JP7004342B2 - Painted coating molded product - Google Patents

Description

The present invention relates to a coating-coated molded product in which the surface of a resin-molded product molded in a mold is coated with a coating agent having a viscosity lower than that of the molten resin of the resin-molded product, and the surface is cured and coated. In particular, the present invention relates to a coating-coated molded product to be applied to the surface of a resin molded product molded in a mold. By observing the coated molded product, it is similar to the technique of two-color molding and multicolor molding, and the coated film of the resin molded product can be thinned.

For example, in Patent Document 1, a coating agent is injected between the surface of a resin molded product molded in a mold and the mold cavity surface, and the coating agent is cured in the mold to cure the surface of the resin molded product. A molded product in which the coating agent is closely integrated is obtained.
This in-mold coating mold advances and retreats into the sub-cavity that forms a part of the back surface of the main cavity on the entire outer circumference of the main cavity and inside the outer peripheral portion on the anti-painting surface side of the sub-cavity. A movable core and a high temperature portion are provided at positions facing the movable core.

Therefore, according to this in-mold coating mold, the movable core presses the vicinity of the outer peripheral portion of the sub-cavity portion of the resin molded product against the mold sub-cavity surface. Therefore, according to Patent Document 1, the paint does not leak to the outside of the portion where the outer peripheral portion of the sub-cavity portion of the resin molded product is pressed against the mold sub-cavity surface.
Further, according to this in-mold coating mold, the coating film can be instantaneously cured by providing the high temperature portion at a position facing the movable core of the sub-cavity. Thereby, in the invention of Patent Document 1, it is possible to surely prevent the coating film from leaking to the outside of the mold.

In addition, Patent Documents 2 to 5 disclose and are known methods for obtaining a molded product in which a coating agent is closely integrated on the surface of the resin molded product.
Japanese Unexamined Patent Publication No. 2002-172657 Japanese Patent No. 3843833 Japanese Patent No. 382332 Japanese Unexamined Patent Publication No. 2006-256088 Japanese Unexamined Patent Publication No. 2009-220327

In the technique of Patent Document 1 described above, the vicinity of the inside of the outer peripheral portion of the sub-cavity portion of the resin molded product on the painted surface side is pressed against the mold sub-cavity surface by the movable core inside the outer peripheral portion on the anti-painted surface side of the sub-cavity. This prevents the coating agent (coating film) from leaking to the outside.
However, in the technique of Patent Document 1, the sub-cavity portion and a part of the back surface of the main cavity portion are integrally molded around the entire outer circumference of the main cavity portion of the resin molded product, and the mold is slightly opened to cover the coating agent. When injecting, the main cavity of the resin molded product is pressed against the mold cavity surface on the anti-painted surface side by the coating agent injection pressure and the mold cavity internal pressure due to the subsequent remolding operation. The cavity portion is pressed against the mold subcavity surface on the painted surface side by the movable core.

Therefore, in the technique of Patent Document 1, the main cavity portion and the sub-cavity portion, which are integrally resin molded products, are pressed in opposite directions. As a result, unreasonable stress is applied to the main cavity, which is the product, and there is a concern that the product may be deformed. At the same time, the sub-cavity is also sealed to prevent the coating material from leaking to the outside, which is the original purpose. The pressure can be uncertain due to the deformation extending from the main cavity, the injection of the coating, and the internal pressure during remolding.

It is also described that a thin-walled portion is provided in the sub-cavity in order to reduce these possibilities, but the effect is that the thin-walled portion must have strength that does not break even when subjected to the deformation or pressure. Will be limited.
In addition, with this technology, the coating agent cannot be poured into the back surface side (anti-covered surface side mold cavity surface) of the main cavity portion integrated with the sub-cavity portion, and the sub-cavity portion follows the product shape. The post-process of cutting is also complicated and requires high accuracy.

For example, when the final product is mounted on top of another part, the uncovered surface cut in the subsequent process can be seen from the slight mounting gap between the covered product surface and the other part, and the design is as seen from the outside. It becomes a problem. Therefore, since the mounting method itself is restricted, it is possible to apply some coating agent to the anti-covering surface side, and this restriction can be solved.
Most of the conventional techniques represented by Patent Documents 2 to 5 and the like do not have a pressing portion and the sealing performance is determined only by the shape of the sub-cavity, and the type of resin and the type of coating material change. Therefore, each time the viscosity of each changes, it is necessary to examine the dimensions of the shape and make trial and error. In addition, the sealing performance depending on the shape may not be partially uniform, and the shape may change over time in mass production, so it cannot be said that the sealing performance is reliable.

For example, in Patent Document 5, a parting surface sealing member is formed by circulating a molten resin from the cavity to a penetrating portion having a minimum necessary cross-sectional area in an auxiliary cavity located on the entire outer circumference apart from the cavity. .. In addition, in order to press the parting surface sealing member against the auxiliary cavity forming groove and the auxiliary cavity forming surface, the inclined surface of the arm portion presses the pressing surface of the parting surface sealing member in close contact with the inclined surface. It is a thing.
However, the inventions of Patent Documents 1 to 5 are techniques premised on two-color molding, and in principle, the surface of the resin molded product molded in the mold is based on the viscosity of the molten resin of the resin molded product. Is also coated with a coating agent of a low-viscosity fluid, but the influence of the flow of the coating agent of the low-viscosity fluid occurs on the coating, and the thickness of the coating agent needs to be about 1 mm or more. Nevertheless, there was a phenomenon in which the influence of the flow of the dressing appeared on the dressing.

Therefore, in order to solve the above problems, the present invention does not generate burrs between the molds even if the maximum coating film thickness is a polyurethane coating film, and "fluid characteristics (pressure energy, velocity energy, position). An object of the present invention is to provide a coating-coated molded product in which the influence of air entrainment of a sudden coating agent of "energy)" is unlikely to occur in the coating.

The coating-coated molded product according to the invention of claim 1 is a coating-coated molded product in which the surface of the resin-molded product molded in the mold is coated with a coating film having a viscosity lower than the viscosity of the molten resin of the resin-molded product. Therefore, the coating film of the two-component mixed type polyurethane paint that covers the surface of the coating coating molded product can be used as a polyurethane coating film having a thickness of 0.2 mm or more. The inlay between the molds is improved to an accuracy of 1/100 mm, and Bernoulli's theorem is applied to pressure p [Pa], density ρ [kg / m ³ ], velocity V [m / s], and height z [m]. , Gravity acceleration When expressed by g [m / s ² ], "velocity energy" is fixed within a predetermined range.
At this time, the thickness of the resin paint that covers the surface of the resin molded product molded in the mold with the resin paint having a viscosity lower than the viscosity of the molten resin of the resin molded product is thick. It can be molded from the newly made 0.1 mm to more than the known 0.8 mm polyurethane coating for multicolor molding.

Further, it was confirmed that in the coated molded product, even if the in-row processing between the molds has an accuracy of 1/100 mm or less and the in-row processing has a conventionally known accuracy, it is better to have it than not to have it. The accuracy of the inlay between the molds at which a practical effect is exhibited is preferably in the range of 1/1000 mm to 7/1000 mm.
Then, Bernoulli's theorem applies to the fluid pressure p [Pa], density ρ [kg / m ³ ], velocity (velocity) V [m / s], height z [m], and gravitational acceleration g [m / s. ² ], p + ρV ^2/2 + ρ gz = Const (constant), so that the sum of "pressure energy" + "velocity energy" + "position energy" is equal, "fluid characteristics (pressure energy, velocity energy, The cross-sectional area of "positional energy)" is controlled to be Const (constant). At this time, the velocity V is the velocity [m / s] of the fluid, and the velocity V of the input / output fluid is set to Constant (constant). On the contrary, when the velocity V [m / s] is not constant (constant), the filling can be completed.

A coating film coated with a coating film having a viscosity lower than that of the molten resin of the invention of claim 1 The coating film of a two-component mixed type polyurethane paint that covers the surface of a molded product has a thin coating film and a thick thickness. The polyurethane coating film is 0.2 mm or more, and the inlay between the molds is improved to an accuracy of 1/100 mm.
Furthermore, when Bernoulli's theorem is expressed by pressure p [Pa], density ρ [kg / m ³ ], velocity V [m / s], height z [m], and gravitational acceleration g [m / s ² ], The "velocity energy" is fixed, and the "pressure energy" and "positional energy" are variable.
Therefore, since the difference in the velocity V [m / s] affects the square, the velocity V [m / s] is set to Const (constant), and the error is reduced by itself.
Bernoulli's theorem fluid pressure p [Pa], density ρ [kg / m ³ ], velocity (flow velocity) V [m / s], height z [m], gravitational acceleration g [m / s ² ] When expressed, p + ρV ^2/2 + ρ gz = Const (constant), and "fluid characteristics (pressure energy, velocity energy, position energy)" so that the sum of "pressure energy" + "velocity energy" + "position energy" becomes equal. To make "Const", the gravitational acceleration does not change in g [m / s ² ], so it corresponds to the pressure p [Pa] and height z [m] of the fluid. A value with little error can be obtained.

At this time, the surface of the resin molded product molded in the mold is coated with a coating film having a viscosity lower than the viscosity of the molten resin of the resin molded product. Since the polyurethane coating film has a thickness of 0.2 mm that does not cause entanglement, a thin polyurethane coating film can be formed.
Further, it was confirmed by the inventors that the accuracy of the in-row between the molds is set to 1/100 or less in the coated molded product, and it is better to have the accuracy of the conventional in-row than to have it. .. The accuracy of the inlay between the molds is preferably in the range of 1/1000 mm to 7/1000 mm, and the generation of burrs can be suppressed.

FIG. 1 is a viscosity characteristic diagram showing the viscosity characteristics of a polyurethane paint. FIG. 2 is a characteristic chart showing the relationship between temperature and viscosity when isocyanate A and polyol B are mixed. FIG. 3 is an explanatory diagram illustrating the generation of burrs (a) and the entrainment treatment (b) of burrs in the molded product. 4A and 4B are explanatory views for explaining the principle of inlay, FIG. 4A is a perspective view of an upper mold, and FIG. 4B is an explanatory view of a state in which a perspective view of a lower mold is disassembled. FIG. 5 is an explanatory diagram of an example of a lower mold for explaining an inlay. FIG. 6 is an explanatory diagram of an example of the lower die of the cutting line AA of FIG. 5 for explaining the inlay. FIG. 7 is an explanatory diagram of an example of an upper mold for explaining an inlay. FIG. 8 is an explanatory diagram of an example of the upper mold of the cutting line BB of FIG. 7 for explaining the inlay. FIG. 9 is an explanatory diagram of an upper mold and a lower mold for explaining the inlay. FIG. 10 is an explanatory diagram of a lower mold for explaining the inlay. FIG. 11 is an explanatory diagram of an upper mold for explaining the inlay. 12A and 12B are painted-coated molded products (side moldings), FIG. 12A is a plan view showing the length direction thereof, FIG. 12B is a front view, and FIG. 12C is a rear view. FIG. 13 is an explanatory diagram (b) showing a molded product (a) showing the coating-coated molded product according to the embodiment of the present invention and a concept of acquiring an area of a cross section.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiment, the same symbol and the same reference numeral in the illustration are the same or corresponding functional parts, and therefore the overlapping description thereof will be omitted here.
[Embodiment]

In FIGS. 1 and 2, the viscosity of the resin (75 ° C.) such as polyurethane paint is 97 (mPa · s). Incidentally, the viscosity of water at 20 ° C. is 1.0 (mPa · s), and the viscosity of general synthetic resin at a temperature of 260 ° C. is 1.0 × 10 ⁵ to 1.0 × 10 ⁶ (mPa · s). Therefore, the viscosity of polyurethane (75 ° C.) is close to the viscosity of water. The viscosity of the general synthetic resin at a temperature of 260 ° C. is 1.0 × 10 ⁵ to 1.0 × 10 ⁶ (mPa · s), and the viscosity of polyurethane (75 ° C.) is generally the general resin. It can be seen that the viscosity is 1000 to 10000 times lower than that of water, and the viscosity is close to that of water. On the other hand, the viscosity of a general synthetic resin at a temperature of 260 ° C. is not only high in molding temperature, but also has a viscosity of 1.0 × 105 ⁽ mPa · s) at a temperature of 260 ° C., which makes injection molding difficult to control. Therefore, in this embodiment, polyurethane (75 ° C.) is used.

Incidentally, the relationship between isocyanate A (Puronate 960/1) and polyol B (Puroclear 3351 IT) will be described by taking a two-component mixed type polyurethane resin (paint) as an example.
The resin paint for carrying out the present invention is a copolymer made of a copolymer having a urethane bond, and can be mentioned as characterized by high substrate adhesion, film characteristics having impact resilience, and a balance between elongation and hardness. .. That is, in the two-component mixed type of isocyanate A and polyol B, the viscosity of the liquid mixed type becomes soft at 70 ° C or higher, that is, 70 ° C to 80 ° C, and the viscosity becomes 6 × 10 ² (mPa · s) at 30 ° C or lower. ) More viscous. That is, it is a two-component mixed type resin paint whose viscosity is softer than 1.15 × 10 ² (mPa · s) at 70 ° C or higher and harder than 6 × 10 ² (mPa · s) at 30 ° C or lower. be.

The relationship between the temperature and the viscosity of isocyanate A and polyol B is shown in FIG. Since the viscosity weakens at 70 to 80 ° C and the viscosity is relatively low in the range of 60 to 80 ° C, resin processing in this temperature range results in processing of polyurethane resin with a light load and relatively high fluidity. It can be performed.
However, the fact that the viscosity of polyurethane (75 ° C.) is much weaker than that of general synthetic resin is that the mold for the coating-coated molded product 13 forming the coating-coated molded product 13 is in-row processed (accuracy 1/100) 21a to 21d. Even if the burrs are formed, the burrs 29 shown in FIG. 3A are generated in the gaps of the mold for the coating coated molded product, and the removal of the burrs 29 cannot be simplified. In addition, it is not possible to completely excise with one operation. It was invented that in order to cut the burr 29 of this highly fluid polyurethane paint, the distance between the lower mold 20 and the upper mold 30 must be in the range of accuracy 1/1000 mm to 7/1000 mm. Confirmed by the person.
The shapes of the lower mold 20 and the upper mold 30 are omitted because they are complicated, but the lower mold 20 and the upper mold 30 may be divided into three or four pieces. In the form, since the resin molded product 11 and the coated molded portion 12 are formed, it is naturally possible that the coated molded portion 12 before formation is a part of the mold. Of course, the resin molded product 11 may be used as a mold.

The relationship between the temperature and viscosity of isocyanate A and polyol B is shown in FIG. Since the viscosity decreases at 70 to 80 ° C and the characteristics are stable in the relatively low range of 60 to 80 ° C, processing of polyurethane resin with a light load and relatively high fluidity can be performed in this temperature range. It can be carried out.
However, the fact that the viscosity of polyurethane (75 ° C.) is much smaller than that of general synthetic resin means that the mold for the coating-coated molded product 13 forming the coating-coated molded product 13 is in-row processed (accuracy 1/100 mm) 21a to 21d. Even if the burrs 29 are formed, the burrs 29 shown in FIG. 3A are generated in the gaps of the mold for the coating coated molded product, and the removal of the burrs 29 cannot be simplified. Further, as shown in FIG. 3 (b), the burr 29 cannot be removed with one stroke and the entire surface cannot be excised. In order to cut the burrs 29 of this highly fluid polyurethane resin, the burrs cannot be cut unless the distance between the lower mold 20 and the upper mold 30 is in the range of accuracy 1/1000 mm to 7/1000 mm. Confirmed by the inventor and others.

For example, the mold for molding the coating-coated molded product 13 is in-row processed 21a to 21d. However, as shown in FIGS. 4 to 13, since the accuracy of the in-row processing 21a to 21d is about 1/100, there is a high probability that a highly fluid polyurethane resin burr 29 having an accuracy of about 1/100 mm is generated.
FIG. 4 is a reference explanatory view of inlay processing, in which a convex portion 30X having a protruding shape is formed on the upper mold 30, and a concave portion 20Y is formed on the lower mold 20 fitted with the convex portion 30X. The convex portion 30X under the upper mold 30 and the concave portion 20Y in the lower mold 20 to be fitted are formed so that both the upper mold 30 and the lower mold 20 can be positioned at positions close to the outer diameter. It is desirable to do.
A molding die having a predetermined shape for fitting is formed so as to form a convex portion 30X having a protruding shape on the upper mold 30 and a concave portion 20Y having a protruding shape on the lower mold 20 shown in FIG. ..

As shown in FIG. 4, the parts in the state where the upper mold 30 and the lower mold 20 are formed are engaged with each other by using an in-row method between the molds and covering the surface of the coated molded product. That is. In particular, the portions of the convex portion 30X and the concave portion 20Y where the parts fit nicely are called "inrows". This is a field term. Here, as shown in FIGS. 4 to 8, the accuracy of in-row processing of the mold for coating coated molded products is reduced to 1/100, 1/200, 1/300, 1/400, and the finishing accuracy is increased. Logically, the occurrence of burrs 29 is reduced.
4 to 11 show an in-row method of a mold used for injection molding.

The coating-coated molded product 13 holds a resin-molded product 11 and a coating-molded portion 12 with a resin paint on the resin-molded product 11, and as shown in FIGS. 12 and 13, the base is a resin-molded product 11 and a resin is placed on the base. A coating molding portion 12 made of paint is formed. The base of the resin molded product 11 has a cross-sectional area so that the area of the cross section in the width direction, that is, the length [m] of the width and the [width m × thickness h] of the thickness [h] become specific values. I have decided. In the figure, the resin molded product 11 is formed in a substantially concave shape, but in reality, the corners are chamfered so that the flow of the synthetic resin is not disturbed. The [width m x thickness h] consisting of the width length [m] and its thickness [h] is determined from the constant velocity (flow velocity) V [m / s] of Bernoulli's theorem.

As shown in FIGS. 4 to 13, in the lower die 20, four square pillars for inlaying 21a to 21d are formed at four corners thereof by an NC processing machine. Similarly for the upper mold 30, the quadrangular prisms of inlaying 22a to 22d are finished with an accuracy of about 1/100 mm. That is, the error of the set value is minimized by the taper with an accuracy of 1/100. In the figure, the bolt hole 2 holds the paint-coated molded product 13, and the upper mold 30 and the lower mold 20 are connected by the bolt 3.
The in-row processes 23a to 23d shown in FIG. 9 are formed of recesses that mesh with the in-row processes 22a to 22d, and form a pair of the in-row processes 21a to 21d.
The in-row processing carried out in the present invention is not limited to the one in which irregularities are arranged at the four corners, and an in-row structural form from a known form can be adopted.

As shown in FIGS. 4 to 11, the four-sided prisms of in-row processing 22a to 22d are cut with an accuracy of 1/100 mm by NC processing equipment such as NC lathes and NC machine tools. Of course, when the present invention is carried out, cutting may be performed with an accuracy of 1/100 mm by using a cylinder and a taper, and the inlaying method thereof is not limited.
It should be noted that the in-row processing is indicated by, for example, as an accuracy of 1/100 mm in the text, which means that the machine is set to an accuracy of 1/100 mm. Therefore, the accuracy of the inlay is only a guide.
The molds of the coating-coated molded products 13 other than the in-row processing 21a to 21d, that is, the lower mold 20 and the upper mold 30, have the base as the resin molded product 11 and the coating-molded portion 12 by the coating film formed on the resin molded product 11. ing. The coating-coated molded product 13 is formed by forming the resin molded product 11 and the coating-molded portion 12, and the coating-molded portion 12 before formation is used as a cavity in which the coating-coated molded product 13 is formed.

However, even if the processing accuracy of in-row processing is improved (even if the numerical value is reduced), if the pair of dies does not fit well, the accuracy of the entire mold is lowered and the overall processing accuracy of in-row processing is improved. Can't.
Therefore, the inventors verified the fit of the lower die 20 and the upper die 30 based on the in-row machining accuracy of cutting 1/1000 mm to 1/100 mm with an NC machining device such as an NC lathe or an NC machine tool. ..

The inventors cut a square pillar having a size of 1/1000 mm to 1/100 mm as an inlay process and used it as a test material. At 8/1000 mm or less, the temperature changed depending on the position, and stable characteristics could not always be obtained. Further, at 8/1000 mm or more, the burr 29 of the polyurethane resin tends to be strong due to the gap between the molds. As a result, if it was 1/1000 mm to 8/1000 mm, the effect of improving the accuracy as inlay processing was obtained.
In particular, when the accuracy is 1/1000 mm or more, the molds are correctly tightened by the bolt holes 2 and the bolts 3 between the molds due to the stable fitting.
However, when the accuracy of inlaying was 1/1000 mm or more, the bolts 2 and the bolt holes 3 were correctly tightened due to the stable fitting of the mold.
When the burr 29 of the polyurethane resin is minimized based on the conventional inlay processing with an accuracy of 1/100 mm, the polyurethane coating has a thickness of 0.1 mm or more and a thickness of 0.8 mm or more in the conventional two-color molding. As the film, the burr cutting was reduced when the inlay between the molds was in the range of 1/1000 mm to 7/1000 mm. At 6/1000 mm and 7/1000 mm, it is being investigated how much expansion / contraction occurs due to temperature.

That is, according to the experiments by the inventors, a polyurethane coating film having a thickness of 0.1 to 0.8 mm and a thickness of 1 mm or less can be obtained in the range of inlay processing accuracy of 1/1000 mm to 7/1000 mm. That is, when the surface tension of the polyurethane paint is maintained, a part of the volume of the polyurethane paint becomes the temperature expansion of the mold and tilts toward the capacity reduction side, so that the lump of the polyurethane paint (the lump resulting from the stagnation) bursts. It is presumed that it does not lead to (burst).
In particular, in a polyurethane coating film having a thickness of 0.8 mm or more, the volume is maintained by surface tension, and when the spread due to the capillary phenomenon is added, the thickness is larger than the numerical value in the range of 0.1 to 0.8 mm. It doesn't grow. It is presumed that this factor is due to surface tension and capillarity.
In particular, in a polyurethane coating film having a thickness of 0.8 mm or more, the volume of the polyurethane coating film is about to be rounded due to surface tension, and when the spread due to the capillary phenomenon is added, the thickness is in the range of 0.1 mm or less. Does not get bigger than. It is presumed that surface tension and capillarity act on this factor.

In particular, in order to improve the appearance, the thickness may be as thin as 0.1 to 0.8 mm, and in particular, the thickness may be 0.8 mm or more, but uneven thickness appears when the polyurethane coating film is applied. It will be easier. A polyurethane coating film having a thickness of 0.1 mm, particularly preferably a polyurethane coating film having a thickness of 0.8 mm or more, can be molded by two-color molding. Therefore, when it is removed, the thickness is 0.1 to 0.8 mm. It is presumed that the polyurethane coating film has a good balance between capillarity and surface tension.

In the molded product of FIGS. 12 (a) to 12 (c) and the coating coated molded product (side molding) 13 of FIG. 12, for example, at the measurement points divided into 20 equal parts, the molten resin was W = 50, 51, 52. ... The molten resin is sequentially injected into 56, 57, 58, 59, 60, ..., Etc. This is set so that the measurement point in the width direction, that is, the area of the cross section in the width direction, the length m of the width and its thickness h are expressed as [width m × thickness h] within ± 30%. There is. Here, the molten resin W has a uniform [width m × thickness h].
Each measurement point W = 50 is the input speed where V ₁ = V [m / s], and the measurement point on the right end side is the output speed where W = 50 is V ₂ = V [m / s], near the center. At the measurement point of the change point of, and the measurement point W = 59, it becomes V ₃ . Further, in the places having different thicknesses, concave portions and convex portions are formed in the resin molded product 11 so as not to cause sink marks and voids.

From Bernoulli's theorem, p ₁ + ρ ₁ (V ₁ ) ^2/2 + ρ ₁ g ₁ z ₁ = p ₂ + ρ ₂ (V ₂ ) ^2/2 + ρ ₂ g ₂ z ₂
From the formula above, when the width of the coating molding portion 12 is ejected from the left end, it is tripled in width on the way, so V ² [m / s] and (V / 3) ² [m / s]. Other controls are needed so that are equal. Here, it can be seen that control from speed V to V / 9 is required.

From the design value of the coating-coated molded product 13, the measurement point W = 50 in the one-dimensional length direction of the resin molded product 11 by the coating-molded portion 12 as the cavity of the lower mold 20 and the upper mold 30 ... Get 70. Further, the cross-sectional area of the side molding at each cross-sectional point is calculated, and the cross-sectional shape of the covering molded portion 12 of the cavity is obtained. When the velocity V [m / s] is made uniform based on those cavities, the height z [m], the gravitational acceleration g [m / s ² ], the fluid pressure p [Pa], and the density ρ [kg / m]. With ³ ] as a variable, a uniform velocity V [m / s] is obtained so that the molding does not change.

As shown in FIGS. 12A and 12B, the coating molding portion 12 of the coating coating molded product 13 such as the side molding of FIG. 12 of the present embodiment has a lower mold 20 and an upper mold 30. It is a portion that becomes a cavity on the surface of the resin molded product 11 molded inside.
In the description of the present embodiment, the coating film forming portion 12 may refer to a case where the coating film forming portion 12 is formed by a coating film and a cavity in which the coating film forming portion 12 is formed by the coating film.

It is coated with a coating film having a viscosity lower than that of the molten resin in the resin molded product 11. As shown in the front view of FIG. 12B, it can be seen that the measurement point in the width direction is changed with respect to the measurement point X in the one-dimensional length direction of the resin molded product 11. However, not only the measurement point of the width (two-dimensional length) is changed, but also the side view is shown from the plan view, the front view, and the rear view shown in FIGS. 12 (a) to 12 (c). The mall is curved.

In the molded product of FIGS. 12 (a) to 12 (c) and the coating coated molded product 13 such as the side molding of FIG. 13, for example, the measurement points divided into 20 equal parts are W = 50, 51, 52, ... The detection points are 56, 57, 58, 59, 60, .... As for the measurement point W on the left end side, assuming that W = 50 is V ₁ = V [m / s], the measurement point of the change point near the center is V ₂ = V / 3 [m / s] at the measurement point W = 59. ] Is the cross section. Further, it is considered that W = V ₂ = V ₁ = V [m / s].
It should be noted that the equal division of the measurement point W is not limited to 10 equal divisions or 20 equal divisions, and it is not always necessary to divide the measurement points W into equal parts. It suffices to correspond to one-to-one.
From Bernoulli's theorem, p ₁ + ρ ₁ (V ₁ ) ^2/2 + ρ ₁ g ₁ z ₁ = p ₂ + ρ ₂ (V ₂ ) ^2/2 + ρ ₂ g ₂ z ₂
From this equation, since the width of FIG. 12 (b) is tripled near the central part, V ² [m / s] and its square (V / 3) ² [m / s] should be equal. Needs control. That is, it can be seen that 1/9 control is required here.

That is, if the velocity V ₁ = V [m / s] of the cross section on the left end side and the velocity V ₂ = V / 3 [m / s] near the center, the cross section near the center has a velocity of 1/9. There is a need.
According to Bernoulli's theorem, if the velocity V [m / s] of the cross section is not changed and is set to Const (constant), the height z [m] and the gravitational acceleration g [m / s ² ] do not change, so the fluid pressure p. [Pa], the density will change ρ [kg / m ³ ].

The velocity V [m / s], height z [m], gravitational acceleration g [m / s ² ], fluid pressure p [Pa], and density ρ [kg / m ³ ] are the values of the coated coating product 13. Therefore, the measurement point W in the one-dimensional length direction of the resin molded product 11 is obtained from W = 50, ..., 70 by the coating molding portion 12 as the cavity of the lower mold 20 and the upper mold 30. The cross section of the side molding at each cross-sectional point is calculated, and the cross-sectional shape of the covering molded portion 12 of the cavity is obtained. Velocity V [m / s], height z [m], gravitational acceleration g [m / s ² ], fluid pressure p [Pa], density ρ [kg / m ³ ] are calculated based on these cavities. do.

That is, the coating-coated molded product 13 in the lower mold 20 and the upper mold 30 is coated with a coating film having a viscosity lower than the viscosity of the molten resin in the resin molded product 11, and is also coated and molded as a side molding. The product 13 has an injection port SG for injecting a coating film on the surface of the resin molded product 11, sprays paint along the surface of the resin molded product 11 in the length direction, and the resin molding is performed from the injection port SG. When the paint is sprayed along the surface of the product 11 in the length direction, the "fluid characteristics" of the fluid adjusting mechanism 90 are always controlled to be uniform.
This fluid adjustment mechanism 90 can detect the position of the measurement point W in the lateral direction with a stepping motor or a servo motor, and can be used even with a pulse motor or the like equipped with a coded or compounded code board. be.
The "fluid characteristics" of Bernoulli's theorem are velocity V [m / s], height z [m], gravitational acceleration g [m / s ² ], fluid pressure p [Pa], and density ρ [. kg / m ³ ] refers to the individual characteristics.

The injection port SG for spraying the paint on the surface of the resin molded product 11 has an injection port for spraying the paint in the form of mist, and in the present embodiment, a predetermined width can be applied.
As the injection port SG, an ion air compressor, an electrostatic eliminator air gun, or the like can be used.
Further, the fluid adjusting mechanism 90 attaches the injection port SG along the coating coated molded product 13, and at least sprays the paint along the surface of the resin molded product 11 in the length direction, and one-dimensionally or two-dimensionally. The head moves.
In the conceptual diagram of FIG. 12, the fluid adjusting mechanism 90 moves a rail having an injection port SG that moves one-dimensionally or two-dimensionally at the lower end.

Here, the fluid adjusting mechanism 90 of the present embodiment reaches the measurement point X in the length direction of the resin molded product 11 when the paint is sprayed from the injection port SG along the surface of the resin molded product 11 in the length direction. The moving "fluid characteristic" is set so that the "fluid characteristic" is the same at any position of the fluid adjusting mechanism 90.
At this time, it is efficient to paint the side of the measurement points W = 50, ..., 70 by the injection port SG while removing air from one end of the side molding.

The fluid adjusting mechanism 90 associates the position of the fluid adjusting mechanism 90 of the injection port SG with the speed V [m / s], the height z [m], the gravitational acceleration g [m / s ² ], and the fluid pressure p. Calculate [Pa] and density ρ [kg / m ³ ]. From Bernoulli's theorem for the total length of fluid resistance, the assumption of "pressure energy" + "velocity energy" + "potential energy" is calculated.
Then, from the design value of the coating-coated molded product 13, the measuring point W in the one-dimensional length direction of the resin molded product 11 is provided by the coating-molded portion 12 created based on the cavities of the lower mold 20 and the upper mold 30. = 50, ..., 70 is obtained. Further, each cross section of the side molding is calculated, and "pressure energy" + "velocity energy" + "potential energy" is calculated from the cavity of the coating coating molded product 13.

Here, the measurement point W in the one-dimensional length direction of the coating coating molded product 13 is divided into equal parts, and the entrainment of air on the surface of the resin molded product 11 is divided into the one-dimensional length of the coating coating molded product 13. The change of the two-dimensional measurement point W is also reduced with respect to the measurement point W in the direction. Of course, it is desirable to subdivide the distance to be equally divided, but this detection position can be estimated from the input end and the output end of Bernoulli's theorem.

In the experiments of the inventors, p ₁ + ρ ₁ (V ₁ ) ^2/2 + ρ ₁ g ₁ z ₁ = p ₂ + ρ ₂ (V ₂ ) ^2/2 + ρ ₂ g ₂ z ₂
When there is an error within 30%, the entrainment of air on the surface is suppressed and the appearance of the painted coating molded product 13 does not deteriorate so much. It is desirable to reduce. In particular, since the speed is affected by the square of the speed V [m / s], it is preferable to keep the error within 30%.

In this embodiment, the lower mold 20 and the lower mold 20 in which the surface of the resin molded product 11 molded in the lower mold 20 and the upper mold 30 is coated with a paint having a viscosity lower than the viscosity of the molten resin in the resin molded product 11 A coating-coated molded product 13 in which the surface of the resin molded product 11 molded in the upper mold 30 is coated with a paint having a viscosity lower than the viscosity of the molten resin in the resin molded product 11, and is the surface of the resin molded product 11. An injection port SG for injecting paint is attached to the injection port SG, the paint is sprayed along the surface of the resin molded product 11 in the length direction, and the paint is sprayed from the injection port SG along the surface of the resin molded product 11 in the length direction. When this is done, the fluid adjusting mechanism 90 that constantly controls the "fluid characteristics" to be uniform is provided.

The two-component mixture type paint, which is the coating molding portion 12 of the present embodiment, covers the surface of the coating coating molded product 13 and has a viscosity of 1.15 × 10 ² (mPa · s) at 70 ° C. or higher. It is also soft and hardened to a viscosity of 6 × 10 ² (mPa · s) or more at 30 ° C. or lower.
Here, if the viscosity is softer than 1.15 × 10 ² (mPa · s) at 70 ° C. or higher, the two-component mixed type paint is not necessarily specified by the value, and the viscosity is about 30%. Even if they are different, it may not be a problem depending on the form of the coating molding portion 12.
Similarly, even if the viscosity is hardened to 6 × 10 ² (mPa · s) or more at 30 ° C. or lower, there may be no problem depending on the form of the coating molding portion 12 even if the viscosity is different by about 30%. I will add.

The injection port SG for spraying the resin paint on the surface of the resin molded product 11 has an injection port for spraying the resin paint in the form of mist, and in the present embodiment, a predetermined width can be applied.
Further, the injection port SG is attached, and at least the coating film is sprayed along the surface of the resin molded product 11 in the length direction, and the polyurethane paint moves to a one-dimensional or two-dimensional flat surface or a curved surface. When the coating film is sprayed from the injection port SG along the surface of the resin molded product 11 in the length direction, the fluid adjusting mechanism 90 always moves uniformly at any position.

In the coating coated molded product 13 according to the present invention, the resin paint sprayed along the surface of the resin molded product 11 is a polyurethane paint.
Here, since the paint sprayed along the surface of the resin molded product 11 is a polyurethane paint, spraying along the surface of the resin molded product 11 is a one-dimensional or two-dimensional plane or curved surface. It is something to do. In particular, the premise of Bernoulli's theorem is that the polyurethane is a non-viscous fluid with little friction, so the polyurethane paint can be regarded as a non-viscous fluid.

The injection port SG for spraying the resin paint on the surface of the resin molded product 11 has an injection port for spraying the resin paint in the form of mist, and in the present embodiment, a predetermined width can be applied.
Further, the fluid adjusting mechanism 90 attaches the injection port SG, sprays the resin paint at least along the surface of the resin molded product 11 in the length direction, and moves to a one-dimensional or two-dimensional plane or a curved surface.
The "fluid characteristic" of the fluid adjusting mechanism 90 always moves uniformly at any position when the resin paint is sprayed from the injection port SG along the surface of the resin molded product 11 in the length direction. ..

Further, in the coating coating molded product 13 according to the present invention, the paint sprayed along the surface of the resin molded product 11 is a polyurethane paint.
Here, injecting along the surface of the resin molded product 11 is a one-dimensional or two-dimensional plane or a curved surface. In particular, the premise of Bernoulli's theorem is that the fluid is a non-viscous fluid with little friction, and the polyurethane paint is viscous to the extent that it can be regarded as a non-viscous fluid.

The coating-coated molded product 13 passes through a mold in which the resin paint and air to be sprayed at the injection port SG are specified to pass by the in-row processing. Adhesion is obtained by inlaying the mold, and the passage of the resin paint and air sprayed at the injection port SG passes through the specified mold cavity, so there is no time change to pass there. The steady flow and fluid can be designed as a non-viscous fluid with less friction.

The surface of the resin molded product 11 molded in the lower mold 20 and the other molds of the upper mold 30 is covered with a resin coating having a viscosity lower than the viscosity of the molten resin of the resin molded product 11. The paint to be coated on the surface of the paint-coated molded product 13 is a polyurethane paint, and the inlay between the molds is 5/1000 mm or less, and further, the "pressure" of Bernoulli's theorem is set. The "fluid characteristics (pressure energy, velocity energy, position energy)" are set so that the sum of "energy" + "velocity energy" + "positional energy" becomes equal.

A coating-coated molded product 13 in which the coated molded portion 12 on the surface of the resin molded product 11 molded in the lower mold 20 and the upper mold 30 is coated with a resin paint having a viscosity lower than the viscosity of the molten resin of the resin molded product 11. The resin paint to be coated on the surface of the paint-coated molded product 13 is a polyurethane paint having a thickness of 0.1 to 0.8 mm or 0.2 to 0.8 mm, and the inlay between the molds is 1. The range is from / 1000 to 7/1000, and the "fluid characteristics" are set so that the sum of "pressure energy" + "velocity energy" + "positional energy" in Bernoulli's theorem is equal.

A coating-coated molded product 13 in which the surface of the resin-molded product 11 molded by another mold is coated with a resin paint having a viscosity lower than the viscosity of the molten resin of the resin-molded product 11, and is the surface of the coating-coated molded product 13. The coating film to be coated is a polyurethane coating film, the in-row between the molds is in the range of 1/1000 mm to 7/1000 mm, and the sum of the energies of Bernoulli's theorem is equal. It controls.

The coating coated molded product 13 according to the present invention is a polyurethane paint made of a resin paint sprayed along the surface of the resin molded product 11, and has a one-dimensional or two-dimensional plane or a curved surface along the surface of the resin molded product 11. Is to be sprayed. In particular, the premise of "pressure energy" + "velocity energy" + "positional energy" = Const (constant) according to Bernoulli's theorem is that it is a non-viscous fluid with little friction, so polyurethane paint is regarded as a non-viscous fluid. But no problem was confirmed.

In the coating-coated molded product 13 in which the surface of the resin molded product 11 molded in the lower mold 20 and the upper mold 30 is coated with a resin paint having a viscosity lower than the viscosity of the molten resin in the resin molded product 11, the resin molded product The resin paint sprayed on the surface of the resin molded product 11 is in the length direction of the resin molded product 11 so that the "fluid characteristics" consisting of the "pressure energy", "velocity energy", and "positional energy" of the fluid adjusting mechanism 90 are always uniform. Polyurethane paint is sprayed along the surface of the injection port SG to control the output of the injection port SG. An injection port SG for spraying the resin paint is attached to the surface of the resin molded product 11, the resin paint is sprayed along the surface in the length direction of the resin molded product 11, and the resin molded product 11 is sprayed from the injection port SG in the length direction of the resin molded product 11. When the resin paint is sprayed along the surface of the above, when the "fluid characteristics", for example, the velocity V [m / s] is always set to Const (constant), the others are controlled as variables. In this way, the surface of the resin molded product 11 molded in the lower mold 20 and the upper mold 30 is covered with a resin paint having a viscosity lower than that of the molten resin in the resin molded product 11.

The polyurethane coating film sprayed along the surface of the resin molded product 11 is a one-dimensional or two-dimensional plane or a curved surface. In particular, the "fluid property" of Bernoulli's theorem is that the polyurethane coating film is regarded as a non-viscous fluid because it is a non-viscous fluid with little friction as a fluid.
That is, the energy of a compressible fluid passing through the cross section of two fluid flows is Bernoulli's theorem: fluid pressure p [Pa], density ρ [kg / m ³ ], velocity V [m / s], high. If it is expressed by z [m] and gravitational acceleration g [m / s ² ],
p + ρV ^2/2 + ρ gz = Const (constant),
From "pressure energy" + "velocity energy" + "positional energy" = Const (constant), the cross section perpendicular to the two flow directions of the inlet and outlet is a steady flow that does not change with time, "fluid characteristics". Is a non-viscous fluid with low friction. Here, the "fluid characteristic" passing through the cross section perpendicular to the two flows affects the square of the velocity V. Therefore, if the velocity V [m / s] is set to Const (constant), the density ρ [kg / m ³ ] does not change, so that the spray atmosphere of the resin paint of the spray gun can be made uniform, and the finished surface becomes uniform. can.

A coating-coated molded product 13 in which the surfaces of the resin molded product 11 molded in the lower mold 20 and the upper mold 30 are coated with a resin paint having a viscosity lower than the viscosity of the molten resin of the resin molded product 11 and coated. The resin paint to be coated on the surface of the coated molded product 13 is a polyurethane coating having a thickness of 0.1 to 0.8 mm or 0.2 to 0.8 mm, and the inlay between the molds is 1/1000 to 7 The range is set to / 1000 mm, and the "fluid characteristics" are controlled so that the sum of "pressure energy" + "velocity energy" + "positional energy" in Bernoulli's theorem becomes equal.

The coating coated molded product 13 according to the present invention sprays polyurethane paint along the surface of the resin molded product 11 in the length direction so that the "fluid characteristics" of the fluid adjusting mechanism 90 are always uniform, and the injection port SG is used. Controls the output of. An injection port SG for spraying the resin paint is attached to the surface of the resin molded product 11, the resin paint is sprayed along the surface in the length direction of the resin molded product 11, and the resin molded product 11 is sprayed from the injection port SG in the length direction of the resin molded product 11. When the resin paint is injected along the surface of the above, the surface of the resin molded product 11 molded in another mold is resin-molded with a fluid adjusting mechanism 90 that constantly controls the "fluid characteristics" to be uniform. It is coated with a resin paint having a viscosity lower than that of the molten resin in the product 11.

The object of the polyurethane paint sprayed along the surface of the resin molded product 11 to be sprayed along the surface of the resin molded product 11 is a one-dimensional or two-dimensional plane or a curved surface. In particular, the premise of Bernoulli's theorem is that the fluid is a non-viscous fluid with little friction, so the polyurethane paint can be regarded as a non-viscous fluid.

That is, the energy of the compressible fluid passing through the cross section perpendicular to the direction of the flow of the two fluids is the fluid pressure p [Pa], density ρ [kg / m ³ ], and velocity V [m] of Bernoulli's theorem. If it is expressed by / s], height z [m], and gravitational acceleration g [m / s ² ], p + ρV ^2/2 + ρ gz = Const (constant).
From "pressure energy" + "velocity energy" + "positional energy" = Const (constant), the cross section perpendicular to the two flows is a steady flow that passes through it without time change, and the fluid is non-viscous with little friction. It is a fluid.
Here, the fluid passing through the two cross sections affects the square of its velocity V.
Therefore, if the velocity V [m / s] is set to Const (constant), the density ρ [kg / m ³ ] does not change, so that the spray atmosphere of the resin paint of the spray gun can be made uniform, and the finished surface becomes uniform. can.

The resin paint sprayed from the injection port SG along the surface of the paint-coated molded product 13 is a polyurethane paint. Here, injecting along the surface of the resin molded product 11 is one-dimensional or two-dimensional, that is, a flat surface or a curved surface. In particular, the premise of Bernoulli's theorem is that the fluid is a non-viscous fluid with little friction, so the polyurethane paint can be regarded as a non-viscous fluid.
If 1.0 × 10 ² polyurethane paint is used, the inlay between the lower mold 20 and the upper mold 30 is 5/1000 or less, and the film formation has a thickness of 0.1 to 0.8 mm. It can be carried out to the desired thickness. Further, if the yield is taken into consideration and the safety is taken into consideration, the coating coated molded article 13 can be obtained with high efficiency.
The resin paint to be coated on the surface of the paint-coated molded product 13 is a polyurethane paint having a thickness of 0.1 to 0.8 mm, the inlay between the molds is 5/1000 or less, and the energy of Bernoulli's theorem. It controls so that the sum of is equal.

Although described in the case of storing and molding in the lower mold 20 and the upper mold 30, the same can be used for the core. Further, according to Bernoulli's theorem, "pressure energy" + "velocity energy" + "potential energy" is special, but when the present invention is carried out, items that are easy to control may be controlled.
By this molding, the same texture as that of polyurethane single-color molding or two-color molding can be obtained. In particular, the resin molded product 11 may be formed in the lower mold 20 and the upper mold 30, or may not move entirely in the lower mold 20 and the upper mold 30. Therefore, it is possible to have multiple layers, and there is no sense of discomfort due to the multiple layers.

In the coating-coated molded product of the present embodiment, the surface of the resin molded product 11 molded in the lower mold 20 and the upper mold 30 is coated with a resin paint having a viscosity lower than that of the molten resin of the resin molded product 11. A two-component mixed type that covers the surface of the coating-coated molded product 13 to be coated. The supply is supplied according to the cross-sectional area of the coating form of the resin molded product 11 used as a product, and the cross-sectional area is kept constant to keep the resin filling speed constant, and / or an overflow portion is provided to entrain air bubbles. It is an invention that separates the part from the molded product part.

A coating-coated molded product 13 in which the surface of the resin-molded product 11 is coated with a resin paint having a viscosity lower than the viscosity of the molten resin covering the resin-molded product 11, and the resin to be coated on the surface of the coating-coated molded product 13. The paint shall be a polyurethane coating. Since polyurethane is almost non-viscous, it is easier to entrain air bubbles than general resin. Therefore, due to the influence of air entrainment, the phenomenon that the flow of the dressing appears on the dressing has occurred. Therefore, as a plan to improve the appearance defect, the cross-sectional area of the coating coating molded product 13 and the runner may be kept constant to keep the speed constant, or an overflow portion may be provided to separate the portion where air bubbles are caught from the coating coating molded product 13. I can handle it. On the contrary, for example, when the speed V [m / s] used up to that point is not constant, the filling control can be terminated at that time.

11 Resin molded product 12 Coated molded part (cavity of mold of painted coated molded product)
13 Painted coating molded product 20 Lower mold 29 Burr 30 Upper mold SG injection port

Claims (1)

A method for manufacturing a coating-coated molded product in which the surface of a resin-molded product molded in a mold is coated with a resin paint having a viscosity lower than the viscosity of the molten resin of the resin-molded product.
The coating film of the two-component mixing type polyurethane paint that covers the surface of the resin molded product is a polyurethane coating film having a thickness of 0.1 mm or more and has an inlay between the molds.
Furthermore, when Bernoulli's theorem is expressed by pressure p [Pa], density ρ [kg / m ³ ], velocity V [m / s], height z [m], and gravitational acceleration g [m / s ² ], At p + ρV ^2/2 + ρgz = Const (constant), the "pressure energy" + "velocity energy" + "positional energy" is sprayed along the surface of the resin molded product so that the sum of the "pressure energy" + "velocity energy" + "positional energy" is constant. A method for manufacturing a coated coated product, characterized in that the value of "velocity energy" when controlling "fluid characteristics (pressure energy, velocity energy, position energy)" is fixed within a predetermined value.

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