JP2008100465A - Composite member molding method and composite member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite member in which the outside layer, or outside member, has high repulsive force and the inside layer, or inside member, has low repulsive force and a method of forming the composite material. <P>SOLUTION: In the method to form a composite member composed of a substrate 3, a first member 6b and a second member 6c, a thermoplastic material being the first member 6b is melted and injected onto the surface of a substrate, or penholder 2, composed of a thermoplastic material; a laminate is formed by tightly adhering the first member to the substrate, or penholder 2; a thermoplastic elastomer being the second member and softer than the first member is melted and injected between the substrate, or penholder 2, and the first member 6b being in a tightly adhered state; a gap between the substrate, or penholder 2, and the first member is filled with the second member 6c, so as to cause an elastic deformation of the first member 6b under the injection pressure of the thermoplastic elastomer; and the second member 6c is formed to a specified shape. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for molding a composite member and a composite member, and, for example, a method for molding a composite member and a composite in which a second member made of a thermoplastic material is injection-molded with respect to a first member molded from a thermoplastic material. It relates to members.

Conventionally, various proposals related to a method for forming a composite member have been made.
For example, Japanese Patent Laid-Open No. 9-212272 (Patent Document 1) shows a keypad as a composite member. The keypad 51 will be described with reference to FIG. This keypad 51 has a pattern layer 53, and a portion corresponding to a plurality of button portions 55 of a flexible, transparent or translucent plastic sheet 52 is formed as a convex portion, and a silicone rubber composition 54 is formed in a concave portion on the back surface of the plastic sheet 52. Is filled.
In such a keypad 51, portions corresponding to the plurality of button portions 55 of the transparent or translucent plastic sheet 52 are formed as convex portions, and the concave portions on the back surface of the plastic sheet 52 are filled with the silicone rubber composition 54. Therefore, it has a beautiful design effect and an effect that the button portion 55 is automatically restored by the silicone composition.

In addition, JP 2003-512960 A (Patent Document 2) shows a grip of a writing instrument as a composite member. This grip will be described with reference to FIG.
The grip 61 includes a low durometer hardness thermoplastic elastomer layer 62 and a flexible outer layer 63 that resists oil absorption. In such a grip 61, since the outer layer 63 is a flexible layer that resists oil absorption, it has oil resistance and does not substantially pass oil secreted from humans and sebum oil.
JP-A-9-212272 Special table 2003-512960 gazette

  Conventionally, composite members have been widely used in various fields and have different purposes. As described above, in the composite member described in Patent Document 1, the plastic sheet 2 is installed on a flexible silicone for decoration or surface protection, and is configured to automatically return by the silicone. Moreover, in the composite member described in Patent Document 2, a flexible outer layer that resists oil absorption is provided outside the thermoplastic elastomer layer to improve oil resistance.

  By the way, for example, in the grip of a writing instrument, there is a demand for a composite member in which the outer layer (outer member) has high resilience and the inner layer (inner member) has low resilience. Such a composite member can suppress a user's feeling of fatigue due to writing and can give the user a special feeling that has not been heretofore, and its appearance has been desired.

  As a result of earnest research on the composite member, the inventors of the present application have stretched the outer layer (outer member) with the filling pressure of the inner layer (inner member) having a low repulsion feeling, and provided initial elasticity to the outer layer (outer member). Giving and increasing the resilience led to finding a composite member having a low resilience inside and a high resilience outside.

  The present invention has been made in view of the above circumstances, and includes a composite member in which an outer layer (outer member) has high resilience and an inner layer (inner member) has low resilience, and a method for molding the composite member. It is intended to provide.

  The composite member molding method according to the present invention made to achieve the above object is a method for molding a composite member comprising a first member and a second member on a base material. The thermoplastic material as the first member is melt-injected onto the surface of the base material made of, and the first member is brought into close contact with the surface of the base material and molded into a laminated state. The softer heat than the first member As the second member, the plastic elastomer is melt-injected between the substrate and the first member in a close contact state, the first member is elastically deformed by the injection pressure, and has an initial elastic force. The second member is filled and molded into a predetermined shape.

As described above, in the molding method of the composite member, the thermoplastic material as the first member is melt-injected onto the surface of the base material, and the first member is brought into close contact with the base material surface to be laminated. The thermoplastic elastomer that is softer than the first member is used as the second member, and the second member is melt-injected between the substrate and the first member that are in close contact, and the first member is elastically deformed by the injection pressure. I am letting.
Here, the close contact does not mean a welded and integrated state, and the first member is detachable from the base material, and a gap is formed between the first member and the base material surface. Without meaning, the state where the 1st member is formed in the substrate surface is meant.
In addition, the initial elastic force means that the first member has tension and the cut portion opens greatly when cut. In order to maintain the tension of the first member, the material of the first member preferably has a maximum elongation ratio of about 10% to 90% when stretched.

Thus, the 1st member has a high repulsion feeling, and the 2nd member with which it filled between the base material and the 1st member has a low repulsion feeling. Therefore, it is possible to obtain a composite member in which the outer layer (outer member) has a high resilience feeling and the inner layer (inner member) has a low resilience feeling.
Moreover, since the first member is formed into a predetermined shape by filling the second member between the base material and the first member, a composite member having a desired shape can be easily formed.

  The composite member according to the present invention made to achieve the above object is formed on the surface of a base material made of a thermoplastic material in a composite member made of a first member and a second member formed on the base material. A first member made of a thermoplastic material, and a second member made of a thermoplastic elastomer softer than the first member, which is housed between the base member and the first member, This member is characterized by being elastically deformed by the second member accommodated between the base member and the first member and having an initial elastic force.

  In this composite member, since the first member is elastically deformed and has an initial elastic force, the outer layer has a high rebound feeling. Moreover, since the 2nd member which consists of a thermoplastic elastomer softer than a 1st member is filled between a 1st member and a base material, an inner side layer has a low resilience feeling.

The composite member molding method according to the present invention made to achieve the above object is a composite member molding method for molding a composite member composed of a first member and a second member. A plastic material is melt-injected into a mold, a first member is molded in close contact with the mold, and a thermoplastic elastomer softer than the first member is used as a second member; The second member is filled between the mold and the first member so that the first member is melt-injected between the first member, the first member is elastically deformed by the injection pressure, and has an initial elastic force. And is formed into a predetermined shape.
Here, the close contact does not mean a welded and integrated state, but the first member is detachable from the mold and a gap is formed between the first member and the mold surface. It means that the first member is formed on the mold surface. In addition, the initial elastic force means that the first member has tension and the cut portion opens greatly when cut. In order to maintain the tension of the first member, the material of the first member preferably has a maximum elongation ratio of about 10% to 90% when stretched.

As described above, in the molding method of the composite member, the thermoplastic material that is the first member is melt-injected into the mold, and the soft thermoplastic elastomer that is the second member is bonded to the gold that is in a close contact state. Melt injection is performed between the mold and the first member, and the first member is elastically deformed by the injection pressure.
Therefore, by this molding method, a composite member can be obtained in which the outer layer has high resilience and the inner layer has low resilience. Moreover, since the first member is formed into a predetermined shape by filling the second member between the mold and the first member, a composite member having a desired shape can be easily formed.

  A composite member according to the present invention made to achieve the above object is a composite member composed of a first member and a second member, and a first member made of a thermoplastic material formed by injection molding. A second member made of a thermoplastic elastomer softer than the first member, formed by injection molding on the first member, the first member elastically deformed by the second member, and It has an initial elastic force.

  In this composite member, since the first member is elastically deformed and has an initial elastic force, the outer layer has a high rebound feeling. Further, since the second member is formed of a thermoplastic elastomer that is softer than the first member, the inner layer has a low repulsive force feeling.

Moreover, it is desirable that the 100% modulus of the first member is 0.1 to 10 MPa, and the maximum elongation ratio of the first member is 10% to 90%.
When the property of the first member is configured in this way, a suitable initial elastic force can be obtained.
Here, the 100% modulus represents a force for returning the member in a state where the member is doubled. In addition, the maximum elongation rate means the elongation rate of the most extended portion in the first member.
The 100% modulus of the first member is preferably higher than the 100% modulus of the second member, and the hardness of the first member is preferably larger than the hardness of the second member. In such a case, for example, when used for a grip of a writing instrument, it is difficult to play a pen, and it is possible to reduce writing fatigue to the user. Furthermore, it is possible to give the user a feeling of use that is not conventional.

  As described above, according to the present invention, it is possible to obtain a composite member in which the outer layer (outer member) has high resilience and the inner layer (inner member) has low resilience and a molding method of the composite member. .

  Below, 1st embodiment of this invention is described based on FIG. 1 thru | or FIG. In the first embodiment, a case where the composite member is applied to a grip of a ballpoint pen will be described as an example. 1 is a side view of the ballpoint pen, showing the grip in cross section, FIG. 2 showing the grip, (a) a longitudinal sectional view of the grip, and (b) showing the grip. FIG. 3 is a schematic cross-sectional view and FIG. 3 is a schematic view showing a manufacturing process of the grip.

As shown in FIG. 1, a ballpoint pen 1 includes a pen shaft 2 in which an ink core (not shown) of a pole pen is accommodated, a mouth plug 3 attached to a tip portion of the pen shaft 2, and the pen shaft 2. The tail plug 4 is attached to the rear end portion, and the writing tip 5 is formed at the tip of the ink core (not shown) and is a ball tip protruding from the mouth plug 3.
A grip 6 is attached to the front portion 2 a of the pen shaft 2. This grip 6 is mounted to improve the problem that the pen can be bent on the finger when the ball pen 1 is used for a long time due to the surface of the pen shaft 2 being hard, or the ball pen 1 slips due to perspiration. .

  The grip 6 is formed in a substantially cylindrical shape, and a convex portion 6a is formed on a part of the outer peripheral surface thereof. The reason why the convex portion 6a is formed on a part of the outer peripheral surface of the grip 6 in this manner is that it is difficult to make a pen and the fatigue of writing to the user is reduced.

The grip 6 is composed of a first member 6b that forms a cylindrical portion and a second member 6c that forms the inside of the convex portion 6a.
The first member 6b is formed by melting and molding the first thermoplastic material A. The second member 6c is formed by melting and filling the second thermoplastic material B in a part of the inner peripheral surface of the first member by a method described later.
The first member 6b and the second member 6c are not fused and integrated, but the first member 6b and the second member 6c are formed to be separable and peelable. .

The first thermoplastic material A is a thermoplastic elastomer, and the solidified first member 6b is made of a material that generates a high rebound feeling, that is, a material having a high elasticity.
Specifically, it is preferable that the material of the first member 6b has a 100% modulus of 0.1 to 10 MPa.

  Examples of the first thermoplastic material A include, for example, polystyrene elastomers (trade names, actimators, manufacturer names, Riken Technos), polyolefin elastomers (trade names, Miralastomers, manufacturer names, Mitsui Petrochemical Industries), polyurethane elastomers. , Polyester elastomer, polyamide elastomer, polybutadiene elastomer, ethylene-vinyl acetate elastomer, polyvinyl chloride elastomer, natural rubber elastomer, fluororubber elastomer, trans polyisoprene elastomer, chlorinated polyethylene elastomer, acrylic Mention may be made of elastomers.

Further, as the first thermoplastic material A, when the amount of bleed of oil from the second thermoplastic material B described later is large, it is preferable to use a material provided with polarity in order to suppress bleed.
Further, when a material having a stronger polarity is selected as the first thermoplastic material A, the plasticity of the first thermoplastic material A is improved by, for example, improving adhesion to soft vinyl chloride or the like. In order to prevent sticking to an external resin or the like due to migration, it is preferable to contain an inorganic material such as talc, calcium carbonate, or mica that is generally added.

The second thermoplastic material B is a thermoplastic elastomer, and the solidified second member 6c is a material that generates a low rebound feeling, that is, a material having a low elasticity feeling.
Specifically, it is preferable that the material of the second member 6c has a 100% modulus of 0.01 to 2.0 MPa.

  The second thermoplastic material B is selected from the viewpoint of 100% modulus, hardness, and color, which is an elastomer of the same system as the first material among the materials mentioned in the first member. Is preferred.

The second thermoplastic material B is preferably a softer thermoplastic elastomer than the first thermoplastic material A, and the molecular weight of the oil (plasticizer) for softening maintains the softness. However, in view of characteristics, it is preferable that the change in weight is 2% or less in a volatilization loss test at 80 ° C. for 100 hours. This is because if it exceeds 2%, it will cure at room temperature over time.
Further, the second thermoplastic material B preferably contains silicone or a metal stearate salt to prevent blocking.

In addition, for example, in order to reduce pen fatigue with a pen or the like and to reduce the fatigue of writing to the user, the hardness of the first member (first thermoplastic material A) is shore. A range of A hardness A / 20/1 to A / 70/1 (measured hardness within 1 second of Shore A hardness) is preferable.
In order to make it difficult to make a pendulum, the grip should be soft, and the hardness of the first member is preferably a Shore A hardness of 70 or less. On the other hand, if the deformation that causes the grip to shift in the axial direction due to the pressure of writing increases, the nib is not stabilized and a feeling of fatigue appears. Therefore, the hardness of the first member is preferably 20 or more in Shore A hardness. Accordingly, the hardness of the first member is preferably in the range of A / 20/1 to A / 70/1 in Shore A hardness.

  Further, the softer the second member, the better the feel, and the hardness of the second member is in the range of Shore A hardness A / 0/1 to A / 30/1 (measurement within 1 second of Shore A hardness) Hardness) is preferred.

Furthermore, it is preferable to select a material in which the hardness of the first member 6b in which the first thermoplastic material is solidified is larger than the hardness of the second member 6c in which the second thermoplastic material is solidified.
Further, it is preferable to select a material in which the 100% modulus of the solidified first member 6b is higher than the 100% modulus of the solidified second member 6c.
When the first member 6b is a polystyrene-based elastomer and the second member 6c is a material obtained by increasing the ratio of the balaffin oil component in the polystyrene-based elastomer, the material having such hardness and 100% modulus is related. Etc. can be mentioned as an example.

Thus, the hardness of the first member 6b is greater than the hardness of the second member 6c, and the 100% modulus of the solidified first member 6b is higher than the 100% modulus of the solidified second member 6c. Therefore, the surface is firmly and securely gripped, and the inside is held in a moist and low repulsion state, so that it is difficult for the pen to be drawn and the fatigue of writing to the user can be reduced. Furthermore, it is possible to give the user a feeling of use that is not conventional.
That is, since the hardness of the second member 6c forming the convex portion 6a is smaller than the hardness of the first member 6b and 100% modulus is low, the amount of deformation is large, and according to the gripping of the user's writing instrument. A deformation can be achieved.
In addition, since the 100% modulus of the solidified first member 6b is higher than the 100% modulus of the solidified second member 6c, the surface can be firmly and securely gripped without feeling sticky.

Further, by pressing the convex portion of the first member 6b, not only the first member 6b but also the second member 6c formed in a laminated shape can be obtained, and the single member is formed. A different feel can be obtained.
On the contrary, when the hardness of the second member 6c is greater than that of the first member 6b, or the 100% modulus of the solidified first member 6b is solidified. If it is lower than the 100% modulus of the second member 6c, the softness will be felt mainly by the first member 6b, and the effect of suppressing the pen and writing fatigue will be reduced.

Further, the maximum thickness dimension t1 of the convex portion of the second member 6c is formed to be not less than 1.2 times the thickness t2 of the film of the first member 6b, as shown in FIG. Yes. When the maximum thickness dimension t1 of the convex portion of the second member 6c is less than 1.2 times the thickness t2 of the film of the first member 6b, the first member thickness is 10 mm. Assuming T1 = 0.5 mm, the maximum elongation is 10%. This is because the initial elastic force cannot be felt as a tense feel unless a minimum elongation of 10% is secured.
Similarly, if the maximum thickness dimension t1 of the convex portion of the second member 6c exceeds 5 times the thickness t2 of the film of the first member 6b, scratches on the first member will occur. This is not preferable because the rupture due to is remarkable. Assuming that the outer diameter of the substrate is 10 mm and the film thickness t2 of the first member 6b is 0.5 mm, this corresponds to a maximum elongation of 90%. Therefore, it is desirable to set the maximum elongation rate to 90% or less.

Next, a method for forming the grip will be described with reference to FIG. FIG. 3 is a cross-sectional view showing a part of the mold. Here, the case where the above-mentioned thermoplastic elastomer resin is used as the first thermoplastic material A and the polystyrene elastomer in which the paraffin oil of the material A is doubled is used as the second thermoplastic material B, for example. explain.
First, as shown in FIG. 3A, the first thermoplastic material A is melted, and the cylindrical first member 6 b is injection-molded using the molds 7 and 8.
Next, as shown in FIG. 3B, a mold 10 having a recess 10 a is prepared, and the second thermoplastic material B is melted from the gate G between the first member 6 b and the mold 7. The second member that injects and forms the convex portion of the first member 6b is injection-molded.

At this time, as shown in FIG. 3C, the first member 6b is deformed by the injection pressure of the melted second thermoplastic material B, and the second member 6c is formed inside the convex portion of the first member 6b. As a result of molding, a convex portion 6a is formed on the first member 6b.
At this time, the first member is given a force to return by being stretched by the injection pressure of the second member, that is, an initial elastic force, which acts as a surface tension, as if the balloon was inflated. A feeling is given.
In order to maintain the initial elastic force, that is, the tension of the first member, in the first member material having physical properties such as 100% modulus and hardness, the maximum elongation when stretched is 10%. It is preferable to be about ~ 90%.

  According to such a molding method, since the convex portion 6a is formed by the injection pressure of the second thermoplastic material, it is not necessary to use the first member 6b in which the convex portion is formed in advance. That is, it is not necessary to form a concave portion in the mold 8 and mold the first member having the convex portion by using the mold. For example, a plate-like or cylindrical member is used as the first member. Therefore, the cost of the mold or the like can be reduced.

Next, a modification of the first embodiment will be described with reference to FIGS.
The modification shown in FIG. 4 is a tag in which the second member 12 is formed on the plate-like first member 11 and the letters “ABC” are formed as convex portions. That is, the present invention is not limited to a cylindrical body such as the above-described grip, and can be applied to a plate-shaped body.
At this time, when the thickness of the convex portion is T1, the thickness of the first member is T2, and the thickness of the second member is T3, T1> T2 in order to clarify the outline of the character. It is preferable.
Furthermore, when the second member is colored and transparent, and the first member is transparent or semi-transparent enough to show the color of the second member, the second member is thick depending on the thickness. Since it can be seen, it is preferable that T1 + T2> T3 in order to clarify the difference in character density.
Further, in order to apply an initial elastic force to the first member, the length of T1 is set so as to be 10% or more and 90% or less in the minimum cross-sectional length of the character.

Further, in the modification shown in FIG. 5, the second member 14 is formed on the plate-like first member 13 and the letters “ABC” are formed as convex portions, similarly to the case shown in FIG. 4. Although it is a tag, as shown in FIG.4 (d), by forming the gate G which inject | emits the 2nd thermoplastic material B in the position corresponding to each character, it can form independently for every character. it can.
In the above description, the tag has been described as an example, but the present invention is applied to a telephone operation button, a keyboard key button, and the like.

  Furthermore, a second embodiment will be described based on FIG. This embodiment is characterized in that the first member is directly formed on the base material. FIG. 6 is a schematic cross-sectional view showing a case where the composite member shown in FIG. 1 is directly formed on a base material, and also in this embodiment, a case where the composite member is applied to a grip of a ballpoint pen will be described as an example. To do.

  As shown in FIG. 6A, first, a base material (ball pen shaft cylinder) 30 is formed using a mold 20 and a core pin 21. The shaft tube 30 is made of a hard resin material. For example, polycarbonate, acrylonitrile / butadiene / styrene resin, acrylonitrile / styrene resin, polystyrene, methacrylic resin, polyacetal, polypropylene, or the like can be used.

It should be noted that the resin material constituting the base material only needs to maintain a certain degree of rigidity. However, if a first member 6b described later is molded on the base material (shaft tube) in a bonded state, the second material Since it becomes difficult to fill the member, it is preferable to use a nonpolar resin material that does not adhere to the first member as the base material.
Specifically, when a polar resin is used to improve oil resistance for the first member, if acrylonitrile / butadiene / styrene resin, polycarbonate, or polyethylene terephthalate is used for the base material, the adhesive strength is increased. The second member cannot be filled. Therefore, it is preferable to use nonpolar resin polypropylene or polystyrene for the substrate.

Subsequently, as shown in FIG. 6B, a first member 6 b constituting the grip 6 is formed on the outer peripheral surface of the shaft cylinder 30 using a mold 32. At this time, the first member 6 b is formed on the outer peripheral surface of the shaft tube 30. The first member 6 b formed on the outer peripheral surface of the shaft tube 40 is formed in a close contact state without being fused to the shaft tube 30. The close contact state does not mean a welded and integrated state, but the first member is detachable from the shaft tube 30 and a gap is formed between the first member and the shaft tube 30. The state which the 1st member is formed in the axial cylinder 30 without meaning is meant.
After that, as shown in FIG. 6C, the heat of the second member 6c from the gate G between the shaft cylinder 30 and the first member 6b using the mold 23 in which the recess 23a is formed. A plastic material is melt-injected and molded.

At this time, the first member 6b formed in close contact with the shaft tube 30 is peeled off by the injection pressure of the thermoplastic material of the second member 6c, and the shaft member 30 and the first member 6b are separated. Is filled with the second member. Then, the first member 6b is deformed by the injection pressure of the second member 6c, and a convex portion 6a is formed following the concave portion 23a of the mold 23 (see FIG. 6D).
At this time, the first member is elastically deformed, and the first member has an initial elastic force. That is, the first member is formed so that the elongation percentage is 10% or more and 90% or less.
After molding, the mold 23 and the core pin 21 are detached, and the base material (ballpoint pen barrel) 30 with the grip 6 formed on the outer peripheral surface is taken out (see FIG. 6E).

  In this way, the first member 6b made of the thermoplastic material formed in close contact with the surface of the base material 30 made of the thermoplastic material, and accommodated between the base material 30 and the first member 6b. And a second member 6c made of a thermoplastic elastomer softer than the first member 6b, and the first member 6b is accommodated between the base member 30 and the first member 6b. Thus, a grip 6 that is elastically deformed and has an initial elastic force is obtained.

  Further, the first member 6b is directly formed on the surface of the base material (shaft cylinder) 30 made of a hard material, and then the heat of the second member 6c is between the first member 6b and the surface of the base material. The composite member (grip) 20 can be directly formed on the base material (shaft cylinder) 40 by melt-injecting the plastic material, deforming the first member 6b, and forming the convex portion 6a on the first member 6b. Therefore, the installation work can be omitted.

In addition, since the second member is melt-injected between the mold and the first member that are in close contact, and the first member is elastically deformed by the injection pressure, the first member of the grip is The second member formed inside the first member has high resilience and low resilience.
In such a grip (composite member), it is possible to give the user a special touch that is not conventionally provided without giving the user a feeling of fatigue.

Further, since the composite member (grip) 20 is directly formed on the base material (shaft cylinder) 30, the base material (shaft cylinder) 30 is taken out of the mold as compared with the case where the composite member (grip) is molded alone. Thus, the composite member (grip) can be easily taken out.
Further, since the composite member (grip) is not in contact with the core pin 31, it does not adhere to the core pin 31. As a result, the composite member (grip) can be taken out without generating wrinkles or the like. Even when a softer composite member (grip) is molded, the composite member (grip) can be taken out from the mold in a good state.

  The composite member molding method and composite member according to the present invention are widely used in all fields where plastic members are used in addition to writing instrument grips, tags, telephone operation buttons, game machine operation levers and keyboard keys. It is what

FIG. 1 is a view showing a grip as an embodiment of the present invention, and is a partial cross-sectional view of a ballpoint pen with a grip attached thereto. 2A and 2B are views showing the grip shown in FIG. 1, wherein FIG. 2A is a longitudinal sectional view of the grip, and FIG. 2B is a transverse sectional view of the grip. FIG. 3 is a partial cross-sectional view showing a manufacturing process of the grip shown in FIG. 4A and 4B are views showing a modification of the embodiment according to the present invention, in which FIG. 4A is a perspective view, FIG. 4B is a plan view, and FIG. 4C is a cross-sectional view taken along line II of FIG. FIG. 5 is a view showing a modification of the embodiment according to the present invention, in which (a) is a perspective view, (b) is a plan view, (c) is a sectional view taken along line II-II in (b), and (d). ) Is a schematic view showing a production method. FIG. 6 is a diagram showing a third embodiment, and is a schematic sectional view showing a case where the composite member shown in FIGS. 1 to 3 is directly formed on a substrate. FIG. 7 is a sectional view showing a conventional composite member. FIG. 8 is a sectional view showing a conventional composite member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ball-point pen 6 Grip 6a Convex part 6b 1st member 6c 2nd member 7 Mold 8 Mold 10 Mold 10a Concave 11 1st member 12 2nd member 13 1st member 14 2nd member 20 Gold Mold 21 Core pin 22 Mold 23 Mold 23a Recess 30 Base material (shaft tube)
G Gate

Claims (10)

In the molding method of the composite member for molding the composite member composed of the first member and the second member on the base material,
A thermoplastic material that is a first member is melt-injected onto the surface of a base material made of a thermoplastic material, and the first member is brought into close contact with the surface of the base material and molded into a laminated state,
The thermoplastic elastomer softer than the first member as the second member, melt injection between the substrate and the first member in a close contact state,
A molding method for a composite member, wherein the second member is filled and molded into a predetermined shape so that the first member is elastically deformed by the injection pressure and has an initial elastic force. In the composite member composed of the first member and the second member formed on the base material,
A first member made of a thermoplastic material formed on the surface of a base material made of a thermoplastic material, and a thermoplastic elastomer softer than the first member housed between the base material and the first member A second member,
The composite member, wherein the first member is elastically deformed by a second member accommodated between the base material and the first member and has an initial elastic force. In the molding method of the composite member for molding the composite member composed of the first member and the second member,
The thermoplastic material that is the first member is melt-injected into the mold, and the first member is molded in close contact with the mold,
A thermoplastic elastomer that is softer than the first member is used as the second member, and is melt-injected between the mold in close contact with the first member,
The second member is filled between the mold and the first member and molded into a predetermined shape so that the first member is elastically deformed by the injection pressure and has an initial elastic force. A method for forming a composite member. In the composite member consisting of the first member and the second member,
A first member made of a thermoplastic material formed by injection molding, and a second member made of a thermoplastic elastomer softer than the first member, formed by injection molding on the first member,
The first member is a composite member that is elastically deformed by the second member and has an initial elastic force.   The 100% modulus of the first member is 0.1 to 10 MPa, and the maximum elongation ratio of the first member is 10% to 90%. The composite member described in 1.   The 100% modulus of the first member is 0.1 to 10 MPa, and the maximum elongation percentage of the first member is 10% to 90%. The molding method of the composite member described in 2.   6. The 100% modulus of the first member is higher than the 100% modulus of the second member, and the hardness of the first member is greater than the hardness of the second member. Composite member.   The 100% modulus of the first member is higher than the 100% modulus of the second member, and the hardness of the first member is greater than the hardness of the second member. A method for forming a composite member.   8. The composite member according to claim 2, wherein the composite member including the first member and the second member is a grip for a writing instrument. .   The composite member comprising the first member and the second member is a grip for a writing instrument, wherein the composite member according to any one of claims 1, 3, 6, and 8 is used. Molding method.

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