JP2003103676A - Resin molded member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a trim material for a vehicle imparting proper elasticity and flexibility and enhanced in oil resistance, scratch resistance or the like. SOLUTION: A foamed elastomer 30 is molded on the basis of an injection foam molding technique utilizing a core back type mold, and composed of an inner foamed layer 32 having proper elasticity and flexibility and the outer skin layer 34 covering the inner foamed layer 32 to be exposed to the outside. The foamed elastomer 30 is applied to the outer surface of the substrate 12 of the trim member 10 for the vehicle to obtain a member outer surface 14 enhanced in soft feeling and scratch resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded member which is made of a foamed elastic body having appropriate elasticity and flexibility to improve the tactile sensation.

[0002]

2. Description of the Related Art For example, as a vehicle interior member installed in a passenger compartment of a passenger car, a resin molded member having a desired rigidity and hardness formed by a desired shape (injection molding etc.) is preferably implemented. There is. Among vehicle interior members such as resin molded members, for example, an instrument panel, an armrest provided on a door trim and a center console, a grip, and the like have an appropriate elasticity and a softness on the outer surface of the member directly contacted by an occupant. It is often the case that the tactile sensation is improved by providing a structure having a softness and softness.

FIG. 11 is a schematic perspective view showing simultaneously three types of armrests 64, 66, 68 mounted and fixed to a door trim (not shown) as an example of a vehicle interior member made of a resin molded member. Generally, the armrest is the upper surface 1 of the member outer surface portion 14 with which the elbow of the occupant is in contact.
It is necessary to improve the tactile sensation as described above by imparting an appropriate soft feeling (elasticity) to the 4a and the side surface 14b. Here, as a form for imparting elasticity to the member outer surface portion 14, a relatively thick skin 16 made of an olefinic thermoplastic resin (TPO) is formed on the outer surface of the polypropylene (PP) molding base material 12. An armrest 64 (FIG. 12) of a type that is integrally formed at the same time as molding the molding base 1 made of PP.
2 has an armrest 66 (FIG. 13) of a type in which a separately molded TPO skin 18 is attached to the outer surface of the molding base 12, and a thin TPO skin 20 on the outer surface of the molding base 12 made of PP.
Also, an armrest 68 (FIG. 14) of a type to which a polyurethane foam 22 is attached has been proposed and put into practical use.

Here, an armrest 64 of the type described above
Then, the base material 1 injection-molded into a required shape in advance.
2 is set in a molding die (not shown) for molding the skin 16, and the skin 16 is molded (insert molding), whereby the skin 16 is molded and, at the same time, adhered to the outer surface of the base material 12. It is manufactured by doing. The armrest 66 of the type described above is manufactured by individually molding the base material 12 and the outer skin 18, and then locking and attaching the outer skin 18 to the outer surface of the base material 12 in a subsequent step. To be done. Further, in the armrest 68 of the above-mentioned type, the base material 12 and the outer skin 20 which have been molded in a required shape in advance are set in a foam molding die (not shown), and then both members 12, 20 are formed.
It is manufactured by foaming a urethane raw material between them and interposing the foam 22 therebetween.

[0005]

By the way, the armrests 64, 66, 68 of the above-mentioned respective modes have problems and problems inherent therein. First, in the armrest 64,
By using a resin material (TPO) having a higher compounding ratio of rubber (EPDM) or oil (liquid paraffin, etc.) to PP or the like, the outer skin 16 formed is provided with appropriate elasticity,
As a result, a soft feeling is given to the outer surface portion 14 of the member constituted by the outer skin 16, but since the entire outer skin 16 is softened, oil resistance and scratch resistance are deteriorated, and There has been an inherent problem that the amount of resin material used is increased to increase the thickness and the cost is increased. Although it is possible to coat the outer surface of the surface skin 16 and improve the scratch resistance with the coating film formed thereby, the cost will increase further. Further, in the armrest 66, a large number of pin-shaped or rib-shaped projections 18a are provided on the back surface of the outer surface of the skin to provide elasticity by the bending deformation of the projections 18a. 14 gives a soft feeling, but the problem that the projection surface 18a on the back surface of the skin causes defects such as sink marks and uneven gloss on the skin surface (outer surface), and the projection 18a. However, when it was completely buckled, there was a drawback in that the elasticity suddenly deteriorated and a feeling of strangeness was brought about. Further, in the armrest 68, since the foam 22 is rich in elasticity, it is possible to appropriately give a soft feeling to the outer surface portion 14 of the member, but the base material 12 and the skin 20.
Since the (olefin resin) and the foam 22 (polyurethane) are composed of different materials, there was a problem in recyclability.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to suitably solve the above-mentioned problems, and is composed of a foamed elastic body molded on the basis of the injection foam molding technique, so that it has appropriate elasticity and flexibility. It is an object of the present invention to provide a resin-molded member which has improved oil resistance, scratch resistance and the like.

[0007]

In order to solve the above problems and achieve the intended purpose, the resin molded member according to the present invention comprises:
It is characterized by being constituted by a foamed elastic body composed of an internal foamed layer having appropriate elasticity and flexibility, and an external skin layer covering the internal foamed layer and exposed to the outside.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a resin molded member according to the present invention will be described below with reference to the accompanying drawings with reference to the preferred embodiments. As described above, the resin molded member targeted by the present application is a vehicle interior member such as an instrument panel, an armrest and a grip, and various other members provided with an elastic member outer surface portion. Therefore, in this embodiment, an armrest will be described as an example.

FIG. 1 is a schematic perspective view showing an armrest as a resin molding member according to the present embodiment, and FIG. 2 is II- of FIG.
It is a II sectional view. The armrest 10 of the embodiment includes a base material 12 made of a synthetic resin (olefin resin such as PP) injection-molded into a required shape, and a member outer surface portion 14 provided on the outer surface of the base material 12. . The outer surface portion 14 of the member has a foamed elastic body 30 including an inner foam layer 32 having appropriate elasticity and flexibility, and an outer skin layer 34 that covers the outer surface of the inner foam layer 32 and is exposed to the outside. It is composed of.

The foamed elastic body 30 is molded based on a known injection foam molding technique using a core back type molding die 40 shown in FIG. 4 and described later.
As shown in (a), the total thickness h is generally uniform and formed to be about 3 mm, of which the outer skin layer 34 has a thickness Sh of about 0.5 mm and the inner foam layer 32 has a thickness Fh of about 2 mm. ing. When the outer surface of the elastic foam body 30 is pressed from the outside, the inner foam layer 32 is deformed in a crushing manner and the outer skin layer 34 is deformed in a recessed manner. The elasticity for ensuring the softness required for the member surface portion 14 is secured.

Here, as the resin material for molding the foamed elastic body 30, polypropylene: rubber: oil
An olefin resin raw material (TPO) with a mixing ratio of (liquid paraffin, etc.) of 50: 70: 2, and an appropriate foaming agent 3
It is said to be added by weight%. In the foamed elastic body 30 of the embodiment molded under the required molding conditions using such a resin material, the outer skin layer 34 itself has a hardness of about 80 to 90 "Shore A hardness". On the other hand, the hardness of the inner foam layer 32 through the outer skin layer 34 is formed to be "Shore A hardness" of about 60 to 70.

Therefore, as shown in FIG. 3 (b), when the occupant's elbow 24 or the like is pressed against the member outer surface portion 14 composed of the foamed elastic body 30, the inside corresponding to the pressed portion The inner spaces 36 of the foam layer 32 are crushed to crush the inner foam layer 32, and the outer skin layer 3
Since 4 deforms like a recess, a sufficient soft feeling can be obtained. Further, since the outer skin layer 34 is relatively hard, oil resistance and scratch resistance can be improved, and deterioration due to oil content can be preferably prevented, and scratches and scratches are less likely to occur. . The thickness Sh of the outer skin layer 34 can be adjusted by setting molding conditions at the time of molding by a core back type molding die 40 described later.

FIG. 4 is a sectional view showing a core back type molding die 40 for molding the foamed elastic body 30. This molding die 40 is a pair of a first molding die 42 (cavity mold) provided with a concave molding surface 42 a formed based on the shape of the outer surface portion 14 of the member of the armrest 10, and a pair of the first molding die 42. The mold is closed while sliding vertically downward, and the convex molding surface 44a is opposed to the concave molding surface 42a.
And a second molding die 44 (core die) provided with. Then, when the second molding die 44 is closed with respect to the first molding die 42, a cavity 46 is defined between the molding surfaces 42 a and 44 a, and the second molding die 44 with respect to the first molding die 42. The thickness and volume of the cavity 46 can be changed by sliding. The second molding die 44 has an injection port 48 communicating with the cavity 46, and the resin material B supplied from an injection nozzle 49 closely aligned with the injection port 48 can be injected into the cavity 46. It is like this. In addition, the first molding die 42 and the second molding die 44 respectively include molding surfaces 42a,
A cooling means (not shown) for cooling 44a is built in, and the resin material B injected into the cavity 46 is cooled.
It is designed to accelerate curing.

With such a molding die 40, the foamed elastic body 30 having different characteristics can be molded by setting molding conditions. For example, the timing (time) of the backward movement (core back) of the second molding die 44, the temperature of the molding surfaces 42a, 44a of the molding dies 42, 44 (resin temperature at the time of core back), etc. The thickness Sh and the like of the layer 34 can be adjusted. Specifically, if the timing of the backward movement of the second molding die 44 is delayed or the temperatures of the molding surfaces 42a and 44a are lowered, the thickness Sh of the outer skin layer 34 can be increased, and conversely the second The thickness Sh of the outer skin layer 34 can be reduced by advancing the timing of the backward movement of the molding die 44 or increasing the temperature of the molding surfaces 42a and 44a. Further, (1) characteristics of the resin material B (density, unit gas generation amount of foaming agent, expansion ratio, etc.), (2) cavity 4
The hardness and the like of the inner foam layer 32 can be changed by various factors such as the injection amount of the resin material B into the resin 6, (3) the movement amount of the second molding die 44 and the like.

Next, a method of molding the foamed elastic body 30 using the molding die 40 described above will be described.

First, the second molding die 44 is closed with respect to the first molding die 42 of the molding die 40, and the second molding die 44 is stopped at the first position. Then, when the preparation for molding is completed, as shown in FIG.
After reaching and aligning with, the predetermined amount of the resin material B is injected into the cavity 46. The injection amount of the resin material B is set according to the characteristics of the resin material B, but in the embodiment, it is substantially the same as the volume of the cavity 46.

Resin material B injected into the cavity 46
Begins to harden from the portions in contact with the respective cooled molding surfaces 42a, 44a, and the solidified outer skin layer 34 is gradually formed in these portions. Assuming that there is no loss of foaming gas when the resin material B injected into the cavity 46 flows in the cavity 46, all the gas generated by the decomposition of the foaming agent is compressed and It is in a state of being contained in the material B.

After the injection of the resin material B is completed, when the outer skin layer 34 having a required thickness is formed on the surface of the injected resin material B, the second molding die 44 is moved upward in the drawing as shown in FIG. The second molding die 44 is stopped at the second position by sliding (core backing) the required amount. At this time, since the pressure applied to the resin material B is reduced as the volume of the cavity 46 is increased, the gas contained in the resin material B in a compressed state is sequentially bubbled into a large number of large and small. The inner space 36 is formed, and the inner foam layer 32 is formed inside the outer skin layer 34. The external skin layer 34
Since the resin material B is hardened in the state of enclosing the dissolved gas, the gas existing in this portion does not bubble.

Then, the slide movement of the second molding die 44 is performed.
When the molding of the inner foam layer 32 is completed by (core back), the second elastic mold 44 is separated from the first elastic mold 42 and opened, and the elastic foam body 30 is released from the mold. Since the unnecessary portion 38 formed by the resin material B cured in the injection port 48 remains in the foamed elastic body 30 immediately after molding, the unnecessary portion 38 is cut and removed to obtain the foamed elasticity. The forming of the body 30 is completed (FIG. 7).

The armrest 10 of the embodiment in which the foam elastic body 30 molded by using the molding die 40 based on the injection foam molding technique is used as the member outer surface portion 14,
(A) When molding the base material 12 using a molding die for molding the base material, the foamed elastic body 30 is formed on the outer surface of the base material 12 to be molded.
(FIG. 8 and FIG. 9), and (B) a method of attaching and fixing the foamed elastic body 30 to the outer surface of the base material 12 which has been formed into a predetermined shape by an appropriate fixing means (FIG. 10). ), Etc.

The manufacturing method of (A) uses an injection molding die 50 for molding a base material shown in FIG.
The foamed elastic body 3 is formed on the concave molding surface 52 a of the first molding die 52.
The second pair which is paired with the first mold 52 under the setting of 0.
The molding die 54 is closed, and a required amount of the molten resin C is injected from the injection nozzle 59 into the cavity 56 defined thereby (insert injection molding). The foamed elastic body 30 is gradually cured while being in contact with it, and when the molding is completed, the foamed elastic body 30 is integrally attached to the outer surface of the base material 12. The molten resin C injected into the cavity 56
Does not impregnate the inner foam layer 32 with the outer skin layer 34. Then, the molding of the base material 12 and the base material 12
After the mounting of the foamed elastic body 30 on the base material 12 is completed, the base material 12 when released from the injection molding die 50 is
As shown in FIG. 9, since the unnecessary portion 60 formed of the molten resin C cured in the injection port 58 remains, the unnecessary portion 60 is cut and removed to complete the manufacture of the armrest 10. To do.

On the other hand, in the manufacturing method (B), as shown in FIG. 10, an adhesive, a double-sided tape or the like is applied to the outer surface of the base material 12 which is injection-molded in advance by using an injection molding die (not shown). The foamed elastic body 30 is attached using the fixing means 62 or the like. Although not shown, the foamed elastic body 30 may be attached to the outer surface of the base material 12 by locking the end edge portion of the foamed elastic body 30 to the end edge portion of the base material 12. Further, a boss is formed on the lower surface of the outer skin layer 34 of the foamed elastic body 30, and the boss is thermally caulked to the base material 12 to adhere the foamed elastic body 30 to the outer surface of the base material 12. The method can also be adopted.

As described above, the foamed elastic body 30 has a rubber content or an oil content (liquid paraffin, etc.) with respect to polypropylene.
Resin raw material with a lower compounding ratio (PP / rubber /
The blending ratio of the oil component was 50/100/10, whereas in the present application, the blending ratio of each is 50/70/2) and the resin material B is formed on the basis of the injection foam molding technique. Therefore, the hardness of the outer skin layer 34 itself is about 80 to 90 in Shore A hardness, and the hardness of the inner foam layer 32 through the outer skin layer 34 is 60 to 7 in Shore A hardness.
It is about 0. Moreover, since the inner foam layer 32 is foamed substantially uniformly as a whole based on the core-back molding method, the foamed elastic body 30 has uniform elasticity in any portion. Therefore, in the armrest 10 of the embodiment in which the member outer surface portion 14 is composed of the foamed elastic body 30 described above, a uniform soft feeling can be obtained even if any portion of the member outer surface portion 14 is touched by the inner foamed layer 32 described above. The outer skin layer 34 described above improves oil resistance and scratch resistance, improves both soft feeling and durability, and sufficiently satisfies the conditions required for the vehicle interior member.

Further, in the armrest 10 of the embodiment, both the foamed elastic body 30 and the base material 12 which compose the armrest 10 are made of the same olefin resin, so that the armrest 10 is excellent in recyclability.

If the molding die 40 shown in FIG. 4 is slightly modified, the second molding die 44 is moved further upward from the second position after the molding of the foam elastic body 30 is completed as described above. By slidingly moving the base material 1 between the foamed elastic body 30 molded and the molding surface 44a of the second molding die 44.
Since the space in which 2 can be molded is defined, it is possible to inject the molten resin C into this space to mold the base material 12 following the molding of the foamed elastic body 30. If such a molding method becomes possible, an injection foam molding process of the foam elastic body 30, an injection molding process of the base material 12, a mounting process of the foam elastic body 30 to the base material 12,
The molding die 40 can be used continuously and efficiently, and the injection molding die 50 shown in FIG. 8 is not required.

Further, as described above, the resin molded member to which the present invention is applied is not limited to the armrest 10, but may be a vehicle interior member such as an instrument panel or a grip, or other elastic member outer surface portion. Various members provided with are targeted.

[0027]

As described above, according to the resin molded member of the present invention, the foamed elastic body is formed of the inner foamed layer having appropriate elasticity and flexibility and the outer skin layer covering the foamed layer. By doing so, it is possible to obtain a uniform soft feeling due to the elasticity of the inner foam layer, while exhibiting a beneficial effect that the outer skin layer can appropriately improve oil resistance and scratch resistance. . That is, the foamed elastic body uses a resin material in which an appropriate foaming agent is added with a small compounding ratio of rubber and oil,
Since the core back type molding die is used for molding based on the injection foam molding technique, the outer skin layer can be formed hard and the inner foam layer can be formed soft. As a form of applying the foamed elastic body to the outer surface of the base material, a method of integrally applying to the outer surface of the base material simultaneously with molding of the base material,
It is possible to adopt a method of attaching and fixing to the outer surface of the preformed base material by an appropriate fixing means.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an armrest as a resin molded member according to a preferred embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3 (a) is an enlarged view of a portion A of FIG. 2, and FIG. 3 (b) is a foamed elastic member forming the outer surface of the member when the elbow of the occupant presses the outer surface of the member from the state of (a). It shows a state in which the inner foam layer of the body is deformed crushed and the outer skin layer is deformed concavely.

FIG. 4 is a cross-sectional view of a mold for injection foam molding an elastic foam body.

5 is a cross-sectional view showing a molding process of the foamed elastic body by the molding die shown in FIG. 4, in which the resin material injected from the injection nozzle into the cavity starts to cure from a portion in contact with the molding surface of the molding die. The state where the external skin layer is formed is shown.

FIG. 6 is a cross-sectional view showing a process of molding a foamed elastic body,
It shows a state in which the foaming agent in the resin material is bubbled by slidingly moving (core-backing) the second molding die, and the internal foaming layer is formed inside the external skin layer.

FIG. 7 is a cross-sectional view of the foamed elastic body completed by cutting and removing unnecessary portions after completion of molding.

FIG. 8 is an explanatory cross-sectional view showing the method for manufacturing the armrest, wherein the base material is molded by injection molding the base material with the completed foamed elastic body set in a molding die for molding the base material. The state where the foamed elastic body is integrally attached to the outer surface of the base material is shown.

FIG. 9 is a cross-sectional view of an armrest that has been manufactured by cutting and removing an unnecessary portion after the molding of the base material and the attachment of the foamed elastic body to the base material are completed.

FIG. 10 is an explanatory cross-sectional view showing another manufacturing method of the armrest, wherein (a) shows a state before the foamed elastic body is adhered and fixed to the outer surface of a separately molded base material by an appropriate fixing means, (b) shows a state in which the foamed elastic body is adhered and fixed to the outer surface of the base material.

FIG. 11 is a schematic perspective view showing an armrest as an example of a conventional resin molded member.

FIG. 12 is a cross-sectional view showing an armrest of a type in which a skin is formed on the outer surface of a molding base material and at the same time, is integrally adhered to the molding base material, taken along line XX in FIG.

13 is a cross-sectional view showing an armrest of a type in which a separately molded skin is locked and attached to the outer surface of a molding base material, taken along line XX in FIG. 11.

FIG. 14 shows an armrest of a type in which a separately molded skin and foam are formed and adhered to the outer surface of a molding substrate.
It is sectional drawing which fractures | ruptures and it shows in the XX line part of 1.

[Explanation of symbols]

12 Base material 30 foamed elastic body 32 Internal foam layer 34 External skin layer 40 Mold (for molding elastic foam) 50 Mold (for base material molding) 62 fixing means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // B29K 105: 04 B29K 105: 04 B29L 9:00 B29L 9:00 F term (reference) 3D023 BA01 BB25 BC01 BD32 BE31 4F100 AT00B AT00C BA02 BA03 BA07 BA10B BA10C DJ01A EC03 EC032 EH17 GB33 JK07A JK11 JK12B JK13 JK13A YY00B 4F202 AD05 AD08 AD17 AG03 AG20 CA11 CB01 QC12 AD02 JQ20 AD17B03A08 AD02B03AD08 AD02 AD05 AD08 AD12 AD05 AD08B03C08

Claims (5)

[Claims] 1. A foamed elastic body comprising an inner foam layer (32) having appropriate elasticity and flexibility, and an outer skin layer (34) covering the inner foam layer (32) and exposed to the outside. 30) A resin molded member characterized by being constituted by 2. The resin molded member according to claim 1, wherein the foamed elastic body (30) is molded based on an injection foam molding technique using a core back type molding die (40). 3. The foamed elastic body (30) is formed into a required shape by molding the base material (12) after being set in a molding die (50) for molding a base material. The resin molded member according to claim 1 or 2, which is integrally attached to the outer surface of (12). 4. The elastic foam body (30) according to claim 1 or 2, wherein the foaming elastic body (30) is adhered and fixed to the outer surface of the base material (12) which is formed in a predetermined shape by a fixing means (62). Resin molded member. 5. An outer skin layer (34) of the foamed elastic body (30).
Is a resin molded member according to any one of claims 1 to 4, which has a Shore A hardness of 80 to 90.