JPS6219776B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention can meet the demands of the era of material saving, and has a foaming pattern with an extremely large difference in unevenness that is unbelievable based on the conventional concept of foaming ratio. The present invention relates to a method for manufacturing a decorative material in which a non-foamed pattern having a substantially flat surface is adjacent to each other to form a decorative pattern.

The present invention aims to obtain a decorative material having a novel uneven pattern by skillfully combining a foaming agent-containing synthetic resin and a non-foaming synthetic resin. Conventionally,
A so-called print foaming method has been used in which a non-foaming synthetic resin is preliminarily laminated on a base material, a foaming agent-containing synthetic resin is formed in a pattern on the base material, and then heated and foamed. In order to increase the difference in unevenness of foaming using this conventional method, foaming was carried out to a foaming ratio that was just one step before the foaming surface became rough, in order to create a sense of three-dimensionality and volume as much as possible.

Therefore, if it is desired to further increase the remarkable three-dimensional effect, it has been considered that the only solution is to increase the amount of synthetic resin containing a foaming agent to be printed and coated in a pattern.

However, increasing the amount of resin used means increasing the weight of the product, and if it is to be used as a wall covering, it will meet the requirements for certification as "wallpaper", a legal fire-retardant wall covering established by the Ministry of Construction. This would not only exceed the current weight limit, but also increase costs, and was not a desirable solution from the standpoint of saving resources, materials, and energy.

By the way, if we consider what kind of foam structure should be in order to obtain a remarkable difference in unevenness, even if the foam layer forming the surface layer has the normal foaming ratio mentioned above, the height of the foam layer on the surface layer is It can be said that a structure in which the core portion is raised upward by the interposition of a large hollow core portion is a desirable embodiment.

Therefore, the present inventor has conducted extensive research on how to interpose the large hollow core portion in the height direction as described above, and has skillfully used the attributes of conventionally known decomposable foaming agents to further improve the non-foaming properties. It was found that the problem could be solved by combining it with a synthetic resin, and the present invention was finally completed.

The present invention will be described in detail as follows.

In foaming methods that use blowing agents, decomposable blowing agents are widely used as blowing agents, and decomposable blowing agents include organic blowing agents such as azo compounds, sulfohydrazide compounds, nitroso compounds, and azide compounds. It is well known that there are inorganic blowing agents, each with a different decomposition temperature and gas generation amount.

In general, the decomposition temperature changes greatly when mixed with resins, plasticizers, solvents, stabilizers, acids, bases, etc., and especially when blowing agents are dissolved in the compounding agent. For example, azodicarbonamide (ADCA) oxybisbenzenesulfonyl hydrazide (OBSH).
It is easy to select two types of decomposable blowing agents that exhibit a relatively large difference in decomposition temperature, as shown in the figure, which is about 130°C in the system.

Furthermore, in order for the resin layer to swell with the decomposed gas of the decomposable blowing agent, the synthetic resin containing the blowing agent itself must be melted and softened to some extent near the decomposition temperature of the blowing agent. Even if a blowing agent is blended with a synthetic resin that does not soften even above the decomposition temperature and heated to the blowing agent decomposition temperature, the resin itself does not actually bulge.

Furthermore, even if the blowing agent-containing synthetic resin part is coated with a non-foaming synthetic resin having a softening temperature higher than the decomposition temperature of the blowing agent and then heated to the blowing agent decomposition temperature, the resin will still expand due to decomposition of the blowing agent. No phenomenon occurs.

This is because the non-foaming synthetic resin covering the foaming agent-containing synthetic resin has not yet reached its softening temperature, and therefore the expansion of the resin due to the pressure of the decomposed gas of the foaming agent is inhibited.

Therefore, in the present invention, as shown in FIG. 1-A, a first synthetic resin layer 2 containing a foaming agent is formed in a pattern on one surface of the base material, for example, by printing and coating, and then this layer is coated with the foaming agent. a second foaming agent-containing synthetic resin layer 3 having a decomposition temperature higher than the decomposition temperature of the first foaming agent; and a third non-foaming synthetic resin layer 3 having a softening temperature higher than the decomposition temperature of the first foaming agent. 4, the second synthetic resin layer 3 and the third non-foamed synthetic resin layer 4 were coated so as to be adjacent to each other in a pattern, and then heated and foamed.

Figure 1-B shows that the second synthetic resin layer 3 and the third non-foaming synthetic resin layer 4 are printed and applied so as to be adjacent to each other and cover the first synthetic resin layer 2. It shows.

When the product in the state shown in Fig. 1-B is heated and foamed, the first and second synthetic resin layers are foamed.
The process is completed through the states shown in Figure D and Figure 1-E showing the final stage, and eventually the surface layer, which is the foamed layer of the second synthetic resin covering the pattern, is replaced with the second synthetic resin layer. A hollow core portion 5 that is a trace of the first synthetic resin layer 2 foaming while still maintaining airtightness.
Each step is specifically explained as follows. In the initial stage of foaming shown in Figure 1-C, the foaming agent in the first layer 2 in the portion covered by the second layer 3 has already started to decompose and generate decomposed gas; Although the covering second layer 3 has started to soften, the blowing agent has not yet decomposed and the sealing membrane remains as it is, so the decomposed gas from the first layer 2 is not released to the outside. Unable to escape, it has no choice but to push the second layer 3 upwards and swell.

The third layer 4, which is a non-foaming synthetic resin, has not yet reached its softening temperature at this stage, so even if the foaming agent in the first layer 2 decomposes and generates gas, the third layer 4 There isn't enough force to push it up and make it swell.

In this process, minute cells are scattered within the first layer 2 in the area covered by the second layer 3, but as the foaming progresses, the minute cells grow larger and even become adjacent to neighboring cells. The comrades are connected and turn into a set of multiple coarse cells as shown in Figure 1-D. 1st-
In the state shown in Figure D, foaming has gradually begun in the second layer 3, but the decomposed gas from the first layer 2 has not yet reached the point where it can escape freely.
The above-mentioned push-up will continue to grow higher and higher.

Then, the plurality of coarse cells finally become one large bubble, forming the hollow core portion 5.
At the final stage of foaming shown in the figure, the 3 portions of the second layer are foamed with an appropriate foaming ratio, resulting in a foamed product with a good surface condition without any surface roughening.

At this final stage of foaming, the third layer 4, which is the non-foaming synthetic resin part, has also begun to soften to some extent, so it is partially pushed up a little, but by the time it forms extremely high convexities like the second layer. Instead, only a low convex portion (cavity shape) is formed. In this way, the convex portions and concave portions of the second layer, and the convex portions and concave portions of the third layer,
A foam with a very complex and three-dimensional effect is obtained by forming a double-triple uneven pattern. The size of the hollow core portion 5, which dramatically increases the swelling effect, depends on the amount of decomposed gas from the blowing agent contained in the first layer 2. may be appropriately determined in relation to the desired size of the hollow core portion 5. In addition, if the difference in decomposition temperature between the first and second blowing agents is small, there will be little deviation in the foaming states of both synthetic resins, and the decomposed gas from the first blowing agent inside will not be retained inside and will easily escape to the outside. In this case, it becomes difficult to expect much from the swelling effect of the hollow core portion 5, so an appropriate difference should be provided between the two decomposition temperatures, and the difference is preferably at least 30°C or more.

Furthermore, since the purpose of the third layer 4, which is a non-foaming synthetic resin, is not originally intended to be raised, it is a necessary condition that it has a softening temperature higher than the decomposition temperature of the foaming agent in the first layer 2. However, the softening temperature is preferably higher than the decomposition temperature of the second blowing agent.

In addition, the first synthetic resin can be coated and printed using a printing machine such as a screen printing machine, a rotary screen machine, or a gravure printing machine, and the second and third synthetic resins can also be printed and laminated using the same printing machine. , other known methods may be used.

As is clear from the above description, the method of the present invention applies to the second foaming agent-containing synthetic resin layer 3 for forming the surface foam layer laminated in a pattern. Due to the difference in blowing agent decomposition temperature, the first synthetic resin layer 2 containing a foaming agent foams while the second layer 3 still maintains its airtightness, and from fine cells to coarse cells, and from coarse cells to a single hollow shape. When the second layer 3 forms a surface foam layer by actively expanding until it becomes the core part 5, it is expanded by the interposition of the hollow core part 5, without increasing the amount of resin. This results in an extremely large difference in unevenness, which is two to three times that of ordinary foam.

The first layer 2 covered with the third layer 4, which is a non-foaming synthetic resin, hardly foams or remains at the stage where it has just begun to foam due to the difference between the softening temperature and the foaming temperature. .

Furthermore, if the colors of the synthetic resins of the second layer 3 and the third layer 4 forming the surface layer are made different in advance, the resulting product will have a so-called valley-dyed pattern, making it extremely excellent as a decorative material. ing. If the volume of the unevenness is the same as before, the method of the present invention has the advantage of requiring about half the amount of materials required, and also has the advantage of being able to obtain a valley-dyed pattern without using a valley-dye embossing machine. When you think about it, it can be said to be an extremely economical method.

The obtained product is also lightweight, soft, has excellent heat insulation and sound absorption properties, and is extremely excellent in terms of resilience and cushioning properties.

Examples are shown below.

The flow sheet of this example is shown in FIG.

First, the first blowing agent-containing polyvinyl chloride paint 2' (decomposition temperature of the blowing agent is 130°C) shown in formulation table A is applied to a wallpaper flame-retardant backing paper 1 with a thickness of about 0.12 mm using a rotary screen machine 5 to form a 3 mm square square. It was printed and applied in a pattern of fine spots. 2 shows the coating layer of the first blowing agent-containing polyvinyl chloride paint. The coating layer 2
The thickness of the coating was approximately 0.04 mm, and the amount of coating per m ² was extremely small.

The backing paper 1 on which the coating layer 2 has been formed is then heated to 120°C.
The second blowing agent-containing polyvinyl chloride paint 3' (decomposition temperature of the blowing agent is 170°C) shown in recipe B is applied in the rotary screen machine 7 for 60 seconds to dry and gel. It was printed and applied in the form of a 10cm square tile. 3 shows the coating layer of the second blowing agent-containing polyvinyl chloride paint. The thickness of the coating layer 3 was a normal coating layer thickness of about 0.15 mm. In this way, coating layer 3 is placed on coating layer 2.
The backing paper 1 formed into a tile pattern was passed through a drying oven 8 at 120° C. for 80 seconds to dry and gel.
The backing paper 1, on which the coating layer 3 is formed on the coating layer 2 in a tile pattern, is then passed through a rotary screen machine 9 to a non-foaming synthetic resin paint 4' colored brown as shown in the recipe C. (Softening temperature 150℃)
was applied by printing onto the part where the coating layer 3 was not applied, that is, the joint part of the tile pattern (about 5 mm in width) so as to be adjacent to the coating layer 3. 4 shows a coated layer of non-foaming synthetic resin paint colored brown.

The thickness of the coating layer 4 was a normal coating layer thickness of about 0.15 mm.

In this way, the backing paper 1 has the coating layer 4 laminated on the coating layer 2 so as to be adjacent to the coating layer 3.
The coating layer 4 was dried and gelled by passing it through a drying oven 10 at 120° C. for 60 seconds.

The backing paper 1 thus obtained is passed through a foaming furnace 11 at 180°C for 60 seconds to sequentially foam the first and second foaming agent-containing polyvinyl chloride paints according to the foaming process described above. The product was obtained by cooling.

The resulting product has a 10cm square tile-like area that foams in a dewdrop pattern and stands out in a very three-dimensional manner, while the dark brown non-foaming synthetic resin area surrounding it has almost no bulge, and is a valley-dyed area. It showed a pattern, and the height of the foamed part was about 3 mm.

From the cut end surface, it was clearly confirmed that the foamed portion had a hollow core portion, which caused it to swell.

Formulation table A (parts are parts by weight) 100 copies of PVC DOP 30 copies 15 parts flame retardant plasticizer Stabilizer 3 parts Foaming aid 1 part Foaming agent (OBSH type) 20 parts Aluminum hydroxide 10 parts Recipe B (parts are parts by weight) 100 copies of PVC DOP 28 parts 20 parts flame retardant plasticizer 2 parts of epoxy plasticizer Stabilizer 3 parts Foaming agent (ADCA type) 5 parts Foaming aid 1.5 parts Filling material 50 parts Titanium oxide 20 parts Recipe C (parts are parts by weight) 100 copies of PVC DOP 20 parts 20 parts flame retardant plasticizer 3 parts of epoxy plasticizer Stabilizer 3 parts Filling material 70 parts 10 parts brown coloring pigment

[Brief explanation of the drawing]

1-A to 1-E are explanatory diagrams from before foaming to after foaming in the method of the present invention. Second
The figure is a flow sheet showing the manufacturing process. 1: base material, 2, 3: foaming agent-containing synthetic resin layer,
4: non-foaming synthetic resin layer, 5: hollow core portion.

Claims (1)

[Claims] 1. A first blowing agent-containing synthetic resin layer formed in a pattern on the substrate surface is combined with a second blowing agent-containing synthetic resin having a decomposition temperature higher than the decomposition temperature of the blowing agent. A non-foaming synthetic resin having a softening temperature higher than the decomposition temperature of the blowing agent is coated in a desired pattern so that they are adjacent to each other, and then heated and foamed, and the second blowing agent is The surface layer portion of the foamed synthetic resin layer is expanded by the hollow core portion that is the trace of foaming of the first synthetic resin layer while the second synthetic resin layer still maintains its airtightness. A method for producing a decorative material, characterized by: