JP3203469B2 - Display panel base plate, display photo panel, and method of preventing blister of display photo panel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base plate used for creating a display panel by pasting photographs and posters for display, a display photograph panel having a photograph attached to the base plate, and this display photograph panel. The prevention of swelling of the photographic surface.

[0002]

2. Description of the Related Art Conventionally, an adhesive (also referred to as a "pressure-sensitive adhesive") is applied to the entire surface of a rigid foamed plastic plate or a veneer plate as a base plate for attaching photographs or posters for display. There is something. Of these, those using a rigid foamed plastic plate as a base material have been favorably used in recent years because of their light weight and ease of processing.

[0003]

By the way, an exhibition panel in which photographs and posters for exhibition are stuck on a base plate is used for exhibiting in photo exhibitions and contests, displaying large posters for advertisements and various event guides, and the like. Alternatively, it is used for personal hobbies such as inteliers, and it is required that pictures, posters, and the like be clearly attached. Therefore, when attaching a photo or poster to the base plate, it is necessary to take great care to prevent air from being trapped in the adhesive and to prevent misalignment due to poor positioning of the photo or poster. However, there was a problem that the sticking required skill.

[0004] Immediately after a photograph, poster, or the like is pasted on the base plate, it is not noticeable, but after a while, "blisters", that is, air bubbles (blisters) are generated on the surface of the pasted photograph, poster, or the like. The appearance was sometimes significantly impaired. The occurrence of this "blistering" is a phenomenon that is often seen particularly in large-sized photographs. However, large-sized photographs (photographic paper) are expensive, and the base plate that does not generate such "bloating" is often used by photographers and photographers. It was strongly desired by poster creators.

[0005] Japanese Patent Publication No. 50-23706 discloses that the area of a surface paper (corresponding to "photographs, posters, etc." in the present specification) changes when left in a humid place or a dry place for a long time. Thus, there is described a problem that stretching stress is generated, and thus irregularities and wrinkles are generated on the surface. In the invention of Japanese Patent Publication No. 50-23706, it has been proposed to include a special crosslinking component in the pressure-sensitive adhesive in order to solve the above problems.

[0006] However, the term "swelling" as used in this specification
Is a foreign substance which cannot be solved by including a crosslinking component in the pressure-sensitive adhesive as described above.

[0007] There are various theories regarding the cause of the "bulge", but the present inventors have made the following hypothesis.

That is, in the operation of attaching a photograph, a poster, or the like to the base plate, the worker pays careful attention so as not to trap air between the surface of the adhesive and the back surface of the adhered photograph or poster.

However, since the surface of the pressure-sensitive adhesive and the back surface of the photograph or poster are not mirror surfaces, it is impossible that air is not taken into the interface between them. It is conceivable that both the surface of the pressure-sensitive adhesive and the back of the photograph or poster have a number of fine irregularities, and are immediately bonded and integrated by a number of point bonds immediately after pasting. Conversely, it is considered that a large number of fine airs intervene at the interface of the region where the point bonding is not performed.
The only way to minimize the amount of air is to raise the temperature of the adhesive to extremely lower the viscosity of the adhesive, and at the same time press with as high a pressure as possible to eliminate air at the interface when attaching. This is not done in the pasting operation. Therefore, it is considered that a considerable amount of air is taken into the interface no matter how careful the bonding operation is performed.

On the other hand, since the pressure-sensitive adhesive is a liquid having a low surface tension and a high viscosity, it is considered that the pressure-sensitive adhesive flows slowly over time. In other words, with the slow flow of the pressure-sensitive adhesive, the neighboring point-adhesion parts gradually come together,
Eventually, it will spread to surface bonding. That is,
Partial "wetting" of the adhesive on the back of the photo or poster expands to "wetting" of the entire surface. This is because the surface energy of the pressure-sensitive adhesive is low with respect to the back surface of the photograph or poster paper, which is the surface to be bonded. In this way, the air at the interface is gradually replaced by the adhesive. In this process, the fine air particles existing at the interface aggregate and grow into an air aneurysm, and the relatively weak point bonding portion is peeled off during the aggregation / growth process, and the air air agglomerates into a larger air nodule at this peeled portion. grow up. This is a blister, a blister.

When ordinary paper having a low gas-shielding property is adhered, the air is naturally released to the outside, so that such "blowing" does not occur. “Blistering” is a phenomenon that appears only on an adherend having high gas barrier properties, such as photographic paper for photographs and art paper for posters (particularly high-grade art paper).

Incidentally, the order of the magnitude of the surface energy is as follows: release sheet surface (silicon coated surface) <adhesive agent <back side of photographic printing paper or poster art paper.

The credibility of the above hypothesis is supported by the fact that most of the gas components are air when the gas in the blister is analyzed by gas chromatography.

Furthermore, the adhesive strength is relatively weak in the very early stage when a photograph or poster for exhibition is pasted on the base plate, and the re-peelability is so high that it is usually difficult to reapply. However, as the time elapses, the adhesive strength or the adhesive strength is improved and stabilized, so that re-peeling does not occur. These facts further confirm the credibility of the above hypothesis.

The time required for the adhesive strength to stabilize is
Depending on the ambient temperature, the viscosity of the adhesive, etc., the higher the ambient temperature, the faster the lower the viscosity of the adhesive. If it is early, it will be stable in 1 to 24 hours. It may take more than a month at late times. For example, those applied during the cold season in cold regions may not be stable until spring.

By the way, the following is a conventional theory regarding the cause of the occurrence of "blistering".

Before the pressure-sensitive adhesive is applied to the substrate, the pressure-sensitive adhesive is sufficiently stirred, and it is assumed that fine air is carried into the pressure-sensitive adhesive and diffused during the stirring. Such fine air particles gradually separate from the adhesive and condense into large particles, but are not discharged to the outside due to the high gas shielding properties of high-grade art paper used for photographic printing paper and posters. If there is a portion of the adhesive surface provided on the entire surface where the adhesive strength is weak, air gathers there.

It is supposed that the solvent or water used for dispersing the pressure-sensitive adhesive remains when it is insufficiently dried after being applied to the substrate. Alternatively, it is supposed that unreacted monomers remain in the polymer that is the main component of the pressure-sensitive adhesive. These materials gradually evaporate, but are not discharged to the outside due to the high gas shielding property of high-grade art paper used for photographic paper and posters.
If there is a weak adhesive part, volatiles will collect there.

When a foamed plastic plate is molded, a foaming agent is used. The foaming gas present in the cells gradually leaks out of the substrate. This is also not discharged to the outside due to the high gas barrier properties of high-grade art paper used for photographic paper and posters. If there is weak adhesion, the gas will collect there.

However, these various theories have the following empirical and logical difficulties, and are difficult to adopt as a cause of "bulging".

First, as described above, when the gas in the blister is analyzed by gas chromatography, most of the gas components are air, so the above and the above statements are inappropriate. Next, even if the base plate has been manufactured for more than half a year, this phenomenon may appear when a photo or poster is pasted on it, and this may occur in about one day after pasting. In the state where the release sheet is pasted before applying the photo or poster, the release sheet is swelled.
Does not occur. In addition, the degree of occurrence of “swelling” is not so different between a base plate that has just been manufactured and a base plate that has been manufactured for one year or more. Based on these facts, the theory cannot explain the cause of blistering.

On the other hand, according to the above-mentioned hypothesis, any of the above-mentioned facts can be rationalized, and the probability as the true cause of "bulging" is extremely high.

The present invention has been made based on such considerations, and achieves the following objects.

(1) The present invention provides a base plate which does not generate blisters, that is, bubbles (blisters) on the surface of a photograph, a poster or the like attached to the base plate provided with the adhesive.

(2) To provide a base plate that can be attached to a base plate with less caution than before and without embracing air in an adhesive.

(3) To provide a base plate which can be easily corrected in the case where misalignment occurs due to poor positioning of a photograph, a poster or the like.

(4) Provided is a base plate in which the attached photograph, poster, or the like is stably adhered to the base plate for a long time, and does not peel off or wrinkle with the passage of time.

[0028]

For this purpose, according to the first aspect of the present invention, as shown in FIGS.
The adhesive 2 is attached to the surface of the display panel, and the release sheet 3 is provided so as to cover the adhesive.
A permanent adhesive type adhesive having an initial adhesive strength of 0.3 to 2
kg / 50mm, 1.5-4kg / 50mm over time
The display panel base plate is provided in a mesh shape so that the adhesive strength of the display panel is stable .

Further, the present invention will be described with reference to the drawings.

The substrate 1 is a veneer plate or a foamed plastic plate. Historically, veneer boards have been used for a long time, but hard foamed plastic boards are preferred because of their light weight and good workability.

The foamed plastic plate has a thickness of 2 to 2.
An extruded expanded polystyrene plate having a thickness of 30 mm and a density of 20 to 200 kg / m ³ is preferable. If the thickness is too thin, the rigidity of the base material tends to be insufficient, and if it is too thick, it is bulky, which is likely to cause inconvenience for display. On the other hand, if the density is too low, the rigidity of the base material tends to be insufficient, and if the density is too high, the weight increases and it is difficult to handle, and the material tends to be uneconomical.

The surface of the foamed plastic plate is preferably as smooth as possible for displaying photographs, posters and the like. An extruded polystyrene plate having a skin layer formed on the surface thereof, which satisfies such a requirement, preferably has a surface roughness of 0.5 mm or less obtained by an optical displacement sensor. More preferably, it is 0.2 mm or less. The skin layer is a smooth layer formed on the surface of the foamed plastic plate by extrusion foaming and having a higher density than the inside.

The above-mentioned optical displacement sensor receives reflected light by irradiating light to the surface of the object to be measured while moving at a constant speed while maintaining a constant distance from the surface of the object to be measured.
By utilizing the fact that the unevenness displacement of the surface of the object to be measured is proportional to the light reflectance, the surface roughness can be obtained from the reflectance of the light output to the recorder after being converted into an electric signal. is there.

The surface roughness of the extruded expanded polystyrene plate in the present invention is obtained as a vertical difference between the waves by moving the optical displacement sensor in the width direction with respect to the extrusion direction, reading the maximum value and the minimum value of the wave from the chart of the recorder. Value.

The pressure-sensitive adhesive 2 is of a permanent adhesive type and has a strong adhesive strength to high-grade art paper used for photographic printing paper and posters, and has a higher layer breaking strength than photographic paper and high-grade art paper. However, such strong strength immediately after sticking makes it difficult to stick photos, posters, etc. to the base plate, so it is easy to re-stick at the very beginning. It is preferable that there is a property. That is, it is preferable that the adhesive force or the adhesive force be improved by gradually progressing the adhesion of the adhesive 2 to the back surface of the photographic paper or the high-grade art paper with the passage of time.

The specific composition of the pressure-sensitive adhesive 2 is not particularly limited, but the pressure-sensitive adhesive 2 used in the present invention is preferably one mainly composed of an acrylate polymer. Can be used. Particularly, in the present invention, as described later, since the pressure-sensitive adhesive 2 is attached as a pattern leaving the non-attached portion 4,
An adhesive having an initial adhesive strength of 0.3 to 1.2 kg / 50 mm can be easily obtained. In normal pasting work,
It can be easily peeled off at around 0.8 kg / 50 mm.
In addition, it is possible to improve the adhesive strength with the passage of time after attaching a photograph, a poster, or the like.
It is possible to prevent re-peeling stably with an adhesive strength of 0 mm. Such a state is referred to as permanent adhesion of the pressure-sensitive adhesive in this specification.

On the surface of the base plate, an adhesive 2 is provided as a fixed mesh pattern, and the provided surface is covered with a release sheet 3. The fact that the adhesive 2 is provided in a fixed mesh pattern means that the adhesive 2 is not provided on the entire surface of the base material 1, but the attached portion of the adhesive 2 and the non-attached portion 4 have a fixed ratio. , Which means that the attached portion has a mesh pattern. Particularly, the non-attached portion 4 is a region where the air separated from the adhesive 2 escapes.

The ratio of the portion where the pressure-sensitive adhesive 2 is provided and the portion where the pressure-sensitive adhesive 2 is not provided depends on the pattern to be formed.
70/30 . Within such a range, the initial adhesive strength is relatively small, and when a shift occurs, it can be more easily corrected than before, and a strong adhesive strength can be reliably obtained with the passage of time.

The line width ratio between the portion where the adhesive 2 is attached and the portion 4 where the adhesive 2 is not attached is preferably about 1: 1 to 1: 2, and the width of the adhesive 2 is 0.5 to 2.0 mm, especially It is preferably about 1.0 mm.

When a plastic foam plate is used as the base material 1, it is often charged with static electricity when left unattended, and if this adsorbs dust in the air, the back surface and the end surface of the base plate become black and dirty. To prevent this, an antistatic agent (often having a surfactant as a main component) is applied to the back surface of the base plate, that is, the surface and the end surface opposite to the surface on which the adhesive 2 is provided. Is preferred.

The application of the pressure-sensitive adhesive 2 to the substrate 1 can be carried out by applying the pressure-sensitive adhesive 2 to the substrate 1 using a gravure roll type rotary coating machine or a roll coater. The mesh pattern for applying the pressure-sensitive adhesive 2 to the roll is grooved, and the pressure-sensitive adhesive 2 is scraped off from the roll surface to leave the pressure-sensitive adhesive 2 only in the groove. The adhesive 2 can be provided in a fixed pattern.

[0042]

When the peeling sheet 3 is peeled off and a photograph (printing paper) or a poster (art paper) or the like is stuck to the surface on which the adhesive 2 is attached, the base material 1 in the non-attached portion 4 of the adhesive 2 and the photograph or poster A small space will be left between them. The air at the interface between the back of the photo or poster and the adhesive 2
A large number of these small spaces can be dispersed and escaped, thereby preventing blisters.

Although the position of a photograph, a poster, or the like may be shifted with respect to the base plate, the initial adhesive strength of the adhesive 2 in the mesh pattern is weak, so that it is easy to correct this. That is, since the adhesive 2 is not provided on the entire surface of the base material 1 but the attached portion of the adhesive 2 and the non-attached portion 4 are present at a fixed ratio, the bonding of the base plate at the very beginning is performed. The force is relatively weak and has removability.

However, the adhesion of the pressure-sensitive adhesive 2 gradually progresses over time to the back surface of the photographic paper or the high-grade art paper as the adherend, and the adhesive force or the adhesive force is improved. As a result, permanent adhesion between the base plate and the adherend is realized.

As the adhesion of the pressure-sensitive adhesive 2 progresses, fine air particles existing at the interface between the pressure-sensitive adhesive 2 and the photograph or poster gradually aggregate and condense into large particles. Adhesive 2
The non-attached portion 4 is an area where the coagulated air escapes.

The photographic printing paper or poster art paper to be adhered is a chrysanthemum (636 × 639) or a 46 (6).
88 × 1091) can be used.

By the way, for example, Japanese Utility Model Publication No. 47-35863
The publication states that a photo preservation album is described as follows: "A pressure-sensitive adhesive is applied to the surface of a thick substrate, and the upper surface of the plate is peelably covered with a transparent film. In this example, a "plate for storing photographs and the like, characterized in that the agent is provided in oblique lines", is shown.

However, the adhesive used for such a photo preservation album must have removability. That is, it is required as a basic characteristic that the adhesive force or the adhesive force of the pressure-sensitive adhesive to the transparent film is smaller than the cohesive force of the pressure-sensitive adhesive itself for a long time. Furthermore, the adhesive or adhesive strength of the removable adhesive must not be greater than the layer breaking strength of the photographic paper to be stored. This re-peelability is an essential requirement for repeatedly attaching and detaching the transparent film to and from the album mount.

In the above-mentioned publication, the reason why the pressure-sensitive adhesive is provided in a linear shape is mainly to facilitate peeling of the transparent film. Others, 1-89
Also in Japanese Patent Publication No. 176, the first object is to make it easy to repeatedly peel the transparent film in the photo album. It is important for the removable adhesive to maintain weak adhesiveness for a long period of time.

On the other hand, the pressure-sensitive adhesive used in the present invention is of a permanent adhesive type, and is not for repeatedly sticking or peeling a photographic paper or a poster. The permanent adhesive type adhesive has a strong adhesive strength to high-grade art paper used for photographic printing paper and posters, and this adhesive strength is usually stronger than the layer breaking strength of photographic paper and high-grade art paper.

From the above, the technique used for the album for storing photographs basically differs from the present invention in the purpose and the problem to be solved, and also in the function.

[0052]

【Example】

Example 1 An extruded polystyrene foam plate having a thickness of 7 mm and a density of about 100 kg / m ³ was used as a substrate 1 to prepare a base plate as shown in FIGS. 1 and 2. As the pressure-sensitive adhesive 2, an acrylic emulsion type pressure-sensitive adhesive was used, which was provided in a network pattern. The width of the portion provided with the adhesive 2 was 1 mm, the ratio of the width of the portion provided with the adhesive 2 to the width of the non-attached portion 4 was 1: 1 and the amount of the adhesive 2 provided was about 30 g / m ² (dry).

When the initial adhesive strength of the obtained base plate to the following photographic paper was measured, it was about 0.8 kg / 50 m.
m. One month later, it was impossible to remove the adherend again.

As an adherend, 760 × 1080 m
m (B all sizes) (Photo paper: Fuji Bromide WP
Using FM3) and Western paper (art paper: 100 g / m2), the workability of pasting and the stability when exhibited after pasting were examined.

Table 1 shows the results.

Example 2 A base plate was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive 2 was provided at about 25 g / m ² (dry).

When the initial adhesive strength of the obtained base plate was measured, it was about 0.6 kg / 50 mm. After a lapse of two weeks, it was impossible to remove the adherend again, and if it was forcibly peeled off, layer cracking occurred.

Further, using the same adherend as in Example 1, and under the same environment as in Example 1, the workability of pasting and the stability at the time of display after pasting were examined.

Table 1 shows the results.

Comparative Example 1 A base plate was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive ² was provided at about 40 g / m ² (dry) on one entire surface of the substrate 1.

An attempt was made to measure the initial adhesive force of the obtained base plate, but re-peeling was impossible, and layer cracking occurred.

Further, using the same adherend as in Example 1, and under the same environment as in Example 1, the workability of sticking and the stability of the display after sticking were examined.

Table 1 shows the results.

Comparative Example 2 A base plate was prepared in the same manner as in Example 1 except that an adhesive 2 of an acrylic rubber-based solvent type was attached at about 30 g / m ² (dry) on one entire surface of the substrate 1. .

With respect to the obtained base plate, it was impossible to measure the initial adhesive strength.

Further, using the same adherend as in Example 1, and under the same environment as in Example 1, the workability of pasting and the stability of the display after pasting were examined.

Table 1 shows the results.

[0068]

[Table 1] (Note) ◎: Satisfied more than enough ○: Satisfied △: Somewhat dissatisfied ×: Not satisfied at all

[0069]

The present invention is as described above, and has the following effects.

(1) Since the occurrence of “bulging” on the surface of a photograph, a poster or the like attached to the base plate is drastically reduced, even an expensive photograph or the like can be attached with confidence.

(2) In the work of attaching to a base plate, a photograph or a poster can be attached with less caution than in the past so as not to embrace air, and a high level of skill is not required. Easy to handle.

(3) Even if a displacement occurs due to a poor positioning of a photograph, a poster, or the like, correction can be made more easily than before, and failures can be reduced.

(4) The stuck photos, posters, etc. are stably adhered to the base plate for a long time, and do not peel or wrinkle with the passage of time, and also reduce the overall warpage. Can be.

(5) Since the expansion and contraction stress caused by the change in temperature and humidity is evenly diffused, the unevenness generated on the surface of a photograph, a poster or the like is not seen. Therefore, it is not necessary to use a special crosslinking agent as described in the prior art.

(6) The above effects can also be achieved by providing the adhesive in a number of parallel lines or dots. However, in such a pattern, since there is a high probability that the adhesive does not exist at the edge of the panel, it is likely to cause the edge of the adherend, such as a photograph or a poster, to cause a curl, and the appearance of an exhibit such as a photograph, a poster, etc. In addition, there is a concern that the commercial value will be significantly impaired. With the mesh pattern of the present invention, such a concern is completely unnecessary.
Furthermore, in the case of parallel lines, the resistance to expansion and contraction of an adherend such as a photograph or a poster due to a change in temperature and humidity is in only one direction, and there is a concern that the panel may be warped. With the mesh pattern of the present invention, the drag is equalized, and such a concern is less.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a base plate according to the present invention.

FIG. 2 is a partially enlarged view of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material 2 Adhesive 3 Release sheet 4 Non-attached part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 1-15273 (JP, U) JP-A 63-31976 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 G09F 7/00-7/22 G09F 15/00 B42F 5/00-5/06

Claims (5)

(57) [Claims] 1. An adhesive is provided on a surface of a plate-shaped substrate,
In the display panel base plate on which the release sheet is provided so as to cover it, the adhesive is a permanent adhesive type
Adhesive strength of 0.3-2kg / 50mm, 1.5
A base plate for an exhibition panel, which is provided in a mesh shape so as to be stable with an adhesive strength of 4 kg / 50 mm . 2. The display panel base plate according to claim 1, wherein the plate-shaped substrate is a foamed polystyrene plate having a skin layer on the surface. 3. The line width ratio of the adhesive-attached portion to the non-attached portion is 2: 1 to 1: 2, and the line width of the adhesive-attached portion is 0.5 to 2.0 mm. 2. The display panel base plate according to claim 1, wherein 4. An exhibition photograph panel, wherein a release sheet of the display panel base plate according to any one of claims 1 to 3 is peeled off, and a photograph is attached to a surface provided with an adhesive. 5. The exfoliating sheet of the display panel base plate according to any one of claims 1 to 3 , wherein fine air existing at the interface between the photograph and the pressure-sensitive adhesive is removed from the base material of the pressure-sensitive adhesive-free portion and the photograph. A method for preventing blisters on an exhibition photo panel, wherein the blisters are prevented from escaping to a space left between them.