JPH02461B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Summary of the Invention The present invention relates to interior materials used for vehicles, such as automobiles, and examples of the interior materials include inset ceilings for automobiles, door linings,
Concerning the structure and manufacturing method of vehicle interior materials such as trunk lining and pillars,
In particular, the interior material is a laminate of fiber webs, especially those whose shape is retained by the main fibers forming the interior material being partially bonded by softening or melting other types of adhesive fibers. Further features are that webs with different apparent densities, especially webs with an apparent density of 0.4 g/cm ³ or less and webs with an apparent density of more than 0.3 g/cm ³ , and where the difference in apparent density is 0.1 g/cm ³ or more, consisting of a certain laminate (with a basis weight of 200 to 1500 g/m ² ), preferably with a difference in apparent density between the webs.
This invention relates to a vehicle interior material made of a laminate of webs having a weight of 0.3 g/cm ³ or more.

B. Prior art Conventionally used interior materials for vehicles include materials in which a thin fabric such as a film, knitted fabric, or non-woven fabric is attached to the surface of a molded product made of resin;
Alternatively, a molded fiber plate impregnated with a thermosetting resin or a foamed polyurethane sheet pasted onto cardboard and a surface material pasted thereon are mainly used. In both of these conventional methods, the inner side (core side) of the interior material is a resin molded product, a molded product impregnated with resin, or a cardboard paper, so there is little elongation, and therefore it is difficult to stretch depending on the shape of the vehicle. There is a drawback that it is difficult to withstand mold matching to match the shape of the interior material to be used, especially so-called deep drawing molding, and for example, deep drawing molding with a depth exceeding 20 cm is difficult. These conventional interior materials have no problem when used as flat or gently curved interior materials, but resin plates and resin-impregnated fiberboards are extremely heavy, and cardboard cannot be deep drawn. In addition, even if the initial rigidity was high, it would break if subjected to large deformation, so there were many problems, such as the fact that it could not be installed in some vehicle models. Another drawback of conventional interior materials is that it is necessary to finish the surface of the core-side molded product, which has a small elongation as described above, by pasting it with a film or fabric in order to prevent it from being exposed to the outside (surface side) of the vehicle interior material. The point is that there is.

C. Details of the invention First, the problems solved by the present invention are that the elongation of the core side of the interior material is increased to enable deep drawing, and that the surface of the interior material is made mainly of fibers. Two points are that there is no need to attach a film, etc. The present invention solves these two problems by creating a web consisting of main fibers and adhesive fibers, which retains its shape by partially bonding the main fibers with at least some of the adhesive fibers, and which is particularly suitable for interior materials. The apparent density of the web on the surface side and the web on the core side is different, and the basis weight of the entire interior material is 200 to 1500 g/m ² . In particular, the apparent density of the web layer on the surface side of the interior material is reduced to 0.4 g/cm ³ or less,
That of the core web layer should exceed 0.3 g/cm ³ , and the density difference between the two should be at least 0.1 g/cm ³ , preferably 0.3
g/ ^cm3 or more, more preferably core side web 0.9~
By creating a hard web layer with a high apparent density of 1.3 g/cm ³ , the core web has a hardness that allows deep drawing, while the surface web has a flexible finish. That's to be expected. By doing so, the interior material of the present invention does not require the finishing operation of pasting a film or fabric to the surface side, which is essential for conventional interior materials, and the process can be shortened. This, of course, also leads to energy conservation.

As far as the present inventor is aware, there has been no vehicle interior material obtained by bonding main fibers with adhesive fibers as in the present invention, and the present inventor considers the present invention to be a novel interior material. .

The interior material of the present invention will be described in detail below.

First, the interior material of the present invention basically has a web layer with an apparent density of 0.4 g/cm 3 or less, and a web layer with an apparent density of 0.3 g/cm ³ or less.
Density difference by creating a web layer with an apparent density exceeding g/ ^cm3
It is sufficient that the interior material can be divided into two layers having a content of 0.1 g/cm ³ or more, and to that extent, the interior material does not need to be derived solely from a laminate of two or more webs as the initial starting material. However,
A preferred embodiment is one obtained by heat-treating a stack of two or more webs to soften or melt bond at least a portion of the adhesive fibers in the web to the main fibers. Depending on the selection of heat treatment conditions, by changing the heat treatment conditions for the surface side and the core side of one main fiber web containing adhesive fibers, it is possible to change the heat treatment conditions for the surface side web and the core side web. The apparent density difference can be set within the above range. Accordingly, the main feature of the present invention is that the main fibers have a density difference between the outer core webs due to the bonding of the adhesive fibers, and that the density exhibits a so-called two-layer structure. . Furthermore, the second feature of the interior material of the present invention is that its basis weight is 200 to 1500 g/m ² . The reason for providing such a difference in apparent density between the two layers in the present invention is to make one hard and the other soft, and the density difference is 0.1 g/cm ³ or more, preferably 0.3 g/cm ³ or more. It is advantageous for the purposes of the present invention. In other words, the preferred web apparent density for interior materials is 0.4 on the surface side.
g/cm ³ or less, core side 0.7 g/cm ³ or more, especially 0.9 to 1.3
g/cm ³ is desirable. Furthermore, in the interior material of the present invention, a film, other web, resin-impregnated paper, knitted fabric, etc. may be interposed between both web layers, but even in that case, the surface side web and core side web of the interior material must satisfy the above conditions.

Hereinafter, the method for obtaining the interior material of the present invention will be described in detail.

First, as the main fibers in the present invention, various organic synthetic fibers, recycled fibers, natural fibers, inorganic fibers, or mixtures thereof are used for both the core side web and the surface side web. The main fibers in the core side web are preferably thick fibers because it is necessary to provide rigidity to the molded product, and fibers of 6 to 20 d,
Desirably 10 to 15 d, more preferably hollow fibers. Also, the appropriate length is 30 to 80 mm. On the other hand, the main fibers in the front side web need to provide a flexible surface, but depending on the part used as interior material, severe abrasion resistance is required, and the fiber thickness must be selected according to the application. Must be. For example, if flexibility is important, a fineness of 2 to 6d is appropriate, and if abrasion resistance is considered, fineness is 6d.
~20d is suitable, and length 30~80mm is suitable. Here, the main fibers in the surface side web do not necessarily have to be of the same material as the main fibers in the core side web, but since they are used on the surface, materials with good light resistance and coloring with good light resistance can be achieved. Must have been. Furthermore, it is preferable that the main fiber is endowed with various properties such as antifouling properties, antistatic properties, flame retardant properties, etc. either as a raw material or as a result of post-processing.

Next, to explain the adhesive fiber in the present invention, it must be one that softens or melts at a temperature below the melting point of the above-mentioned main fiber.
Examples of such thermoplastic components include polyolefin, polyamide, and polyester polymers. Adhesive fibers are fibers in which the entire fiber is made of the thermoplastic component, and the entire fiber softens and melts at the heat treatment temperature, or the component that melts at the treatment temperature and the component that does not melt have a core-sheath shape. Composite fibers with a bimetallic or sea-island cross-sectional shape may also be used, and in consideration of shrinkage during melting, it is more preferable to use composite fibers because of their low shrinkage. In particular, considering that the material is exposed to fairly high temperatures during use in automobiles, there is a possibility that the material may be deformed or its surface condition may change after being molded as an interior material. For this reason, it is desirable that the adhesive fiber preferably has a melting point of 130°C or higher. However, due to deterioration of the main fibers due to the processing temperature during molding of interior materials and demands from productivity, the appropriate processing temperature is often 160 to 220℃, and therefore the melting point of adhesive fibers is 130 to 200℃.
temperature, more preferably in the range of 150°C to 180°C. In addition, the adhesive fibers of the core side web and the front side web do not necessarily have to be made of the same material; in particular, the adhesive fibers of the front side web have light resistance,
It is preferable that various properties such as coloring, antifouling properties, antistatic properties, and flame retardant properties are imparted to the material as a raw material or through post-processing.

When composite fibers are used as such adhesive fibers, the composition of the melting component/non-melting component is polyethylene/polypropylene, polyethylene/polyester, polyethylene/polyamide,
Various combinations are possible, such as polypropylene/polyester, polypropylene/polyamide, copolyester/polyester, copolyester/polyamide, copolyamide/polyester, and copolyamide/polyamide, depending on the main fiber used and the molding heat treatment temperature for the interior material. The combination and composition ratio can be selected as appropriate. Here, since adhesive fibers soften and melt, their thickness and length do not have a major effect on the final product, but from the viewpoint of card passage during web production, fineness of 2 to 20 d and length are recommended. 30~80mm
is appropriate.

When producing the web in the present invention, these main fibers and adhesive fibers are thoroughly blended separately in the core side web and the front side web in a cotton blending process, and then made into a web using a card or a random web and laminated. Although it is generally used as a raw material fiber layer, in some cases it can also be obtained by applying different molding conditions to the core and surface of a single layer web.

The important point in the present invention is the mixing ratio of the main fiber and the adhesive fiber, which has a great influence on the properties of the final product. The core side web primarily exhibits rigidity and shape retention after molding. Therefore, adhesive fibers are the main fibers in the core web, and the ratio of main fibers/adhesive fibers is 45/55 to 10/1.
90 is appropriate. In addition, when the adhesive fiber is a composite fiber, the ratio of molten component/non-melt component also affects the adhesive fiber, but the remaining non-melt component will play the role of the main fiber, so in extreme cases, the adhesive It is also possible to make the core side web only from the composite fibers used as the synthetic fibers. On the other hand, the web on the front side is required to have a soft or felt-like appearance, so the main fiber is the main fiber, and the ratio of main fiber/adhesive fiber is 55/45 to 90/10, preferably 65/35 to
80/20 is appropriate. Here, when the proportion of adhesive fibers becomes high, a smooth plastic-like surface is often obtained even if the molding temperature or pressure is lowered. On the other hand, if the amount of adhesive fibers is less than 10%, the surface-based fibers will not be bonded and fixed, resulting in a significant decrease in wear resistance, which is unsuitable.

As described above, as a typical starting material of the present invention, as web A, main fiber/adhesive fiber = 45/55 ~
It is a laminate of a web on the core side with a ratio of 10/90 and a web on the front side with the same ratio = 55/45 to 90/10 as web B.

The weight of the fiberboard material used as a vehicle interior material, that is, the basis weight, must be between 200 and 1500 g/ ^m2 , and if the weight is less than 200 g/ ^m2 , the thickness will be extremely thin and the shape retention of the molded product will be poor. or stiffness cannot be obtained. Moreover, if it exceeds 1500 g/m ² , shape retention and rigidity are sufficient, but problems arise as opposed to weight reduction and cost reduction. And the suitable weight range is 500 to 1000
g/ ^m2 . In the interior material of the present invention, it is effective for rigidity and shape retention when the weight of the core side web is greater than that of the surface side web within this range of basis weight, and the weight ratio of the core/surface portion is 55/45. ~90/10 is desirable.

In the present invention, after these two types of webs are laminated, at least a portion of the adhesive fibers are subjected to softening and melting treatment under pressure or no pressure. The heat treatment conditions are uniform heat treatment on both sides of the laminated web, below the melting point of the main fibers and above the softening point of the adhesive fibers. At the same time, the web is temporarily bonded by softening and melting, and at the same time, the entire web is densified by shrinkage. In the present invention, it is necessary to subsequently perform reheating treatment and pressure treatment. That is, since the desired product cannot be obtained only by the first stage of uniform heat treatment, the second stage of non-uniform heat treatment is always required. In other words, with non-uniform heat treatment, the processing equipment must be within the same range as the first stage, but the important point is that the front and back sides of the temporarily bonded and shrunk web after the first stage heat treatment (i.e. the interior When used as a material, it is necessary to give different heat treatment effects to the surface side and core side, and therefore different heat treatment temperatures are set and applied. This point is the most important feature of the manufacturing method of the present invention, and the second feature of the manufacturing method of the present invention is the second feature of the manufacturing method of the present invention.
Pressure treatment, that is, heating and pressure molding (hot pressing) is carried out at the same time as the uneven heat treatment of the stage, or pressure treatment, that is, cold pressing is carried out during cooling after the uneven heat treatment, and it is only by such hot pressing or cold pressing that the present invention You can get what you want.

As described above, in the manufacturing method of the present invention, uniform heat treatment on the web → non-uniform heat treatment and simultaneous hot press treatment or sequential cold press treatment are essential steps. There is no problem in applying needle punching treatment. In particular, in the case of an improved embodiment of the present invention in which a film or other sheet-like material is interposed between webs A and B, needle punching is effective. In addition, especially when a film is interposed, it is more effective to partially soften and melt the film together with the adhesive fibers in the web. It should be sufficiently shrunk during the uniform heat treatment of the stage. Otherwise, there is a risk that the film will shrink during the second-stage non-uniform heat treatment, resulting in a molded product with wrinkles as a whole for the interior material. In this regard, in order to keep the shrinkage small, it is possible to use a film with a low shrinkage rate or use composite fibers as adhesive fibers.

The molded product of the present invention can be used in various parts of a vehicle. In this case, parts that come into close contact with the body do not require much rigidity, but parts that do not come into close contact with the body or interior materials that have a fairly large area require considerable rigidity in terms of handling and sway during use. is required. In order to compensate for this, it is possible to interpose a thermoplastic resin film as described above between webs A and B, or to reinforce the thermoplastic resin by distributing it as uniformly as possible between the webs. This is merely an improved embodiment of the present invention. Of these, it has been found that the former method, that is, the film intervening method, is preferable, and in that case, a film thickness of about 50 to 300 .mu.m is desirable. Here, if the film thickness is less than 50μ, there is substantially no effect of improving rigidity, and if it exceeds 300μ, needle breakage is observed. Furthermore, if the melting point of the film is too low, it is difficult to expect shape retention and rigidity of the molded product in a heat resistance test at 85°C for 24 hours. Therefore, polypropylene was found to be the most suitable film. Furthermore, other than films, the basis weight is 100 to 200.
g/m ² of kraft paper etc. is impregnated with phenol resin, etc., then heat treated and cross-linked for 50 to 80 minutes.
It is also effective to use paper that has been advanced to %. When needle-punching the web into which this sheet-like material has been inserted, the paper is not very hard and easy to process, and the subsequent uniform heat treatment and non-uniform heat treatment will achieve the crosslinking stage of 100%. The product will be able to exhibit sufficient rigidity.

The temporarily bonded and shrunk web that has undergone the first stage of uniform heat treatment of the present invention can be made into a product by hot pressing, which is uneven on both sides of the web in the second stage, or cold after a non-uniform heat treatment that does not involve pressure. It is made into a product by being pressed. However, in the hot press method, the adhesive fibers are compressed against the main fibers in a sufficiently softened and molten state, so the molded surface tends to become plastic-like, and when the molded product is taken out, it has poor shape retention and is easily deformed. So,
It is important to cool the heated mold or transfer it to another cooled mold of the same shape to give it shape retention before taking it out. However, if one side is heated to high temperature,
It is desirable to use a mold with the other side at a low temperature because it facilitates removal, and the high-temperature treated side is molded to look like plastic and the low-temperature treated side to look like felt. On the other hand, in cold pressing, the adhesive fibers are heated to sufficiently melt them during the heat treatment before pressing, and are cooled at the same time as compression molding during pressing to develop shape retention, so they can be taken out immediately after pressing, resulting in high productivity. Therefore, cold pressing is preferable as a manufacturing method for the molded product of the present invention. According to the research of the present invention, when cold pressing is performed, when the temperature of the mold surface is below 50℃, the surface of the molded product is almost unchanged from that of a mold at room temperature, and in general, it is not smooth and plastic-like. It becomes felt-like without becoming a surface. Furthermore, if the surface temperature of the mold exceeds 50°C, especially 70°C or higher, the surface of the molded product will be quite smooth and dense, but will not have the smoothness of plastic. The surface temperature of the mold is 120
When the temperature exceeds ℃, the surface becomes plastic-like as in the case of hot pressing, and the rigidity becomes high.
Based on the above cold pressing results, when producing the interior material of the present invention, as a method to finish the surface side like felt and the core side to be hard, after sufficiently melting the molten component of the adhesive fiber, Keep the surface side mold temperature below 50℃, and the core side mold temperature 70℃.
By doing the above, a molded product having a good surface and a highly rigid core can be manufactured by one molding.

As mentioned above, the cold press method is suitable for press molding in the present invention. Therefore, the optimal manufacturing method for obtaining the interior material of the present invention is to uniformly heat-treat the web laminate with hot air or the like, then perform non-uniform heat treatment by changing the heat treatment temperature on one side and the other side of the web, and then This is a cold pressing method that changes the contact temperature on both sides.

According to the present invention, an interior material which has two or more layers on the front and back in appearance, has a difference in apparent density, and can be formed by deep drawing is provided by a simple molding method.

The present invention will be explained below with reference to Examples.

Example 1 Hollow polyester fiber 12d×51 as main fiber
mm, a web with a basis weight of 500 g/m ² made by blending 4 d x 51 mm of polypropylene/polyester sea-island fiber (70/30) in a ratio of 45/50 as the adhesive fiber is used as the core forming web, and raw dyed polyester is used as the main fiber. Fiber 5d x 51mm, polypropylene/polyester sea-island fiber (70/30) as adhesive fiber 4d x 51
A web with a basis weight of 200 g/m ² made by mixing cotton in a ratio of 80/20 was used as the web for forming the surface portion. Both fiber webs were spun from two cards, laminated on a latteis, needle-punched at 100 fibers/ ^cm3 from the surface side, and then treated with hot air at 170°C for 1 minute (first stage uniform heat treatment). ) to obtain a plate-like product. Next, the plate-like material was heated with infrared rays from the core side to a temperature of 200°C on the core side surface and 170°C on the front side surface (second stage non-uniform heat treatment), and then the metal on the core side was Mold temperature 70℃,
Press molding (cold pressing) was performed using a deep drawing mold with a mold temperature of 20°C on the surface side. At this time, the press pressure was 0.8 Kg/cm ³ and the press time was 30 seconds.

The molded product obtained in this way was not sufficiently rigid to be used for automobile ceilings, trunk rooms, etc., but it was sufficiently rigid to be used for pillars, and the surface had a luxurious feel similar to that of felt pasted. It had a warmth to it. This molded product has a core thickness of 1.3 mm and an apparent density of 0.8 g/cm ³ , a surface portion thickness of 1.5 mm and an apparent density of 0.2 g/cm ³ , and has heat resistance, abrasion resistance, It was a good interior material that passed various tests such as light resistance.

Example 2 When spinning the core web and surface web used in Example 1 from two cards, a polypropylene film (thickness 100μ) was placed on the core web on a latex, and the film was After laminating the surface web on top and punching 100 needles/ ^cm2 from the surface area, hot air treatment at 170°C for 1 minute (first stage uniform heat treatment) was performed to remove the film-interposed plate. Obtained. Next, the plate-like product was subjected to a second stage of non-uniform heat treatment and a cold press (press pressure 0.4 kg/cm ² ) according to the method of Example 1 to form a molded product. Although the obtained molded product was somewhat insufficient in rigidity for applications where there are parts that do not adhere completely to the body, such as trunk rooms, it had enough rigidity to be used as a ceiling material. This molded product has a core thickness of 1.9 mm and an apparent density of 0.6 g/cm ³ , a surface portion thickness of 1.3 mm and an apparent density of 0.25 g/cm ³ , and the surface area is finished with conventional nonwoven fabric. It has the same luxurious feel and appearance as felt-like ceilings, and it weighs 790g/
A light and very good ceiling of m ² was obtained. In addition, in the deep drawing test conducted at this time, deep drawing was possible to a depth of 30 cm, making it suitable for the ceiling of a high-roof vehicle.

Example 3 Hollow polyester fiber 12d×51 as main fiber
mm, the core forming web is a web made by blending polypropylene/polyester (70/30) 4d x 51mm in a ratio of 30/70 (basis weight 500g/m ² ) as the adhesive fiber, and undyed polyester fiber as the main fiber.
15d×76mm, polypropylene as adhesive fiber/
Polyester sea-island fiber (70/30) 4d×51mm
80/20 blended web (basis weight 200g/m ² )
was used as the web for forming the surface portion. Both webs were coated with polypropylene film (thickness:
200μ) and perform needle punching to 170
A hot air treatment (uniform heat treatment) for 1 minute at °C was performed to obtain a plate-like product. Next, a molded product was obtained from the plate-like product by a method that did not involve cold pressing (that is, a hot pressing method). The conditions for the hot press at that time were a mold temperature of 160℃ on the surface web side, a mold temperature of 200℃ on the core web side, a press pressure of 2Kg/cm ² , and a press time of 2 minutes.After the press was finished, the mold was cooled with water. After that, the molded product was taken out. The molded product thus obtained has a core thickness of 1.4 mm and an apparent density of 1.1 g/
cm ³ , surface thickness 1.5 mm, and apparent density 0.3 g/cm ³ . This product had considerable rigidity and did not dent even when used in areas that did not come into close contact with the body. This material has passed the strict abrasion resistance test for floor materials, has good light resistance and heat resistance, and has a felt texture similar to needle punch carpet.
It could also be used under fairly harsh conditions, such as the storage space (luggage) in the rear of a five-door car.

Claims (1)

[Claims] 1. A laminate of webs in which the main fibers are bonded by softening and melting at least a portion of adhesive fibers, the apparent density of the web on one side being 0.4 g/cm ³ or less,
The web on the other side is characterized by having an apparent density difference of 0.1 g/cm ³ or more, with the web exceeding 0.3 g/cm ³ , and the basis weight of the entire laminate being 200 to 1500 g/m ² . Interior materials for vehicles. 2 In the first term, the apparent density difference between the two webs is
A vehicle interior material characterized by having a content of 0.3 g/cm ³ or more. 3. The vehicle interior material according to item 1 or 2, characterized in that the web on the high apparent density side has an apparent density of 0.7 g/cm ³ or more. 4 In paragraph 3, if the apparent density is 0.9 to 1.3
A vehicle interior material characterized by g/ ^cm3 . 5 In any of paragraphs 1 to 4, webs with an apparent density difference of 0.1 g/cm ³ or more between a web with an apparent density of 0.4 g/cm ³ or less and a web with an apparent density of more than 0.3 g/cm ³ An interior material for a vehicle, characterized in that it has both surface webs, and further interposes another web, paper, knitted fabric, and/or film between them. 6 Web A in which the main fiber and adhesive fiber with a lower melting point than the main fiber are mixed in a weight ratio of 45:55 to 10:90, and Web B in which both types of fibers are mixed in a weight ratio of 55:45 to 90:10. The laminate is laminated to have a basis weight of 200 to 1500 g/m ² , and the laminate is uniformly heat-treated at a temperature above the softening point of the adhesive fibers and below the melting point of the main fibers, and then the laminate is heated to the same temperature range as described above to form a web. The processing temperature for web A is higher than the processing temperature for web B, and the front and back surfaces of the laminate are subjected to non-uniform heat treatment without pressure, and then cold-pressed at a temperature below the heat treatment temperature.The main fiber is at least the adhesive fiber. It is a laminate of webs bonded by partial softening and melting, and the apparent density of one side of the web is 0.4 g/
cm ³ or less, that of the web on the other side exceeds 0.3 g/cm ³ and has an apparent density difference of 0.1 g/cm ³ or more,
A method for producing a vehicle interior material, wherein the laminate has a basis weight of 200 to 1500 g/m ² as a whole. 7 In item 6, the temperature of the web A side of the mold during cold pressing should be 70℃ or higher, and the temperature of the web B side should be 70℃ or higher.
A method for manufacturing vehicle interior materials characterized by a temperature of 50℃ or less. 8. Web A is a blend of main fiber and adhesive fiber with a lower melting point than the main fiber at a weight ratio of 45:55 to 10:90, and web B is a blend of both types of fibers at a weight ratio of 55:45 to 90:10. Laminated so that the basis weight is 200 to 1500g/ ^m2 ,
The laminate is uniformly heat-treated at a temperature higher than the softening point of the adhesive fibers and lower than the melting point of the main fibers, and then the laminate is kept in the same temperature range as above, and the processing temperature for web A is higher than the processing temperature for web B. A laminate of webs in which the main fibers are bonded by softening and melting at least a portion of the adhesive fibers, characterized in that the front and back sides of the laminate are subjected to non-uniform heat treatment under pressure; The hanging density is 0.4g/ ^cm3
Hereinafter, the web on the other side has an apparent density difference of more than 0.3 g/cm ³ and is more than 0.1 g/cm ³ ,
A method for producing a vehicle interior material, wherein the laminate has a basis weight of 200 to 1500 g/m ² as a whole.