JPH01123729A - Manufacture of port-sealed porous - Google Patents

Abstract

PURPOSE:To adhesively treat a porous structure and its sealants in arbitrary arrangement relation, while the flowing out of molten material from its adhesive position by its dead weight is prevented, by using the adhesive sheet providing adhesion property under foaming expansion in heat treatment. CONSTITUTION:The closing treatment by sticking sealers 1 for the surface with exposed holes in a porous structure is achieved by using an adhesive sheet. In order to achieve said adhesion treatment, the adhesive sheet is caused to intervene in between the surface with exposed holes and the sealer, and they are heat-treated under pressure. The adhesive sheet is expanded by foaming, and the expanded layer advances into the holes on the surface with exposed holes, thereby forming fillets 21. The sealants 1 is stuck to the surface with exposed holes or the wall with holes by an expanded adhesive layer 2 of the adhesive sheet, whereby the port-sealed porous structure in which the exposed holes are closed with the sealants 1 is produced. The adhesive sheet used is composed of the sheetlike formed object of the thermoplastic resin compounded with a foaming agent, and is foamed by heating, and further has the adhesive force due to molten thermoplastic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a method for sealing porous structures with excellent adhesive strength and processing efficiency, in which a porous structure is sealed with a sealing material using an adhesive sheet made of a thermoplastic resin containing a foaming agent. This invention relates to a method for manufacturing a structure.

Prior Art and Problems Porous hollow structures such as honeycomb structures are used for various purposes such as heat insulation, and depending on the use, it is required to close the exposed pore surfaces.

Conventionally, as a method for manufacturing a sealed porous structure in which the exposed pore surface of a porous structure, such as the above-mentioned porous hollow structure, is closed, a thick hot melt adhesive sheet is used, and this is used to close the exposed pore surface of the porous structure. A method has been known in which heat bonding is performed by interposing a sealing material such as a plate material between a surface and a sealing material such as a plate material for closing the exposed surface of the hole.

However, there are problems in that the formed adhesive body has poor adhesive strength, and hot melt adhesive sheets do not adhere well.

In order to avoid melting and flowing out of the bonded area, it is necessary to place the sealing material in such a way that it serves as a tray for receiving the molten adhesive, and the work must be done for each closed surface. However, there was a problem that processing efficiency was poor.

Means for Solving the Problems The present invention overcomes the above problems by using an adhesive sheet made of a thermoplastic resin containing a foaming agent.

That is, the present invention provides an adhesive sheet made of a thermoplastic resin containing a foaming agent between the pore-exposed surface of a porous structure such as a honeycomb structure and a sealing material for closing the pore-exposed surface. The present invention provides a method for manufacturing a sealed porous structure, which is characterized in that the porous structure and the sealing material are bonded under the foam engraving of an adhesive sheet by interposing the porous structure and the sealing material by heat-treating the same under pressure. .

An adhesive sheet made of a thermoplastic resin containing a foaming agent is foamed by heat treatment, and the thermoplastic resin melts and functions as an adhesive. At this time, the molten thermoplastic resin follows the foaming and expansion of the adhesive sheet, thereby preventing the melt from flowing out from the bonded area, thereby avoiding the problem of unbonded areas. Also, foam expansion progresses into the pores, which form fillets.

Examples of Constituent Elements of the Invention In the present invention, an adhesive sheet is used to seal the exposed hole surface of a porous structure by adhering a sealing material thereto. This is done by interposing an adhesive sheet between the two and heat-treating the adhesive sheet under pressure. As a result, as shown in the figure, the adhesive sheet foams and expands, and the engraving layer advances into the inside of the hole on the hole-exposed surface to form a fillet 21, and the hole-exposed surface or the hole-exposed surface of the sealing material 1 and the porous structure 3. The hole walls are adhered to each other by the engraving adhesive layer 2 of the adhesive sheet, and a sealed porous structure in which the exposed hole surface is closed with a sealing material is manufactured. The sealed porous structure illustrated in the figure is manufactured by simultaneously bonding the upper and lower sealing materials 1.1.

The adhesive sheet used in the present invention is made of a molded sheet of thermoplastic resin mixed with a foaming agent, and has adhesive strength based on the thermoplastic resin which is foamed by heating and melted.

Therefore, a thermoplastic resin having melt adhesive strength is used to form the adhesive sheet. Typical examples include polyolefins such as polyethylene and polypropylene, ethylene and
Examples include acrylic acid copolymers, acrylic polymers such as ethylene/ethyl acrylate copolymers, ethylene/vinyl acetate copolymers, polyvinyl chloride, polyvinylidene chloride, and ionomers.

Also, known foaming agents can be used. Examples include inorganic substances such as ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, azides, azobisisobutyronitrile, azodicarbonamide, barium Azo compounds such as azodicarboxylate, paratoluenesulfonylhydrazide, diphenylsulfone-3,3''-disulfonylhydrazide, 4
,4'-oxybis(benzenesulfonylhydrazide)
, hydrazine compounds such as allyl bis(sulfonyl hydrazide), semicarbazide compounds such as ρ-toluylenesulfonyl semicarbazide, 4,4'-oxybis(benzenesulfonyl semicarbazide), and 5-morpholyl-1,2,3゜4 - Organic compounds represented by triazole compounds such as thiatriazofur, N-nitroso compounds such as N,N'-dinitrosopentamethylenetetramine, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, etc. Note that the foaming agent may be encapsulated in microcapsules.

The amount of the foaming agent to be added is appropriately determined depending on the thickness of the foamed layer to be formed. In general, the bulk of the adhesive sheet depends on the type of foaming agent used, heating conditions, etc.
．． The amount used is twice or more, particularly 2 to 50 times. Typically, the amount is 1 to 30 parts per 100 parts by weight of thermoplastic resin.
It is 0 parts by weight. Note that the adhesive sheet is generally 50um-
The thickness is about 1 ow, and common additives such as anti-aging agents, cross-linking agents, and plasticizers are added as necessary.

The porous structure to be subjected to sealing treatment in the present invention has a surface in which a large number of pores are exposed.

That is, because of the unevenness caused by the large number of holes, the proportion of the occupied area of the exposed plane of the component that forms the surface to be adhered is small. A typical example thereof is a porous hollow structure such as a honeycomb structure, but in the present invention, hollow bodies such as pipes or tubes are arranged, arranged and bound, or each hollow body is bonded and integrated with each other. It may also be a porous structure made of, for example,

The pore-exposed surface of the porous structure that is subject to the plugging process is the surface with many pores as shown in the figure (the adhesive surface in the figure), or the side surface of the porous structure 3 in the pore axis direction, such as the side surface of the porous structure 3 in the figure. The cut surface of the crystal is uneven due to the cut holes.

As the sealing material used to close the exposed surface of the hole, a plate or sheet-like material can be used, and in the present invention, a rough surface material with unevenness can also be used.

There are no particular limitations on the material of the adherend, that is, the material of the porous structure and the sealing material. Representative examples include metals such as steel, aluminum, steel, stainless steel, and brass, ceramics such as glass, plastics, wood, paper, cloth, and filter materials.

Effects of the Invention According to the method of the present invention, since an adhesive sheet is used which exhibits an adhesive function under the foam engraving by heat treatment, it is possible to cause the melted thermoplastic resin as an adhesive to follow the foam engraving. As a result, the melt can be prevented from flowing out from the bonding area due to its own weight, and thereby the porous structure and the sealing material can be bonded in any desired arrangement relationship. As a result, a plurality of exposed holes, such as upper and lower or left and right sides, can be simultaneously bonded and closed, resulting in excellent processing efficiency.

Furthermore, as the molten material follows the engraving and enters the hole, it is possible to form a wide adhesive area through the hole wall, etc., and as a result of forming a fillet at the entrance of the hole, the adhesive strength is excellent. .

Examples Reference Example 1 Kneaded product consisting of 100 parts (by weight, the same applies hereinafter) of ethylene/vinyl acetate copolymer, 20 parts of azodicarbonamide, 1 part of dicumyl peroxide, and 0.1 part of anti-aging agent. was extrusion-molded to obtain an adhesive sheet with a thickness of 211III+.

Reference Example 2 100 parts of ethylene/ethyl acrylate copolymer; 4.
4゛-Oxybis(benzenesulfonylhydrazide) 3
A kneaded product consisting of 3 parts and 3 parts is extruded to a thickness of 3III and 11 parts.
An adhesive sheet was obtained.

Example 1 Vertical 3 cut in the direction perpendicular to the honeycomb hole
(! II A sealing material made of a diagonal plate with a thickness of 8 III m is placed on both sides of a porous structure made of a cardboard board with a width of 8 cta and a thickness of 1 cta via the adhesive sheet of Reference Example 1, The upper and lower parts are heated to 180°C with a press.
, and was sandwiched under a pressure of 5 kg/cd and heated for 5 minutes for adhesion treatment.

The fillet depth (the depth of penetration of the foamed adhesive layer into the hole) in the obtained sealed porous structure was about 5Il111,
The shear adhesive force between the porous structure and the sealing material is 2 kg/c
a (20°C).

Example 2 A porous structure made of a cardboard board with a length of 3 elm % width of 8 cm and a thickness of 2 cm was cut in a direction of 60 degrees to the honeycomb hole. Stainless steel plate (SUS 3) with a diameter of 0.43 mm
A sealing material consisting of 04) was placed, and this was sandwiched at a pressure of O, l kg/cd using a press heated to 160°C, and heated for 1 minute to perform an adhesive treatment to obtain a primary processed product of a sealed porous structure. .

Next, using the two primary processed products described above, the same stainless steel plate as above was placed on the cardboard board side of one of the products via the adhesive sheet of Reference Example 2, and the stainless steel plate of Reference Example 2 was placed on the other stainless steel side. Place the remaining primary processed product through the adhesive sheet with the cardboard side facing inside, and place it at 160mm.
0,1 kg/cn? by press heated to ℃.
They were sandwiched under a pressure of 160° C. and heated for 3 minutes in an atmosphere of 160° C. to perform an adhesive treatment, thereby obtaining a secondary processed product of a sealed porous structure.

The fillet depth in the obtained secondary processed product is approximately 211
II, and the shear adhesive strength between the cardboard plate and the stainless steel plate was 1 kg/cJ (20°C).

[Brief explanation of the drawing]

The figure is a partially sectional perspective view showing an example of the structure of a sealed porous structure. 1: Sealing material 2: Engraving adhesive layer of adhesive sheet 21: Fillet 3: Porous structure patent application filed Nitto Electric Industry Co., Ltd.

Claims (1)

[Claims] 1. Between the pore-exposed surface of a porous structure such as a honeycomb structure and a sealing material for closing the pore-exposed surface,
A sealing method characterized by interposing an adhesive sheet made of a thermoplastic resin containing a foaming agent, heat-treating the adhesive sheet under pressure, and bonding the porous structure and the sealing material while the adhesive sheet expands. A method for manufacturing a porous structure. 2. The manufacturing method according to claim 1, wherein surfaces opposite the pore-exposed surfaces of the porous structure are simultaneously subjected to adhesive treatment.