JPS5857161B2 - It's been a long time since I've been in the middle of a long time since I've been in the middle of a long time. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of embossing a raised pattern into a polymeric sheet article.

Conventional methods for embossing patterns on polymer sheets include heating an engraved roll or engraved metal plate to a certain temperature and pressing the polymer sheet to emboss the pattern;
There is a method of pressing a polymer sheet using heat conduction heating or high-frequency heating using a mold made of a curable resin model mold.

However, a mold was made from a model upper with a very uneven pattern like the upper of a shoe, commonly known as a "Tsumami Mocha," which is made by pinch-sewing natural leather to form a U-shaped protrusion. When embossing a sheet material, none of the above methods can faithfully and clearly reproduce the irregularities of the original shape, so it is impossible to obtain a product with sufficient commercial value.

In order to improve the reproducibility of large uneven patterns, it is necessary to press the polymer sheet 1 ~ so strongly that it impairs the texture and mechanical performance of the product. In many cases, it is not possible to reproduce the unevenness of the surface.

As a method for improving the above-mentioned drawbacks, the present inventors have already proposed a method of filling the mold recesses with a polymer solution or solid and embossing the polymer solution or solid.

However, according to subsequent research by the present inventors, it was surprisingly found that by filling the recesses of the mold with a combination of a polymer solution and a solid and stamping, the polymer solution alone or the polymer solid The present invention was developed based on the recognition that it is possible to obtain a much more three-dimensional and fine-grained uneven pattern than by filling and embossing alone.

That is, in the present invention, the specific evaporation rate when normal butyl acetate is taken as 100 is placed in the concave part of a mold made of a curable resin composition molded from a shoe upper model having an artificially formed three-dimensional decorative pattern. A solution of at least one polymer selected from polyamides and polyurethanes having a softening point of IOO'C or more and 200°C or less dissolved in a low boiling point solvent of 350 or more is applied, and the solution is roughly applied to the recesses at a temperature of 100°C or more and 200°C or less. A solid polymer of at least one of polyamide and polyurethane having a softening point is filled, a polymer sheet having a surface layer made of a polymer compatible with the polymer is placed thereon, and the recess is filled. A method for making a decorative pattern on a polymer sheet material by pressing it under pressure at a temperature higher than the softening temperature of the solution or solid polymer. .

To explain the present invention based on the accompanying drawings, first, in the method of the present invention, a mold 1 made of a curable resin composition is molded as shown in FIG. A solution 2 of at least one polymer selected from polyamide and polyurethane having a softening point of 100° C. or more and 200° C. or less dissolved in a low boiling point solvent is applied.

Next, as shown in FIG. 3, the recess is filled with a solid 3 of at least one polymer selected from polyamide and polyurethane having a softening point of 100° C. or more and 200° C. or less.

Then, a polymer sheet 4 having a surface layer made of a polymer compatible with the polymers 2 and 3 above is placed thereon as shown in FIG.

In FIG. 4, the dotted portions of the polymer sheet 4 are surface layer portions made of a polymer that is compatible with the 2°3 polymer.

Thereafter, as shown in FIG. 5, the polymer sheet is heated and pressed at a temperature higher than the softening temperature of polymers 2 and 3.

In addition, in FIG. 5, 5 is a heating/pressure plate, and 6 is a pressure plate.

By heating, pressurizing, and embossing in this way, the solvent of the polymer 2 evaporates, the polymers 2 and 3 are softened, and the polymers 2 and 3 and the polymer sheet 4 are bonded and integrated, and then When the polymer sheet is removed from the mold, the sixth
As shown in the figure, a sheet material having a vivid uneven pattern on the surface is obtained.

Embossing here refers to heating and pressing using a mold made of a curable resin composition by heat transfer from the mold side, and preferably by performing a cooling press to fix the pattern immediately after heating and pressing. This is a method of patterning a polymer sheet, or a method of patterning a polymer sheet by applying high frequency heating and pressure using a mold made of a curable resin composition.

In addition, the polymer sheet material to be applied in the present invention includes, for example, a porous sheet material manufactured by impregnating a fiber aggregate with a rubber elastic polymer, and a porous sheet material having a polyurethane resin or polyamide resin on the surface using the porous sheet material as a base material. It means a sheet material provided with a porous or non-porous surface layer, a sheet material provided with a porous surface layer on a knitted fabric base, and a foamed polymer sheet material.

The method of the present invention will be described in detail below.

A model upper with large irregularities, such as the upper of a shoe commonly known as a "Tsumami Mocha", which is made by pinch sewing natural leather to form a U-shaped protrusion, is fixed on a flat plate or a curved plate.
A curable resin liquid is applied to the model surface by brushing or pouring, and then a flat plate is placed and left to harden.

The mold obtained in this way faithfully reproduces even the details of the grains on the surface of natural leather.

The hardness of the mold is adjusted to a Shore hardness of 35 to 95 degrees, preferably 60 to 90 degrees, by adjusting the type of curable resin or the diluent or filler added.

The mold is placed on a heat transfer heating type press plate or a high frequency heating type press plate.

A polymer solution prepared by dissolving either type I polyamide or polyurethane or a mixed polymer of both in a low boiling point solvent is applied to the mold concave portion corresponding to the model upper convex portion.

Generally, in the shoe manufacturing process, the heat setting process is performed in an atmosphere of 100°C to 140°C, so the softening temperature of the polymer needs to be 100°C or higher, preferably 1206°C or higher, and the embossing is performed at a temperature higher than the softening temperature. Therefore, considering the heat resistance of the polymer sheet and its performance after embossing, the temperature must be 200°C or less.

Most of the solvent in the polymer solution needs to evaporate between the time it is applied and the end of embossing, so it is important to choose a solvent that has a high evaporation rate.
Suitable solvents have a specific evaporation rate of 350 or more when the evaporation rate of butyl acetate is 100, and specific examples include methyl acetate, ethyl acetate, isopropyl acetate, acetone, methyl ethyl reketone, tetrahydrofuran, benzene, and methyl alcohol. One type of solvent or a mixed solvent of two or more types is selected and used from among these.

The solution may be colored by adding a dye or a pigment, if necessary.

Among the above-mentioned polymers, particularly polyurethane, suitable examples are as follows.

That is, soft segments such as polyethylene brecol, polypropylene glycol, polytetramethylene glycol, polyethylene adipate glycol, polybutylene adipate glycol, polyhexamethylene adipate glycol, polycaprolactone glycol, and ethylene glycol, butane glycol, hexane glycol, ethanolamine, and hydrazine. Polyurethane suitable for the present invention can be obtained by polymerizing each component selected from chain extenders such as, and diisocyanates such as diphenylmethane-4,4'-diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and xylene diisocyanate. It has a softening temperature as mentioned above,
In order to dissolve in the above-mentioned low boiling point solvents, it is particularly preferable that the molecular weight of the soft segment is 500 or more and 3000 or less, and the nitrogen content based on isocyanate groups is 2% or more and 6% or less based on the polymer.

Next, in the present invention, the mold recesses coated with the solution are filled with a solid polymer.

The constraints on the polymer are the same as those for the solution polymer, and the form of use is appropriately selected depending on the shape of the model carapace convexity, such as film, string, or powder.

In this way, the recesses of the mold are filled with the polymer twice, once in solution form and once in solid form.

The reason for using a polymer solution in the first place is to fully reproduce the fine grain, so the polymer solution applied to the recesses of the mold flows into the fine pattern of the mold.

However, a polymer in the form of a solution alone is insufficient to fill the mold recesses, and there is insufficient polymer to form the convex portions of the upper of the embossed polymer sheet corresponding to the mold recesses.

This appears during shoemaking, and during the shoemaking process, there is a process called tsurikomi, which puts tension on the upper, and if there is not enough filler polymer, the convex parts formed after embossing become very flat and lack a three-dimensional feel. become.

Filling with solid polymer is thus required.

Note that the solid polymer may also be colored if necessary.

Note that if the solid polymer is uniformly filled into the recesses of the mold, the unevenness of the mold will be formed on the polymer sheet with good reproducibility, as shown in Figure 7. When the recesses of the mold are filled unevenly, for example, when the solid polymer 3 is filled in a folded state in the recesses as shown in FIG.
It is thought that the uneven filling of the solid polymer causes wrinkles on the surface of the polymer sheet, but in reality, uneven filling of the solid polymer is caused by the formation of the solid polymer under heating and pressure conditions. Because it softens and flows, it is modified,
No wrinkles appear on the surface of the resulting polymer sheet.

After filling the polymer, a polymer sheet material to be embossed is placed, and the sheet material is made of a material that is compatible with the above polymer.
Preferably, the surface layer should be formed of the same polymer.

For embossing, it is preferable to apply a cushioning material to the back side of the polymer sheet, and the embossing is performed using a heat transfer heating force type or a high frequency heating force type.

Care should be taken here to set the embossing conditions so that the maximum temperature of the mold surface during embossing does not become lower than the softening temperature of the filled polymer.

In the case of the heat conduction heating method, it is desirable to perform cooling embossing immediately after hot embossing to fix the pattern.

The polymer sheet product taken out after embossing reproduces every detail of the surface of the original model, and even the decorative patterns with large unevenness and steps.

Furthermore, the three-dimensional effect is not impaired even during the fishing process.

Next, the present invention will be explained by examples.

Example 1 A three-dimensional nonwoven fiber entangled body made of nylon-6 fibers was impregnated with an acid solution of polyester polyurethane elastomer,
Further, a solution of the above-mentioned polyurethane elastomer with a coloring agent added thereto was applied and wet coagulated to produce a polymer sheet, which was then colored by applying a solution of the polyurethane elastomer with a colorant added thereto.

The mold used for single-press stamping was created as follows.

Approximately 2.
5. A shoe upper consisting of a coating base commonly known as Tsumami Mocha with a convex part formed thereon was fixed on a flat plate, and a crosslinking agent was added to Shin-Etsu Silicon KE113RTV (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) as a curable resin. Knead the material thoroughly and apply it to a thickness of 4 mm. After curing, remove the silicone mold. The thickness of the mold corresponding to the knob mocha is 1.5 mm, and the thickness of the other parts is 4 mm. The surface pattern was faithfully copied.

The polymer solution to be applied to the mold was prepared as follows.

A polyurethane polymerized from polypropylene glycol having a molecular weight of 1000, diphenylmethane-4,4'-diisocyanate and ethylene glycol and having a softening temperature of 165°C and a nitrogen content of 3.6% by weight was dissolved in tetrahydrofuran to form a 20% liquid.

The solid polymer to be filled in the mold recess was prepared by cutting a 0.5 mm thick film made of the above-mentioned polyurethane into a shape that could be embedded in the mold recess.

The above mold was placed on the lower plate of a press machine with an electric heating device built into the lower plate, the polyurethane solution was applied to the concave part of the mold corresponding to the mocha part of the model's upper, and the cut pieces of the polyurethane film were placed on top of the above. Layer the polymer sheet material and the cushioning material in this order, and heat from the mold side to a pressure of 1 k, g/cytf so that the maximum surface temperature of the polymer sheet material is 170°C.

Immediately after pressurizing for 30 seconds, the sample was transferred to a water-cooled press and cooled and pressurized at the same pressure and for the same time.

The cushioning material referred to here is a polymer sheet. It is an elastic material that is used to press uniformly regardless of uneven thickness. It is made of polyurethane foam, silicone resin, etc., and has a Shore hardness of about 20 degrees to 50 degrees. Preferably, in this embodiment, Shin-Etsu silicone KE1 having a Shore hardness of 35 degrees after curing is used.
2RTV (trade name manufactured by Shin-Etsu Chemical Co., Ltd.) was used.

In this way, the polymer sheet material taken out after embossing faithfully reproduces the coat pattern, and has good texture and wrinkles when folded.
The convex part of the mocha part has a height of 2.4 mm and fully reproduces the model carapace.

Furthermore, even after the shoemaking was done, the height of the convex portion was 2.0 mm, and there was almost no deterioration in the three-dimensional effect.

Comparative Example 1 The coating pattern was faithfully reproduced as a result of placing the polymer sheet directly on the mold and embossing under exactly the same conditions as in Example 1, without using either the polyurethane solution or the polyurethane film. However, the mocha protrusions after embossing had no three-dimensional effect, and the height of the protrusions was only 1.0 mm.

In addition, as a result of similar embossing using only polyurethane solution, a mocha convex height of 1.6 mrn was obtained, and although the three-dimensional effect was considerably improved compared to when no polyurethane solution was used, it was still lacking in terms of commercial value. It was enough.

Furthermore, as a result of similar embossing using only Polywarekun film, the height of the convex part was 1.9 degrees and a considerable three-dimensional effect was obtained, but the grain of the mocha convex part was not reproduced, and There was a difference in the film between the area where the film was placed and the area where it was not, resulting in a product with poor commercial value.

The effects of Example 1 and Comparative Example 1 are as follows.

A mold was made by making a mold from a mocha-type model upper in which calf leather cut into a U-shaped band with a width of 1 crr and a thickness of 2 mm was overlapped and sewn onto the kid's upper for decoration.

A phosphorus-containing curable epoxy resin was used as the curable resin, and the thickness of the mold was 3 mrn except for the mocha portion, which was 1 mrn.

Next, polyurethane solution polymerized from polybutylene adipate glycol, xylylene diisocyanate ethylene glycol, and polyurethane polymerized from polypropylene glycol, diphenylmethane-4,4'-diisocyanate, and ethylene glycol used in Example 1 were mixed in a ratio of 1:1. A polyurethane solution obtained by dissolving the polyurethane solution to a concentration of 15% in tetrahydrofuran is applied to the recessed part of the mold, and a polyurethane polymerized from the polybutylene dibate glycol, xylylene diisocyanate, and ethylene glycol is injection molded. A string-like polyurethane was filled into the recess.

The softening temperature of the string-shaped polyurethane was 145°C.

Further, an ester-based urethane prepolymer and a crosslinking agent are dispersed and mixed in methyl ethyl ketone and a petroleum-based hydrocarbon liquid, extruded onto a woven fabric, shaped into a sheet, cured, and the surface is colored black to obtain a polymer sheet. Place the items on top and layer the cushioning material.

Place these on the lower plate of a press machine that has an electric heating plate device built into the lower plate with the mold facing down. 0,51<g/c
r? Embossed for 40 seconds at a pressure of t.

At this time, the temperature of the electric heating plate was set at 270°C so that the maximum temperature on the mold surface was 155°C.

Immediately after hot stamping, light pressure was applied using a room-temperature press plate to cool the product.

The polymer sea i material upper that was taken out reproduces the kid's wrinkles well, shows the sharp lines of the layered mocha, and the height of the convex part is 1.9 mm, giving it a three-dimensional feel. there were.

It also had excellent mechanical performance.

Example 3 A carapace made of a calf base and having a three-dimensional decorative pattern with a height of 2.8 cm obtained by passing a string alternately between the cuts and having cuts made at 3-space intervals was fixed on a flat plate and used as a hardening resin. Toshiba Silicone TSE-34ORTV (trade name, manufactured by Toshiba Silicone Co., Ltd.) to which a crosslinking agent was added was applied and cured to a thickness of 3.5 mounds to prepare a mold.

The above mold has a maximum output of 35kW and an oscillation frequency of 27.1
Place it on the MHz high frequency well-goo lower electrode, apply a 10% methanol solution of 8 nylon to the recess of the mold, and then apply a 1.5 mm thick 8 nylon film (softening temperature 160°C) to the shape of the mold recess. Cut out and embed.

Note that both of the above solution films were colored in advance by adding a small amount of carbon black.

Next, a polymer sheet material in which a nylon coating composition was applied to the woven fabric, foamed, and the surface was colored black was placed on the fabric, and while applying a pressure of 1.5 kg/- to the upper electrode,
High frequency was applied for seconds, and after stopping, pressurization was continued for 5 seconds, and then the pressure was removed.

The polymer sheet material that was taken out clearly reproduces the large irregularities of the model's upper skin, and the height of the raised part is 2.6 mm, and it has an appearance that is completely similar to the model, making it a highly commercially valuable upper skin. It could be manufactured efficiently and at low cost.

[Brief explanation of the drawing]

1 to 6 show the method of the present invention step by step. Furthermore, FIGS. 7 and 8 show the relationship between the solid polymer filling method and the surface unevenness pattern of the resulting polymer sheet.

Claims (1)

[Claims] 1. A mold with a specific evaporation rate of 350 or more when butyl acetate is taken as 100 is placed in the concave part of a mold made of a curable resin composition molded from a shoe upper model with an artificially formed three-dimensional decorative pattern. Applying at least one polymer solvent selected from polyamide and polyurethane having a softening point of 100° C. or more and 200° C. or less dissolved in a boiling point solvent,
Furthermore, the recess is filled with a solid of at least one polymer selected from polyamide and polyurethane having a softening point of 100° C. or more and 200° C. or less, and a polymer having a surface layer made of a polymer compatible with the polymer. A sheet is placed, and the low boiling point solvent is evaporated and removed by heating and pressing the polymer sheet at a temperature higher than the softening temperature of the solution and solid polymers filled in the recesses. A method for making a decorative pattern-embossed upper of a polymer sheet article with a three-dimensional effect, characterized in that the polymer and the polymer sheet article are integrated together, and then the polymer sheet article is taken out of the mold.