JPH04145208A - Synthetic resin made clip - Google Patents

Abstract

PURPOSE:To obtain a clip with appropriate elastic resiliency so as to prevent damage of the other material by forming a clip base body of resin material made of thermoplastic polyester as main material, and molding resin material made mainly of soft thermoplastic polyester elastomer compositely on the surface or surface fitting part of the clip base body by a double molding method or a bicolor molding method. CONSTITUTION:A basic molded body 1 is formed of resin material made of thermoplastic polyester as main material by primary molding. Secondary material made of polyester elastomer as a main component is then molded/fused on the flexibility requiring surface part or fitting sliding part of the basic molded body 1 by a double molding method, a bicolor molding method, or the like. A clip thus formed is lightweight and has appropriate elastic resiliency so as to prevent damage of the other material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a synthetic resin clip for attaching and locking an article or a component to a mating member in an automobile or the like by utilizing elastic repulsive force.

[Prior Art and its Problems] In automobiles and other equipment, instruments, etc., there are many uses for lips, such as attaching and locking articles or parts to mating materials using elastic repulsive force. However, if such a clip is made of a hard material, whether it is a metal one or a synthetic resin one, repeated use will cause the mating material to deteriorate, for example, if the mating material to be locked is soft. This is not preferable because it may cause damage to the mating material during locking, or if the surface of the mating material is painted, the paint may peel off. In order to avoid this problem, a soft material such as a rubber product is interposed between the clip and the mating material, but this is structurally complicated. Further, although a flexible soft resin is sometimes used as the clip material, such soft resin materials generally have a low elastic modulus, so there are problems such as a weak locking force as a clip.

In order to solve these problems, we applied double molding or two-color molding (hereinafter collectively referred to as two-color molding) of soft resin material on the surface of the molded product whose primary material is hard resin material or on the locking fitting part of the surface. Attempts have also been made to create a clip that solves the above problems by composite molding using a composite molding method (referred to as heavy molding, etc.). There are composite clips, or composite clips that are made by primary molding polyacetal resin and double molding the surface fitting part with urethane elastomer, but even in such composite molded products, it is generally repeated. When used, the bonding surfaces of the primary and secondary molding materials tend to peel off and the appearance is poor, and depending on the material, when used in environments where gasoline, oils, and waxes may adhere, Due to their adhesion, problems such as crank formation on the surface and surface erosion occur over time.

[Means for Solving the Problems] In order to solve the above problems, the present inventors have developed a method using two types of resin materials, primary and secondary, when producing a clip as a composite molded product using a double molding method or the like. After extensive research into combinations, we have completed the present invention.

That is, the present invention molds a clip base using a resin material mainly consisting of thermoplastic polyester as the 4 primary material,
It is a synthetic resin crimp that is integrally composite molded by double molding or two-color molding using a resin material mainly consisting of soft thermoplastic polyester elastomer as a secondary molding material on the surface or the fitting part of the surface. .

The present invention uses a resin material mainly composed of thermoplastic polyester as the primary material to form a base body of the clip that has an elastic repulsion force, and then this surface or a portion that is slidably fitted during locking. A clip made of synthetic resin is made by using a resin material mainly composed of a soft thermoplastic polyester elastomer as a secondary material to form a flexible part by a double molding method, etc. It is characterized by being integrally composited using a combination of specific primary and secondary resin materials, and has appropriate elasticity as a clip.
Moreover, even when the clip is repeatedly locked, fitted, and removed, it does not damage the mating material, and because of its composite integration, the secondary material of the clip itself does not take into account the adhesive or anchor shape (but has sufficient welding strength). The clip does not peel off at the interface, and will not deteriorate, crack, or roughen the surface even in usage environments where it comes into contact with gasoline, oils, and waxes. This makes it possible to provide the following information.

The primary materials and secondary materials that characterize the present invention will be described below.

The resin material used as the primary material may be any resin material mainly composed of thermoplastic polyester.

Specifically, polyalkylene terephthalate (alkylene group has 2 to 4 carbon atoms) typified by polybutylene terephthalate and polyethylene terephthalate, and known copolymers containing these as main components, or other thermal It may also contain a small amount of plastic resin.

Such 4 primary resin materials need to be fused with a secondary material in secondary molding, so materials with extremely high melting points are not thermally decomposed because it is necessary to raise the resin temperature of the secondary material even higher in secondary molding. It is preferable to select a material with a melting point of 10° C. or lower, since this may easily cause problems in molding due to an abnormal decrease in viscosity. Particularly preferably, the temperature is 220°C or lower.

From this point of view, polybutylene terephthalate or a copolymer or mixture containing polybutylene terephthalate as a main component is preferred as the primary material. The type of copolymer component is not particularly limited, and known copolymer components may be used, but the amount introduced is generally preferably 40% or less from the viewpoint of elastic modulus.

In addition, as a primary material, inorganic fillers may be used to reinforce the mechanical properties, heat resistance (heat distortion temperature), dimensional accuracy, etc., and especially when it is necessary to increase the elastic modulus of the final molded product. May be blended.

Inorganic fillers include, but are not limited to, fibrous reinforcing agents such as glass fiber and carbon fiber, glass flakes, glass powder, glass peas, mica, calcium carbonate, and other granular or plate-like fillers. Rather, any known inorganic filler can be selectively used to impart the desired physical properties. Two or more types of inorganic fillers may be used in combination.

Originally, the clip of the present invention generally utilizes elastic repulsive force, and since such elasticity is determined by the bending elastic modulus of the primary molded product, the selection of the material composition of the subsequent molded product is determined by the desired clip. - The type and amount of the thermoplastic polyester resin used as the blow molding material, the type and amount of the copolymer component, the type and amount of other auxiliary thermoplastic resins, and the inorganic filler. It is possible to adjust according to the purpose depending on the type and amount of the agent, but -JI
G has a bending elastic modulus of 10,000 due to its function as a clip.
It is desirable that it is at least kg/d.

Next, the resin material for forming the flexible surface part or fitting part of the composite molded product as the clip of the present invention is mainly composed of thermoplastic polyester elastomer, and for the purpose of imparting flexibility, - For fishing, the bending modulus is 7000.
kg/cm or less is preferable. More preferably 50
00 kg/ctil or less.

The main polyester elastomer constituting the secondary material may be any random or block copolymer polyester having a soft segment such as polyoxyalkylene glycol ester as a constituent unit, and any commercially available product or prepared product may be used. You can.

A typical example is a polyester copolymer having polyoxyethylene glycol or polyoxybutylene glycol phthalate ester as a soft segment and butylene terephthalate or ethylene terephthalate as other constituent units.

Also, a small amount of other thermoplastic resin may be supplementarily blended. The degree of flexibility of the surface of the clip depends on the content of soft segments, such as polyoxyalkylene glycol ester segments, in the polyester elastomer constituting such secondary material, the molecular weight of the segments, other copolymer components, or other auxiliary components. The desired value can be adjusted by appropriately selecting the additive resin and the like.

The clip of the present invention is made by covering a base molded product that is primarily formed using the above-mentioned primary material with a secondary material by a double molding method or the like, targeting the surface area or the fitting sliding area that requires flexibility. The resin temperature of the secondary material in secondary molding must be at least higher than the melting point of the primary material, and preferably the resin temperature is 10 to 70°C higher than the melting point of the primary material. Desirable for strengthening the garment.

〔Effect of the invention〕

The synthetic resin clip of the present invention is composite-molded by a double molding method or the like by selectively using two specific polyester resin materials as described above, and (1) the clip as a whole has an appropriate elastic repulsion force. (2) The surface or the mating locking portion on the surface remains flexible and does not damage the corresponding mating material, and (3) - The fire-formed base and the flexible surface portion remain strong. It fuses and is difficult to peel off (4) It also has excellent mechanical properties, heat resistance, and chemical resistance, and is particularly resistant to deterioration when attached by gasoline, oils, waxes, etc. ) It is also lightweight, and is suitable as a lip because it is repeatedly attached and detached from automobiles, other equipment, appliances, etc.

〔Example〕

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto.

Examples 1 to 5, Comparative Examples 1 to 3 As a primary molded product, a clip base having the shape shown in Figure 1 was injection molded using the primary resin material shown in Table 1, and then the secondary resin shown in Table 1 was injected into this. A portion of the surface of the material was composite molded using the double molding method to create a clip, as shown in Figure 2.

For this clip, we used a painted steel plate with a fitting hole as the mating material, and repeated locking and disconnecting a certain number of times.
We checked for damage to the paint on the mating material and damage to the clip itself (separation of secondary material, etc.).

In addition, the clips were left in gasoline at 60° C. for a certain period of time, and surface deterioration (occurrence of cranks, tendency to roughen the surface, tendency to peel off secondary materials, etc.) was observed and evaluated.

The results are shown in Table 1.

The primary materials and secondary materials used for the composite molded product are as follows.

Note-1) 4 Primary material A-1: Polybutylene terephthalate resin (melting point 225
C1 flexural modulus 26000) cg/d) A-2: Polybutylene terephthalate copolymer resin containing a small amount of polybutylene isophthalate (melting point 205" C1 flexural modulus 26000 kg)
/cd) A-3: Polybutylene terephthalate copolymer (melting point 1
85℃, flexural modulus 15000 kg/cii) A-4
: Polycarbonate (melting point approx. 240℃ 1 flexural modulus 23
000 kg/aj) 8-5: Polyacetal resin (melting point 177°C, flexural modulus 27000 kg/d) Note-2) Secondary material B-1: Polyester elastomer (melting point 182°C, flexural modulus 720 kg/d) cffl) B-2: Polyester elastomer (melting point 198°C, flexural modulus 1100 kg/c+11) B-3: Polyamide elastomer (melting point 170°C, flexural modulus 3500 kg/cd) B-4= Polyurethane elastomer (melting point 160°C,
Flexural modulus 1000kg/c-)

[Brief explanation of drawings]

Figure 1 is a diagram showing the shape of a primary molded product as an example of the clip of the present invention, (a) is a plan view, (b) is (a)
(C) is a bottom view. Figure 2 is a diagram showing an example of the composite molded clip of the present invention (composite molded by secondary molding using Figure 1 as a base).
a) is a plan view, (b) is a sectional view taken along line X-X of (a), (C
) is a bottom view. 1. Primary molding section 2: Secondary molding section

Claims (1)

[Claims] 1. A clip base is molded using a resin material mainly composed of thermoplastic polyester as the primary material, and a soft thermoplastic polyester elastomer is mainly used as the secondary molding material on the surface or the fitting portion of the surface. A synthetic resin clip that is integrally composite molded using a double molding or two-color molding method using a resin material. 2. The synthetic resin clip according to claim 1, wherein the resin material mainly composed of thermoplastic polyester constituting the primary material has a bending elastic modulus of 10,000 kg/cm^2 or more. 3. Claim 1 or 2, wherein the resin material mainly composed of thermoplastic polyester constituting the primary material has a melting point of 230°C or less.
Synthetic resin clip as described. 4 The thermoplastic polyester constituting the primary material is polyalkylene terephthalate (alkylene group has 2 to 4 carbon atoms).
) or a copolymer or mixture mainly composed of the same. 5. The synthetic resin clip according to any one of claims 1 to 4, wherein the resin material mainly composed of polyester elastomer used for secondary molding has a bending elastic modulus of 7000 kg/cm^2 or less.