JPS5924735A - Vehicle carpet backing resin composition - Google Patents

Abstract

PURPOSE:A resin composition excellent in filler dispersibility and capable of forming vehicle carpet backings having a moderate flexural rigidity and a good pile pulling strength, prepared by mixing low-density polyethylene, an ethylene/ vinyl acetate copolymer, and an inorganic filler. CONSTITUTION:100pts.wt. low-density polyethylene (preferably, one having a melt index according to JIS 6760 of about 10-50) is mixed with 15-60pts.wt. ethylene/vinyl acetate copolymer (or its graft copolymer, preferably one having a melt index of about 10-75) and 30-200pts.wt. inorganic filler (e.g., calcium carbonate). These components are mixed preferably as follows. The inorganic filler granulated with the aid of a binder together with the ethylene/vinyl acetate copolymer is pelletized, and the pellets are dry-blended with the low-density polyethylene.

Description

[Detailed description of the invention] This invention relates to Penot's resin composition for banoking.

Conventionally, one of the methods of bunoking automobile carpets is to use low-density polyethylene (hereinafter referred to as LDPE).
There was a method of extruding it with a T-die and pressing it onto the back side of the carpet with a lamination roll.

In this case, the basis weight of LDPE is usually 200~1.3;0
The range is 9/R.

Carpets banked by this method have the following problems. In other words, due to the high rigidity of the banoking layer, the cushioning properties when laid on the floor are poor, and in relation to this, when the basis weight of the banoking layer is increased for the purpose of improving sound insulation, the rigidity becomes too high. becomes unusable.

Furthermore, since it is difficult to mix all of the L I) PE fl filler, the cost increases. That is, the dispersion of the filler within the LDPE was non-uniform, resulting in avatars and other defects. In fact, it is impossible to incorporate more than 30% filler in terms of strength.

As a method other than the above, the above drawbacks can be improved and the conventional LD
There is a method of using a material with the following composition instead of PE.

The material is a mixture of an ethylene copolymer such as an ethylene vinyl acetate copolymer, a filler such as calcium carbonate, and a binder such as a low molecular weight resin such as acid polypropylene or paraffin wax.

This material is especially suitable for sound insulation materials, so the basis weight of the backing layer is k/ky/n? In the case of -F, it is possible to maintain effective and good stiffness and removal strength of the pile. However, when the backing weight is less than 2/-, there are drawbacks such as insufficient heat resistance and too much flexibility, making it difficult to place on the floor.

The object of the present invention is to overcome the above-mentioned conventional drawbacks, and to disperse the filler in the resin by blending low-density polyethylene, ethylene vinyl acetate copolymer or graft copolymer, and inorganic filler in the required proportions. A vehicle in which the hardness of the backing material is adjusted to give optimal rigidity to pets when the backing weight is 200 to 100 θ'y/m''. The present invention provides carpet backing resin compositions for use in carpets.

The formulation of the composition of the present invention is as follows.

(a) Low-density polyethylene (LDPE).../θ0 JISK to maintain workability during backing of heavy sensitive parts
It is preferable that the melt index (hereinafter referred to as M・■) is in the range of 70 to S0. Copolymer: 75 to 60 parts by weight M, 1. from the viewpoint of processability. 'i/θ to 7S is preferable, and the M of LDPE is 1. The ratio i/
: 7j~/j:/ is preferable in order to make the mixing uniform.

(c) Inorganic filler...30~. 20 parts by weight As the inorganic filler, calcium carbonate, barium sulfate, mica, talc, aluminum hydroxide, etc. can be used.

(d) Binder: θ ~ = 20 parts by weight This includes acrylic polypropylene, low molecular weight resins such as rough-in wax, plasticizers, flame retardants, antistatic agents, and coloring pigments. etc., if necessary.

There are various methods for mixing the composition of the present invention, but
- For example, an inorganic filler is pre-hardened into granules with a binder, pelletized with EVA, then tri-blended with LDPE and extruded into a film using a T-die to be used for carpet backing. be.

Next, examples of the present invention and comparative examples will be shown, and the two will be compared and evaluated.

Example/Formulation M, 1. is 3j of LDPE...,.../θ0 parts by weight M,
1. is jo's EVA... 3θ 〃Cal carbonate/
Ram...7θ rrEVA and calcium carbonate were pelletized in advance and triblended with LDPE.

This was applied to the back side of a tufted carpet with a bail basis weight of 7 trt at 35θV/-.

Example) Formulation M, 1. LDPE with 3j.../θθ weight part M, 1. is 2θ EVA ・・・・・・ 3θ 〃
Calcium carbonate...7θ Atactic polypropylene...7 EVA, calcium carbonate, and atactic polypropylene are pelletized in advance and placed on the back side of the carburetor vent as in the example.
3;0? /ltl was applied.

Comparative Example/Compound LDPE with MI of 2θ...700 parts by weight 3502/r/? Coated.

Comparative Example EVA with blend M and I of 20 30 parts by weight Calcium carbonate 7θ n Atactic polypropylene 7 This was applied to the same carpet as Example/3jθ2 /m2 backing 7′? :
n The above Example/1.2 and Comparative Example/9.2 were evaluated and compared based on the following closing side items.

Evaluation item/bending rigidity Five specimens each with a length of 200 mm and a width of 23 rtrm were taken from the vertical and horizontal directions, and one end was 17.
Place the backing layer down on a horizontal table with a 5° slope and a smooth surface.
Slide the test piece at a speed of n/36 C and read the distance traveled by the other end when one end of the test piece touches the slope.

! The plain pile was fixed on a test piece of suitable size and strength, and a bundle of piles was grasped with a crocodile clamp, and the spring school (θ
~, S k? ) and measure the load required for the pile to come off.

3.Moldability Evaluate the backing carpet based on tearing, wrinkling, and recovery after molding when molded to match the floor of a car.

Table 1 shows the results of this evaluation. In Table 1, the bending rigidity of the comparative example is 1lJ of the present invention.
Gi example/,,,? taller than. This shows that the carpet's compatibility is poor. Also, Example/is LD
Since PE is used alone and no filler is used, the cost is high.

On the other hand, comparative example, 2. was inferior to Example 1.2 of the present invention in pile draft strength and formability.

The effects of the present invention will be explained as follows. That is, it is impossible to mix a filler such as calcium carbonate into LDPE due to poor dispersion, but in the present invention, since it is mixed in advance with a filler such as EVAe calcium carbonate, Its dispersion is good. Therefore, since the filler can be mixed in at a constant rate, it is possible to reduce the material cost of the backing resin.

In the present invention, although the main components are all composed of fillers such as LDPE, EVA, and calcium carbonate, it is important to ensure that the final product carpet has the optimum bending stiffness (if the stiffness is too high, the bending properties will deteriorate). , if it is small, the work of attaching it to the body will be reduced), good pile drafting strength, and good formability.

-2;

Claims (1)

[Claims] / Carpet for a vehicle comprising 700 parts by weight of low-density polyethylene, 7.5 to 20 parts by weight of an ethylene-vinyl acetate copolymer or its graft copolymer, and 200 parts by weight of 3 to 3 inorganic fillers. Backing resin composition. ! The melt index (M
, 1. ) is 70 to j0, and M of the ethylene vinyl acetate copolymer or its graft copolymer is 1. ga/θ~
7S, and M and I of both of the above. Ratio i/: 1. The carpet backing resin composition according to claim 1, wherein the carpet backing resin composition has a hardness of s~7.5~/.