JP2018034428A - Resin molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin molded product which can be obtained simply at a low cost and is excellent in scratch resistance and gloss.SOLUTION: There is provided a resin molded product 1 which is made of a resin material and comprises a surface 2 having gloss and a plurality of protrusions 3 which are protruded from the surface 2 and arranged along a predetermined direction, wherein the area ratio of the surface 2 to the total area of the surface 2 and the top face of the protrusions 3 is set to 50% or more and in the predetermined direction, the interval between the plurality of protrusions 3 is set to 420 μm or less and the height of the protrusions 3 is set to 26 μm or more. Since the protrusions 3 protruded from the surface 2 are formed with the predetermined pattern in the resin molded product 1, both excellent scratch resistance and excellent gloss can be achieved. Further, the resin molded product 1 can be obtained simply at a low cost since a filler or coating treatment is not required.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin molded body.

  Conventionally, resin moldings obtained by injection molding of resin materials are used for exterior materials such as automobile bumpers and interior materials such as automobile instrument panels.

  Such a resin molded body may be required to have excellent gloss from the viewpoint of design and the like. As a method of obtaining a resin molded body having excellent gloss, for example, a method of injection molding a resin material using a mold whose inner surface is polished is considered. In such a method, since the inner surface of the mold is polished, the surface (mold contact surface) of the resulting resin molded body has excellent gloss.

  On the other hand, such a glossy surface is easily scratched, and scars are conspicuous, so that improvement in scratch resistance is required. Therefore, it has been proposed to add a filler or the like to the resin material in order to improve the scratch resistance.

  Specifically, for example, an injection molded body obtained by injection molding a polyamide resin composition containing a polyamide resin and cellulose fibers using a surface-polished mold has been proposed (for example, Patent Document 1). reference).

Japanese Patent Laying-Open No. 2015-0516131

  However, when a filler such as cellulose fiber is contained in the resin material, there is a problem that costs are increased.

  Further, as a method for improving the scratch resistance without containing a filler in the resin material, for example, it is also considered to form a coat layer by coating a hard coat paint on the surface of an injection molded body. However, even such a method has a problem that it takes time and cost.

  An object of the present invention is to provide a resin molded body which is obtained simply and at low cost and has excellent scratch resistance and gloss.

  The present invention [1] is a resin molded body made of a resin material, and includes a glossy surface and a plurality of convex portions protruding from the surface and arranged along a predetermined direction. The area ratio of the surface with respect to the total area with the top surface of the part is 50% or more, the interval between the plurality of convex parts in the predetermined direction is 420 μm or less, and the height of the convex part The resin molded body whose length is 26 micrometers or more is included.

  Since the convex part which protrudes from the surface with the above-mentioned predetermined pattern is formed in the resin molded body of the present invention, it is possible to achieve both excellent scratch resistance and excellent gloss.

  Furthermore, since the resin molded body of the present invention does not require a filler or coating treatment, it can be obtained simply and at low cost.

FIG. 1 is a schematic perspective view of an embodiment of the resin molded body of the present invention. FIG. 2 is a cross-sectional view of the resin molded body shown in FIG. 3 is a schematic view showing a method for producing the resin molded body shown in FIG. 2, wherein FIG. 3A is a step of preparing a mold, FIG. 3B is a step of polishing the mold, and FIG. 3C is a resin material. Each of the steps for molding the material is shown. FIG. 4 is a schematic perspective view of another embodiment of the resin molded body of the present invention (a configuration in which convex portions are arranged in a wavy line). FIG. 5 is a schematic perspective view of another embodiment of the resin molded body of the present invention (a mode in which relatively small diameter convex portions and relatively large diameter convex portions are alternately arranged). 6 is a photograph of the resin molded product obtained in Example 1. FIG. FIG. 7 is a graph showing the relationship between the spacing along the alignment direction of the protrusions and ΔL ^* in the scratch resistance test. FIG. 8 is a graph showing the relationship between the height of the convex portion and ΔL ^* in the scratch resistance test.

  1 and 2, a resin molded body 1 is a molded body made of a resin material (described later).

  The shape in particular of the resin molding 1 is not restrict | limited, For example, lump shape, box shape, plate shape, etc. are mentioned, Preferably, plate shape is mentioned. 1 and 2 show a plate-shaped resin molded body 1.

The resin molded body 1 has a thickness (thickness of a portion excluding the convex portions 3 described later) h ¹ of, for example, 1000 μm or more, preferably 1500 μm or more, for example, 4000 μm or less, preferably 3500 μm or less.

  In addition, at least a part of the region S on the outer surface of the resin molded body 1 is subjected to uneven processing (texture processing) with a predetermined pattern. In other words, the resin molded body 1 has a region S that has been concavo-convex (textured) in a predetermined pattern.

  As shown in an enlarged view in FIG. 1, the region S includes a glossy surface 2 and a convex portion 3 protruding from the surface 2.

  The surface 2 is a portion excluding the convex portion 3 in the region S. That is, the surface 2 is the entire surface of the region S excluding the top surface 4 of the convex portion 3.

  The surface 2 has a gloss, and preferably has a specular gloss.

  More specifically, the surface 2 has a 20-degree specular gloss (based on JIS Z 8741 (1997)) of, for example, 50 or more, preferably 65 or more.

  If the surface 2 has gloss, the designability of the resin molding 1 can be improved.

  In addition, it does not restrict | limit especially as a method to provide the surface 2 glossiness, For example, the method of grind | polishing the surface 2 directly, For example, the method of shape | molding the resin molding 1 using the metal mold | die with which the inner surface was grind | polished ( For details, see below). Preferably, a method of molding the resin molded body 1 using a mold whose inner surface is polished is mentioned.

  The convex portion 3 is a projection protruding from the surface 2 in the region S.

  The shape in particular of the convex part 3 is not restrict | limited, For example, various shapes, such as a column shape and a polygonal column shape, are mentioned, Preferably a column shape is mentioned. In FIGS. 1 and 2, a cylindrical protrusion 3 is shown.

  In the region S, a plurality of convex portions 3 are formed and arranged at intervals along a predetermined direction. More specifically, the convex portions 3 are arranged in a straight line along the vertical direction of the paper in FIG. 1 (hereinafter, a predetermined direction in which the convex portions 3 are aligned and arranged (the vertical direction of the paper in FIG. 1). ) May be referred to as an arrangement direction.

  Moreover, the convex part 3 is formed and arrange | positioned by the predetermined pattern from a viewpoint of the flaw resistance of the resin molding 1, and glossiness.

  More specifically, the diameter D of the convex portion 3 is, for example, 100 μm or more, preferably 200 μm or more, more preferably 300 μm or more, for example, 1000 μm or less, preferably 900 μm or less, more preferably 800 μm. It is as follows.

  When the diameter D of the convex portion 3 is in the above range, both excellent scratch resistance and excellent gloss can be achieved.

The height ^{h 2} of the protrusions 3 is, 26 .mu.m or more, preferably, 30 [mu] m or more, more preferably at 35μm or more, e.g., 100 [mu] m or less, preferably, 80 [mu] m or less, more preferably 60μm or less.

If the height h ² of the convex portion 3 is long exceeds the above lower limit, it is possible to achieve both good scratch resistance, and excellent gloss. Also, the height h ² of the convex portion 3 is long below the upper limit, it is possible to suppress the like fabric is caught to the resin molded body 1, furthermore, it is possible to improve safety.

  Further, the interval P between the convex portions 3 adjacent to each other in the arrangement direction is 420 μm or less, preferably 370 μm or less, more preferably 300 μm or less, and further preferably 250 μm or less, for example, 50 μm or more, preferably 100 μm. As mentioned above, More preferably, it is 150 micrometers or more.

  If the interval P between the convex portions 3 is within the above range, both excellent scratch resistance and excellent gloss can be achieved.

  In addition, the space | interval P of the convex part 3 is the shortest distance between the edges of the convex part 3 mutually adjacent | abutted in the arrangement direction of the convex part 3. FIG.

  Moreover, the convex part 3 may be arrange | positioned along two or more directions, for example, the convex part 3 is a predetermined direction (for example, the up-down direction of the paper surface of FIG. 1), and the direction orthogonal to the predetermined direction (for example, For example, it may be disposed along the left and right direction of FIG.

  In such a case, the interval between the adjacent convex portions 3 in at least one direction (for example, the vertical direction in FIG. 1) may be in the above range. The distance between the protrusions 3 in other directions (for example, the left-right direction in FIG. 1) is not particularly limited, and is appropriately set according to the purpose and application within a range that does not impair the excellent effects of the present invention.

  Moreover, the convex part 3 is arrange | positioned so that the area ratio of the surface 2 in the area | region S and the convex part 3 may become a predetermined range.

  More specifically, the area ratio of the surface 2 with respect to the total area of the area of the surface 2 in plan view of the region S and the area of the top surface 4 of the convex portion 3 is 50% or more, preferably 50 %, More preferably 55% or more, for example, 90% or less, preferably 80% or less, more preferably 70% or less, and further preferably 60% or less. Further, the area ratio of the top surface 4 of the convex portion 3 is, for example, 10% or more, preferably 20% or more, more preferably 30% or more, still more preferably 40% or more, and 50% or less, preferably Is less than 50%, more preferably 45% or less.

  If the area ratio of the surface 2 and the convex part 3 is the said range in the area | region S, outstanding scratch resistance and outstanding gloss can be made compatible.

  A method for forming such a resin molded body 1 is not particularly limited. For example, a method of etching the region S of the resin molded body 1 or a mold corresponding to the surface 2 and the convex portion 3 is used, for example. And a method of molding a resin material.

  Preferably, the resin material is molded using a mold corresponding to the surface 2 and the convex portion 3.

  Examples of the resin material include an amorphous resin. Specifically, for example, an acrylic resin (PMMA resin (polymethyl methacrylate) or the like), an ABS resin (acrylonitrile / butadiene / styrene copolymer), ASA, or the like. Examples include thermoplastic resins such as resins (acrylonitrile / styrene / acrylate copolymers), polystyrene resins, polycarbonate resins, amorphous polyarylate resins, polysulfone resins, polyethersulfone resins, polyetherimide resins, and cyclopolyolefin resins. . These can be used alone or in combination of two or more. Of these, acrylic resin, ASA resin, and polycarbonate resin are preferable.

  The resin material may be colored by a known method. Specifically, the resin material can contain a colorant as long as the effects of the present invention are not impaired.

  Examples of the colorant include titanium white, zinc white, carbon black, iron black, dial, chrome vermillion, cadmium red, ultramarine, cobalt blue, yellow lead, titanium yellow, titanium dioxide-coated mica, and basic carbonic acid. Examples of the inorganic pigment include organic pigments such as phthalocyanine blue, indanthrene blue, isoindolinone yellow, benzidine yellow, quinacridone red, polyazo red, and perylene red, and metal pigments such as aluminum and brass. These can be used alone or in combination of two or more. In addition, the content rate of a coloring agent is suitably set according to the objective and use.

  In addition, the resin material is, for example, an organic fiber, an inorganic fiber, a rust inhibitor (rust inhibitor pigment), an antioxidant, an ultraviolet absorber, a light stabilizer, a silane coupling agent, within a range not impairing the effects of the present invention. Epoxy resin, catalyst, coatability improver, leveling agent, nucleating agent, lubricant, mold release agent, antifoaming agent, plasticizer, surfactant, organic or inorganic fine particles, antifungal agent, flame retardant, filler, etc. Additives can be contained as appropriate. In addition, the mixture ratio of an additive is suitably set according to the objective and use.

  The method of molding a resin material using a mold is not particularly limited, and examples thereof include known molding methods such as melt extrusion molding, injection molding, compression molding, inflation molding, and preferably injection molding. It is done.

  In the injection molding, for example, first, as shown in FIG. 3A, the above-described resin material and a mold corresponding to the shape of the resin molded body 1 are prepared.

  The mold 11 is a mold corresponding to the surface 2 and the convex portion 3, and specifically has an inner surface 12 corresponding to the surface 2 and a concave portion 13 corresponding to the convex portion 3.

  Next, in this method, as shown in FIG. 3B, the inner surface 12 of the mold 11 is polished with an abrasive. In FIG. 3B, the polished surface of the mold 11 is indicated by a thin line.

  The abrasive is not particularly limited, but the abrasive particle size is, for example, 1000 mesh or more, preferably 3000 mesh or more, more preferably 5000 mesh or more, for example, 50000 mesh or less.

  By polishing the inner surface 12 with the abrasive having the above-described abrasive particle size, excellent gloss can be imparted to the surface (that is, the surface 2) that contacts the inner surface 12 of the resin molded body 1.

  In this method, for example, a mold 11 whose inner surface 12 is previously polished can be prepared. Further, in this method, the concave portion 13 can be polished in the same manner as the inner surface 12 as necessary.

  Next, in this method, as shown in FIG. 3C, the resin material is injection-molded using the mold 11 described above.

  The molding conditions in the injection molding are not particularly limited, but the injection temperature is, for example, 200 ° C. or higher, preferably 220 ° C. or higher, for example, 300 ° C. or lower, preferably 280 ° C. or lower.

  The mold temperature is, for example, 20 ° C. or higher, preferably 40 ° C. or higher, for example, 100 ° C. or lower, preferably 80 ° C. or lower.

  Thereafter, by removing the resin molded body 1 from the mold 11, a resin molded body 1 having a surface 2 corresponding to the inner surface 12 and a convex portion 3 corresponding to the concave portion 13 is obtained (see FIGS. 1 and 2). ).

  And since the convex part 3 which protrudes from the surface 2 with the said predetermined pattern is formed in such a resin molded object 1, the some convex part 3 carries out the contact from the outside of the surface 2 which is easy to be damaged. Can inhibit and protect the surface 2. Therefore, the resin molded body 1 can achieve both excellent scratch resistance and excellent gloss. Furthermore, since the resin molding 1 does not require a filler or a coating process, it can be obtained simply and at low cost.

  Therefore, such a resin molded body 1 can be suitably used as, for example, an automobile exterior material (bumper, etc.), an automobile interior material (instrument panel, etc.), and scratch resistance and gloss are particularly required. It can be suitably used as an automobile exterior material.

  In the above description, the convex portions 3 are arranged in a straight line along the vertical direction of the paper. For example, as shown in FIG. 4, the convex portions 3 may be arranged in a wavy line. Good. Preferably, the convex portions 3 are arranged in a straight line.

  In the above description, all the convex portions 3 are formed in a columnar shape having the same diameter. For example, as shown in FIG. 5, the diameters of the convex portions 3 may not be the same. . For example, the relatively small-diameter convex portions 3 and the relatively large-diameter convex portions 3 may be mixed, and they are alternately arranged along a predetermined direction (for example, linear or wavy). May be.

  In such a case, the diameter of the relatively small convex portion 3 is, for example, 100 μm or more, preferably 200 μm or more, for example, 500 μm or less, preferably 400 μm or less. Moreover, the diameter of the comparatively large convex part 3 is 400 micrometers or more, for example, Preferably, it is 500 micrometers or more, for example, is 1000 micrometers or less, Preferably, it is 900 micrometers or less. The ratio of the diameter of the relatively large-diameter convex portion 3 to the diameter of the relatively small-diameter convex portion 3 (the diameter of the relatively large-diameter convex portion 3 / the diameter of the relatively small-diameter convex portion 3) is, for example, 1.5 or more, preferably 2.0 or more, for example, 5.0 or less, preferably 4.0 or less.

  Even in such a resin molded body 1, since the convex portion 3 protruding from the surface 2 is formed in the above-described predetermined pattern, both excellent scratch resistance and excellent gloss can be achieved. Furthermore, since the resin molding 1 does not require a filler or a coating process, it can be obtained simply and at low cost.

  Therefore, such a resin molded body 1 can be suitably used as, for example, an automobile exterior material (bumper, etc.), an automobile interior material (instrument panel, etc.), and scratch resistance and gloss are particularly required. It can be suitably used as an automobile exterior material.

  Next, although this invention is demonstrated based on an Example and a comparative example, this invention is not limited by the following Example. “Part” and “%” are based on mass unless otherwise specified. In addition, specific numerical values such as a blending ratio (content ratio), physical property values, and parameters used in the following description are described in the above-mentioned “Mode for Carrying Out the Invention”, and a blending ratio corresponding to them ( Substituting the upper limit value (numerical value defined as “less than” or “less than”) or the lower limit value (number defined as “greater than” or “exceeded”) such as content ratio), physical property values, parameters, etc. be able to.

Examples 1-6 and Comparative Examples 1-3
A mold having a predetermined pattern of recesses was prepared. Specifically, the interval P between the protrusions along the alignment direction of the protrusions, the height h ² of the protrusions, the diameter D of the protrusions, and the surface (the portion where the protrusions in the uneven processing region are not formed) The mold was prepared so that the area ratio of) and the arrangement direction of the protrusions were values shown in Table 1, respectively (see FIG. 3A).

  Next, the inner surface of the mold was polished with an abrasive (4000 mesh) (see FIG. 3B).

  Thereafter, HAT360 (mixed resin of PMMA resin and ASA resin, manufactured by UMG ABS) as a resin material was injection molded using the above mold. The mold temperature was 60 ° C and the injection temperature was 260 ° C.

  And thereby, the resin molding which has the area | region S by which the uneven | corrugated process (texture process) was carried out was obtained.

  The 20-degree specular gloss (based on JIS Z 8741 (1997)) of the surface (surface excluding the convex portion) of the resin molded body was 72.6 and had gloss. The 20-degree specular gloss was measured with a GM-26PRO gloss meter (manufactured by Murakami Color Research Laboratory).

  The resin molded product obtained in Example 1 is shown in FIG.

Evaluation The area | region S by which the uneven | corrugated process (texture process) of the resin molding was performed was evaluated with the following method. The results are also shown in Table 1.

(1) Appearance (Glossy)
The appearance (glossiness) of the resin molding was visually evaluated. The criteria for evaluation are as follows.

  ○: The fluorescent lamp reflected in the area S looks clear.

  X: The fluorescent lamp reflected in the area S looks dull.

(2) Scratch resistance test Using a Gakushin type friction fastness tester (manufactured by Daiei Kagaku Seiki Seisakusho Co., Ltd.), the scratch resistance of the resin molded body was evaluated with a friction area of 100 x 20 mm.

More specifically, first, before the friction test, the L ^* value (lightness) of the resin molding was measured with a color difference meter.

  Next, a piece of 20 × 20 mm double-sided tape (polyurethane foam, tape thickness 0.8 mm) with glass beads (Potters Parrotini's blasting beads (JIS grain size series J-54)) bonded to the friction piece Adhesion was fixed to obtain a friction element.

  Next, the transparent flat glass was set in a testing machine and reciprocated 20 times with a load of 21.6 N to smooth the glass beads.

  Next, the resin molded body was set in a testing machine and reciprocated 50 times with a load of 21.6 N (friction test).

Then, after lightly wiping with a soft cloth, the L ^* value (lightness) of the surface was measured within 1 hour.

And (DELTA ⁾ L ^* was calculated | required with the following formula | equation.

| ΔL ^* (lightness change amount) | = | (L ^* value after friction test) − (L ^* value before friction test) |
(3) Snowbrush scratch resistance test The snowbrush scratch resistance of the resin molding was evaluated by the following method.

  That is, a snow brush (SNB-02 manufactured by Daiichi Kogyo Co., Ltd.) was pressed against the resin molded body with a load of about 20 N and reciprocated manually 50 times. Thereafter, the friction surface was lightly wiped with a soft cloth, and the appearance (glossiness) of the resin molded body was visually evaluated.

  The criteria for evaluation are as follows.

  ○: The fluorescent light reflected in the area S after the test is clearly visible.

  X: The fluorescent lamp reflected in the area S after the test appears dull.

(Discussion)
FIG. 7 shows the relationship between the interval P along the alignment direction of the protrusions and ΔL ^* in the scratch resistance test from Examples 1-2 and Comparative Examples 1-2.

From FIG. 7, when the interval P along the alignment direction of the convex portions is 420 μm or less, ΔL ^* was 1.0 or less, and it was confirmed that the scratch resistance and gloss were excellent.

FIG. 8 shows the relationship between the height h ² of the convex portion and ΔL ^* in the scratch resistance test from Example 1, Example 3 and Comparative Example 3.

8, if the height h ² of the convex portion is 26μm or more, [Delta] L ^* is 1.0 or less, it was confirmed that excellent scratch resistance and gloss.

  From the results of the appearance evaluation, it was confirmed that the appearance was excellent when the surface area ratio was 50% or more with respect to the total area of the surface and the convex portion.

  From the above results, the surface area ratio with respect to the total area of the surface and the convex portion is 50% or more, the interval between the convex portions is 420 μm or less, and the height of the convex portions is 26 μm or more. In this case, it was confirmed that a resin molded body excellent in scratch resistance and gloss was obtained at a simple and low cost.

1 resin molding 2 surface 3 convex part 4 top surface

Claims (1)

A resin molded body made of a resin material,
A surface having gloss, and a plurality of convex portions protruding from the surface and arranged along a predetermined direction,
The area ratio of the surface with respect to the total area of the surface and the top surface of the convex portion is 50% or more,
In the predetermined direction, an interval between the plurality of convex portions is 420 μm or less, and
A resin molded product, wherein the height of the convex portion is 26 μm or more.