third step is to coat the undercoat on the lower surface of the vacuum aluminized layer, which is used as a link layer to enhance the bonding force when the aluminized surface is bonded with the adhesive. The double-sided coating process used on the aluminum-plated side is a new method of film production for in-mold injection molding.

Feature 2: Coating adhesive to match the injection molding process of ABS or PC resin.

The present invention uses the hot-melt adhesive resin for bonding used in dry lamination machine and screen roller secondary coating and ABS or PC injection molding process to continuously coat to make pre-coating film for in-mold injection molding, which solves the problem of silk screen printing process, low efficiency and low quality. Bad question. It is a new method and technical improvement of film production for in-mold injection molding.

Feature 3: The surface of the hot-melt adhesive resin pre-coating film has an adhesion-promoting layer.

In order to improve the peeling force between the ABS or PC resin and the product of the present invention for the injection molding process, the present invention adopts the technical design of coating the initial bonding layer on the surface of the adhesive, which is used as the adhesion-promoting layer.

Feature 4: The coating process uses a dry compound machine, combined with on-line corona treatment, and the product has a wide range of applications.

In the present invention, the film base material is subjected to surface UV curing coating friction-resistant treatment, secondary primer coating, primary vacuum coating, primary matching ABS or PC adhesive coating, and primary adhesion-promoting coating. The production surface has Pre-coating effect and pre-coating film suitable for in-mold injection molding processes such as ABS or PC.

Feature 5: The surface of the in-mold injection product of the present invention can be coated with a UV curable resin with a specific effect by using a gravure printing/coating process.

The product of the present invention, in addition to the characteristics of the present invention having the basic IMD function and aluminum coating, high temperature resistance, non-fading and non-discoloration, also has decorative functions such as surface hardening, friction resistance, matt or bright light, and 3D touch of gravure patterns .

The pre-coated film for in-mold injection manufactured by combining the above-mentioned technical process is a new type of packaging product that integrates more special coating technical processes. It is widely used in household appliances, electronics, automobiles, daily chemicals, food packaging and other industries. Such as stationery, clothing, furniture decoration, automotive interiors, food boxes, jewelry boxes, injection packaging and lamination of luxury goods. Especially through the preparation of special primer resin and the use of hot-melt adhesive coating process, the ABS or PC resin pre-coating film for in-mold injection molding is a new type of packaging product that integrates multiple technologies. Therefore, this invention also covers thin strip products that can be made into coils such as non-woven fabrics and paper-plastic composite films. After the multi-layer technology process, it will become a pre-coated film product for in-mold injection molding with specific functions.

Although the present invention has been described in detail with general descriptions and specific examples above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (9)

1. a kind of pre-coating film of carving characters for in-mould injection, which is characterized in that the surface including setting gradually has UV to solidify antifriction Film substrate (1), vacuum aluminium coated layer (3), the adhesive coating (5) and adhesion promoting layer (6) for ABS or PC for rubbing layer, in institute The upper and lower surfaces for stating vacuum aluminium coated layer (3) are separately provided for enhancing the vacuum aluminium coated layer (3) surface coating binding force The lower priming coat (4) of upper priming coat (2) and enhancing and ABS or PC adhesive coating (5) binding force.

2. a kind of pre-coating film of carving characters for in-mould injection according to claim 1, which is characterized in that the film substrate It (1) is specially BOPET, BOPA, PC, any one in BOPP film.

3. a kind of pre-coating film of carving characters for in-mould injection according to claim 1, which is characterized in that the upper priming coat It (2) is one or more of polyurethane resin, copolyesters, acrylate esters resin, the lower priming coat (4) is propylene One or more of acid, alkane resinoid, the adhesive coating (5) are used for raising ABS or PC casting resin bonding Hot melt adhesive coating.

4. a kind of pre-coating film of carving characters for in-mould injection according to claim 1, which is characterized in that the adhesion promoting layer It (6) is specifically one or more of acrylate, modified poly ester polyol blends, modified isocyanate addition product.

5. a kind of preparation process of the pre-coating film of carving characters for in-mould injection, which comprises the steps of:

Step 100, on the film substrate inner layer that surface has UV to solidify rub resistance coating, be coated with a strata urethane, copolyesters, third One or more of olefin(e) acid esters resin is as the upper priming coat for increasing vacuum aluminum-coated layer surface coating binding force；

Step 200 primary vacuum aluminum-coated obtains plating aluminium profiles film；

Step 300, on the plating aluminium profiles film surface that surface has UV to solidify rub resistance coating, be coated with one layer of acrylic acid, alkanes One or more of resin, as the lower priming coat for increasing aluminium plated surface and adhesive resin binding force；

Step 400, lower priming coat surface coating needle to ABS or the injection molding gluing oxidant layer of PC resin and adhesion promoting layer；

After step 500, rewinding and cutting, the product after shape by die-cutting is placed in mold, carries out being molded ABS or PC tree in mold Rouge is bonded in the state of heating pressurization and is covered to form integral structure.

6. a kind of preparation process of pre-coating film of carving characters for in-mould injection according to claim 5, which is characterized in that In step 100, the preferred 15-100 μ of the preferred 500-1800mm of film substrate width, thickness that surface has UV to solidify rub resistance coating m。

7. a kind of preparation process of pre-coating film of carving characters for in-mould injection according to claim 5, which is characterized in that In step 100 and step 300, the preferred 0.01-0.5g/m2 of dry weight of upper priming coat and lower priming coat, the preferred 0.01-0.1 μ of thickness m。

8. a kind of preparation process of pre-coating film of carving characters for in-mould injection according to claim 5, which is characterized in that glue Adhesive coating layer and adhesion promoting layer the preparation method comprises the following steps: the coating fluid of adhesive and adhesion promoting layer is passed through using coating machine or dry compound machine It crosses net roll to be sequentially coated on metallized film, by 85-90 DEG C of drying tunnel of drying, using receipts after cooling in cooling roller Volume.

9. a kind of preparation process of pre-coating film of carving characters for in-mould injection according to claim 8, which is characterized in that institute The dry weight of the gluing oxidant layer (5) of coating is 1-5g/m², coating thickness is 1-8 μm.