JPH05185880A - Molding for vehicle - Google Patents

Abstract

PURPOSE:To form an urethane paint film of good adhesive property only by means of primer process by forming the core part out of olefine series thermoplastic elastomer(TPE) and the surface layer part out of polyamide series TPE, and constituting the polyamide series TPE out of specific components. CONSTITUTION:The core part 1a of a molding main body is formed out of olefine series thermoplastic elastomer(TPE), and the surface layer part 1b is formed out of polyamide series TPE. The polyamide series TPE is constituted of ethylenepropylene rubber to be a soft segment, polyamide to be a hard segment, and compatibilizer. The compatibilizer is ethylenepropylene rubber chemically modified out of any one sort of or over two sort of monomer among unsaturated epoxy monomer, unsaturated hydroxy monomer, unsaturated carboxylic acid, and multifunctional monomer containing one or more amino group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding for a vehicle in which a molding body is composed of a core portion and a surface layer portion and is made of TPE. In particular, the present invention is suitable for a vehicle molding, such as a protector molding for an automobile, which is required to be lightweight and aesthetic.

[0002] In the present specification, the unit of composition is a unit of weight unless otherwise specified.

JIS used without description in this specification
The following is a list of abbreviations defined by ISO, ISO and ASTM.

(I) Abbreviation of plastic PVC ... Polyvinyl chloride, PP ... Polypropylene, PE ... Polyethylene, PA ... Polyamide, (ii) Abbreviation of rubber EPM ... Ethylene propylene rubber (binary copolymer system), EPDM ... Ethylene propylene Rubber (non-conjugated diene copolymer system), IIR ... butyl rubber,

[0005]

2. Description of the Related Art Usually, a molding as described above is mainly formed of a soft PVC molding material which is low in cost, has good workability, and can be easily adjusted to a required hardness and flexibility. However, soft PVC has a large specific gravity of 1.16 to 1.35 (see "Chemical Handbook Applied Chemistry II Materials Edition" page 1130), which is not desirable from the viewpoint of weight reduction. Therefore, the thermoplastic resin (hereinafter referred to as "TPE") has the smallest specific gravity (density) of 0.88 as a material for forming the molding body ("Polymer Material One point-19 Elastomer" edited by the Society of Polymer Science, (See page 67) and it is conceivable to use TPO which is excellent in weather resistance and cold resistance.

[0006]

However, although the olefinic TPE has good weather resistance, it is inferior in scratch resistance and abrasion resistance. Therefore, when applied to a molding, it is inevitable to paint the molded product.

At this time, since the olefin-based TPE is a non-polar material, the urethane finish coating is
In order to form a good adhesion on a molded article made of PE, it was necessary to carry out as follows.

[0008] That is, after the mold-molded product after release from the mold, it is surface-cleaned with a chlorine-based solvent (unfavorable from the viewpoint of working environment and ozone layer depletion), and then subjected to an undercoat coating process using a chlorinated polyethylene-based primer or the like, Top coat with a general-purpose urethane paint (which has excellent scratch resistance).

Further, even if the molding body made of olefin-based TPE is finished with a urethane-based coating film, it is still difficult to obtain sufficient surface hardness (which affects scratch resistance) and heat resistance. Problems may also occur in wax remover resistance (hydrocarbon solvent resistance).

In view of the above, the present invention provides a lightweight vehicle molding containing an olefinic TPE as a main component of a TPE molding material, even if the molded product body after mold release is not washed with a chlorine-based solvent. It is an object of the present invention to provide a vehicle molding capable of forming a urethane coating film having good adhesion on the surface of the molding body through the above.

Another object of the present invention is olefinic TPE.
(EN) A lightweight vehicle molding mainly composed of TPE molding material, which is excellent in scratch resistance, heat resistance, and wax remover resistance.

[0012]

A vehicle molding according to the present invention solves the above problems by the following constitution.

The molding body is composed of a core portion and a surface layer portion.
A molding for a vehicle made of PE, wherein the core portion is made of olefinic TPE and the surface layer portion is made of polyamide TPE, and the polyamide TPE is an EPR that is a soft segment. , A PA serving as a hard segment, and a compatibilizer.

[0014]

[Detailed Description of Means] Next, a detailed description will be given of each configuration of the above means.

A. In the molding of the present invention, the main body 1 has the core portion 1a.
And a surface layer portion 1b, and is formed of TPE as a precondition.

(1) The hardness of the core portion 1a is H _S (JIS A) 50-9.
The hardness of the surface layer portion 1b is Shore D (ASTM D
2240) It is desirable to design the material so that it is 30 to 70. Since the core portion 1a can share the flexibility of the entire molding and the surface layer portion 1b can share the wear resistance and scratch resistance, it is easy to design a higher performance molding. Here, the thickness of the surface layer portion 1b is set to 0.05 to 1 mmt. If the surface layer portion is too thin, it is difficult to obtain the excellent scratch resistance, heat resistance, and wax remover resistance that are the object of the present invention in the molding body. On the other hand, if the surface layer portion 1b is too thick, the polyamide-based TPE, which is the material for forming the surface layer portion, is more expensive (about 1.5 to 3 times) than the olefin-based TPE, which is a cost disadvantage.

In the illustrated example, the insert 3 is embedded to limit thermal expansion and contraction of the molding. The material of the insert 3 is usually made of steel plate. In this case, in order to secure the bonding strength with the molding body 1, the insert portion 3
A coupling hole is formed in.

A double-sided tape 5 is attached to the molding body 1 for convenience of attachment to the vehicle body. The double-sided tape 5 is a support 7 made of polyethylene foam sheet or the like.
Having pressure sensitive adhesive layers 9 and 9 on both sides thereof, and the pressure sensitive adhesive layer 9 on the outer surface side
Are protected by a release paper 11.

The core portion 1a of the molding body 1 may be of a foam type or a tubular body in order to increase the weight reduction effect of the molding.

(2) TPE is composed of a soft segment (soft layer) having rubber elasticity in the molecule and a hard segment (hard layer) which is incompatible with the soft segment and prevents plastic deformation, The hard segment is characterized by being plasticized by heating and rehardened by cooling. Therefore, it can be processed by a usual thermoplastic resin molding machine and scrap can be reused, and it is expected as a polymer material replacing rubber in a wide range of fields.

B. The vehicle molding of the present invention is characterized in that the core is made of olefinic TPE.

(1) Here, the olefinic TPE means that the hard segment is made of one or more crystalline polymers selected from PP, ethylene copolymerized PP and PE, and the soft segment is made of EPM, EPDM and an amorphous compound selected from two or more selected from IIR. And olefinic TP
E includes both a blend type and a polymerization type.

The ratio of the hard segment to the soft segment of the olefin-based TPE is the former / the latter = 30/70 to 70/30 (preferably 40 /
60 to 60/40). If the ratio of the hard segment is too large, it is difficult to impart flexibility to the core and the hardness becomes too high. On the other hand, if the ratio of the soft segment is too large, the physical properties such as strength of the core part deteriorate.

The propylene content of the EPM or EPDM which is the soft segment is 10 to 40% (desirably 15 to 25%).

When the olefinic TPE is a blend type, it is desirable to use a dynamic vulcanization type in which the soft segment is an organic peroxide which is partially crosslinked or completely crosslinked during kneading. When the soft segment is partially cross-linked or completely cross-linked, the oil resistance and heat resistance of the molded product and the physical properties of the molded product such as tensile strength and tear strength are increased compared to when the soft segment is not cross-linked. is there.

(3) In order to use the above olefinic TPE as a molding material, the above olefinic TPE which is the above polymer is
Usually, a mixture of a plasticizer (for example, process oil) and, if necessary, an auxiliary material such as a coloring agent (for example, carbon black) is kneaded and prepared into pellets.

Here, the physical properties of the molded product are
Hardness (JIS A) of 50 to 90, tensile strength (JIS K 630
1, T_B ) Is 100 kgf / cm² Or more (preferably 130
kgf / cm ² Above), the olefinic TPE and
Select the type and amount of other auxiliary materials. Furthermore, extrudability
From, material flow MFR (ASTM D 1238) 0.5g / 10min
It should be above (preferably 4g / 10 minutes or more)
Fin-based TPE and other auxiliary materials are selected.

Specific examples of the above-mentioned olefin-based TPE are "Thermoran" (Mitsubishi Petrochemical Co., Ltd.), "Milastomer" (Mitsui Oil Co., Ltd.), and "Santoprene" (Mitsubishi Monsanto). From commercially available products, select appropriately and cut into pieces.

C. Another feature of the molding of the present invention is that the surface layer portion 1b is formed of a polyamide TPE.

(1) As a polyamide TPE, EPR as a soft segment and PA as a hard segment
And a compatibilizer.

The ratio of the hard segment and the soft segment of the polyamide TPE is usually the former / the latter = 50.
/ 50 to 90/10 (desirably 60/40 to 85/1
5). When the ratio of the hard segment (PA) is too large, it becomes difficult to obtain the fusion bond strength with the core portion 1 formed of the olefinic TPE, and the hardness becomes too high, which is originally required for the molding. Problems tend to occur in buffer performance. On the other hand, if the ratio of the soft segment (EPR) is too large, it is difficult to expect improvement in heat resistance, surface hardness, and wax remover resistance of the molding, which is the object of the invention.

The compounding amount of the compactor is
The above EP varies depending on the type of the compactor.
Usually, 5 to 20 with respect to 100 parts of the total amount of R and PA.
Part.

The EPR is a concept including the EPM / EPDM.

Examples of PA include 6-nylon, 6,6-nylon, 11-nylon and 12-nylon.

(2) Here, the compactor (Comp
The term "atiblizer" refers to a polymer that is incompatible with each other, here, PA and EPR, in order to mix them, and that exhibits an action equivalent to that of a surfactant in the case of a water-oil emulsion ("polymer"). Material One point-12 Polymer Alloy ", Polymer Society of Japan, pp. 39).

The compoundizer may be any one of unsaturated epoxy monomers, unsaturated hydroxy monomers, unsaturated carboxylic acids, and polyfunctional monomers containing one or more amino groups, or A modified EPR (hereinafter abbreviated as "M-EPR") chemically modified with two or more kinds of monomers is desirable.

Specifically, JP-A-64-85206,
Japanese Unexamined Patent Publication No. 1-259047, 259048, 259049
It is possible to use the M-EPR described in Japanese Patent Publication No.

That is, the TPO is blended in an amount of 0.01 to 10 parts of the unsaturated monomer having the specific functional group with respect to 100 parts of the total amount of the hard segment component (PP etc.) and the soft segment component (EPDM etc.). The blended product is dynamically heat-treated in the presence of an organic peroxide to partially crosslink the soft segment component.

Next, the above functional monomers are not particularly limited, but the following examples are also preferable.

Unsaturated epoxy monomer: glycidyl methacrylate, glycidyl acrylate.

Unsaturated hydroxy monomer: hydroxypropyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate.

Examples of the unsaturated carboxylic acid include maleic acid, bicyclo [2,2,1] hept-2-ene-5,
6-dicarboxylic acids or their anhydrides are preferred.

Examples of the polyfunctional monomer having an amyl group include unsaturated amides such as allylamide, acrylamide and methacrylamide, unsaturated amines such as vinylamine and allylamine, and various amino alcohols, diamines, polyamines and acid amides. -Hydrazine and aromatic amines can be used.

(3) In order to use the above polyamide TPE as a molding material, the above polyamide TPE which is the above polymer is added to
Usually, a mixture of auxiliary materials such as a plasticizer (for example, paraffin wax type) and a coloring agent (for example, carbon black, brown pigment) and the like is kneaded and prepared into pellets.

Specific examples of the polyamide TPE include "1018I" (Ube Industries, Ltd.) "Zytel.
Among the products manufactured and sold by each company under the product names of "ST 801" (Dyupon Co., Ltd.), "Tore UTN 141" (Tore Co., Ltd.), and "Leona TR250" (Asahi Kasei Co., Ltd.),
It can be appropriately selected and used.

D. The molding method of the molding is extrusion molding or injection molding. Since the molding body 1 includes the core portion 1a and the surface layer portion 2a, two-color extrusion molding or two-color injection molding is used. The molding conditions are: extrusion material temperature: 240 to 270 ° C. in the case of extrusion molding, injection material temperature 250 to 280 ° C., molding pressure of 100 to 200 kgf / cm ^{2 in} the case of injection molding.

Then, using the above-mentioned general-purpose olefin TPE molding material and the above polyamide TPE molding material,
The molding body molded as described above is painted.

That is, the mold body after release is washed with a water-based or alcohol-based solvent and then primed with a primer,
Apply top-coat paint (usually urethane type). The coating method is not particularly limited, but spray coating or dip coating is used. The coating film formed on the surface of the molding body thus produced has sufficient coating adhesion strength for practical use, as will be shown in Examples below, without using a chlorine-based solvent as a cleaning agent.

[0049]

The operation and effects of the present invention have the following operations and effects due to the above-described structure.

(1) The present invention uses an olefinic TPE as a TP.
In a lightweight vehicle molding that is mainly made of E molding material,
Even if the molded product body after release from the mold is not washed with a chlorine-based solvent, a urethane coating film having good adhesion can be formed on the surface of the molding body through the primer treatment.

(2) The vehicle molding of the present invention is a lightweight vehicle molding mainly composed of an olefinic TPE as a TPE molding material, and is excellent in scratch resistance, heat resistance, and wax remover resistance.

[0052]

EXAMPLES Examples will be described below in order to better understand the present invention.

(1) Olefin-based TPE molding material: composition formulation EPDM: 60 parts, PP: 30 parts, M-EPR: 10
Part, process oil: 30 parts Physical property specific gravity: 0.876 (JIS K 7112), hardness (JIS A): 71 (JIS K 6301), 100% tensile stress: 27 kgf / cm ² (JIS K 6301), tensile strength: 49kgf / cm ² (JIS K 6301), Tear strength (B type): 30 (JIS K 6301), Compression set (70 ° C × 22h): 68%, (2) Polyamide TPE molding material: Composition prescription EPDM : 20 parts, PA: 70 parts, M-EPR: 10
Part, physical properties Specific gravity: 1. (JIS K 7112), hardness (Shore D): 37 (ASTM D 2240), tensile strength: 360 kgf / cm ² (JIS K 6301), tear strength (B type): 50 (JIS K 6301), compression set (70 ° C x 22 h): 49% (JIS K 630
1), (3) Molding / painting of molding body Using the above-mentioned olefin-based / polyamide TPE molding materials, a molding body having the shape shown in Fig. 1 (excluding coating film) was subjected to two-color extrusion molding. Molding condition is effective L / D = 2
2. Die temperature 250 ℃, extrusion speed 400mm / min.
The insert 3 was made of steel plate.

Subsequently, the mold body after the mold release is washed with isopropyl alcohol, and then a chlorinated polyolefin-based primer ("P801" manufactured by Mitsui Petrochemical Co., Ltd.) is sprayed to a coating film thickness of 5 to 20 μm. It was applied. After the coated molding is left at room temperature for 3 minutes to dry the undercoat coating film, the urethane coating (“Solex 26
0 "manufactured by Kansai Paint Co., Ltd.) was applied by spraying so as to obtain a coating film thickness of 30 μm.

(4) Physical Property Test and Test Results The moldings of the above examples were tested for the following items.

Coating film peeling test Test method: After coating, after standing for 24 hours at room temperature, a goggles peeling test was conducted at three points on both sides and the upper surface of the molding.

Results: The values were 0/100 at all three points, indicating that the coating film had sufficient adhesion strength.

Adhesive strength between core and surface layer: Method: The adhesive strength between the core and surface layer was determined by a 180 ° peel test (pulling speed 25 mm / min).

Results: The adhesive strength between the core and the surface layer is
It was 35 kgf / 2.54 cmc and had sufficient practical strength.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view showing an example of a molding to which the present invention can be applied.

[Explanation of symbols]

 1 mall body, 3 inserts, 5 double-sided tape,

Claims (3)

[Claims] 1. The molding body comprises a core portion and a surface layer portion,
A molding for a vehicle, which is formed of a thermoplastic elastomer (hereinafter abbreviated as "TPE"), in which an upper coating film is formed on the upper surface of the molding body through a primer treatment, and the core portion is an olefin-based molding. While being formed of TPE,
The surface layer portion is formed of a polyamide-based TPE, and the polyamide-based TPE is composed of ethylene propylene rubber (hereinafter abbreviated as “EPR”) that is a soft segment, PA that is a hard segment, and a compatibilizer. A vehicle mall characterized by the following. 2. The polyfunctional monomer according to claim 1, wherein the compatibilizer is an unsaturated epoxy monomer, an unsaturated hydroxy monomer, an unsaturated carboxylic acid, and one or more amino groups. A vehicle molding, which is an EPR chemically modified with any one or more of the above monomers. 3. The hardness according to claim 1, wherein the hardness of the core portion is H.
_S (JIS A) is 50 to 90, and the hardness of the surface layer portion is Shore D (ASTM D 2240) 30 to 70.