JPS6280011A - Manufacture of synthetic resin sheet with hole in its surface - Google Patents

Abstract

PURPOSE:To make holes in a sheet surface by a method in which the mold surface having the holes with bottoms is coated with the stock solution for molding sheet which covers the holes, and then the stock solution is heated and cured and simultaneously the air trapped in said hole of the mold surface is expanded, whereby a part of the air penetrates into the stock solution. CONSTITUTION:A mold surface 1a is coated with the stock solution 3 such as a reactive resin solution or thermoplastic resin solution used for molding the ordinary synthetic resin sheet, while covering the holes 2 in the mold. When the mold for molding sheet is heated to cure the stock solution, the holes 5 are made on the surface of the sheet 4 obtained by the curing of the stack solution, correspondingly to the position of each hole 2 made in the mold surface 1a. This is due to following. The holes 2 of the mold surface 1a is covered with the film of the stock solution applied onto the mold surface 1a, whereby the air trapped in the hole 2 is expanded by heating the mold for molding sheet, and a part of the air penetrates into the stock solution 3, and meantime the stock solution is cured at the state where the air is trapped. Thus, the cavity opening in the surface of the sheet 4 may be formed. The depth of the hole 5 is nearby in proportion to the depth of the hole 2 made in the molding surface 1a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a synthetic resin sheet having holes on its surface, particularly a synthetic resin sheet having a large number of independent small holes on its surface.

[Conventional technology]

Conventionally, in order to manufacture a synthetic resin sheet that has many small holes on its surface, projections that model the shape of the holes to be formed in the sheet are provided on the mold surface, and reactive resin liquid or thermoplastic resin is applied to the mold surface. Apply a sheet forming stock solution such as liquid, heat it to harden the stock solution, and if the stock solution contains a foaming agent, foam and harden this, peel it off from the mold surface, and leave protrusions on the sheet surface. The method used was to open a hole that mimicked the shape.

[Problem that the invention seeks to solve]

However, when using the above method, it is very difficult to manufacture and process the mold, especially when opening a large number of small holes in rows and columns, the same number of protrusions must be aligned and planted on the mold surface, and after molding, It becomes difficult to release the sheet from the mold. Moreover, only sheet-like products with a limited area can be obtained, and long sheets cannot be manufactured.

It cannot be applied to the basolateral area. Further, the shape of the hole opened in the sheet is limited by the shape of the protrusion on the mold surface and cannot be made variable.

An object of the present invention is to solve the above-mentioned problems and provide a method for manufacturing a synthetic resin sheet having a large number of small holes on the surface using a simple mold structure.

[Means for solving problems]

In the present invention, a sheet forming stock solution such as a reactive resin liquid or a thermoplastic resin liquid is applied to a mold surface having a hole with a bottom, and a film of the stock solution formed on the mold surface covers the hole with a bottom. coated with
The stock solution is heated to harden or foam to form a sheet with a predetermined thickness, and the air trapped in the pores of the mold surface expands to allow some of it to penetrate into the stock solution, forming a part of the mold surface that corresponds to the hole. This is a method for producing a synthetic resin sheet having holes on its surface, which is characterized by forming holes with or without a bottom on the surface of the sheet.

The present invention will be explained below using figures.

In FIG. 1, the sheet mold 1 used in the present invention includes:
A hole 2 with a bottom is provided in the mold surface 1α. A stock solution 3 such as a reactive resin liquid or a thermoplastic resin liquid, which is usually used for molding synthetic resin sheets, is applied to the mold surface 1α to a certain thickness, covering the surface of the holes 20, and the sheet mold is heated to form a solution 3. When cured, holes 5 as shown in FIG. 2 are formed on the surface of the sheet 4 obtained by curing the stock solution, corresponding to the positions of the holes 2 opened in the mold surface 18.

This is due to the coating of the stock solution 3 applied to the mold surface 1a.
The holes 2 are covered, and the air trapped in the holes 2 expands due to the heating of the sheet mold, and a part of it hardens while remaining in the stock solution 3, forming a cavity that opens on the surface of the sheet 40. It is. .

The shape of the hole 5 formed in the sheet 4 is the hole 2 of type ff1lα.
The depth is approximately proportional to the depth of the hole 2 formed in the mold surface 1α as shown in FIG.

In the present invention, it is important to prevent the stock solution applied to the mold surface from flowing into the holes 2 of the mold. Therefore, there are limits to the diameter of the holes opened in the mold surface or the viscosity of the stock solution.

However, in order to prevent the stock solution 3 from flowing into the holes 2 on the mold surface, it depends on the diameter of the opening edge of the holes 2. For example, as shown in Fig. 3 (α), (b), and (C) By narrowing down the opening diameter of the hole 2 and providing an enlarged portion inside it, the capacity of the hole as a whole can be increased. In this case, the holes in the sheet are not necessarily similar to the holes in the mold surface. The larger the amount of air trapped in the hole 2, the more the hole 2 will expand due to expansion.
The amount of air discharged from the inside increases and eventually breaks through the sheet 4 covering the mold surface and is discharged, but at this time a through hole is formed in the sheet 4.

The sheet molding die may be a metallic mold or an endless belt-shaped die. According to the present invention, since only a hole with a bottom is provided on the mold surface, a major feature is that a belt-shaped mold capable of molding a long sheet can be used.

The stock solution for sheet molding is liquid, and its viscosity is 300 to 3
00,000 cps, can be applied to any thickness or shape (e.g. medium convex, medium diagonal, etc.) using a doctor, etc., and must be a thermoplastic or reactive resin liquid. However, this requirement is not particularly limiting. Substantially most of the sheet molding resin liquids conventionally used are included.

Specific examples of thermoplastic or reactive resin liquids include those that gel and solidify when heated, such as vinyl chloride paste;
There are urethane crosslinkers that are crosslinked by heating to accelerate the reaction, and liquid rubber compounds dissolved in organic solvents that are crosslinked by heating.

It also includes those in which a foaming agent is added to these resin components.

The sheet may be a laminate sheet made by laminating woven fabrics, knitted fabrics, nonwoven fabrics, films, etc. in addition to a single resin. It is also possible to provide a density difference in the structure between the sheets.

When producing a sheet by applying a normal thermoplastic or reactive resin stock solution to a thickness of 0.5 to 10 mm, the preferred diameter of the opening edge of the bottomed hole that opens on the mold surface is 0.5 to 5 mm. This is the range of If it is less than 0.50, processing is difficult and the air expansion pressure required to form holes in the sheet cannot be obtained. On the other hand, if it exceeds 50, the stock solution will flow into the holes in the mold surface and protrusions will be formed on the sheet surface. [Examples] Examples of the present invention are shown below.

(Example 1) Parts by weight 1.4 Butanediol (chain extender) 5 BHT (antioxidant) 0.5 Tinupin 328 (ultraviolet absorber) 0.5 DOP (plasticizer) 30 Methylene chloride (
Foaming agent) 5 The above formulation (viscosity 600 cps
) was placed in a stirrer and stirred to uniformly disperse and mix the ingredients.

The polyisocyanate was adjusted to have an NGO10H index of 105 using a prepolymer synthesized from a triol with a molecular weight of 700 using pure MDI so as to have an NC of 20%. This formulation was applied to a diameter of 3 grams and a depth of 2.5%.

It was applied uniformly to a thickness of 1 inch onto a belt having bottomed holes with a hole interval of 51 (a belt made of chloroprene rubber backed with glass cloth and covered with a Teflon film and having bottomed holes). Heat this belt to 150°C to 1600° from the bottom.
Heat for 3 minutes at
．． 3%) was laminated and further heated for 5 minutes to perform a crosslinking reaction, and then the molded body was peeled off from the belt. The resulting sheet is a 2.5X thick foam with approximately the same diameter as the belt holes.
A sheet having shaped holes on the surface was obtained. The hole depth was 2.0% and no holes penetrated the sheet.

(Example 2) Part by weight DOP (plasticizer) 60 DOA (1) 20C-1
30P (Epoxidized soybean oil) 4 Pannlup H
(Secondary plasticizer) 10 Calcium carbonate (filler) 10 Uniform d (foaming agent) 2 Mineral Spirift (
Diluent) 4 Add the above formulation/plastisol to a viscosity of 3
The mixture was adjusted to 0.00 CPS, applied onto the belt used in Example 1, and heat-treated to obtain a foamed sheet with a thickness of 3 mm. The resulting sheet surface has approximately the same holes as the belt.
A shaped hole was formed, and no through hole was observed.

(Example 3) 0.5' of each of the formulations of Example 1 and Example 2.

1.0', 3.0', 5.0', 7.0', 9.0'
+7) Diameter depth 2.5% Coating is applied to the mold surface of an aluminum concave mold with a bottomed hole to a thickness of 3 mm, and after heat treatment, it is peeled off from the mold surface to form a sheet. I got it.

As a result, for holes with a diameter of 50 or less on the mold surface, holes are opened in the sheet surface, and for holes with a diameter of 70 or more, a rim shaped like the hole on the mold surface is formed on the sheet surface. Ta.

〔Effect of the invention〕

As described above, according to the present invention, a sheet having holes on the surface can be obtained by simply opening a hole with a bottom in the mold surface of a sheet molding die, and in particular, a perforated sheet can be produced using an endless belt-shaped mold. The resulting sheet can be widely used as a cushion material, carpet backing material, shoe insole, etc.

[Brief explanation of drawings]

FIGS. 1 and 2 are cross-sectional views showing the manufacturing process of the present invention in the order of steps, and FIGS. It is.

Claims (1)

[Claims] (1) Apply a sheet-forming stock solution such as reactive resin liquid or thermoplastic resin liquid to the mold surface with the bottomed holes, and fill the bottomed holes with a film of the stock solution formed on the mold surface. The undiluted solution is coated and heated to harden or foam to form a sheet of a predetermined thickness, and the air trapped in the pores of the mold surface expands to allow some of it to infiltrate into the undiluted solution, corresponding to the pores of the mold surface. 1. A method for producing a synthetic resin sheet having holes on its surface, the method comprising forming holes with or without a bottom on the surface of the sheet at the portions of the sheet.