JP2008105306A - Synthetic resin molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic resin molded body especially having good water resistance and suitable for various applications such as building materials like floor materials having no deformation pressed from below caused by thermal expansion, wall materials, ceiling materials and fittings, interior trims of vehicles, components for electric machines and instruments, and box bodies. <P>SOLUTION: In the synthetic resin molded body, an upward cutout with 1/4-1/2 depth of the thickness of the molded body is provided at a position separated by 1/4-1/2 of the thickness of the molded body toward the inside of the molded body from the molded body side of a downward recessed part on the back face side of the synthetic resin molded body, and an upward cutout with 1/4-1/2 depth of the thickness of the molded body is provided at a position separated by 1/4-1/2 of the thickness of the molded body toward the inside of the molded body from the molded body side of an upward recessed part on the back face side of the synthetic resin molded body. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a synthetic resin molded article having a downward concave portion at one end and an upward convex portion at the other opposite end, in particular, having good water resistance and being pushed up by thermal expansion. The present invention relates to a synthetic resin molded article suitable for various uses such as building materials such as floor materials, wall materials, ceiling materials, and joinery items, vehicle interior materials, parts and casings of electrical machinery and equipment.

  Conventionally, the water around the house such as kitchens, washrooms, dressing rooms, etc. is always exposed to a moist environment, and it is also splashed with water, so wooden flooring tends to cause swelling, stains, mold, etc. The flooring was difficult to use. For this reason, many homes use cushion floors around the water. However, with increasing consumer awareness of interior decoration in recent years and the appearance of dining integrated with the kitchen, flooring tends to be required. For this reason, water resistance is also required for flooring, and a water-resistant floor in which a resin-type decorative sheet is stuck on a plywood has been put to practical use.

  However, the above water-resistant floor is less likely to cause blisters and stains due to water absorption from the surface and the end of the floor compared to the normal flooring, but the grooves and fitting parts made by post-processing have plywood on the surface, and water resistance is sufficient I couldn't say that.

  Therefore, resin-based flooring using wood powder-containing polypropylene resin as the base material and laminated with a thermoplastic resin decorative sheet has come out, but it is under the resin-based flooring due to water soaking from the fitting part. The wood base and joists of the underlay could be rotted. Further, if the gap between the fitting portions is eliminated, there is a risk that the resin-based flooring material will thermally expand and cause a push-up or the like.

In addition, if the cross-sectional shape is a simple shape such as a circle or a rectangle, there is no significant problem. However, if the shape is a thin plate with a thin thickness compared to the width or a shape having complex irregularities on the surface, a foamed resin As a result of the relative increase of the contact area with the inner surface of the cooling sizing mold in comparison with the cross-sectional area of the material, the influence of frictional force is strong, and the above-mentioned various molding failure accidents may occur. . For these reasons, there are various foaming ratios of synthetic resin moldings that can be produced while maintaining a good shape and dimensional accuracy by the foam extrusion molding method, the properties of the thermoplastic resin used, the cross-sectional shape of the moldings, etc. However, the current situation is that it is not able to sufficiently meet market demands such as weight reduction, high heat insulation, price reduction, high functionality, and application expansion, which are becoming increasingly stronger in recent years.
JP 2003-112354 A

  The present invention has been made in order to solve the above-described problems in the prior art, and the problem is that the floor material, wall material, which has particularly good water resistance and does not push up due to thermal expansion, It is an object of the present invention to provide a synthetic resin molded article suitable for various uses such as building materials such as ceiling materials and fittings, vehicle interior materials, parts and casings of electric machine devices.

  The present invention solves this problem, that is, the invention according to claim 1 has a downward concave portion having a downward convex portion at an outer end and a downward convex portion at one of the opposed side surfaces of the substantially rectangular flat member. In the synthetic resin molded body provided on the other side, the synthetic resin molded body is provided with an upward concave portion that can be fitted with the downward concave portion and that has a front side cut off and has an upward convex portion at the outer end. On the back surface side of the molded body, at a location about one-quarter to one-half of the thickness of the molded body from the molded body side of the downward concave portion toward the inside of the molded body, it is a quarter of the thickness of the molded body. An upward notch having a depth of one-half is provided, and the back side of the synthetic resin molded body is a quarter of the thickness of the molded body from the molded body side of the upward recess toward the inside of the molded body. ˜1 / 2 to the thickness of the molded body A synthetic resin molded article characterized by comprising providing the first depth of the upward cutouts.

  Further, the invention according to claim 2 is provided such that a downward concave portion having a downward convex portion at an outer end portion is provided on one of the opposing side surfaces of the substantially rectangular flat member, and the downward surface is provided on the other side surface. In the synthetic resin molded body that can be fitted with the concave portion of the upper surface and is provided with an upward concave portion having an upward convex portion at the outer end and provided on one or both of the upper surface and the lower surface of the upward convex portion. A synthetic resin molding comprising a notch having a depth of ¼ to ½ of the thickness of the convex portion.

  According to the third aspect of the present invention, there is provided a downward concave portion having one of the opposite side surfaces of the substantially rectangular flat member, the lower surface side of which is cut off and having a downward convex portion at the outer end portion, and the downward facing portion on the other side surface. In the synthetic resin molded body that can be fitted with the concave portion of the lower surface and is provided with an upward concave portion having an upward convex portion at the outer end, one of the bottom surface of the downward concave portion and the back surface corresponding to the bottom surface Or it is a synthetic resin molding by which the notch of the depth of 1/4 to 1/2 of the thickness from a bottom face to a back surface is provided in both.

  According to the first to third aspects of the present invention, the notch provided at the indicated position does not cause a push-up due to a temperature change even if the molding accuracy is rough. Moreover, moderate fitting strength can be obtained. Furthermore, precise molding accuracy is not required to improve water resistance. The expansion / contraction of the end portion of the fitting portion eliminates the gap, so that a synthetic resin molded body having good water resistance can be obtained by blocking water.

FIG. 1 shows a cross-sectional structure of one embodiment of the synthetic resin molding of the present invention.
As for the synthetic resin moldings 20 and 21 of this invention, the cushion materials 23 and 24 are suitably provided in the bottom face. And it has the notch 25 by the side of the molded object of the downward recessed part of Claim 1, and the notch 26 by the side of the molded object of the upward recessed part.
FIG. 2 shows a cross-sectional structure of another embodiment of the synthetic resin molding of the present invention. The synthetic resin molded bodies 20 and 21 and the cushion materials 23 and 24 are the same as those in FIG. 1, and the upper notch 276 of the upward convex portion and the lower notch of the upward convex portion according to claim 2. 28, and has a notch 29 on the bottom surface of the upward concave portion and a notch 30 on the back surface of the bottom surface of the upward concave portion.

  As the resin used as the main material for the synthetic resin molded bodies 20 and 21 in the present invention, a thermoplastic resin is suitable, but there is no particular limitation on the type, and any thermoplastic resin is selected according to the application. do it. Specifically, for example, polyolefin resins such as polyethylene, polypropylene, polybutene, polymethylpentene, olefinic thermoplastic elastomer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene- (meth) acrylic acid ( Ester) copolymer, ethylene- (meth) acrylic acid copolymer, neutralized olefin copolymer resin (so-called ionomer resin), polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, etc. Polyvinyl resins, polyethylene terephthalate, polybutylene terephthalate, polytetramethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polyarylate, polycarbonate and other polyester resins, polymethacrylic acid Acrylic resins such as chill, polyethyl methacrylate, polybutyl methacrylate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyacrylonitrile, polymethacrylonitrile, styrene such as polystyrene, AS resin, ABS resin Resins, polyamide resins such as 6-nylon and 6,6-nylon, polyvinyl fluoride, polyvinylidene fluoride, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer Fluorine-based resins such as coalescence, etc., or a mixture of plural kinds or copolymers thereof may be used. In addition, the foamed layer can also be constituted by a multi-layer laminate composed of the same or different thermoplastic resins by a multilayer extrusion method or the like.

  In the case of foaming the thermoplastic resin, the type of foaming agent added is not particularly limited, and may be appropriately selected from conventionally known foaming agents. Specifically, as a conventionally known thermoplastic resin foaming method, generally, a chemical foaming method using a chemical substance (chemical foaming agent) having a property of generating gas by thermal decomposition or chemical reaction, It can be classified into a physical foaming method using a phenomenon in which a low boiling point liquid or a gas liquefied under high pressure (physical foaming agent) is vaporized by the action of heat. Examples of the chemical foaming agent used in the former include sodium bicarbonate (sodium bicarbonate), ammonium carbonate, ammonium bicarbonate, ammonium nitrite, sodium borohydride, light metals (aluminum, magnesium, etc.), azide compounds (sodium azide, etc.), etc. Inorganic foaming agents, azo (azodicarbonamide, azobisisobutyronitrile, etc.), nitroso (dinitrosopentamethylenetetramine, dimethyldinitrosotephthalamide, etc.), hydrazide (p, p'-oxybisbenzene) Organic foaming agents such as sulfonyl hydrazide, p-toluenesulfonyl hydrazide, etc.) can be used alone or in any combination of plural kinds. In particular, when a high foaming ratio exceeding 2 times is required, the physical foaming method is suitable. In this case, inerts such as pentane hexane and heptane) and chlorofluorocarbons (so-called Freon gas) are used. Gas is mainly used. Further, in foam extrusion molding by physical foaming, a chemical foaming agent can be used in combination for the purpose of adjusting the cell shape of the foam.

  In addition to the thermoplastic resin and foaming agent described above, the synthetic resin moldings 20 and 21 may include, for example, a thermal stabilizer, an acid neutralizer, an ultraviolet absorber, a light stabilizer, and a colorant (dye, pigment, etc.) as necessary. Various additives such as a filler, an antistatic agent, a lubricant, a nucleating agent, a flame retardant, an antiblocking agent, a light scattering agent for making translucent, and a gloss adjusting agent can be appropriately added. Among these additives, hindered phenols, sulfurs, phosphoruss, etc. as heat stabilizers, stearic acid metal salts, hydrotalcite, etc. as acid neutralizers, benzotriazoles, benzoates as ultraviolet absorbers, etc. Type, benzophenone type, triazine type, etc., hindered amine type as light stabilizer, halogen type, phosphorus type, chlorine type, etc. as flame retardant, inorganic type as filler (calcium carbonate, silica, titanium oxide, barium sulfate, Zinc oxide, alumina talc, clay, magnesium silicate, potassium titanate, magnesium sulfate, aluminum hydroxide, magnesium hydroxide, iron oxide, carbon black, metal powder, carbon fiber, glass fiber, etc.) or organic (nylon, polycarbonate) System, polyurethane, acrylic, wood wool, wood powder, paper powder, etc.) As the agent, hydrocarbon-based, fatty acid-based, higher alcohol-based, fatty acid amide-based, metal soap-based, ester-based, etc. As the nucleating agent, carboxylate metal salt-based, sorbitol-based, phosphate ester metal salt-based, etc. as pigments Is condensed azo, insoluble azo, quinacridone, isoindolinone, anthraquinone, imidazolone, phthalocyanine, carbon black, titanium oxide, iron oxide, cobalt blue, pearl pigment (titanium oxide coated mica, etc.) These various additives can be used in any combination.

  For example, when used as a building material such as a wall material, flooring material, or ceiling material in a building such as a house, its excellent strength, physicochemical stability, economic efficiency, moldability, etc. In terms of surface, it is desirable that the synthetic resin molded bodies 20 and 21 are mainly composed of a polypropylene resin.

  The polypropylene resin used here is mainly a general homopolypropylene, random polypropylene, block polypropylene, propylene-α-olefin copolymer, etc., and polybutene, polyisoprene, ethylene-propylene copolymer as necessary. , An ethylene-vinyl acetate copolymer, an ethylene-α-olefin copolymer, an ethylene-ethyl acrylate copolymer, an acid-modified product thereof, an ionomer resin, etc. A composition or the like can be used. However, when using a mixture of a plurality of types of resins, select a combination of resins that are as compatible as possible or add a compatibilizer to ensure the physical properties after recycling. Consideration is required.

  For the use of the building materials described above, for example, machinability equivalent to that of wood, which is the most commonly used conventional building material, is often required, such as machinability with saws, cones, scissors, etc., nailing properties, and screwing properties. . In order to impart such performance to a polypropylene resin, it is most desirable to add a wood filler to the resin. For the above purpose, it is sufficient that the wood filler is mainly added to the synthetic resin molded body, and the addition of the wood filler of the synthetic resin molded bodies 20 and 21 has a warm tactile sensation similar to wood. There are also advantages such as being obtained.

  Further, the push-up of the flooring material due to thermal expansion cannot be generally said due to the kind of thermoplastic resin such as polypropylene resin or polyethylene resin, the resin structure, the heat history, etc., but the synthetic resin molding of the present invention can be used indoors. If used, the temperature often falls between 0 ° C and 40 ° C. In the example of the present invention, resin blending of polypropylene resin 70 wt% / wood flour (rice husk, etc.) 20 wt% / talc 10% foamed 1.6 times and 0.35% in the 150 mm substrate width direction ( Elongation amount is 0.5 mm) and 0.15% in the length direction of the base material (thus not considered in the present invention) (between 0 ° C. and 40 ° C.), so the notch of the real part in the width direction is 0 About 5 mm is sufficient.

  The wood-based filler material can be selected without any particular restrictions, but in general, the wood is broken by a cutter mill or the like, and this is pulverized by a ball mill or impeller mill to obtain a fine powder. Use things (wood flour). In addition, when the blending amount is higher than 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin, the dispersibility in the resin is particularly important, and the granular wood filling with relatively little cilia It is preferable to use an agent. As the wood filler with less cilia, abrasive powder obtained by polishing particle board or the like is mainly used. Further, the blending amount of the wood filler can be appropriately selected, and the optimum blending amount varies depending on the use of the decorative material. Generally, it is 20 to 400 weights with respect to 100 parts by weight of the thermoplastic resin. Designed to the extent of about parts.

  The method of kneading the thermoplastic resin and the wood filler when adding the wood filler to the thermoplastic resin constituting the synthetic resin moldings 20 and 21 is not particularly limited, but the kneading is performed by a Henschel mixer and the pelletizer is used. A method of pelletizing, a method of mixing and pelletizing with a twin screw extrusion kneader, and the like are common. Moreover, when recycling the molded product produced by the production method of the present invention, a wood-based filler, a thermoplastic resin, various additives and the like can be added to the crushed molded product as necessary. . The kneading method and pelletizing method at that time are the same as described above, and are not particularly limited.

  After the foam molded body is cut to an arbitrary size, the dimensional stability of the foam molded body is improved by performing aging at 40 ° C. to 90 ° C. for about 20 hours to 72 hours. Moreover, it is necessary to cope with the surface of the synthetic resin moldings 20 and 21 by subjecting them to surface activation treatment such as corona discharge treatment or ozone treatment.

  70 parts by weight of a commercially available low melt tension homopolypropylene resin (manufactured by Prime Polymer Co., Ltd .: “E-105GM”) having a melting temperature of 160 ° C., 30 parts by weight of a homopolypropylene resin modified with maleic acid, a wood filler (wood cutter) 400 parts by weight of a wood powder having an average particle size of about 20 μm, which was broken by a mill and pulverized by a ball mill, was kneaded and pelletized at 220 ° C. by a twin-screw extruder kneader. 100 parts by weight of the pellets thus obtained were mixed with 3 parts by weight of a homopolypropylene resin-based masterbatch containing 45% by weight of a sodium bicarbonate citrate chemical foaming agent, put into an extruder and extruded at 230 ° C. Is injected at an extrusion speed of 1 m / min from an extrusion mold having a hollow portion with a height of 50 mm × width of 295 mm at the center, and then a hollow portion with a cross-sectional shape of height 2.5 mm × width 295 mm at the center. Extruded into a long shape that is a rectangle with a height of 5 mm x a width of 300 mm, and this is introduced into a cooling sizing mold having a cross-sectional shape of the inner wall surface of a height of 5.2 mm x width of 300 mm, and at the same time after cooling and taking And cut to a length of 1800 mm. Next, aging was performed in a heating furnace at 80 ° C. for 8 hours.

  Thereafter, notches having a depth of 1.5 mm and a width of 0.5 mm shown in 25 and 26 in FIG. 3 were provided by a router machine in the width direction of the synthetic resin molded body. Then, after corona treatment was performed on the bottom surface with an output of 1 kW and a distance of 3 mm between the electrodes and the synthetic resin molded body, a 10 mm foamed polyethylene resin cushioning material having a thickness of 2 mm was adhered with a two-component urethane resin adhesive, A synthetic resin molding of the invention was obtained.

  Instead of the 25 and 26 notches, a synthetic resin molded body was prepared in the same manner as in Example 1 except that notches 27 and 28 shown in FIG. 4 having a depth of 0.5 mm and a width of 0.5 mm were provided. Obtained.

  A synthetic resin molded body was prepared in the same manner as in Example 1 except that notches 25 and 26 were provided with notches having a depth of 0.2 mm and a width of 0.5 mm of 29 and 30 shown in FIG. Obtained.

  A molded resin molded article was obtained in the same manner as in Example 1 except that the notch of Example 1 was provided not in the router process but in the mold at the time of extrusion molding and provided by profile molding extrusion.

<Comparative Example 1>
A synthetic resin molded body was obtained in the same manner as in Example 1 except that notches were not provided.

<Performance evaluation>
In order to evaluate water resistance, a 200 ml death cup (made by Terraoka Co., Ltd.) with the bottom cut out is placed on the fitting part of the synthetic resin molded body, sealed with Basque Coke White (made by Cemedine Co., Ltd.) and left for a day and night. And cured. Next, 50 ml of tap water was added to observe the decrease in water. As a result, in Examples 1 to 4, water did not decrease by appearance observation, but in Comparative Examples 1 and 2, water leaked to the bottom of the base material in about 2 hours and disappeared from the top of the death cup.

  The synthetic resin molded body of the present invention is particularly suitable for flooring materials, wall materials, ceiling materials, building materials such as fittings, vehicle interior materials, parts and casings of electromechanical devices, etc. It can be suitably used for various applications.

It is explanatory drawing which shows the structure of the cross section of one Example of the synthetic resin molding of this invention. It is explanatory drawing which shows the structure of the cross section of the other Example of the synthetic resin molding of this invention.

Explanation of symbols

20, 21 ... Synthetic resin moldings 23, 24 ... Cushion materials 25, 26, 27, 28, 29, 30 ... Notches

Claims (2)

On one side of the substantially rectangular planar member, the lower surface side is cut off and a downward concave portion having a downward convex portion is provided on the outer end portion, and on the other side surface, the front side is fitable with the downward concave portion. In the synthetic resin molded body in which an upward concave portion having an upward convex portion on the outer end is provided,
On the back side of the synthetic resin molded body, at a location about one-quarter to one-half of the thickness of the molded body from the molded body side of the downward recess toward the inside of the molded body, the thickness of the molded body Provide an upward notch with a depth of 1/4 to 1/2,
On the back surface side of the synthetic resin molded body, the thickness of the molded body is about 1 to 1/2 of the thickness of the molded body away from the molded body side of the upward concave portion toward the inside of the molded body. A synthetic resin molding comprising an upward notch having a depth of ¼ to ½. On one side of the substantially rectangular planar member, the lower surface side is cut off and a downward concave portion having a downward convex portion is provided on the outer end portion, and on the other side surface, the front side is fitable with the downward concave portion. In the synthetic resin molded body in which an upward concave portion having an upward convex portion on the outer end is provided,
A synthetic resin molded body, wherein a notch having a depth of ¼ to ½ of the thickness of the convex portion is provided on one or both of the upper surface and the lower surface of the upward convex portion.

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