JP3713546B2 - Automotive trim - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automobile trim in which a decorative layer formed of a TPE compound is integrated with a design surface of a trim body, and the trim body is formed of a rubber compound.
[0002]
Here, as a product to which the present invention is applied, a weather strip (trim for automobile) provided with a trim portion and a seal portion will be mainly described as an example. The present invention can be applied to other types of weather strips such as a glass run having a trim portion, and also to an automobile trim having only a trim portion without a seal portion.
[0003]
[Background]
Weather strips are usually manufactured by two-color extrusion (co-extrusion) using a two-color extruder using a solid formulation and a foam formulation EPDM formulation, respectively. The EPDM compound is used because it has good weather resistance and elasticity, low specific gravity, and can contribute to weight reduction. As the vulcanization system of the EPDM blend, a sulfur vulcanization system, which is a general-purpose vulcanization system, is usually used. This is because the sulfur vulcanization system is different from the peroxide vulcanization system, which is the other general-purpose vulcanization system, and can apply hot air vulcanization used for continuous vulcanization of extrudates.
[0004]
And as a formation method of the said decoration layer in a trim part, it laminates | stacks integrally without using an adhesive agent on the trim main body (base | substrate layer) surface by heat sealing | bonding the decoration layer which consists of TPE (compound) in an unhardened state (See U.S. Pat. No. 4,537,825, European Patent 0372745, JP-A-8-230013, etc.). These methods are more productive than conventional methods of cutting a soft thermoplastic resin sheet and bonding them with an adhesive to form a decorative layer. Here, the reason why the decorative layer is formed of TPE is to ensure the ease of bending when the weather strip trim is assembled to the body flange or the like.
[0005]
However, it has been found that the following problems occur in the decorative layer in the weather strip having a configuration in which the decorative layer formed by the above method is heat-sealed and integrated with the trim body surface.
[0006]
(1) The decorative layer is less likely to exhibit a required color due to the influence of the ground color of the trim body (base layer). This is because the solid-form EPDM compound that forms the trim body contains a large amount of carbon black, which is a rubber reinforcing agent, and has high blackness (saturation).
[0007]
(2) The decorative layer tends to yellow due to the influence of sunlight over time. It is confirmed that there is a high possibility that the cause is a shift of the sulfur vulcanizing agent (sulfur and its vulcanization accelerator) in the vulcanized rubber to the decorative layer (Japanese Patent Laid-Open No. 9-193299). reference).
[0008]
The influence of the ground color and the yellowing degree in the decorative layer become more prominent than when the color of the decorative layer is light or light. In other words, a weather strip (trim) having a configuration in which the decorative layer is heat-sealed to the trim main body is difficult to meet the demand for light and light colors of the decorative layer.
[0009]
In order to make it difficult for yellowing to occur in the decorative layer, in the above-mentioned patent publication (Japanese Patent Laid-Open No. 9-193299), the TPE compound forming the decorative layer contains hydrotalcite as a discoloration inhibitor. It has been proposed to let
[0010]
However, hydrotalcite is currently expensive and increases the overall material cost of the weatherstrip. Therefore, other measures against yellowing of the decorative layer not based on hydrotalcite are desired.
[0011]
In view of the above, the present invention provides an automotive trim in which the decorative layer can reduce the influence of the ground color (black) of the trim body, and further can reduce the influence of the color-causing agent migrating from the trim body. With the goal.
[0012]
[Means for Solving the Problems]
As a result of diligent development efforts to solve the above problems, the present inventors have found that when the decorative layer is heat-sealed to the trim body via a heat-sealing layer having a predetermined thickness, We discovered that even if the wall thickness of the layer does not hinder the flex flexibility when the trim is mounted on the body, the influence of the above-mentioned ground color and the yellowing degree can be reduced to a practical level, and we have come up with an automotive trim with the following configuration. .
[0013]
One aspect of the present invention is that a decorative layer formed of a thermoplastic elastomer compound (TPE compound) having an olefinic thermoplastic elastomer as a base polymer is heat-sealed and integrated with the design surface of the trim body, body ethylene -α- olefin - in automotive trim molded with rubber compound non-conjugated diene copolymer rubber (EPDM) based, the decorative layer is foamed elastomer, further, the decorative layer The decorative layer is heat-sealed and integrated with the trim body via a heat-sealing layer formed of a thermoplastic resin compound based on a low-density polyethylene resin between the trim body and the trim body. It is characterized by being.
[0014]
According to another aspect of the present invention, a colored decorative layer formed of a thermoplastic elastomer blend having an olefinic thermoplastic elastomer as a base polymer is heat-sealed and integrated with the design surface of the trim body, Is an automotive trim molded with a rubber compound based on a sulfur vulcanized ethylene-α-olefin-nonconjugated diene copolymer rubber (EPDM), between the decorative layer and the trim body. The decorative layer is integrated with the trim body through a heat-sealing layer formed of a thermoplastic resin compound based on low-density polyethylene, and the heat-sealing layer is attached to the vehicle body. The thickness is less than the thickness that does not hinder the bending flexibility at the time, and the thickness of the trim body can be concealed, and the thickness is more than the thickness that can prevent the transition of the discoloration-causing agent containing sulfur-based chemicals from the trim body to the decorative layer Thickness Characterized in that it.
[0015]
The low density polyethylene is desirably a linear low density polyethylene, the thickness of the heat sealable layer is usually, 40 to 300, preferably to 80 to 150.
[0016]
Furthermore, when the decoration layer of TPE is a foam, it can be heat-seal-integrated with a trim main body, without crushing the bubble of a foam.
[0017]
[Detailed description of configuration]
Hereinafter, each configuration (solution means) of the present invention will be described in detail. In addition, a blending unit is a weight unit unless otherwise specified.
[0018]
The weather strip 12 (12A) includes a trim portion 14 (14A) and a seal portion 16 (16A) as shown in FIGS.
[0019]
Here, the trim portion 14 (14A) has a U-shaped basic cross section that serves as a flange gripping portion in the illustrated example, but the present invention is applicable to other forms.
[0020]
The trim part 14 (14A) has two pairs of grip lip parts 26, 26 in FIG. 1, one holding lip part 28 in FIG. 2, and three receiving lip parts 30 in the other. is there. In FIG. 2, a concealing lip 36 that conceals the gap between the inner garnish 32 and the vehicle body flange 34 (34 </ b> A) extends from the U-shaped top of the trim portion 14. An insert mandrel 19 is embedded in the trim portion 14 (14A). Hereinafter, the opening trim part weatherstrip attached to the periphery of the door opening part in FIG. 1 will be described as an example, and the corresponding parts in FIG. 2 will be given the suffix “A” and their explanation will be omitted.
[0021]
In the trim part (trim) 14, a solid decorative layer 18 formed of a thermoplastic elastomer compound (TPE compound) is thermally fused and integrated with a design surface of a trim body (hereinafter “base layer”) 20. The base layer 20 has a metal core 19 embedded therein and is molded from a rubber compound. A heat-sealing layer 22 formed of a thermoplastic resin compound is interposed between the decorative layer 18 and the base layer 20, and the decorative layer 18 heats the base layer 20 by the heat-sealing layer 22. It is fused and integrated.
[0022]
The rubber compound for forming the base layer 20 is usually a solid rubber formulation from the viewpoint of ensuring the form retaining property of the trim portion 14. From the viewpoint of weight reduction, a fine foaming formulation (foaming ratio of 1.5 or less) can also be used. The hollow seal portion 16 has a sponge rubber (foam rubber) formulation from the viewpoint of ensuring elasticity and sealing performance.
[0023]
And as a rubber polymer (base polymer) of this rubber compound, ethylene-α-olefin-nonconjugated diene copolymer rubber (EPDM), styrene butadiene copolymer rubber (SBR), chloroprene rubber (CR), etc. In particular, EPDM is preferable from the viewpoint of aging resistance such as light resistance and ozone resistance and weight reduction.
[0024]
Examples of the α-olefin in EPDM include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and the like, and propylene is particularly preferable. Examples of non-conjugated dienes include 1,4-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, and the like.
[0025]
Preferred ethylene-α-olefin copolymer rubbers include ethylene-propylene copolymer rubber, ethylene-propylene-ethylidene norbornene copolymer rubber, ethylene-propylene-dicyclopentadiene copolymer rubber, and the like. .
[0026]
Further, as described above, a sulfur vulcanization system which is a general-purpose vulcanization system is usually used as the vulcanization system of the EPDM compound.
[0027]
Here, the sulfur vulcanizing agent includes a sulfur vulcanizing agent and its vulcanization accelerator. The sulfur-based vulcanizing agent includes an active sulfur releasing organic vulcanizing agent in addition to sulfur. Examples of the active sulfur releasing organic vulcanizing agent include morpholine disulfide, alkylphenol disulfide, organic polysulfide polymer, and sulfur-containing vulcanization accelerators such as thiuram and thiourea. In the present invention, a peroxide vulcanizing agent, a polyamine vulcanizing agent, and the like can be used in combination as necessary.
[0028]
In addition to the above vulcanized chemicals, carbon rubber, process oil, lubricant, inorganic filler, anti-aging agent, and other auxiliary materials are appropriately blended into the rubber compound, kneaded, etc., and the base layer 20 is extruded. A rubber material for molding is used.
[0029]
The vulcanization system of the rubber compound is not limited to the sulfur vulcanization system, and may be another vulcanization system such as a peroxide vulcanization system.
[0030]
As a base polymer of the TPE compound for forming the decorative layer 18 of the present invention, when the base layer (trim body) 20 is formed of a nonpolar rubber compound such as EPDM, both the base layer 20 and the decorative layer 18 are used. In order to make it easy to ensure the heat-sealing property with the heat-sealing layer, non-polar TPE such as olefin-based TPE (TPO) and styrene-based TPE (TPS) is used as in the past.
[0031]
When the base layer is formed of polar rubber such as chloroprene (CR), polar TPE such as vinyl chloride TPE, polyester TPE, polyamide TPE is used.
[0032]
Usually, since the substrate layer is made of EPDM, (1) TPO and (2) TPS which are TPE suitable for combination with EPDM will be described in detail.
[0033]
(1) TPO is usually composed of an olefin resin and an ethylene-α-olefin copolymer rubber (EPR), and the weight ratio of the former / the latter = 10/90 to 90/10, preferably 30/70. ~ 80/20.
[0034]
As the olefin resin, polypropylene is particularly preferable from the viewpoint of weight reduction. Examples of the α-olefin having 2 or more carbon atoms include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 1-decene, 3-methyl-1-pentene, 4- Examples include methyl-1-pentene and 1-octene. As the olefin resin, one having a melt flow rate (MFR; 2.16 kg) is usually in the range of 0.1 to 100 g / 10 min, preferably in the range of 0.5 to 50 g / 10 min.
[0035]
As the ethylene-α-olefin copolymer rubber (EPR), ethylene-α-olefin copolymer rubber (EPM) or ethylene-α-olefin-nonconjugated diene copolymer rubber (EPDM) can be used. Here, as the α-olefin, those in the EPDM of the base layer described above can be used, and propylene is usually used.
[0036]
Further, the weight ratio of ethylene / α-olefin is usually 90/10 to 30/70, preferably 85/15 to 45/55. When ethylene-α-olefin-nonconjugated diene copolymer rubber is used, the content of nonconjugated diene is usually an iodine value of 5 to 40. An ethylene-α-olefin copolymer rubber and an ethylene-α-olefin-nonconjugated diene copolymer rubber may be mixed and used. Oil-extended rubber may also be used.
[0037]
The Mooney viscosity (ML _{1 + 4} 100 ° C.) of the EPR is usually 10 to 350, preferably 30 to 300. If the Mooney viscosity is too low, the mechanical strength such as wear resistance may be inferior. On the other hand, if the Mooney viscosity is too high, the surface of the decorative layer 18 is likely to be uneven and the appearance may be impaired.
[0038]
In the TPE formulation, EPR is appropriately left uncrosslinked or present in a crosslinked state such as partial crosslinking or dynamic crosslinking. This is because, when crosslinked, the solvent resistance and mechanical strength of TPO can be improved.
[0039]
(2) TPS consists of an olefin resin and a vinyl aromatic compound-conjugated diene compound block copolymer or a hydrogenated product of the copolymer, the weight ratio of the former / the latter = 10/90 to 90/10, Preferably, it is 30 / 70-80 / 20.
[0040]
As the olefin resin, the same olefin resin as in the case of TPO can be used.
[0041]
Examples of the vinyl aromatic compound in the copolymer include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, and the like. Among them, styrene is preferable. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and among them, butadiene and isoprene are preferable.
[0042]
The structure of the copolymer is represented by the general formula (AB) _n , A- (BA) _n , B- (AB) _n (where A is a polymer block mainly composed of a vinyl aromatic compound. B is a polymer block mainly composed of a conjugated diene compound, but the boundary between the A block and the B block is not necessarily clearly distinguished, and n is an integer of 1 or more.) Or a linear block copolymer represented by general formula [(AB) _n ] _m -X, [A- (BA) _n ] _m -X, [B- (AB) _n ] _m -X (where A and B are the same as each other, X represents a branching agent residue, and n is an integer of 1 or more and m is an integer of 3 or more). It is a polymer.
[0043]
The number average molecular weight (M _n ) of the copolymer is usually 5,000 to 500,000, preferably 10,000 to 300,000. If it is 5000 or less, the mechanical strength of TPE will be low, and if it is 500,000 or more, the viscosity of the polymerization solution will be high, so it will be necessary to polymerize at a low concentration, and productivity will decrease. The content of the vinyl aromatic compound in the copolymer is preferably 10 to 50% by weight.
[0044]
Although the copolymer may be used as it is, a copolymer obtained by hydrogenation (decreasing double bonds) is preferable from the viewpoint of light resistance, thermal stability and the like. Moreover, you may use together with EPR.
[0045]
The polymer or the hydrogenated product of the polymer is appropriately used in an uncrosslinked state or in a crosslinked state such as full crosslinking or partial crosslinking. In the case of crosslinking, the solvent resistance of TPS is improved and the mechanical strength is increased as in the case of TPO.
[0046]
The TPE formulation must have colorants (pigments and dyes) for decoration, and include inorganic fillers such as talc and calcium carbonate, flame retardants, lubricants, antistatic agents, and anti-aging agents (heat and light resistance). Additives such as stabilizers are added and extruded and kneaded, and then granulated (pelletized) to obtain an extrusion molding material.
[0047]
If necessary, the TPE blend may be blended with a peroxide non-crosslinked hydrocarbon rubber-like substance represented by polyisobutylene, butyl rubber, etc. and / or a mineral oil softener. In addition, the compounding quantity of a mineral oil type softening agent shall be 5-200phr normally.
[0048]
When the base polymer of the base layer 20 and the decoration layer 18 is nonpolar, the base polymer of the thermoplastic resin composition forming the heat-sealing layer 22 is nonpolar heat such as olefin resin or styrene resin. Use plastic resin. Further, when the base polymer of the base layer 20 and the decorative layer 18 is a polar polymer, a polar thermoplastic resin such as a vinyl chloride resin, a polyester resin, or a polyamide resin is used. This is for ensuring heat-fusibility.
[0049]
Examples of the olefin resin include polyethylene (PE), polypropylene (PP), and a copolymer of propylene and an α-olefin having 2 or more carbon atoms. Among these, low density polyethylene (LDPE) is preferable because of its low melting point and flexibility, and linear low density polyethylene (LLDPE) is particularly preferable because of its excellent heat resistance and mechanical strength. Incidentally, the melting temperatures of high pressure polyethylene (low density polyethylene), medium pressure polyethylene (medium density polyethylene), and low pressure polyethylene (high density polyethylene) are 98 ° C., 120 ° C., and 124 ° C., respectively. (See Plastic Processing Technology Handbook Editorial Board, “Plastic Processing Technology Handbook New Edition”, published by Nikkan Kogyo Shimbun, December 20, 1977, p.713).
[0050]
The thermoplastic resin composition includes those composed of a thermoplastic resin alone, but in order to ensure fluidity and adhesiveness at the time of melting, a softener (plasticizer, process oil, lubricant, etc.) and an adhesive (tackifier) ) Furthermore, when additives such as anti-aging agents are appropriately added and blended, as in the case of the TPE blend, these agents are added to the thermoplastic resin, extruded and kneaded, and then granulated (pelletized). Thus, an extrusion molding material is obtained.
[0051]
And the heat sealing | fusion layer 22 in this invention shall have the thickness which does not inhibit the bending flexibility at the time of the vehicle body attachment of a weather strip (trim). The thickness of the heat-fusible layer 22 is such that the background color of the base layer 20 is concealed, and further the migration (migration) of the discoloration-causing agent containing a sulfur-based chemical from the base layer 20 to the decorative layer 18 is prevented. Determined from balance.
[0052]
For example, in the case of a combination of the base layer 20: EPDM, the thermal fusion layer 22: LDPE, and the decorative layer 18: TPO, the thickness of the thermal fusion layer 22 is 40 to 300 μm, preferably 80 to 150 μm. If the thickness of the heat-fusible layer 22 is too thin, it is difficult to ensure the above-described background color concealing ability or discoloration drug migration inhibiting ability. On the other hand, if the thickness of the heat sealing layer 22 is too large, it becomes difficult to ensure bending flexibility at the time of mounting the vehicle body.
[0053]
In addition, the wall thickness of the decoration layer 18 shall be 200-1000 micrometers normally, Preferably you may be 300-800 micrometers. If the thickness of the decorative layer 18 is too thin, it becomes difficult to obtain a deep and vivid color, and if it is too thick, the amount of the decorative layer material that is expensive compared to the base layer material increases.
[0054]
Next, the method of manufacturing the weather strip will be described in the case of manufacturing a weather strip as shown in FIG.
[0055]
Although other conventional methods are possible, it is preferable to apply the method proposed in Japanese Patent Laid-Open No. Hei 8-230013 and to manufacture by the following method because the thickness can be easily controlled. (See Figures 3 and 4).
[0056]
(1) First, the weather strip body 13 having the base layer 20 and the hollow seal portion 16 is extruded using a two-color extruder 42 for the crosshead type weather strip body 13, and then the microwave vulcanizer (UHF) ) 44, and vulcanize by a hot air vulcanizer (HAV) 46. In this way, the weather strip main body 13 which is a vulcanized rubber extrudate is obtained.
[0057]
(2) Next, by using a two-color extruder 48 for a laminated film, the laminated film 23 composed of the decorative layer 18 and the heat-sealing layer 22 is made to have a predetermined thickness using a TPE compound and a thermoplastic resin, respectively. After laminating extrusion (two-color extrusion) with a width, the laminated film 23 is pressure-bonded to the upper surface of the weather strip body 13 with pressure rollers 52 and 54 before curing, and the laminated film 23 is weather strip body (base layer) 13 (See FIG. 3). The laminated film 23 is extruded into a predetermined shape in a form in which the heat-sealing layer 22 is heat-sealed on the lower surface side of the decorative layer 18.
[0058]
That is, a two-color extruder 48 for film is disposed at the end of the vulcanization process of the weather strip body 13 (outside of the outlet side of the hot air vulcanizer 46 in the illustrated example). First and second pressure-bonding rollers 52 and 54 for upper surface pressure bonding and end surface pressure bonding are respectively brought into contact with each other in the vicinity of the outlet side. In the figure, 58 is a take-up roller. Further, a receiving roller 56 may be disposed corresponding to the first pressure roller 52 (see the two-dot chain line in FIG. 1).
[0059]
The film thickness of the heat sealing layer 22 is 50 to 150 μm, desirably 80 to 120 μm. Moreover, the film thickness of the decoration layer 18 shall be 400-600 micrometers, desirably 450-550 micrometers.
[0060]
Here, the first and second pressure-bonding rollers 52 and 54 and the base body in a state where the heat-sealing layer 22 is at the melting temperature of the thermoplastic resin (heat-sealing layer 22) (100 to 130 ° C. in the case of low density PE). A laminated film 23 is supplied between the layer 20 (vulcanized rubber extrudate). This is to ensure reliable heat-fusibility between the base layer 20 and the decorative layer 18. Further, the first and second pressure-bonding rollers 52 and 54 are cooled below the melting temperature of the thermoplastic resin, and are fed forward from the first and second pressure-bonding rollers 52 and 54 to solidify the heat-bonding layer 22. The decorative layer 18 and the base layer 20 are integrated by heat fusion.
[0061]
The control temperature of the first and second pressure rollers is usually 40 to 50 ° C. In addition, the thermoplastic resin is extruded as a laminated film 23 together with the decorative layer 18 at a temperature higher than the melting temperature, and is bonded to the base layer 20 while the heat-fusible layer 22 can be fused. The weatherstrip body 13 (base layer 20) is preferably maintained at a temperature of 60 to 120 ° C. This is for surely supplying the heat fusion layer 22 made of the thermoplastic resin blend between the first and second pressure rollers 52 and 54 and the vulcanized rubber extrudate at a temperature equal to or higher than the melting temperature.
[0062]
Further, as the decorative layer 18, a foamed elastomer may be used. In particular, the surface may be leather-like as a finely foamed elastomer having a foaming ratio of 1.5 times or less, preferably 1.05 to 1.45 times, or the surface of the foam may be buffed to buff. Further, the first pressure roller 52 can be embossed as an embossing roller.
[0063]
In the case where the decorative layer 18 is made of a foamed elastomer, the foamed bubbles may be crushed by the pressure of the pressure roller without the conventional heat-bonding layer. As a result, the adhesive force was improved, so that the pressing force of the pressure roller could be lowered as compared with the conventional one without a heat-sealing layer, and foamed bubbles were not crushed.
[0064]
In the above description, the decoration layer 18 is formed by pressing the base layer (vulcanized rubber body) 20 with the decorative layer 18 provided with the molten heat-bonding layer 22. The decorative layer 18 and the heat-sealing layer 22 may be integrally extruded and heat-sealed together, and a laminated film (decoration provided with a heat-sealing layer) is applied to the unvulcanized rubber substrate layer 20 immediately after extrusion. The layer) may be formed by pressure welding and heat fusion. Furthermore, while the laminated film 23 is supplied from a reel with a tape-shaped film formed at another position, one or both of the heat-sealing layer 22 and the base layer 20 is heat-sealed by the heat-sealing layer 22. The substrate layer 20 may be integrated by heating to a possible temperature.
[0065]
As shown in FIG. 1, the weather strip manufactured in this way is used by bending the trim part into a U-shape, connecting it appropriately in a ring shape, and attaching it to the vehicle body flange 34 of the vehicle. The same applies to the weather strip shown in FIG. 1 and 2, reference numerals 38 and 38A denote door panels.
[0066]
[Operation and effect of the invention]
The automobile trim according to the present invention has the following operations and effects with the above-described configuration.
[0067]
The heat-sealing layer is made of a thermoplastic resin that lacks flexibility as compared with TPE, but has a thin thickness that does not hinder the flexibility of bending when mounting a vehicle such as an automobile trim (weather strip). Therefore, the vehicle trim mounting workability of the automobile trim is the same as before.
[0068]
In addition, the presence of the heat-fusible layer reduces the influence of the ground color on the base color decoration layer of the base layer, and also reduces the transition of the color change-causing agent contained in the base layer to the decoration layer. . Therefore, it becomes easy to obtain a bright light or light color on the decorative layer on the surface of the trim body, and the discoloration with time (yellowing, etc.) of the decorative layer due to the discoloring agent is reduced.
[0069]
Further, when the base layer is formed of a rubber compound of a fine foaming formulation, the heat-sealing layer does not substantially contain an inorganic filler and has higher fluidity than TPE, so it also penetrates into surface pores. As a result, the welding strength (fusion strength) increases.
[0070]
Furthermore, when the decorative layer is formed of a TPE blend of foaming formulation, the surface can be made leather-like and the heat-sealing layer is provided, so that the fusing power can be improved and the conventional heat-melting layer can be improved. Since the pressing force of the pressure roller can be reduced as compared with the case where no adhesion layer is provided, the foamed bubbles are not crushed.
.
[0071]
【Example】
In the weather strip having the cross-sectional shape shown in FIG. 1, after trimming the trim part using the following EPDM compound, the trim part surface temperature is 90 ± 5 ° C., and then added using the following TPO compound and LLDPE. A laminated film composed of a decoration layer (500 μm) and a heat-sealing layer (100 μm) was subjected to two-color extrusion (extrusion head temperature: 200 ° C.) and heat-sealed by a pressure roller to prepare the weather strip of the example. The temperature of the heat-sealing layer at this time was set to be 120 ± 5 ° C.
[0072]
Further, under the same conditions, a weatherstrip of a comparative example was prepared by thermally fusing a single layer film consisting only of a decorative layer on the base layer in the same manner instead of the laminated film.
[0073]
In each of the weather strips thus prepared, in the case of the example, the decorative layer exhibited a beautiful white color, but the weather strip of the comparative example had a grayish decorative layer.
[0074]
Moreover, although the light resistance test (83 degreeC x 300 h) was done about each weather strip, the Example did not yellow, whereas the comparative example yellowed.
[0075]
EPDM blended formulation EPDM 100 parts MAF carbon 100 parts plasticizer 60 parts zinc white 10 parts stearic acid 3 parts sulfur 1.5 parts vulcanization accelerator 5 parts
TPO formulation Dynamic vulcanized TPO 100 parts (PP / EPDM = 20/80)
Paraffin process oil 5 parts White pigment (TiO ₂ system) 1.2 parts
LLDPE specification Melting temperature (JIS K 7121) 120 ° C
Density (in-water replacement method: JIS K 7112) 0.92
[Brief description of the drawings]
1 is a cross-sectional view of a weather strip showing an example of a product to which the present invention is applied. FIG. 2 is a cross-sectional view of a weather strip showing another example. FIG. 3 is a schematic overall view showing a method of manufacturing the weather strip of FIG. Process diagram [FIG. 4] Front view showing positional relationship between laminated film extrusion die and vulcanized rubber extrudate in FIG.
12 Weather Strip (Automotive trim)
18 Decorative layer 20 Trim body (base layer)
22 heat sealing layer 23 laminated film

Claims (5)

A decorative layer formed of a thermoplastic elastomer compound (TPE compound) containing an olefinic thermoplastic elastomer as a base polymer is heat-sealed and integrated with the design surface of the trim body, and the trim body is an ethylene-α-olefin. An automotive trim molded with a rubber compound based on non-conjugated diene copolymer rubber (EPDM) ;
The decorative layer is a foamed elastomer;
Thermal fusion between the trim body and the decorative layer, the trim body wherein the decorative layer through a heat sealable layer formed of a thermoplastic blend to a low density polyethylene resin base polymer trim for automobiles, characterized in that it is integrated. A colored decorative layer formed from a thermoplastic elastomer blend based on an olefinic thermoplastic elastomer is heat-bonded and integrated with the design surface of the trim body, and the trim body is sulfur vulcanized ethylene-α. An automotive trim molded with a rubber compound based on olefin-nonconjugated diene copolymer rubber (EPDM);
Between the decorative layer and the trim body, the decorative layer is heat-sealed to the trim body via a heat-sealing layer formed of a thermoplastic resin compound based on a low-density polyethylene resin. Integrated,
Transition from the trim body to the decoration layer of the discoloration causative agent containing sulfur-based chemicals that is capable of concealing the trim body ground color and has a thickness that is not less than the thickness at which the heat-fusible layer does not hinder flex flexibility when mounted on the vehicle body An automotive trim characterized by having a thickness greater than a thickness capable of preventing The automobile trim according to claim 1 , wherein the low density polyethylene is a linear low density polyethylene. The automotive trim according to claim 2 or 3, wherein a thickness of the heat-sealing layer is 40 to 300 µm. The automotive trim according to claim 4, wherein a thickness of the heat-sealing layer is 80 to 150 μm.

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