KR101723963B1 - resin composition for backing coat of car mat and manufacturing method car mat - Google Patents

Abstract

The present invention relates to a resin composition for a car mat backing coat, and a production method of a car mat using the same and, more specifically, to a resin composition, and a production method of a car mat using the same. The resin composition has excellent flexibility, heat resistance and cold resistance by suitably mixing an ethylene-olefin block copolymer, an ethylene-alpha-olefin random copolymer, polyethylene, an inorganic filler and processing oil, has no smell, and has excellent extrusion coating processability, thereby being very useful as an automobile interior material and, especially as a backing coat for a car mat.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a car mat backing material,

The present invention relates to a resin composition for a car mat backing material of an automobile and a method for manufacturing an automobile car mat using the resin composition. More particularly, the present invention relates to a resin composition for an automobile car mat backing material and an automobile car mat using the ethylene-olefin block copolymer, The present invention relates to a resin composition which is excellent in flexibility, heat resistance and cold resistance, has excellent odor and extrusion coating processability, and is very useful as a backing coat for automobile interior materials, especially car mat, And a method of manufacturing a car mat.

Polyvinyl chloride (PVC), which is used in many parts as automobile interior materials, has excellent processability and various mechanical properties, and is suitable for instrument panel, door trim, sunvisor, etc. And as a car mat backing material for automobiles.

However, in order to soften PVC, it is necessary to use a large amount of plasticizer. This plasticizer induces the release of environmental hormone, and the substitution to other materials due to the unpleasant odor and heavy metals contained in the heat stabilizer It is a reality that is being pursued steadily.

Generally, the automobile interior car mat has a three-layer structure. The upper layer is mainly nylon fiber, and the intermediate layer is a fabric sheet or nonwoven fabric sheet formed by woven polyethylene terephthalate and polyvinyl acetate copolymer fibers. The nylon fiber is secured to a fabric sheet or nonwoven sheet. The backing material for the lower layer is a polyvinyl chloride or styrene-butadiene-styrene copolymer. The three-layered mat fabric produced by extrusion or calendering molding is cut to the required shape and then the finished product is manufactured by a cutting site sewing operation.

From the viewpoint of the smell that has recently become increasingly important in improving the quality of automobile manufacturers, polyvinyl chloride, which is often used as a material for the bottom layer of a car mat having a three-layer structure, needs flexibility such as rubber to be used as a backing material. Therefore, since a large amount of plasticizer is used for flexibility, it is difficult to fundamentally exclude the unpleasant odor problem caused thereby.

In addition, parts that require regular washing, such as automobile car mats, due to the poor heat resistance and cold resistance of polyvinyl chloride itself, have a problem of being damaged in the winter season and durability when exported to tropical regions. Especially, Since the heat stabilizer used contains a large amount of heavy metal, the heavy metal problem caused by the heat stabilizer added to complement not only the poor physical properties of the polyvinyl chloride material itself but also has an undesirable influence on the environment, Urgent substitution is necessary.

Compared with polyvinyl chloride, the styrene-butadiene-styrene copolymer has relatively good physical properties such as flexibility, heat resistance and cold resistance, but an unpleasant smell is recognized as an inevitable problem.

As an alternative material for polyvinyl chloride or styrene-butadiene-styrene copolymer, olefinic thermoplastic resin is typical. The olefinic thermoplastic resin is excellent in moldability during injection, extrusion and blow molding, and is competitive in terms of cost. However, in order to obtain the low-hardness characteristics required for a material requiring flexibility such as a backing material for automobile car mat It is essential to contain a large amount of rubber.

However, due to the presence of a large amount of rubber, there is a problem in that the extrusion coating and the calendering molding, which are the main molding methods of automobile car mat backing materials, have a problem in adhesiveness and also have a negative effect on the heat resistance of the formed product. In addition, Cost increases are large due to large use.

Therefore, the most important factor in developing a backing material for automobile car mat is high moldability such as extrusion coating and calendering while maintaining low hardness which can have softness as a backing material, high heat resistance and low temperature impact resistance .

As such a material suitable for use as an automobile interior material, particularly as a car mat backing material, there is an urgent need to develop a material having low hardness, high moldability, heat resistance and cold resistance at the same time

Korean Patent Publication No. 10-2012-0106078: Flexible Carpet Tile

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide an ethylene-olefin block copolymer, a styrene-isoprene-styrene copolymer or an ethylene -olefin copolymer, polyethylene, It is possible to have various properties required as an automobile car mat backing material, and it is confirmed that molding can be performed by various molding methods.

Therefore, the present invention relates to an ethylene-olefin block copolymer for improving moldability and a styrene-isoprene-styrene copolymer or a styrene-isoprene-styrene copolymer for improving the bonding strength between an ethylene-olefin block copolymer and a carpet fabric for low hardness and low- An automobile built-in car mat which has an intended hardness and has no objectionable odor and has excellent physical properties such as flexibility, heat resistance, cold resistance and moldability by using an ethylene-? - olefin random copolymer and simultaneously blending a predetermined amount of an inorganic filler with a processing oil And to provide a resin composition for backing material and a method for manufacturing a car mat using the same.

To achieve the above object, the present invention provides a resin composition for a car mat backing material comprising 20 to 50% by weight of an ethylene-olefin block copolymer; 5 to 20% by weight of a styrene-isoprene-styrene copolymer or an ethylene-? -Olefin random copolymer; 10 to 30% by weight of polyethylene; 1 to 30% by weight of any one selected from paraffinic oils, aromatic oils and naphthenic oils; 10 to 50% by weight of any inorganic filler selected from talc, calcium carbonate, magnesium hydroxide, calcium stearate, mica, silica, calcium silicate, clay and carbon black.

The ethylene-olefin block copolymer has a weight average molecular weight of 150,000 g / mol, a density of 0.87 g / cc, and a Shore A hardness of 60.

The styrene-isoprene-styrene copolymer had a weight average molecular weight of 200,000 g / mol, a styrene content of 15 wt%, a density of 0.89 g / cc and a Shore A hardness of 35.

The ethylene -? - olefin random copolymer has a weight average molecular weight of 140,000 g / mol, a density of 0.88 g / cc, and a Shore A hardness of 70.

The polyethylene has a weight average molecular weight of 100,000 g / mol and a density of 0.86 g / cc.

In order to accomplish the above object, the present invention provides a method for manufacturing a car mat of an automobile, which comprises the steps of mixing 20 to 50% by weight of an ethylene-olefin block copolymer and 0.1 to 5% by weight of a styrene- 1 to 30% by weight of at least one selected from the group consisting of paraffinic oils, aromatic oils and naphthenic oils, talc, calcium carbonate, magnesium hydroxide, calcium stearate, 10 to 50% by weight of any inorganic filler selected from mica, silica, calcium silicate, clay, and carbon black; An extrusion molding step of melting the resin composition obtained in the raw material mixing step to extrude the sheet-like backing material; And attaching the backing material to the other surface of the fabric sheet to which the flock fibers are bonded on one surface.

As described above, the present invention provides a styrene-isoprene-styrene copolymer or a styrene-isoprene-styrene copolymer for improving the bonding strength between an ethylene-olefin block copolymer and a fabric for lowering hardness and impact resistance at low temperatures, -olefin random copolymer and at the same time a blending of the processing oil with a certain amount of inorganic filler, it has the flexibility required for the backing material and has no unpleasant odor.

Further, it is excellent in heat aging resistance, heat cycle resistance, ground adhesion, moldability, and the like, and has an effect of improving the physical properties of the backing material of the conventional car mat.

1 is a side view of a car mat manufactured according to an embodiment of the present invention.

Hereinafter, a resin composition for a car mat backing material of an automobile according to a preferred embodiment of the present invention and a method for manufacturing a car mat using the same will be described in detail.

The resin composition for a car mat backing material for automobiles of the present invention is prepared by mixing an ethylene-olefin block copolymer, a styrene-isoprene-styrene copolymer or an ethylene-? -Olefin random copolymer, polyethylene, a processing oil and an inorganic filler.

The ethylene-olefin block copolymer improves the impact resistance, heat resistance and cold resistance at lowering of hardness and at low temperature.

The ethylene-olefin block copolymer has a polymer structure in which a rigid crystalline ethylene-olefin block and an elastic amorphous ethylene-olefin block are alternately linked. Olefins having 2 to 10 carbon atoms such as propylene, butene, pentene, hexene, propene, octene and the like can be used.

The ethylene-olefin block copolymer may have a weight average molecular weight of 150,000 g / mol, a density of 0.87 g / cc (based on ASTM D792) and a Shore A hardness of 60 (based on ASTM D2 240). Further, the ethylene-olefin block copolymer is suitable to have a melting temperature of around 120 캜 and a glass transition temperature of -70 캜 or lower.

The content of the ethylene-olefin block copolymer in the total weight of the resin composition is 20 to 50% by weight. When the content of the ethylene-olefin block copolymer is less than 20% by weight, desired heat resistance and cold resistance can not be obtained. When the content exceeds 50% by weight, the increase of the effect is insignificant.

The styrene-isoprene-styrene copolymer or the ethylene-? -Olefin random copolymer improves the bonding strength of the carpet fabric, that is, the support sheet to which the flock fibers are bonded.

The styrene-isoprene-styrene copolymer may have a weight average molecular weight of 200,000 g / mol, a styrene content of 15 wt%, a density of 0.89 g / cc (based on ASTM D792) and a Shore A hardness of 35 (based on ASTM D2 240). The styrene-isoprene-styrene copolymer preferably has a melting temperature of around 110 캜 and a glass transition temperature of -55 캜 or lower.

The ethylene -? - olefin random copolymer is a copolymer of ethylene and? -Olefin. As the? -olefin,? -olefins having 2 to 10 carbon atoms (propylene, butene, pentene, hexene, propene, octene, etc.) can be used. The ethylene -? - olefin random copolymer may have an? -Olefin content of 20 to 60% by weight.

The ethylene-? -Olefin random copolymer may have a weight average molecular weight of 140,000 g / mol and a density of 0.88 g / cc (based on ASTM D792) Shore A hardness of 70 (based on ASTM D2 240). The ethylene -? - olefin random copolymer has a melting temperature of 100 ° C or higher and a glass transition temperature of -50 ° C or lower.

The content of the styrene-isoprene-styrene copolymer or the ethylene-? -Olefin random copolymer in the total weight of the resin composition is 5 to 20% by weight. When the content is less than 5% by weight, desired adhesiveness, flexibility, elongation, impact resistance and the like can not be obtained. When the content is more than 20% by weight, the increase in the effect is insignificant.

Polyethylene improves processability and formability.

As the polyethylene, any one of high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE) and linear low density polyethylene (LLDPE) can be used. The polyethylene may have a weight average molecular weight of 100,000 g / mol and a density of 0.86 g / cc (based on ASTM D1505).

The content of polyethylene in the total weight of the resin composition is 10 to 30% by weight. When the content of polyethylene is less than 10% by weight, mechanical properties such as tensile strength and workability are deteriorated. When the content is more than 30% by weight, elasticity and flexibility are lowered.

Process oil is introduced for smooth workability while reducing hardness. Processing oil is a kind of softening agent, which aims at facilitating the flexibility and processability of the resin and increasing the volume. By using the processing oil, it is possible to improve moldability, scratch resistance and smell as a car mat backing material.

The processed oil is divided into Paraffinic, Naphthenic and Aromatic. On the other hand, the paraffin type is preferable in terms of the smell.

Paraffin oil has normal paraffin and iso-paraffine. It is excellent in odor side but low in strength, low compressibility, low temperature characteristic and stain resistance. This is a low feature.

Naphthenic oils show intermediate properties between paraffinic oils and aromatics oils. They are excellent in resistance to stains, low temperature, processability, aging resistance and cold resistance. However, they have poor tensile strength and modulus. Especially, Has weakness. Aromatic oils also have good physical properties such as naphthenic oil, but they have a weak smell problem.

Therefore, it is preferable to use a paraffinic system as the processing oil in view of reducing the sense of resistance to odor in the room, which is one of the major objects of the present invention. Paraffin oil has various products according to the kinematic viscosity, and products of 10 to 800 centistokes (cSt, 40 DEG C) can be used, but it is preferable to use products of 50 to 200 centistokes.

The content of the processed oil in the total weight of the resin composition is 1 to 30% by weight. Outside of the above range, oil-bleeding or exudation of the oil component during heat resistance evaluation becomes worse and fogging value becomes high.

The inorganic filler improves thermal deformation, increases stiffness, and improves ground adhesion of the backing material by increasing the weight. The inorganic filler may be at least one selected from talc, calcium carbonate, calcium sulfate, magnesium hydroxide, calcium stearate, mica, silica, calcium silicate, clay and carbon black. It is preferable to use calcium carbonate and talc as the inorganic filler. The inorganic filler preferably has a particle size of 1 to 20 mu m.

The content of the inorganic filler in the total weight of the resin composition is 10 to 50 wt%. When the content of the inorganic filler is less than 10% by weight, the workability may be deteriorated due to excessive tackiness. If the content is more than 50% by weight, the hardness increases and the smell becomes worse.

INDUSTRIAL APPLICABILITY The present invention is superior in flexibility and various physical properties to products made of conventional resin compositions and effectively suppresses an unpleasant smell, so that a better effect can be obtained when used as an automobile interior material, particularly as a backing material for car mats.

It should be understood that the resin composition for a car mat backing material of automobiles of the present invention can be applied to the field of replacing conventional polyvinyl chloride soft sheets such as automobile seat covers, head liners, and the like.

The resin composition for a car mat backing material of an automobile of the present invention can be extrusion-molded to produce a sheet-like backing material. Figure 1 shows a car mat of a vehicle to which such a backing material is applied.

1, a car mat 10 of an automobile includes a sheet-like backing material 20, a support sheet 30 coupled to the top of the backing material 20, And a fiber 50.

The support sheet 30 has a structure in which a fiber yarn is woven, and a polyethylene-based fiber can be used. Polyethylene terephthalate and polyvinylacetate copolymer fibers can also be used. Further, the support sheet 30 may be made of a nonwoven fabric.

The flock fibers 50 are bonded to the support sheet 30. The flock fibers 50 can be made by twisting several strands of nylon yarn.

The backing material 20 is bonded to the lower portion of the support sheet 30. The backing material 20 may be bonded to the support sheet 30 by an adhesive method or a heat fusion method.

The above-described manufacturing method of the car mat will be described.

First, 20 to 50% by weight of an ethylene-olefin block copolymer, 5 to 20% by weight of a styrene-isoprene-styrene copolymer or an ethylene-a-olefin random copolymer, 10 to 30% by weight of polyethylene, To 30% by weight of an inorganic filler and 10 to 50% by weight of an inorganic filler are mixed to prepare a resin composition.

Next, the resin composition is melted to extrude the sheet-like backing material. The extrusion molding can be carried out using a conventional extrusion molding machine.

Next, a backing material is attached to the other surface of the support sheet to which the flock fibers are bonded on one surface to produce a car mat. The backing agent can be attached to the support sheet by an adhesive method or a heat fusion method.

Preferably, the sheet-like backing agent is formed through a T-die laminating extruder, and at the same time, it is superimposed on the back of the fabric sheet and pressed. In this case, an adhesive layer may be previously applied to the back side of the fabric sheet to bond with the backing agent.

Hereinafter, the present invention will be described in detail with reference to the following examples. This is for the purpose of illustrating the present invention in more detail, and the scope of the present invention is not limited to the following examples.

(Example)

An ethylene-octene block copolymer was prepared from an ethylene-olefin block copolymer. The ethylene-octene block copolymer had a weight average molecular weight of 150,000 g / mol, a density of 0.87 g / cc (based on ASTM D792), a Shore A hardness of 60 (based on ASTM D2 240), a melting temperature of 120 캜, and a glass transition temperature of -70 캜 Respectively.

An ethylene-octene random copolymer was prepared from an ethylene- alpha -olefin random copolymer. The ethylene-octene random copolymer has a weight average molecular weight of 140,000 g / mol, a density of 0.88 g / cc (based on ASTM D792), a Shore A hardness of 70 (based on ASTM D2 240), a melting temperature of 100 ° C and a glass transition temperature of -50 ° C Respectively.

A linear low density polyethylene (HDPE) having a weight average molecular weight of 100,000 g / mol and a density of 0.86 g / cc (based on ASTM D1505) was used as the polyethylene.

Normal paraffin, a processed paraffin oil, was used. Talc powder with particle size of about 10 ㎛ was used as an inorganic filler.

A resin composition was obtained by blending 30% by weight of an ethylene-olefin block copolymer, 15% by weight of an ethylene-? -Olefin random copolymer, 20% by weight of polyethylene, 10% by weight of processed oil and 25% by weight of an inorganic filler. Then, the resin composition was extrusion-molded into a sheet-like backing material by using an extrusion-molding machine of a T-die laminating method, and the resin composition was assembled on the back surface of the support sheet to which the flock fibers were bonded and cooled.

(Comparative Example 1)

A sheet-like backing material was extruded by using an extrusion molding machine of a Ti-die laminating system, and then a PVC resin (P-1000, Hanwha Chemical, Korea) was extruded and then foamed on the back surface of the support sheet to which the flock fibers were bonded, Mats were produced.

(Comparative Example 3)

SBS resin (KTR-101, KKPC, Korea) was extrusion-molded into a sheet-like backing material using an extrusion-molding machine of a Ti-die laminating system, Car mat.

<Evaluation of physical properties of car mat>

1. Experimental Method

(1) Shore A hardness

JIS K 6301 and measured with a Shore hardness tester of Zwick, Switzerland on a 15 cm × 15 cm × 0.6 cm backing specimen. Retention time was 10 seconds. The Shore hardness indicates the degree of flexibility of the product, and the lower the value, the softer the product is produced.

(2) Heat aging resistance

The car mat was heat-aged for about 300 hours using a hot air circulating oven at 70 DEG C, and the surface cracking state and the deformation state of the mat were observed. The evaluation criteria were as follows. In actual use, the concentration at the time of use is affected by the climate and the environment of each country. The hotter the fat, the worse the heat aging of the product occurs. Therefore, the better the heat aging resistance, the less the deterioration in performance in hot weather over long periods of use.

(3) Heat resistance Cycle property

(80 ° C. × 3 hr → 25 ° C. × 1 hr → -30 ° C. × 3 hr → 25 ° C. × 1 hr → 50 ° C., relative humidity 95% × 10 hr → 25 ° C. × 1 hr) was performed for 1 cycle (cycle). After 3 cycles, the deformation and appearance changes were observed and evaluated under the weight. The evaluation criteria are shown in Table 1 below.

(4) Ground adhesion

The adhesion was evaluated by whether or not the entire car mat adhered to the flat surface with no floating portion in a state where the car mat was placed on the flat surface. The evaluation criterion was evaluated as "upper" if there was no supersaturation, "middle" when there was a slight supersaturation, and "lower" when it was completely deformed toward the center. When the surface adhesion is 'above', it is excellent in the function of the actual product and appearance in installation.

(5) Fogging Value

The car mat was cut into a 70 mm diameter circle, placed in a beaker, covered with a clean glass plate, heated in a container filled with silicone oil, heated at 100 ° C. for 4 hours, and then the glass plate was measured with a hazemeter.

(6) Moldability

Moldability was evaluated for T-die extrusion coating molding. Adhesion to rolls, adhesion to fabric sheets, and molding conditions of backing materials were evaluated during the compression coating of backing material and fabric sheet.

2. Experimental results

The experimental results are shown in Table 1 below.

division Hardness Heat aging resistance Heat Cycle Property Ground adhesion Litter Formability Example 60A Prize Prize medium 5 Good Comparative Example 1 85A Ha Ha Ha 25 Good Comparative Example 2 55A Prize Prize Prize 3 Good (Note): Up-deformation, medium-deformation, under-deformation + crack

Referring to Table 1, it can be seen that the flexibility required for the backing material is reinforced in the case of the carmat applied with the backing material molded from the resin composition of the embodiment of the present invention. In addition, it was found that the physical properties were improved due to excellent heat aging resistance and heat cycle resistance, and the ground adhesion was also improved. Also, it was found that the moldability which is pointed out as a problem of economical and manufacturing process is good.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation.

10: Car mat 20: Backing material
30: support sheet 50: flock fiber

Claims (6)

delete delete delete delete delete A process for producing an ethylene-octene block copolymer comprising 20 to 50% by weight of an ethylene-octene block copolymer, 5 to 20% by weight of an ethylene-octene random copolymer, 10 to 30% by weight of polyethylene, 1 to 30% by weight of normal paraffin as a processing oil, 10 to 50% by weight of a talc powder having a particle diameter of 10 mu m;
An extrusion molding step of melting the resin composition obtained in the raw material mixing step to extrude the sheet-like backing material;
And attaching the backing material to the other surface of the support sheet to which the flock fibers are bonded on one side and the polyethylene yarn is woven,
The ethylene-octene block copolymer had a weight average molecular weight of 150,000 g / mol, a density of 0.87 g / cc, a Shore A hardness of 60, a melting temperature of 120 캜, a glass transition temperature of -70 캜,
The ethylene-octene random copolymer had a weight average molecular weight of 140,000 g / mol, a density of 0.88 g / cc, a Shore A hardness of 70, a melting temperature of 100 캜, a glass transition temperature of -50 캜,
The polyethylene is a linear low density polyethylene having a weight average molecular weight of 100,000 g / mol and a density of 0.86 g / cc,
Wherein the attaching step is performed by pressing the backing material over the support sheet while being extruded through an extrusion molding machine of a T-die laminate type.

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