JPS6335756B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing a carpet lining that has excellent shape retention, heat insulation, sound absorption, lightness, etc. 2. Description of the Related Art There has been a strong demand for improvements in the comfort of vehicles, mainly passenger cars, and with this, interior materials with excellent interior decoration effects, soundproofing effects, etc., have become popular. This type of interior material includes, for example, ethylene-based carpets containing inorganic fillers on the back side of carpets such as tufted carpets and needle punch carpets.
Carpets lined with a thermoplastic synthetic resin sheet made of vinyl acetate copolymer are in practical use. However, in this case, if the content of the inorganic filler is increased in order to increase sound absorption and reduce material costs, there are disadvantages in that the suture removal strength decreases and hair removal tends to occur. In addition, it has been proposed to line the back side of the carpet with acrylate latex or latex made of styrene-butadiene copolymer (SBR), but these only function as a carpet. It has the disadvantage that properties such as shape retention, heat insulation, and sound absorption are insufficient unless it is backed with a lining. Furthermore, an aqueous resin emulsion containing expandable polystyrene particles is applied to the back side of the original rug,
A laying material has been proposed that has cushioning properties by heating the coated surface to foam the expandable polystyrene particles to form a backing layer with protruding polystyrene foam particles on the back side of the original rug (for example, (See Japanese Patent Application Laid-open No. 60-59183 (unpublished at the time of filing). However, such laying materials have a problem in that they tend to crack at bent portions when shaped by press molding. In view of the above, an object of the present invention is to provide a method for manufacturing a carpet lining that has excellent shape retention, heat insulation, sound absorption, lightness, etc. The gist of this invention is (1) weight ratio, particle size 0.1~
A foam backing composition made by mixing and kneading 65-85% of 2.5 mm foamable resin beads, 35-15% of polymer latex (solid content), and 0.8-4% of short fibers is applied to the back side of the carpet by at least 0.2 mm. Apply to the thickness of
In this method, the carpet lining is subjected to foaming treatment, such as free foaming or pressure foaming, in a temperature range of 90 to 150°C. The expandable resin beads in this invention are, for example, Styropol and Heatpol (trade names) manufactured by BASF, which are expanded polystyrene containing a blowing agent such as an aliphatic hydrocarbon. Polymer latex is an emulsion latex made by uniformly dispersing a polymer as a dispersoid in water as a dispersion medium, and has the functions of preventing thread removal from carpets, preventing hair loss, and as an adhesive for foamed polystyrene resin beads. It is something that we fulfill. The short fibers include, for example, hydrophilic low melting point multi-branched fibers (SWP), recycled fibers, and the like. By determining the appropriate blending ratio of these foamable resin beads, polymer latex, short fibers, etc. and the foaming treatment conditions after kneading them and applying them to the back side of the carpet, we can improve the shape retention and heat insulation properties of the carpet backing. , sound absorption, lightweight, etc. can be adjusted depending on the application. Next, the reasons for limiting the blended raw materials and manufacturing conditions in this invention will be explained. (1) Particle size of expanded polystyrene resin beads When performing foaming treatment in the temperature range described below,
Small particles with a particle size of 0.1 mm or less have poor retention stability of the aliphatic hydrocarbon gas they contain;
If the beads are larger than 2.5 mm, the foamed polystyrene resin beads occupying the surface to which the foamed backing composition is applied will become coarse, making the finished surface uneven and difficult to obtain a flat finished surface.
mm. (2) Mixing ratio of expanded polystyrene resin beads, polymer latex (solid content), and short fibers Among the dozens of basic experiments including reference examples, Table 1 shows a few examples, Experiment No. 11. , the overall composite product was evaluated from the finished state of the backing carpet belonging to No. 45 after pressure foaming treatment, the tendency for fine cracks to occur in the backing foam layer when the rolled backing carpet is rolled out, etc. The carpet linings belonging to No. 4 and No. 18 had good results, and the carpet linings belonging to Experiment No. 26 and No. 38 had good results. In addition, experiment no.
4, No. 11, No. 18, No. 26, and No. 38 are reference examples.

[Table] According to the results of these basic experiments, when the blending ratio of expanded polystyrene resin beads is less than 65%, the foam backing layer becomes thin and the above functions are inferior, whereas when it is more than 85%, the apparent viscosity becomes high. 65
It was set at ~85%. Furthermore, if the blending ratio of emulsion latex (solid content) is more than 35%, the foam backing layer will become thin and the above functions will be inferior; It was set at 35% to 15% because the Next, the above expanded polystyrene resin beads 65~
85% and emulsion latex (solid content) 35~
If the short fibers mentioned above are mixed in at 15%, the tendency for cracks to occur will be eliminated, but the mixing ratio is
It has been confirmed that a range of 0.8 to 4% is suitable. (3) Foaming treatment temperature At low temperatures below 90°C, foaming of expanded polystyrene resin beads tends to become uneven, and at high temperatures over 150°C, it has a negative effect on the carpet.
The temperature was set at 90 to 150°C because the foam lining layer would shrink. (4) Application thickness of foamable backing composition A foamable backing composition consisting of foamed polystyrene resin beads, emulsion latex, or foamed polystyrene resin beads, emulsion latex, and short fibers is applied to the back side of the carpet. When applying the product, it is necessary to apply the product to a thickness of at least 0.2 mm, as if the coating thickness is too thin, the shape retention, heat insulation, sound absorption, lightness, etc. after foaming treatment will be poor. Reference examples related to this invention will be described below. That is, after preparing a foamable backing composition kneaded in the proportions shown in Table 2, it is applied to the back surface of the carpet to a thickness of about 1.5 mm by means not shown. Next, non-pressure foaming and pressure foaming (for example, using a heated roll or hot press) were carried out under the heating and foaming conditions listed in Table 2. In this way, as shown in FIG. 1, a carpet lining was produced in which a foam lining layer 3 was formed on the back side of a carpet 1 having a pile layer 2 on the front side.

[Table] The results of the investigation on shape retention, heat insulation, sound absorption, etc. of the carpet lining shown in Table 2 above are shown in Table 3.
Shown in the table.

[Table] Next, the heat insulation properties of the samples taken from the carpet lining belonging to the continuous production period code XB shown in Table 2 (1 kcal of heat lost in 1 hour from a measurement area of 1 m ² at a temperature difference of 1°C between the inside and outside) As shown in FIG. 2, it was found that the carpet lining related to the present invention has an excellent heat insulating effect even if it is thin. In addition, when we measured the sound absorption coefficient (spatial distance between the installation position and measurement position: 80 mm) of the sample taken from the backing carpet belonging to the continuous manufacturing period code YA shown in Table 2, it was found that the conventional material ( SBR backing material with a thickness of approximately 2.0 mm, above spatial distance: 40 mm)
It was found that the sound absorbing properties (soundproofing properties) in the region below 1000 Hz are superior compared to the previous one. Although the reason for this has not been investigated in detail, it is presumed that it is due to the countless closed cells formed within the foam lining layer. As described above, according to the present invention, the effect of the above-mentioned reference example is combined with the blending effect of short fibers, and the backing foam layer made of a foamable resin is firmly fixed to the back surface of the carpet. It has superior shape retention, heat insulation, sound absorption, etc. compared to the backing layer of It is possible to obtain a backing carpet with good moldability, which exhibits the desired function and does not cause cracks at the bent portion during shaping by press molding. In addition, by not foaming the expandable resin beads during the primary lining, that is, by heating and foaming the unfoamed foamed lining layer during the molding process (see Figure 4), it is possible to simplify the process for achieving various functions. The thus obtained carpet lining can be used as an interior member having a large deformation recovery force due to repeated external stress and having excellent cushioning properties. Therefore, it is suitable not only for vehicle interior materials such as floor materials, door side materials, ceiling materials, etc. of automobiles, mainly passenger cars, but also as architectural interior materials.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention. Figure 1 is an enlarged sectional view of a foam backing layer fixed in irregular lines to the back side of a carpet, and Figures 2 and 3 are a conventional material and a foam backing carpet related to the present invention. FIG. 4 is a graph comparing the thermal insulation properties and sound absorption properties with the reference example of 1. FIG. 4 is a cross-sectional view showing a state in which the unfoamed backing foam layer is heated and foamed during molding. 1...Back side of the carpet, 3...Backing foam layer.

Claims (1)

[Claims] 1 Weight ratio: 65-85% foamable resin beads with a particle size of 0.1-2.5 mm and polymer latex (solid content) 35-85%
After preparing a foamable backing composition by kneading 15% and 0.8-4% short fibers, the foamable backing composition is applied to the back side of the carpet to a thickness of at least 0.2mm, and the foamed backing composition is mixed with 90% A method for producing carpet lining, characterized by carrying out foaming treatment in a temperature range of ~150°C.