JPH037334A - Surface protective film and protecting method for surface - Google Patents

Abstract

PURPOSE:To obtain a protective sheet having excellent shape retentivity when applied to a material to be coated and no loss of flexibility at the material to be coated itself after the application by adhesively so laminating a supporting layer made of a heat resistant sheet on one side face of a sealant layer made of a heat fusible resin film as to be able to be peeled. CONSTITUTION:A sealant layer 1 is desirably 10-100mum thick, a supporting layer 2 is desirably 5-20mum thick, and the layer 2 must be desirably so adhesively laminated on one side face of the layer 1 as to be able to be peeled. The adhering strength between both the layers is desirably set to 400-3g/m<2> at peeling strength of 90 deg., and a peeling agent layer 3a is provided as one example of a close contact preventive layer 3 for disturbing the excessively close contact between both the layers. The agent includes, for example, silicone peeling agent, peeling agent containing polymer including long chain alkyl group as a main ingredient, chromium complex salt, etc. The surface protection of the material to be coated is performed by thermally press-adhering the layer 1 to be disposed at the material to be coated, cooling it, and then removing only the layer 2 by peeling.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a surface protection sheet for protecting the surface of an adherend such as a document, printed matter, or card, and a surface protection sheet for protecting the surface of an adherend using the protective sheet. It is about how to protect.

Conventional technology As a sheet to protect the surface of adherends such as cards and photographs, a surface made by laminating a heat-melting resin film such as ethylene-vinyl acetate copolymer on one side of a heat-resistant sheet such as polyethylene terephraglate. Protective sheets are known. In use, the surface protection sheets are stacked one on top of the other so that the hot-melt resin film side faces the adherend, and are thermocompression bonded to the adherend. Since the hot-melt resin film is supported by a heat-resistant sheet, it has excellent shape retention during thermocompression bonding and is easy to operate.

When a surface protection sheet is adhesively laminated on an adherend, the adherend becomes hard and difficult to bend, and is less prone to scratches and stains, so that the surface of the adherend is protected.

Problems to be Solved by the Invention The surface protection sheet having the above structure has been widely used in recent years because it has excellent surface protection properties for adherends.

However, depending on the application, such as documents and printed matter, it may be necessary to give the adherend flexibility and bendability, and in such cases, the hardness and hardness of bending in the conventional method may actually be a disadvantage.

In view of these circumstances, the present invention provides a surface protection sheet and a surface protection method that have excellent shape retention when applied to an adherend and do not impair the flexibility and bendability of the adherend itself after application. It was made with the purpose of providing.

Means for Solving the Problems The surface protection sheet of the present invention has a structure in which a support layer (2) made of a heat-resistant sheet is removably laminated on one side of a sealant layer (1) made of a heat-melting resin film. It is something that you have.

In addition, the surface protection method of the present invention includes thermocompression bonding the above-mentioned surface protection sheet to an adherend with the sealant layer (1) side facing the adherend, and after cooling, only the support layer (2) is peeled off. It is characterized by removal.

The present invention will be explained in detail below.

L Certification 1 top: “The surface protection sheet of the present invention is supported on one side of the sealant layer (1)! It has a structure in which (2) is laminated in a releasably contact M-layer manner.

The sealant layer (1) is for thermocompression bonding to an adherend while maintaining flexibility, and is made of a hot-melt resin film.

Such hot-melt resin films include low-density polyethylene, medium-high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, and ethylene-methacrylic acid ester copolymer. Single or multilayer films made from resins such as polymers, ionomers, ethylene-propylene copolymers, polypropylene, polyvinyl chloride, polyvinyl alcohol, styrene-butadiene copolymers, styrene-isobutylene copolymers, etc. used.

Flexibility and thermal meltability (melting point/softening point) can be adjusted by resin selection (resin type, degree of polymerization, copolymerization ratio, blend ratio of two or more resins, etc.) and the addition of plasticizers, oils, etc. This is done by adding additives, etc.

It is desirable to set the thickness of the sealant R (1) to about io~1001L11. If the thickness is too thin, the adhesive force to the adherend will be insufficient, and if it is too thick, it will interfere with thermocompression bonding work etc. to the adherend. In addition to this, it is also disadvantageous in terms of cost. The preferred range for # is 20-60 body weight.

A heat-resistant sheet is used as the support layer (2). Examples of heat-resistant sheets include polyester film, polypropylene film, polyamide film, polycarbonate film, polyimide film, cellulose film, acrylic film, fluororesin film,
Examples include metal foil, paper, and laminate films of these materials.

The thickness of the support layer (2) is preferably about 5 to 200 p-m, and if the thickness is too thin, the sealant layer (
It may break when peeled off from 1), and if it is too thick, it may interfere with thermocompression bonding work, etc. to the adherend, and it is also disadvantageous in terms of cost. A particularly preferred range is 10 to 150 jLm.

The support layer (2) needs to be releasably adhesively laminated on one side of the sealant layer (1).

The adhesive strength between both layers is 400 to 3 g/90° peeling strength.
It is desirable to set rrf, especially between 300 and 5 g/rn'; if the value is too large, the smoothness of the peeling operation will be hindered, while if the value is too small, the sealant will not adhere properly during the adhesion operation to the adherend. Misalignment may occur between layer (1) and support layer (2).

In order to make the adhesive force between both layers as weak as this,
The following measures will be adopted:

■ An adhesion prevention layer (3) that prevents excessive adhesion between the two layers is provided on at least one side of the support layer (2) on the side of the sealant layer (1) or the side of the support layer (2) (Ill) of the sealant layer (1). - An exemplary release agent layer (3a) is provided.

As the release agent, for example, a silicone release agent, a release agent based on a polymer having a long-chain alkyl group, a chromium complex salt, etc. are used.

(2) An intermediate layer (3b) is provided between the sealant layer (1) and the support layer (2) as an example of an adhesion prevention layer (3) that prevents excessive adhesion between the two layers. Examples of the intermediate layer (3b) include a method in which an adhesion-preventing resin layer is formed on the sealant layer (1), and a method in which an adhesion-preventing resin layer is formed on the support layer (2). In the former case, the intermediate layer (3b) becomes part of the sealant layer (1), and in the latter case, the intermediate layer (3b) becomes part of the sealant layer (1).
) becomes part of the support layer (2).

(2) Select a combination of sealant layer and support layer (2) that has releasability to the other layer.

The releasability can be obtained by selecting a resin, adding a releasable substance, etc.

To protect the surface of the adherend, the above-mentioned surface protection sheet is thermocompression bonded to the adherend with the sealant layer (1) side facing the adherend, and after cooling, the support layer ( This can be achieved by peeling off and removing only 2). Thermocompression bonding is performed by using a heating roll, a heating plate, or the like. Cooling is performed by cooling, blowing air, contact with a cooling roll, etc.

The surface protection sheet to be subjected to thermocompression bonding to the adherend may be prepared in advance, or may be prepared immediately before the thermocompression bonding operation to the adherend.

Adherents include documents, printed matter, cards, photographs, drawings,
Maps etc. can be given.

Function and Effect of the Invention In the surface protection sheet of the present invention, the sealant layer (1)
plays the role of thermally adhering to the surface of the adherend to protect the surface.

The supporting layer (2) maintains the shape of the sealant layer (1) only until the sealant layer (1) is thermally bonded to the surface of the adherend. It plays the role of preventing the adhesive from adhering to the plate (plate) and facilitating the thermocompression bonding operation.

Since the support layer (2) is peelably adhesively laminated to the sealant layer (1), the peelability of the support layer (2) after the thermocompression bonding operation is good.

After the support layer (2) is peeled off and removed, only the sealant layer (1) remains attached to the adherend, so the flexibility and bendability inherent in the adherend itself is almost lost. Not possible.

According to the present invention, the workability is thus good, the desired surface protection of the adherend is achieved, and the inherent mechanical properties of the adherend are not impaired.

If necessary, other sheets or adherends can be adhesively laminated on top of the sealant layer (1) of the surface-protected adherend by reheating.

Example Next, the invention will be further explained with reference to Examples.

Example 1 (Manufacture of surface protection sheet) FIG. 1 is a sectional view showing an example of the surface protection sheet of the present invention.

As an example of the support layer (2), a polyester film (biaxially oriented polyethylene terephthalate film) having a thickness of 25 ILm and having one side subjected to a corona discharge treatment was prepared.

A silicone release agent solution is applied to the corona discharge treated surface of the support layer (2) at a concentration of 0.5 g/rn' on a dry basis and dried to form the adhesion prevention layer (3). #
After forming (3a), sealan)! (
Example 1) The ethylene-vinyl acetate copolymer (vinyl acetate content: 18% by weight) was coated with Extru-Sicon to a thickness of 30 ha. As a result, the surface protection sheet (4) shown in FIG. 1 was obtained.

<Surface Protection of Adherent> FIG. 2 is a process diagram showing an example of the surface protection method of the present invention.

(4) is the surface protection sheet obtained above, (1) is its sealant layer, and (2) is its support layer.

(5) is an adherend, and in this example, a printed nonwoven fabric with a basis weight of 80 g/m' was used.

(6) is a supply roll for the surface protection sheet (4), (7) is a heat roll, (8) is a blower for blowing cooling air, (
9) is a peeling roll, (10) is a support roll, (11) is a guide roll, (12) is a winding roll for the peeled support layer (2), and (13) is a feed roll.

According to Fig. 2, the surface protection sheet (
While rolling out 4), place the sealant layer (1) side on the adherend (4) and heat roll (7) at a temperature of 150°C.
It was heat-pressed through the gap. The laminate after thermocompression bonding is cooled by blowing air from both sides with a blower (8), and then the support layer (2) is removed from this wI layer by a peeling roll (9).
Only the support layer (2) was peeled off, and the peeled support layer (2) was wound up on a winding roll (12). Note that the support layer (
2) The peel strength (90° peel strength) when peeling is:
Separate measurements showed that the layer was approximately Log/c.

By the above operation, the sealant layer (1) on the surface of the adherend (5)
) protection was achieved continuously. The protected adherend (5) could clearly see through the printed surface, was highly flexible, and had good bendability.

Example 2 FIG. 3 is a process diagram showing another example of the surface protection method of the present invention. In Figure 3, (6a) is the sealant layer (1)
The supply roll (8b) is the supply roll for the support layer (2). (14) consists of a sealant layer (1) and a support layer (2).
) is a heat roll for performing heat fusion with. (5) is the adherend, and in this example, the printed area is 40
g/rr+' glassine paper was used. Other signs are second
Same as in the figure.

FIG. 4 is a sectional view showing another example of the surface protection sheet of the present invention.

As an example of the support layer (2), an untreated polyester film (biaxially oriented polyethylene terephthalate film) with a thickness of 50 prs was prepared.

As an example of the sealant layer (1), polypropylene (thickness: 5 μm) and ethylene-acrylic acid ester copolymer (
A two-layer film coextruded with 35 gm thick was prepared. Among these, the polypropylene layer is the - of the adhesion prevention layer (3).
Although the intermediate layer (3b) as an example, the sealant layer (1
).

According to FIG. 3, the sealant layer (
1), each of the support layers (2) was paid out from the supply roll (6b), and both were superimposed and passed between the heat rolls (14) to be thermocompression bonded to form a surface protection sheet (4).
Subsequently, sealant layer (1) of this surface protection sheet (4) is applied.
) side was overlapped with the adherend (4) and bonded by thermocompression by passing between heat rolls (7) at a temperature of 180°C.

After thermocompression bonding, the laminate is cooled by blowing air from both sides with a blower (8), and then only the support layer (2) is peeled off from the laminate using a peeling roll (8). ) was wound up on a take-up roll (12). In addition, the peel strength (90° peel strength) when peeling the support layer (2) from the above laminate is approximately 20 g/
It was cm.

By the operation described in h, the sealant layer (1) is formed on the surface of the adherend (5).
) protection was achieved continuously. The protected adherend (5) could clearly see through the printed surface, was highly flexible, and had good bendability.

Example 3 FIG. 5 is a process diagram showing still another example of the surface protection method of the present invention. In Figure 5, (15) is a conveyor belt,
(16) is the driving low jl<.

In this embodiment, a cutting sheet is used as the adherend (5), and after the surface has been protected, it can be cut into a predetermined size using a cutting machine (not shown).

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the surface protection sheet of the present invention. FIG. 2 is a process diagram showing an example of the surface protection method of the present invention. FIG. 3 is a process diagram showing another example of the surface protection method of the present invention. FIG. 4 is a sectional view showing another example of the surface protection sheet of the present invention. FIG. 5 is a process diagram showing still another example of the surface protection method of the present invention. (13... sealant layer, (2)... support layer, (3
)...adhesion prevention layer, (3a)...release agent layer, (3b
)...Intermediate layer, (0...Surface protection sheet, (5)...
...adherent, (6)...1 surface protection sheet) (4) supply roll, (6a)...supply roll for sealant layer (1), (6b)...support layer (2) supply roll, (
7)...Heat roll, (8)...Blower, (9)...
・Peeling roll, (10)...Support roll, (11)・
... Guide roll, (12) ... Peeled support layer (
2) Take-up roll, (13)...Feed roll, (14)...Heat roll, (15)...Transport belt, (16)...Drive roll Fig. 1 Fig. 2 Fig. 4 figure

Claims (1)

[Claims] 1. Sealant layer (1) made of hot-melt resin film
A surface protection sheet having a structure in which a support layer (2) made of a heat-resistant sheet is removably adhesively laminated on one side of the sheet. 2. The surface protection sheet according to claim 1 is thermocompression bonded to an adherend with the sealant layer (1) side facing the adherend, and after cooling, only the support layer (2) is peeled off and removed. Characteristic surface protection method.