JPH10192192A - Heating molding for warmed toilet seat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain high electrical conductivity, enable surface to generate uniform heat and provide a light and simple shape by applying the constitution that an extrusion covered and granulated resin made of a thermoplastic resin is formed on carbon fiber roving having surface treated with specific emulsion, and the volumetric resistivity and thermal conductivity thereof are kept within the range of specific values. SOLUTION: A resin is deposited on carbon fiber roving for the coverage thereof through preliminary treatment with resin emulsion having compatibility with an extrusion covered thermoplastic resin or a thermoplastic resin. The roving after dries is extrusion covered with the thermoplastic resin, and injection or extrusion molded, using a thermoplastic resin containing granulated carbon fiber. The thermoplastic resin is thereby formed into a flat or filament type having volumetric resistivity between 0.01 and 100Ω.cm as well as thermal conductivity equal to or above 0.15kcal/ m.Hr. deg.C. The flat or filament types of the resin so prepared are arranged in series or in parallel on a warmed toilet seat. According to this construction, high electric conductivity is obtained by adding a small amount of conductive material, and the surface of the seat evenly generates heat. In addition, the seat becomes light and can be easily molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded article containing a conductive material in a thermoplastic resin, and to a thermoplastic resin molded article having excellent conductivity and thermal conductivity. More specifically, the present invention relates to a heating element for a light heating toilet seat that uses a thermoplastic resin containing carbon fibers as long fibers and has high conductivity, good thermal conductivity and uniform heat generation on the surface.

[0002]

2. Description of the Related Art Thermoplastic resins have been used in various fields because of their excellent moldability. Among them, styrene resins are widely used in housings of electric / electronic equipment and OA equipment, daily necessities, toys, automobile parts and the like. Used in the field. In recent years, resin compositions having excellent conductivity have been obtained by adding a conductive material to a thermoplastic resin which is such a non-conductive substance. Floor heaters, tank heaters, etc. have been used as planar heating elements. It has begun to be widely used as an industrial and household heating element. Among them, various proposals have been made as heating elements for heating toilet seats. However, Japanese Patent Application Laid-Open Nos.
As described in -300914, aluminum, stainless steel, brass and other short metal fibers are used as the conductive material.
There are disadvantages such as abrasion of the screw cylinder of the molding machine, formation of pills of fibers, and an increase in the weight of the molded product. On the other hand, carbon black is used favorably because it has a low specific gravity and requires a small amount of addition per weight.However, since it is a very fine powder, there is a problem in workability. , And the mechanical properties of the molded article are reduced.

For this reason, for example, Japanese Patent Application Laid-Open No. 63-3288
No. 8 proposes a method of forming a sheet heating element using a conductive composition in which carbon black and metal fibers are combined.

[0004]

However, in order to obtain a molded article having an electric resistance of 100 to 300 Ω required for a heating toilet seat, a conductive composition comprising a combination of carbon black and metal fibers requires 20 wt. % Or more, and since it is a planar molded product, a heating element having a complicated shape such as a thinner inner circumference and a thicker outer circumference for uniform heat generation is obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a high conductivity by adding a small amount of a conductive material, generates heat uniformly on the surface, and has a light and simple shape for heat generation for a heating toilet seat. The purpose is to provide goods.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that a carbon fiber roving surface-treated with a specific emulsion is extruded with a thermoplastic resin and granulated. It has been found that by molding, it is possible to provide a thermoplastic resin heat-molded product which has high conductivity with a small amount of conductive material added, has uniform heat generation on the surface, is light and can be easily processed and molded, and has completed the present invention. Was.

[0007] That is, the present invention is a method for extruding a thermoplastic resin or a resin emulsion compatible with the thermoplastic resin, which is extruded and coated on the carbon fiber roving, and the resin is coated and adhered. Injection molding or extrusion molding using a coated and granulated thermoplastic resin containing carbon fibers, the volume resistivity value is 0.01 to 100 Ω · c.
The present invention relates to an exothermic molded product for a heating toilet seat, which is formed by molding a thermoplastic resin having a thermal conductivity of 0.15 kcal / m · Hr · ° C. or more in a planar or linear shape and arranging in series and / or parallel.

The thermoplastic resin used herein is not particularly limited, and any one can be selected from those conventionally used as molding materials. Examples of the thermoplastic resin include a styrene resin, a polyphenylene ether resin, a polyolefin resin, a polyvinyl chloride resin, a polyamide resin, a polyester resin, a polyacetal resin, and an acrylic resin.

Examples of the styrene resin include a homopolymer such as styrene and α-methylstyrene, a copolymer thereof, and a copolymer with an unsaturated monomer copolymerizable therewith. Specifically, general-purpose polystyrene (GPPS), impact-resistant polystyrene (HIPS),
Heat-resistant polystyrene (α-methylstyrene polymer), acrylonitrile-butadiene-styrene copolymer (AB
S), acrylonitrile-butadiene-styrene-α-
Methylstyrene copolymer (α-methylstyrene-based heat-resistant A
BS), acrylonitrile-butadiene-styrene-phenylmaleimide copolymer (phenylmaleimide-based heat-resistant ABS), acrylonitrile-styrene copolymer (A
S), acrylonitrile-chlorinated polyethylene-styrene copolymer (ACS), acrylonitrile-ethylene propylene rubber-styrene copolymer (AES), acrylic rubber-acrylonitrile-styrene copolymer (AAS)
And the like. It can also be made of a polymer blend.

[0010] Polyphenylene ether resin (PPE)
Are, for example, poly (2,6-dimethyl-1,4phenylene) ether, poly (2-methyl-6-ethyl1,
Homopolymers such as 4-phenylene) ether and the like can be used, and those obtained by modifying this with a styrene resin can be used. Typical polyolefin resins include ethylene, propylene, butene-1,3-methylbutene-
1,3-methylpentene-1,4-methylpentene-1
And the like, and copolymers of these and other copolymerizable unsaturated monomers, and the like. Representative examples are high density, medium density, low density polyethylene, linear low density polyethylene,
Ultra high molecular weight polyethylene, polyethylene such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, atactic, syndiotactic, isotactic polypropylene, propylene-ethylene block copolymer or random copolymer And poly-4-methylpentene-1 and the like.

Examples of the polyvinyl chloride resin include a vinyl chloride homopolymer and a copolymer of vinyl chloride with an unsaturated monomer copolymerizable with vinyl chloride. Specifically, vinyl chloride-acrylate copolymer, vinyl chloride-methacrylate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-vinyl acetate copolymer, And vinyl chloride-vinylidene chloride copolymer. Further, those obtained by chlorinating these polyvinyl chloride resins to increase the chlorine content can also be used.

Examples of the polyamide resin (PA) include those obtained by ring-opening polymerization of a cyclic aliphatic lactam such as 6-nylon or 12-nylon, 6.6-nylon, or 6-10-nylon.
Examples thereof include those obtained by polycondensation of an aliphatic diamine and an aliphatic dicarboxylic acid such as nylon and 6,12-nylon, and those obtained by polycondensation of an amine acid such as 11-nylon.

Examples of the polyester resin include those obtained by condensation polymerization of an aromatic dicarboxylic acid and an alkylene glycol. Specific examples include polyethylene terephthalate and polybutylene terephthalate. Examples of the polyacetal-based resin (POM) include a polyoxymethylene homopolymer or a formaldehyde-ethylene oxide copolymer obtained from trioxane and ethylene oxide.

[0014] As the polycarbonate resin,
4'-dihydroxydiarylalkane-based polycarbonate is exemplified. Specifically, bisphenol A-based polycarbonate, modified bisphenol A-based polycarbonate, flame-retarded bisphenol A-based polycarbonate and the like can be used. Examples of the acrylic resin include methacrylic acid ester polymers and acrylic acid ester polymers. Examples of these monomers include methyl, ethyl, n-propyl, isopropyl, and butyl esters of methacrylic acid or acrylic acid. And a typical example is methyl methacrylate resin (PMMA).

[0015] Among these thermoplastic resins, styrene resin, PPE, polyethylene (PE), polypropylene (PP), PA, POM, and PMMA are preferable. Further, styrene resin and PPE, that is, GPPS, HIP
S, ABS, α-methylstyrene heat-resistant ABS, phenylmaleimide heat-resistant ABS, AES, AAS, AS and P
PE is most preferred. These thermoplastic resins may be used alone or in combination of two or more.

The carbon fiber roving as a component constituting the composition of the present invention is not particularly limited, and those produced from polyacrylonitrile, pitch or the like can be used. The diameter of the single fiber is preferably 2 μm or more from the viewpoint of dispersibility in a thermoplastic resin or generation of pills, and is preferably 10 μm or less in order to maintain a long fiber length in a molded article. The amount of addition is preferably from 1 to 30% by weight, more preferably from 5 to 1%, from the viewpoints of volume resistivity, thermal conductivity and workability.
5 wt%.

The thermoplastic resin or an emulsion of a resin compatible with the thermoplastic resin is a styrene-butadiene resin emulsion (SB latex) when the thermoplastic resin is a polystyrene or a modified polyphenylene ether resin, and a hydrogenated styrene-butadiene. It is a resin emulsion or the like. Thermoplastic resin is AS, ABS, PMMA, P
In the case of an ET or PC resin, an acrylic emulsion such as a styrene-acrylic acid copolymer and a styrene-methyl methacrylate copolymer is used. When the thermoplastic resin is a polyolefin resin or polyacetal resin,
Emulsions of vinyl acetate, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer and partial metal salts. When the thermoplastic resin is a polyamide resin, it is a urethane emulsion.

The solid concentration (mainly resin) of the emulsion may be in the range of 30 to 70% which is generally commercially available, and it is not necessary to use a special emulsion. Surface treatment of carbon fibers with an emulsion means that, first, as a method of attaching the emulsion to the surface of the carbon fibers, a spray method of spraying the emulsion on the carbon fibers, a dipping method of dipping the carbon fibers in an emulsion solution, and the like can be adopted. Depending on the case, it is also possible to appropriately squeeze the excessively attached emulsion using an appropriate method. Next, in order to obtain a good dispersion of the carbon fibers, it is necessary to dry the fibers to which the emulsion is attached at a temperature at which the resin does not deteriorate.
When the resin is an amorphous resin, the glass transition temperature of the resin +20
℃ or below, and if the resin is a crystalline resin, the melting point of the resin +2
Drying at a temperature of 0 ° C. or less is preferred.

The amount of resin coating the fiber surface is preferably 0.5 WT% or more on a dry basis from the viewpoint of compatibility with the thermoplastic resin, and is preferably 50% or less from the viewpoint of workability and economy, and more preferably 5 to 20 WT. %. Surface treatment of carbon fiber roving with emulsion, extrusion coating with thermoplastic resin,
The length of the pellet when granulating is preferably 1.5 mm or more from the viewpoint of the volume resistivity. On the other hand, from the viewpoint of preventing a reduction in formability due to the occurrence of bridges in the hopper, the distance is
m or less is preferable. More preferably, it is 3 to 8 mm.

The thermoplastic resin of the present invention may contain a heat stabilizer, an ultraviolet absorber, a light stabilizer, an antioxidant, a plasticizer, a release agent, a lubricant, a flame retardant, a colorant, and the like. It is possible to add another conductive material or a good heat conductive material to adjust the volume resistivity and the thermal conductivity. As a molding method for obtaining the molded article of the present invention, a commonly used molding method, for example, extrusion molding, injection molding or the like can be used. The molded article of the present invention can also be obtained by mixing a masterbatch pellet containing a high concentration of carbon fibers with a thermoplastic resin pellet.

The shape of the molded product may be planar or linear.
Preferably, a linear one is best in terms of uniform heat generation, design, and productivity. When arranged linearly, they can be arranged in series as shown in FIG. Also, as shown in FIG. 2, the number of pieces that can be arranged in the toilet seat can be parallel, and the series and the parallel can be combined. However, when they are arranged in parallel, the electric resistance value is the same. For this purpose, for example, it is necessary to reduce the cross-sectional area of the inner circumference and increase it in accordance with the outer circumference. The cross-sectional shape in the case of linear arrangement is not particularly limited, but is preferably a semicircle from the viewpoint of the heating of the toilet seat surface and the productivity.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail by way of examples. The materials and molding equipment used in Examples and Comparative Examples are as shown below. <Molding device> Injection molding machine-1: IS55EPN Extruder-1 manufactured by Toshiba Machine Co., Ltd .: OB-40 manufactured by Tosoh Precision Industry Co., Ltd. <Thermoplastic resin> HIPS: Styron <Registered trademark> EXG11 Asahi Kasei Corporation ) Manufactured by PMMA: Delpet <registered trademark> 80N Same as above AS: Styrac <registered trademark> AS783 Same as above ABS: Stylac <registered trademark> ABS100 Same as above PPE: Zylon <registered trademark> 100Z Same as above PE: Suntech <registered trademark> HD < Registered trademark> J340 Same as above POM: Tenac <Registered trademark> C4510 Same as above PA: Leona <Registered trademark> 1300S Same as above <Emulsion material> SB emulsion: Styrene-butadiene resin latex (solid content = 40 wt%) AS 〃: Acrylonitrile-styrene copolymer Combined resin latex (AN EVA〃: Ethylene-vinyl acetate copolymer resin latex (vinyl acetate = 20%, solid content = 50 wt%) Urethane〃: Urethane resin latex (solid content = 40 wt%) <Conductive material> Carbon fiber roving (CF-R): HTA-W12K Graphite manufactured by Toho Rayon Co., Ltd .: ACP-1000 Chopped carbon fiber (C-CF) manufactured by Nippon Graphite Industries, Ltd .: A6000 Carbon black manufactured by Mitsubishi Rayon Co., Ltd. ): ECX Lion Akzo Co., Ltd. <Measurement / Evaluation method> (1) Measurement of thermal conductivity Using an injection molding machine-1, the cylinder temperature is set to a molding temperature suitable for each thermoplastic resin, and drying is necessary. The resin is formed into a plate (width 50 mm × length 90 mm × thickness 2.5 mm) from the dried pellets according to a normal molding cycle.

This plate is sandwiched between two thick copper rods which are in close contact with a heating source and a cooling source, and the temperature gradient of the copper rod and the temperature gradient of the plate are measured to measure the thermal conductivity by the temperature gradient method. . (2) Measurement of Volume Specific Resistance Silver paste is applied to both sides of the plate in the length direction (the flow direction of the resin during molding), and after drying, the resistance value (RL) is measured with a tester, and R1 = RL. × AL / L (A
L: cross-sectional area, L: length) is used to calculate the volume resistivity R1. (3) Measurement of heat generation temperature unevenness Using an extruder-1, the cylinder temperature was adjusted to an extrusion temperature suitable for each thermoplastic resin, and the cross section was semicircular (semicircular diameter =
A 2 cm) strand is formed.

This strand is cut into a length of 250 cm, a silver paste is applied to both ends, and dried to form an electrode. While heating this, it is arranged as shown in FIG. 1 and a power of 80 W is supplied by a sliderac to measure the surface temperature at a total of 24 points at 10 cm intervals.

[0025]

Comparative Examples 1 to 4 and Examples 1 to 11 Pellets of respective sizes were prepared from combinations and compositions of thermoplastic resins, emulsions and conductive materials as shown in Table 1 below. As a method for preparing pellets, in Comparative Examples 2, 3 and 4, ABS and an additive were mixed with a tumbler and extruded with a twin screw extruder.
It was cut into 7 mm pellets. Except for Comparative Examples 2, 3 and 4, carbon fiber rovings (CF-R) were immersed in the respective emulsions, dried, extruded with the respective thermoplastic resins, and cut into 5.5 mm.

Next, the obtained pellets are dried for a resin that needs to be dried, molded and processed according to each evaluation method, and the evaluation results are shown in Table 1. In Examples 1 to 4 in Table 1, carbon fibers having a thermal conductivity of 0.2 Kcal / m · Hr · ° C. or more, a volume resistivity R1 of 14 Ω · cm or less, an anisotropy (R2 / R1) of 1.4 or less, It can be seen that a molded product having a temperature variation of the exothermic temperature within ± 5 ° C. with almost no generation of pills can be obtained. Comparing Comparative Example 1 with Example 3, it can be said that if CF-R is contained in a concentration, pills are increased, and the addition of graphite improves anisotropy and reduces heat generation temperature unevenness. By comparing Comparative Examples 2 and 3 with Example 3, the long fiber of the present invention has significantly increased thermal conductivity and volume resistivity, low anisotropy, and low exothermic temperature even with the same amount of carbon fiber added. It can be said that unevenness is reduced. Also, from Comparative Example 4 and Example 4, it can be said that the present invention can provide a molded article having significantly increased thermal conductivity and volume specific resistance value by adding a small amount of a conductive material, and can improve heat generation temperature unevenness. Further, as shown in Examples 5 to 11, resins other than ABS, HIPS, PMMA, AS, PPE, PE, PO
It can be said that similar effects can be obtained for M and PA.

[0027]

[Table 1]

[0028]

As described above, according to the present invention, high conductivity can be obtained by adding a small amount of a conductive material, the surface generates heat uniformly, and it is light and can be easily processed. Therefore, the volume resistivity is 0.01 to 100 Ω · cm and the thermal conductivity is 0.2 Kca.
There is an effect that a linear heating molded article for a heating toilet seat having a simple shape in which the surface having a specific gravity of not less than 1 / m · Hr · ° C. and a specific gravity of not more than 2 is uniformly generated.

[Brief description of the drawings]

FIG. 1 is a schematic view of a heating molded article for a heating toilet seat in which heating elements of the present invention are arranged in series.

FIG. 2 is a schematic view of a molded heat-generating product for a heating toilet seat in which the heating elements of the present invention are arranged in parallel.

[Description of Signs] 1 Toilet seat body 2 Heating element 3 Electrode

Claims (3)

[Claims] Claims 1. A carbon fiber roving is extruded and coated with a thermoplastic resin or a resin emulsion compatible with the thermoplastic resin to be extruded and coated, dried, extruded with a thermoplastic resin, and granulated. Injection molding or extrusion molding of the contained thermoplastic resin, the volume resistivity value is 0.01 to
Thermal conductivity of 0.15Kcal / m · H at 100Ω · cm
Exothermic molded product for heating toilet seat with r · ° C or higher 2. The heat molded article for a heating toilet seat according to claim 1, wherein said thermoplastic resin is made of a styrene resin or a polyphenylene ether resin. 3. The exothermic molded product for a heating toilet seat according to claim 1, wherein the thermoplastic resin containing the carbon fiber is molded linearly and arranged in series and / or in parallel.