JPS6314734B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a high-frequency adhesive porous body in which a powdery high-frequency adhesive is fixed to the skeleton of the porous body. For more details, refer to the skeleton of the specific porous material.
A high-frequency adhesive porous material that is made of a specific polymer with a specific particle size and a specific dielectric loss, and has a structure in which the powdered high-frequency adhesive polymer is sintered and fixed while leaving its particle shape. It's about the body. [Prior Art] Conventionally, latex-impregnated foam, film laminated foam, and coextensive foam are generally known as high-frequency adhesive porous materials and have been put to practical use, but each of them still has problems. Latex-impregnated foam is a high-frequency adhesive porous material that has a structure in which vinylidene chloride copolymer latex is impregnated into polyurethane foam, the water in the latex is evaporated, and the copolymer forms a uniform thin film on the urethane foam skeleton. However, a large amount of water and alcohol-containing water must be evaporated from the porous material, which is supposed to be an insulating material. Therefore,
Special consideration is required for wastewater treatment and drying processes;
When using alcohol, fire, environmental pollution, and health and safety aspects must also be considered. In addition, the resin layer fixed from the latex into the polyurethane foam uniformly forms a thin film and covers the foam skeleton, reducing the texture and elongation of the original foam, and making it difficult to punch out the foam. There are also quality defects such as easy blocking during cutting. Film laminated foam is a porous body in which vinylidene chloride copolymer, vinyl chloride resin, and nylon resin film are laminated on polyurethane foam. Film laminate foam requires a process of laminating film and polyurethane foam, and rework cannot be performed even if loss occurs in the film or foam during the process. In addition, the elongation and texture of the film affect the film lamiform, which may impair the original feel of the urethane foam, or the film lamiform may change over time due to dimensional changes due to changes in the film's environment. There is also the above problem. The co-expanded foam is vinylidene chloride copolymer,
It is a porous body made by dispersing vinyl chloride resin or nylon resin powder in a urethane raw material (for example, polyol or isocyanate), allowing them to coexist and foaming. In order to increase the high-frequency adhesion of the coexisting foam foam to a practical level, it is necessary to increase the high-frequency adhesion resin content, and the foam with resin added to that level has a decrease in hand and elongation. Put it away. On the other hand, there is a problem in that adding a high-frequency adhesive resin to a level that maintains the texture and elongation of the foam does not result in a foam that has practical high-frequency adhesive properties. It is also difficult to control the cell size and expansion ratio of urethane foam. As mentioned above, each foam has its own problems, and a new high-frequency adhesive porous body has been required. In other words, the basic requirements are that it can be manufactured using a dry process, that there is no loss of raw materials, and that even if there is loss, it can be reused, and that
It is a porous body that satisfies four items: it does not impair the original texture of the porous body and it has excellent high frequency adhesion. A high-frequency adhesive composite porous material disclosed in Japanese Patent Publication No. 52-47793 has been attracting attention in recent years as a porous material that can satisfy the above requirements.It has the following three major advantages. are doing. During sewing, adhesive sewing can be carried out by simply applying a high-frequency voltage to a predetermined location to the electrode for a short period of time, and in principle, the adhesive strength can be easily controlled arbitrarily by adjusting the application time of the high-frequency voltage, the contact pressure, and the temperature of the contact area. It is. The sewing process using high-frequency adhesive is easy to automate and can be easily integrated into various continuous assembly processes in-line or by robot. Patterned adhesion is possible, and design adhesion is free. With the recent miniaturization, precision, and improved reliability of high-frequency oscillators and their electronic control equipment, high-frequency bonding machines and sewing machines have become smaller and cheaper, and are being incorporated in-line into various continuous bonding processes. For example, high-frequency bonding machines and sewing machines are extremely effective in the process of continuously manufacturing assembled products that are produced in small quantities at high speed, or in processes that continuously manufacture processed products that are produced in small quantities and at high speed. . Examples of specific assembled products for which such high-frequency adhesive machines and sewing machines are effective are interiors (automobile interior materials, ship interior materials, aircraft interior materials);
For example, ceiling materials, wallpaper, carpets, seats, doors, etc., which are made with complicated curved stitching or locally glued, interior furnishings such as furniture and wallpaper, such as chairs, beds, and sofas, and covering materials made of plywood and laminated wood. There is. A specific product used as an automobile interior will be explained as an example. The interior material for the door lining consists of vinyl chloride leather or fabric as the facing material, high-frequency adhesive polyurethane foam sheet as the cushioning material, and hardboard made of pulp and wood powder hardened with resin as the base material. For practical use, local parts of these covering materials, cushion materials, and base materials are bonded with high frequency in the form of lines or dots, or patterns as designs are engraved while being bonded with high frequency. The interior material for the seat is composed of vinyl chloride leather or fabric as the covering material, high-frequency adhesive polyurethane foam sheet as the cushion material, and nylon nonwoven fabric as the base fabric. For practical use, local parts of these covering materials, cushion materials, and base fabrics are bonded by high frequency in the form of lines or dots, or patterns as designs are engraved while being bonded by high frequency. As is clear from the above-mentioned practical examples, the high-frequency adhesive composite porous material of the present invention can be widely applied as a high-frequency adhesive cushion material for various interiors, and can be used for various purposes such as dotting, line marking, patterning, etc. The design pattern can also be freely changed by changing the high frequency adhesive electrode. Furthermore, the fact that these adhesion processes can be easily automated depending on the shape of the final processed product is due to the feature of the porous body that satisfies the above-mentioned four basic required performances. The high-frequency adhesive porous body essentially consists of a material that is dielectrically induced by an applied high-frequency electric field, generates heat, melts or softens, and crosslinks and hardens, and a communicating porous body. In particular, in order to generate high-frequency dielectric heat generation, high dielectric loss is extremely important at the applied high frequency where a high-frequency adhesive polymer is used. On the other hand, it is common knowledge when using adhesives that if the porous body and the material to be adhered are not sufficiently wetted, peeling will occur at the sintering interface or the adhesive interface, making it impossible to obtain the desired adhesive force. Porous materials that are lightweight and have excellent texture and feel are preferred for interior applications, so plastic foams such as urethane foam or rubber foam, and closed-cell foams made from bead foam are also commonly used. [Problems to be Solved by the Invention] The present invention provides a porous body that satisfies the above-mentioned basic performance requirements and has unprecedented high-frequency adhesive properties. [Means and effects for solving the problems] The present invention provides a powdered high-frequency adhesive made of a specific vinylidene chloride copolymer in the skeleton of a polyurethane foam porous body at a rate of 10 to 500 g per porous body.
It is a high-frequency adhesive porous body made by fixing the particles while leaving the particle shape. The present invention will be explained in detail below. The porous body used in the present invention is an open-cell polyurethane foam with a density of 10 to 500 g/,
Particularly preferred is 15 to 100 g/or less. If the density exceeds 500 g/, the porous material is essentially solid, and if the density is less than 10 g/, the porous material itself may not have the strength to hold itself or may break during handling, which is undesirable. The vinylidene chloride copolymer to be fixed to the porous body is selected from (A) 20 to 93 mol% vinylidene chloride, and (B) an α-monosubstituted ethylene monomer and an unsaturated carboxylic acid monomer that can be copolymerized with vinylidene chloride. One or more monomers7~
80 mol%, and (C) selected from unsaturated carboxylic acids, dicarboxylic acids, α-alkyl substituted carboxylic acids, or acid amides, hydroxylalkyl esters, and glycidyl esters thereof copolymerizable with vinylidene chloride and/or (B) One or more monomers 0
It is a copolymer consisting of ~10 mol%. Monomer component (B) copolymerizable with vinylidene chloride
As the adhesive, a powdered high-frequency adhesive of a copolymer consisting of an α-monosubstituted unsaturated ethylene monomer and an unsaturated carboxylic acid ester monomer can be used.
Preferably, a mixture of one or more selected from vinyl chloride, vinyl acetate, vinyl methyl ether, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, and methacrylonitrile is used. It is a copolymer made of More preferably, vinyl chloride, vinyl acetate, methyl acrylate, ethyl acrylate, butyl acrylate, ethylhexyl acrylate, and acrylonitrile are inexpensive. As the functional monomer (C) copolymerizable with the vinylidene chloride component (A) and/or the monomer component (B), unsaturated monocarboxylic acids, dicarboxylic acids, α-
A copolymer powder high-frequency adhesive made of a monomer component selected from alkyl unsaturated carboxylic acids, acid amides thereof, hydroxyalkyl esters, or glycidyl esters, or a mixture thereof can be used. Preferably acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, fumaric acid,
Copolymers using acrylic amide, methacrylic amide, N-methylol acrylic amide, N-n-butoxymethyl acrylic amide, hydroxyethyl acrylate, glycidyl acrylate, and glycidyl methacrylate are preferred. More preferably acrylic acid, methacrylic acid,
Acrylic acid amide, methacrylic acid amide, itaconic acid, hydroxyethyl acrylate, glycidyl methacrylate, and glycidyl acrylate are preferred because they are easily available industrially. The composition of the copolymer consisting of vinylidene chloride (A) component, (B) monomer component, and functional monomer (C) component is (A) monomer component 20 to 93 mol%, (B) monomer component 7 to 80 mol%, ( C) A copolymer consisting of 0 to 10 mol% of monomer components is preferable. Preferably (A) monomer component 35 to 90 mol%, (B) monomer component 10 to 65 mol%,
(C) A copolymer consisting of 0.05 to 8 mol% of monomer components. More preferably (A) monomer component 40 to 85 mol
%, (B) monomer component 15 to 60 mol%, and (C) monomer component 0.5 to 5 mol%. If the monomer component (A) is less than 20 mol %, the amount of high-frequency dielectric heat generated is small, and the copolymer does not melt or soften enough to sinter into a porous body, which is not preferable. Further, when the porous body of the present invention is further assembled into an assembled product, it is not preferable to obtain a practical high-frequency adhesive strength of the assembled product by high-frequency bonding or high-frequency sewing. (A) A copolymer with a monomer component exceeding 93 mol% will again have a low high frequency dielectric heating value, and the crystallinity of the copolymer will be too high, so it will not melt or soften when sufficiently high frequency dielectric heating is applied, making it practical. I can't offer it. A copolymer into which a functional monomer component (C) is introduced is preferable in order to further improve the practical high-frequency adhesive strength of an assembled product subjected to high-frequency bonding or high-frequency sewing when assembling the porous body of the present invention. Particularly when structural strength is required, such as in furniture such as chairs, beds, sofas, etc., it is preferable to have a functional copolymer terminal formed from a functional monomer component and/or an initiator. For non-structural applications such as bonding the porous body to nonwoven fabrics, woven or knitted fabrics, etc., the amount of the functional monomer component may be small. Even if the functional monomer component exceeds 10 mol %, it is not preferable because the high frequency adhesive strength does not increase even if it decreases compared to the copolymer without the introduction. As a method for analyzing component (C), pyrolysis gas chromatography and conductivity measurement are simple and preferable because of their high analytical accuracy. The accuracy of analysis using these methods can resolve up to 1×10 ^-4 mol/g for the copolymer. On the other hand, it is convenient to calculate the number of functional groups at the polymer terminals of the copolymer obtained by emulsion polymerization method from the number average degree of polymerization. For copolymer, 5×
It can be calculated with good reproducibility up to 10 ^-5 equivalent/g. The structure in which the vinylidene chloride copolymer powder is fixed to the porous body skeleton while leaving a particle form will be described based on scanning electron microscopy and photographs. Figure 1 is a photograph of a 16g/polyurethane foam material. FIG. 2 is a photograph of a high-frequency adhesive porous body in which vinylidene chloride copolymer powder is adhered to a urethane foam skeleton while leaving its particle form intact. As is clear from FIG. 2, it can be seen that the high-frequency adhesive resin powder is discontinuously adhered to the skeleton, leaving a particle shape. It is important to have a structure in which the particles remain discontinuous and are fixed, in order to preserve the characteristics such as the texture inherent in the porous material. It has a porous structure that is endowed with high-frequency adhesion while maintaining the degree of freedom of the porous skeleton against external forces. The degree of discontinuous adhesion to the skeleton is expressed as the coverage of the particles on the skeleton surface, preferably 10 to 90% per skeleton surface, more preferably 20 to 80%.
is good. If the coverage exceeds 90%, the skeleton of the porous material becomes substantially uniform, which is undesirable because the texture of the raw porous material deteriorates. If the coverage is less than 10%, high frequency adhesion is not practical and is not preferred. The particle size range of the powder adhesive is 0.5 μ to 1 mm, preferably 10 to 500 μ, more preferably
It is 100-300μ. When the above particle diameter range is expressed using a JIS standard sieve, it is each 16 mesh passes, preferably 32 mesh passes, and more preferably 42 mesh passes and 200 mesh passes. Particles smaller than 0.5μ are difficult to handle as powder;
It is undesirable because it tends to cause secondary agglomeration or caking during handling. Particles larger than 1 mm are not preferred because the adhesive will be distributed non-uniformly in the porous body, causing non-uniform high frequency adhesion. The amount of high-frequency adhesive to be fixed to the skeleton of the porous body is in the range of 10 to 500 g/to the porous body.
It varies depending on the density of the porous body, the particle size and distribution of the adhesive, and the use of the porous body of the present invention. That is, it differs depending on the flexibility and texture of the porous body and the high-frequency adhesive strength required in the assembly process. For example, if the density of the porous body is selected, for a flexible polyurethane foam with a porous body density in the range of 10 to 100 g/, the adhesive may be applied at a rate of 50 to 500 g/, especially 70 to 100 g/.
The adhesive is preferably
g/It is preferable to fix it. The method of fixing the high-frequency adhesive of the present invention to a porous urethane foam is to spray, dip, or electrostatically adhere the adhesive, and then sinter the adhesive in a hot air or high-frequency microwave heating furnace. A method of forming a porous body into a predetermined porous body is adopted. The only commercial frequencies allowed for high-frequency adhesive machines are those stipulated by the Radio Law. Practically 10~
100MHz is preferred. If it is less than 10MHz, there is a limit to the withstand voltage of the composite porous material, and if it exceeds 100MHz,
High-output vacuum tubes are not manufactured industrially, and local heating of the composite porous body occurs, which is undesirable. Currently, 13.56, 27.12, 40.68MHz, and 2450MHz can be used as industrial frequency bands permitted by the Radio Law, but high-frequency bonding machines commonly use 13.56, 27.12, and 40.68MHz because they allow uniform heating and a long bonding length. has been done. The amount of high-frequency dielectric heat generated is essentially determined by the dielectric loss of the adhesive and the amount of the adhesive in the porous body. Since the amount of adhesive is limited, the higher the dielectric loss of the adhesive, the more practical adhesive strength can be expected with a small amount of adhesive. The practical dielectric loss range is preferably 0.02 or more under the conditions of Q meter (manufactured by Yokogawa Huuretsu Patscard) at 27.12 MHz and 20°C. Preferably 0.04 or more, more preferably 0.05
That's all. If the dielectric loss is less than 0.02, the amount of high-frequency dielectric heat generated will be insufficient, and the adhesive will not be sufficiently melted and/or softened, making it impossible to obtain practical adhesive strength, which is not preferred. Hereinafter, the present invention will be described in detail using specific examples, but the present invention is not limited only to the examples. Example 1 A copolymer of vinylidene chloride component 85 mol%, acrylonitrile component 15 mol%, and itaconic acid component 0.04 mol%, and the molecular chain terminal has a particle size having a functional group component formed from a decomposed component of a sodium persulfate initiator. 20 mesh pass JIS sieve, 200 mesh powder high frequency adhesive with bulk density 16g/6mmt
A composite porous sheet was produced by impregnating a polyurethane foam sheet with 22 g/dip (impregnated by dipping the urethane foam sheet in a powder bath) and sintering it. Table 1 shows the elongation and tensile strength of this composite porous material, and the high frequency adhesive strength to 3 mmt paperboard (manufactured by Nippon Hardboard). 20℃ of this copolymer,
Dielectric loss at 27.12MHz was measured to be 0.022 using a Yokogawa Electric Q meter. It can be seen that various properties are better than those of the comparative example described later. FIG. 1 shows a photograph of the original foam, and FIG. 2 shows a photograph of the porous body of the present invention. Comparative Example 1 A powdered high-frequency adhesive, which is a copolymer made of the same copolymer as in Example and whose only particle size is JIS sieve 20 mesh, was impregnated into urethane foam and sintered under the same conditions as in Example 1. A composite porous body was manufactured. Table 1 shows the results of evaluating the physical properties of the composite porous body under the same conditions as in Example 1. The elongation is smaller than that of Example 1, which is not preferable. Comparative Example 2 Same copolymer as Example 1, but with a different particle size.
The composite porous body produced under the same conditions as in Example 1 was evaluated using a JIS sieve 200 mesh pass. The results are shown in Table-1. Compared to Example 1, the high frequency adhesive strength is low, which is not preferable.

[Table] [Effects of the Invention] The high-frequency adhesive porous body of the present invention has excellent adhesive properties and the texture of urethane foam, and is widely used in various interior goods and the like.

[Brief explanation of the drawing]

FIG. 1 is a scanning electron micrograph showing the cell structure of the original polyurethane foam. FIG. 2 shows a scanning electron micrograph showing the fine structure of a porous body made of polyurethane foam of the present invention, which was prototyped in Example-1.

Claims (1)

[Claims] 1. In the skeleton of a polyurethane foam porous body having a density of 10 to 500 g/, (A) 20 to 93 mol% of vinylidene chloride, and (B) α-monosubstituted ethylene copolymerizable with vinylidene chloride. one or more monomers selected from series monomers and unsaturated carboxylic acid monomers7~
80 mol%, and (C) selected from unsaturated carboxylic acids, dicarboxylic acids, α-alkyl substituted carboxylic acids, or acid amides, hydroxylalkyl esters, and glycidyl esters thereof copolymerizable with vinylidene chloride and/or (B) One or more monomers 0
A powdery high-frequency adhesive made of a vinylidene chloride copolymer with a particle size of 0.5 μm to 1 mm and a dielectric loss of 0.02 or more is applied to the porous body.
High-frequency adhesive porous material that is fixed in an amount of 10 to 500 g/particle while leaving its particle shape.