JP3317424B2 - Resin molded article with skin and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded article with a skin having a resin substrate integrally formed on the back side of the skin, and a method for producing the same. TECHNICAL FIELD The present invention relates to a resin molded article with a skin having a skin and a method for producing the same.

[0002]

2. Description of the Related Art For example, automotive interior parts such as armrests and instrument panels are composed of a skin that gives a surface design and texture, and a resin base material that keeps the skin shaped into a predetermined shape. And as the epidermis,
It is composed of a skin layer such as vinyl chloride resin or fabric and a foam layer laminated on the back side of the skin layer, and the foam layer usually gives an elastic cushioning feeling It is.

[0003] As a method for producing such a resin molded product with a skin, conventionally, the resin molded product was produced by covering the surface of a resin base material formed by injection molding, compression molding or the like with a skin. In recent years, since it is enormous, an integral molding method in which a skin is arranged in a mold to mold a resin base material has become mainstream in recent years. However, in the method in which the skin is placed in a mold and the resin base material is injection-molded, the high-pressure molten resin contacts the skin and strongly presses the skin against the mold surface, so that the surface of the skin is discolored by heat. The appearance quality is impaired in the epidermis such as a fabric having a deformed pattern or a raised fabric due to hair falling or hair flow. Further, depending on the case, the skin may be impregnated or permeated with the molten resin, thereby losing commercial value.

Therefore, a low-pressure injection compression molding method is generally used. In this low-pressure injection compression molding method, a predetermined amount of molten resin is injected into the cavity at a low pressure while the split mold is slightly opened, and at the same time, the molten resin injected by clamping and splitting the split mold is pressed. This is a method of filling in a cavity and performing compression molding. According to this molding method,
Even when the skin is placed in a mold and molded, since the pressure acting on the skin is low, it is possible to produce a resin molded product with a skin having excellent appearance quality without trouble such as hair falling or hair flow. it can.

[0005]

However, even in the low-pressure injection molding method, the pressure of the molten resin at the moment of injection from the gate is relatively high, and a relatively high pressure acts on the skin facing the gate. It will be. The temperature of the molten resin is highest immediately after being injected from the gate. Therefore, high temperature and high pressure act on the foam layer at that portion, and the foam cells of the foam layer may be deformed and the touch may be partially impaired.

In order to avoid this problem, it is quick to make the foam layer thick, but it is difficult to realize a fine curved surface shape, and it is difficult to fold the terminal and wrinkles occur. There is a malfunction to do. It is also conceivable to change the foam layer to a more rigid foam so as not to be deformed by the injection pressure, but there is a problem that the feel is hard.

Further, in order to hold the outer skin in the mold, the outer skin is held in a state in which the peripheral edge is sandwiched between the split dies. Have difficulty. Further, in order to prevent wrinkles from occurring during molding of the resin base material, the skin is generally held in a mold to such an extent that a tensile stress acts during molding. Further, at the time of low-pressure injection compression molding, a tensile stress further acts on the skin due to the pressure from the molten resin. Therefore, tensile stress remains on the skin after the resin base material is molded, and as a result, tensile stress remains in the plane direction of the foam layer, and compressive stress remains in the thickness direction. . Therefore, in the obtained molded article, the foam layer is compressed and thinned in the thickness direction and held between the skin layer and the resin base material, so that it can be restored to the original shape. Becomes difficult,
There is a problem that the touch is impaired by an amount corresponding to the compression of the foam layer.

The present invention has been made in view of such circumstances, and has as its object to improve the tactile sensation by partially increasing the softness while using a skin having a foam layer similar to the conventional one. And

[0009]

Means for Solving the Problems A first method for solving the above problems is described below.
The resin molded article with a skin of the present invention comprises a resin base material, and a skin in which a foam layer and a skin layer are integrally laminated. The skin is arranged in a mold, and the foam of the skin is formed by low-pressure injection compression molding. In a resin molded product with a skin in which a resin base is integrally formed on the layer side, a sheet member is partially interposed between the resin base and the foam layer, and a portion of the skin facing the sheet member is other Characterized by being softer than the portion.

In a second aspect of the present invention, there is provided a method for producing a resin molded article with a skin, comprising: placing a skin comprising a skin layer and a foam layer laminated on the back side of the skin layer in a split mold; A method for producing a resin molded product with a skin, in which a molten resin is injected from a gate at a low pressure and compression molded to form a resin base material on the surface of a foam layer between the mold and the mold surface, and the skin should be soft. The sheet member is partially placed on the mold surface facing the foam layer of the portion, and at least the mold surface of the portion where the sheet member is placed has a gate, and the sheet is pressed by the resin flow from the gate. It is characterized in that the member is molded while being pressed against the foam layer.

Further, the manufacturing method of the third invention is characterized in that the mold surface having the gate on which the sheet member is placed has a concave portion for accommodating and holding the sheet member in the second invention. The resin molded product with a skin according to the fourth invention comprises a resin base material, a skin in which a foam layer and a skin layer are integrally laminated, and arranges the skin in a mold and performs low-pressure injection compression molding on the skin. In the resin molded article with a skin in which a resin base material is integrally formed on the foam layer side, a surface of the resin base material facing the foam layer partially has a concave portion and a portion facing the concave portion of the skin. Is characterized in that the surface is flat and softer than other parts.

The manufacturing method according to a fifth aspect of the present invention for manufacturing the resin molded article with a skin according to the fourth aspect of the present invention includes the step of forming the skin comprising the skin layer and the foam layer laminated on the back side of the skin layer into the first mold and the second mold. A molten resin is injected at a low pressure from a gate provided in the second mold between the foam layer of the skin and the mold surface of the second mold and compression-molded, and the foam layer is placed in a split mold comprising the mold. A method for producing a resin molded article with a skin that forms a resin substrate on the surface,
The first mold has a protrusion protruding toward the mold surface of the second mold .
Type 2 has a concave part facing the convex part, and the skin is along the concave part.
In the state where it is arranged, the peripheral part is immovable
After that, the molten resin is injected at low pressure and compressed.
The resin substrate is molded in a state in which the skin is pressed by the convex portion so as to approach the second mold, and the resin substrate is formed with a concave portion by the convex portion and pressed by the convex portion when the mold is opened. portion of the foam layer the shape recovery amount is large, after the mold opening
Is characterized in that the surface of the portion facing the concave portion of the skin becomes flat .

[0013]

In the method for producing a resin molded article with a skin according to the second invention,
The molten resin injected from the gate first collides with the sheet member, and the sheet member is lifted from the mold surface by its force and pressed against the foam layer facing the gate. Therefore, the pressure of the molten resin injected from the gate is dispersed over the entire surface of the sheet member and transmitted to the foam layer, so that a large local pressure is prevented from acting on the foam layer. Further, since the heat of the molten resin is shielded by the sheet member, the high temperature is prevented from being directly transmitted to the foam layer facing the gate.

That is, since a lower pressure and a lower temperature act on the portion of the foam layer facing the gate as compared with the prior art, deformation of the foam cells of the foam layer in that portion can be prevented. Some parts are particularly softer than others. Therefore, in the obtained resin molded product with a skin of the first invention, even in the thin portion of the foam layer in the portion where the sheet member is present, the foam layer has excellent cushioning properties and partially has a different hardness. Are better. Further, since the sheet member is present between the foam layer of the skin and the resin base material, it cannot be touched directly from the surface and its presence is not known, so that the tactile sensation is not impaired.

Furthermore, if the mold surface on which the gate on which the sheet member is placed is opened is provided with a recess for accommodating and holding the sheet member, the positioning can be reliably performed by the recess when the sheet member is arranged. If there is no concave portion, the volume of the cavity is reduced by the volume of the sheet member, so that the foam layer is further compressed by the volume of the sheet member during compression molding. Further, even if the foam layer attempts to recover its shape after the mold is opened, the skin layer is hardly deformed, so that the foam layer is kept in a compressed state, and the touch feeling is reduced accordingly. However, by forming the concave portion, the volume of the cavity can be made the same as the conventional one, and such a problem can be avoided.

The size of the sheet member needs to be at least larger than the opening of the gate, but its material and thickness can be variously selected according to the temperature and injection pressure of the molten resin. In the manufacturing method according to the fifth aspect of the present invention, the skin is arranged in the mold in a state of being swollen by being pressed by the convex portion of the first mold, so that the skin is arranged in the mold as compared with the conventional arrangement having no convex portion. Area increases. Therefore, the residual tensile stress becomes smaller than before, and the degree of compression of the foam layer also becomes smaller. In addition, in the resin base material molded in that state, a concave portion is formed by a skin that swells by being pressed by the convex portion.

When the mold is opened, the pressure from the convex portion is released, so that the surface of the skin becomes flat due to the tensile stress inherent in itself. As a result, a large volume is secured between the surface of the concave portion of the resin base material and the skin layer, and the tensile stress in the surface direction is smaller than in the past, so that the foam layer has a sufficient shape recovery compared to other portions. Can be done. Therefore, in the resin molded article with a skin of the fourth invention manufactured by the fifth invention, the skin of the portion facing the concave portion of the resin base material has a higher degree of softness and an excellent tactile feeling than other portions.

[0018]

The present invention will be specifically described below with reference to examples. (Embodiment 1) FIG. 2 is a perspective view of an automobile armrest according to the present embodiment, and FIG. 3 is a sectional view taken along line AA of FIG. The armrest includes a resin substrate 1, a skin 2 integrally coated on the surface of the resin substrate 1, and a sheet member 3 sandwiched between the resin substrate and the skin 2.

The resin substrate 1 can be made of a thermoplastic resin such as polypropylene, polyethylene, or ABS. In this embodiment, the resin substrate 1 is made of polypropylene.
The skin 2 is composed of a skin layer 20 serving as a design surface, and a foam layer 21 integrally laminated on the back side of the skin layer 20 by a lamination method. As the skin layer 20, a woven fabric, a nonwoven fabric, a vinyl chloride resin, TPO or the like can be used. In the present embodiment, a 0.4 mm thick vinyl chloride resin is used. As the foam layer 21, a urethane foam or an olefin foam can be used. In this embodiment, a urethane foam having a thickness of 5 mm and a non-woven fabric backing is used.

The sheet member 3 is in the form of a plate having a thickness of 0.7 mm. In this embodiment, the sheet member 3 is formed of vinyl chloride resin in accordance with the shape of the portion where the elbow of the armrest is to be placed (the dashed line in FIG. 2). However, the material and its shape can be variously set. The sheet member 3 has one surface and a side peripheral surface joined to the resin base material 1, and the other surface pressed against the foam layer 21.

In the armrest of this embodiment, the skin 2 at the portion where the seat member 3 exists is particularly soft. This is because the deformation of the foam cells of the foam layer 21 is completely absent. Therefore, the feeling when the elbow is placed is excellent. Hereinafter, a method for manufacturing the resin molded article with a skin according to the present embodiment in which the armrest is manufactured will be described.

FIG. 1 shows a mold used in this embodiment. This mold includes a core mold 4 and a cavity mold 5, and a gate 40 is formed in the core mold 4. This gate 40
Is opened at the center of the portion of the armrest where the elbow is to be placed (indicated by the two-dot chain line in FIG. 2). A concave portion 41 having a depth corresponding to the shape of the sheet member 3 and corresponding to the thickness of the sheet member 3 is formed on the mold surface where the gate 40 opens. Further, a ridge 50 is formed on the inner peripheral edge of the end of the cavity mold 5.

First, the sheet member 3 is inserted into the recess 41 of the core mold 4.
Is placed. Due to the presence of the concave portion 41, the sheet member 3
Is extremely easy to position. On the other hand, the skin 2 is arranged in the cavity mold 5. The skin 2 is a skin layer 2
0, a foam layer 21 and a nonwoven fabric layer 22 are laminated in this order, and the skin layer 20 is arranged so as to face the mold surface of the cavity mold 5.

Then, the core mold 4 and the cavity mold 5 are combined, and as shown in FIG.
Float it. In this state, the periphery of the skin 2 is strongly sandwiched between the ridge 50 of the cavity mold 5 and the side peripheral surface of the core mold 4, and the movement of the periphery is difficult. In this state, first, the molten resin 6 is supplied through the gate 40 for 30 to 50 minutes.
Inject at a pressure of kg / cm ² . At about the same time, the cavity mold 5 is driven so as to be closer to the core mold 4. Then, the sheet member 3 is lifted from the concave portion 41 by the pressure of the molten resin 6 and pressed against the foam layer 21 via the nonwoven fabric layer 22.

The molten resin 6 is spread by being pressed by the injection pressure and the mold clamping pressure, and compression-molded at a pressure of 30 to 50 kg / cm ² to form the resin base material 1. At this time, since the sheet member 3 is pressed against the nonwoven fabric layer 22, no gap is generated between the peripheral portion of the sheet member 3 and the foam layer 21, and the molten resin 6 is applied to the sheet member 3 and the nonwoven fabric layer 22. It is prevented from entering between.

That is, in this embodiment, the molten resin 6 injected from the gate 40 first collides with the sheet member 3 and then spreads radially. And the molten resin 6 having a high pressure are prevented from coming into direct contact with each other. Therefore, deformation of the foam cells of the foam layer 21 at the portion facing the gate 40, which is most easily deformed, is prevented.

Since the nonwoven fabric layer 22 is preliminarily laminated on the surface of the foam layer 21 other than the portion where the sheet member 3 abuts, the deformation of the foam cell in that portion can be further prevented and the foam cell can be prevented from being deformed. The impregnation and solidification of the molten resin can be prevented, and the tactile sensation of the skin 2 is further improved. After the molded resin base material 1 is cooled and solidified, the cavity mold 5 is driven in a direction away from the core mold 4, and after the mold is opened, the skin-molded resin molded body is released. Thereby, the foam layer 21 that has been compressed expands by its own elastic force, and the surface of the skin 2 becomes flat and has a desired design shape. Thereafter, the end of the skin 2 is wrapped around and adhered to the peripheral edge of the resin substrate 1. At this time, since the thickness of the foam layer 21 is the same as that of the related art, the foam layer 21 can be easily rolled in without wrinkles and the like, and an armrest excellent in appearance quality and tactile sensation can be obtained.

If an adhesive is applied to the surface of the sheet member 3 facing the foam layer 21, the sheet member 3 and the foam layer 21 can be integrally bonded during compression molding. In this embodiment, the flat sheet member 3 is used. However, when the place where the sheet member is to be placed is a curved surface, a sheet member shaped in a predetermined shape in advance can be used.

If the sheet member is provided at a place other than the portion facing the gate as necessary, the molten resin easily enters between the sheet member and the foam layer. It is preferable to integrate them in advance by bonding or the like. (Embodiment 2) FIG. 4 shows a mold used in this embodiment. This mold includes a core mold 4 and a cavity mold 5, and a gate 40 is formed in the core mold 4. This gate 40
Is opened at the center of the portion of the armrest where the elbow is to be placed (the dashed line in FIG. 2). A concave portion 42 is formed on the mold surface where the gate 40 opens. A projection 50 is formed on the inner peripheral edge of the end of the cavity mold 5, and a projection 51 is formed on the mold surface facing the recess 42.

In this embodiment, this mold is used to hold the skin 2 as shown in FIG. Then, the core mold 4 and the cavity mold 5 are put together, and as shown in FIG. In this state, the periphery of the skin 2 is formed by the ridge 50 of the cavity mold 5 and the core mold 4.
Is immovably held between the side peripheral surface and the inner peripheral surface. Also skin 2
Are arranged along the recess 42.

In this state, first, the molten resin 6 is injected from the gate 40 at a pressure of 30 to 50 kg / cm ² . At about the same time, the cavity mold 5 is driven so as to be closer to the core mold 4 and compression molding is performed. During molding,
A tensile stress is generated in the skin 2 by the pressure of the molten resin.
FIG. 5 shows the inside of the mold after the compression molding. Since the skin 2 has a concave shape bulging toward the core mold 4 due to the convex portion 51, the concave portion 10 is formed in the molded resin base material 1 ′, and the surface of the skin 2 also follows the convex portion 51. It is concave.

After the resin substrate 1 'is solidified, the core mold 4 and the cavity mold 5 are opened, and the molded product comprising the resin substrate 1' and the skin 2 is released. As a result, the foam layer 21 that has been compressed tries to restore its original shape by its own elastic force. Here, when the pressing from the convex portion 51 is released after the mold is opened, the surface of the skin 2 becomes flat due to the intrinsic tensile stress. As a result, a large volume is secured between the surface of the concave portion 10 and the surface of the skin layer 20, and the shape of the foam layer 21 can be sufficiently recovered.

Therefore, the foam layer 21 expands greatly,
As shown in FIG. 6, the portion of the foam layer 2 facing the concave portion 10
As the thickness of No. 1 became thicker, there was no residual compressive stress, and the tactile sensation at that portion was extremely improved. In addition, it is also preferable to manufacture by combining the manufacturing method of the first embodiment and the manufacturing method of the second embodiment. In this way, it is possible to prevent the cells of the foam layer from collapsing due to the contact of the resin flow generated by the production method of Example 2, and it is possible to produce a molded product having a softer touch and excellent touch. In this case, a gap may be generated between the resin base material and the sheet member or between the sheet member and the foam layer. However, in this case, it is expected that the presence of the air layer in the gap further enhances the tactile sensation.

[0034]

According to the method for producing a resin molded article with a skin of the second invention, deformation of the foam cells of the foam layer at least in the portion facing the gate can be reliably prevented. It is possible to easily and stably produce a resin molded article with a skin having an excellent tactile sensation.

If a concave portion is provided on the mold surface on which the sheet member is placed, positioning of the placement of the sheet member becomes easy, and the appearance quality is further improved. Further, according to the method for producing a resin molded article with a skin of the fifth invention, the degree of compression of the foam layer after molding is reduced, so that the degree of elastic deformation of the foam layer can be increased by that amount, resulting in excellent tactile sensation. Further, a resin molded product with a skin can be easily manufactured.

According to the resin molded articles with skin according to the first and fourth inventions obtained by the above-mentioned manufacturing method, even if the skin is thin, a concave portion is formed on the skin or resin base where the sheet member exists. The surface of the skin where is present is extremely rich in cushioning, so that the feeling of use is excellent. Further, if the tactile sensation is equivalent to that of the related art, the thickness of the foam layer of the skin can be reduced, so that the design shape of a fine portion can be accurately represented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a mold immediately before molding of a resin substrate according to an embodiment of the present invention.

FIG. 2 is a perspective view of an armrest according to one embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a sectional view of a mold immediately before molding of a resin base material according to a second embodiment of the present invention.

FIG. 5 is a sectional view of a mold immediately after molding of a resin base material according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a molded product according to a second embodiment of the present invention.

[Explanation of symbols]

1: resin base material 2: skin 3:
Sheet member 4: Core mold 5: Cavity mold 20:
Skin layer 21: Foam layer 40: Gate 4
1: concave portion 10: concave portion 51: convex portion

Continuation of the front page (51) Int.Cl. ⁷ identification code FI B29L 9:00 B29L 9:00 (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 45/14 B29C 33/12 B29C 45 / 26

Claims (5)

(57) [Claims] 1. A foam comprising a resin substrate, a skin in which a foam layer and a skin layer are integrally laminated, wherein the skin is arranged in a mold and the foam layer of the skin is formed by low pressure injection compression molding. A resin member with a skin in which the resin substrate is integrally formed on the side, wherein a sheet member is partially interposed between the resin substrate and the foam layer and faces the sheet member of the skin. A resin molded product with a skin, wherein a portion to be formed is softer than other portions. 2. A skin comprising a skin layer and a foam layer laminated on the back side of the skin layer is arranged in a split mold, and molten resin is poured between the foam layer and the mold surface of the skin. A method for producing a resin molded article with a skin, wherein the resin base is formed on the surface of the foam layer by injecting at a low pressure from a gate and compression-molding the foam layer, wherein a portion of the skin that is to be soft is opposed to the foam layer. A sheet member is partially placed on the mold surface to be formed, and at least a mold surface has a gate on a mold surface on which the sheet member is placed,
A method for producing a resin molded article with a skin, wherein the sheet member is molded while being pressed against the foam layer by pressing with a resin flow from the gate. 3. The method according to claim 2, wherein the mold surface having the gate on which the sheet member is placed has a recess for accommodating and holding the sheet member. . 4. A foam comprising a resin base material and a skin in which a foam layer and a skin layer are integrally laminated, wherein the skin is arranged in a mold and the foam layer of the skin is formed by low-pressure injection compression molding. A resin molded product having a skin on which the resin substrate is integrally formed, the surface of the resin substrate facing the foam layer partially having a concave portion, and facing the concave portion of the skin. Part has a flat surface
Skin-covered resin molded article characterized in that it is softer than other portions along with it. 5. A skin comprising a skin layer and a foam layer laminated on the back side of the skin layer is arranged in a split mold comprising a first mold and a second mold, and the foam layer of the skin is A resin molded article with a skin, wherein molten resin is injected at a low pressure from a gate provided in the second mold between the mold surface of the second mold and compression molded to form a resin base on the foam layer surface. The method according to claim 1, wherein the first mold has a protrusion protruding toward the mold surface of the second mold, the second mold has a recess facing the protrusion , and the skin is
Peripheral part becomes immovable when placed along the recess
Sandwiched by the split mold, then inject the molten resin at low pressure
The resin base is molded in a state in which the skin is pressed by the protrusions so as to approach the second mold by compression molding , and a recess is formed by the protrusions on the resin base. When the mold is opened, the shape recovery amount of the foam layer in the portion pressed by the convex portion is increased, and after the mold is opened, the concave portion of the skin is removed.
A method for producing a resin molded article with a skin, characterized in that the surface of a part facing the part becomes flat .