KR101814003B1 - Automotive interior foam composition using an olefin block copolymer and method for manufacturing a foam using the same - Google Patents

Abstract

The present invention relates to an automotive interior foam composition using an olefin block copolymer and to a method for manufacturing a foam using the same, according to the disclosure, and more specifically, to an automotive interior foam composition using an olefin block copolymer, which maintains hardness, tensile strength and rebound resilience to have an excellent effect of having excellent durability and improving mechanical properties despite a fact that the specific gravity became lowered as a resin mixture in which the olefin block copolymer is mixed is used for the manufacture. In addition, the foam composition according to the disclosure is applied to the inside of an automobile to mitigate external impact, thereby providing a driver with a sense of stability and comfort at the time of driving.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a foam composition for an automobile interior material using an olefin block copolymer, and a method for manufacturing a foam using the foam composition.

The present invention relates to a foam composition for an automobile interior material using an olefin block copolymer and a method for producing a foam using the foam composition. More particularly, the present invention relates to a foam composition for an automobile interior material using an olefin block copolymer, The present invention relates to a foam composition for an automobile interior material using an olefin block copolymer and a method for producing a foam using the same.

Typical automotive interior materials include dashboards, instrument panels, center fascia, console boxes, glove boxes, car seats, headliners, package trays and door trim.

These automotive interior materials are mainly made by mixing materials such as polyurethane foam, polypropylene, phthalate, woodfiber, woodstock and resin felting, .

However, in the case of the above-mentioned polyurethane foam, since air permeability is insufficient, environmental pollutants are generated in burning, and wood fiber and resin felt contain phenol components which are harmful to human body, and formaldehyde, which is a gas with odor and irritation, It has a disadvantage that the health of the driver is adversely affected and the yellowing phenomenon occurs and the aesthetic appearance is hindered.

In addition, the conventional foam composition for automobile interior materials has a problem in that the production method is complicated, the defective ratio is high, the manufacturing cost is increased, and the demand for high quality and high performance of automobile interior material is not satisfied.

Korean Patent Registration No. 10-1190380 (Oct. Korean Patent Registration No. 10-1554377 (2015.09.14.).

It is an object of the present invention to provide a method for producing a foam for automobile interior materials using a woolen block copolymer having improved durability and mechanical properties while retaining hardness, tensile strength and rebound resilience in spite of its low specific gravity.

In one embodiment, the present disclosure provides a foam composition for an automobile interior material using an olefin block copolymer, which comprises a resin mixture using an olefin block copolymer, a foaming agent, a crosslinking agent, a crosslinking agent, a processing aid, and an additive .

In another embodiment, the disclosure is directed to a process for producing a blend of olefin block copolymers, which comprises mixing a resin mixture, a processing aid and additives mixed with an olefin block copolymer in a first mixing step, mixing the blended mixture through the first mixing step with a foaming agent, A second mixing step, an extrusion molding step of extruding the mixed mixture through the second mixing step, a pellet processing step of processing the extruded molded product through the extrusion molding step into a pellet form, and a pellet processing step And a foaming and injecting step of foaming and injecting the pellets of the present invention.

As another embodiment, the disclosure discloses a method for producing a polyolefin resin composition which comprises a first mixing step of mixing a resin mixture, a processing aid and additives mixed with an olefin block copolymer, a mixing step of mixing a foaming agent, a crosslinking agent and a crosslinking auxiliary agent A second mixing step of extruding the mixed mixture through the second mixing step, an extrusion molding step of extruding the mixed mixture through the second mixing step, a step of processing the extrusion molded product through the extrusion molding step into a sheet form, And a step of press foaming, wherein the olefin block copolymer is produced by a method comprising the steps of:

Since the foam composition for an automobile interior material using the olefin block copolymer as described above is produced by using the resin mixture in which the olefin block copolymer is mixed, the hardness, the tensile strength and the rebound resilience are maintained despite the low specific gravity, And the mechanical properties are improved.

In addition, it is applied to the interior of the vehicle to mitigate the impact of the outside, thereby providing the driver with stability and comfort during driving.

1 is a flowchart illustrating a method of manufacturing a foam for automobile interior using an olefin block copolymer according to an embodiment of the present invention.
2 is a flowchart illustrating a method of manufacturing a foam for automobile interior using an olefin block copolymer disclosed in another embodiment.
3 is a photograph showing a foam injection molding machine used in a method of manufacturing a foamed product according to an embodiment.

Hereinafter, the preferred embodiments of the present disclosure and the physical properties of the respective components will be described in detail, which is explained in detail so as to be easily practiced by those skilled in the art. , And this does not mean that the technical idea and scope of the disclosed contents are limited.

A foam composition for an automotive interior material using the disclosed olefin block copolymer comprises 100 parts by weight of a resin mixture comprising an olefin block copolymer and a resin mixture comprising an olefin block copolymer, a foaming agent, a crosslinking agent, a crosslinking auxiliary, a processing aid, 14 to 22 parts by weight of a blowing agent, 0.5 to 1 part by weight of a crosslinking agent, 0.1 to 0.5 parts by weight of a crosslinking auxiliary, 0.5 to 1.5 parts by weight of a processing aid and 3 to 7 parts by weight of an additive.

The resin mixture in which the olefin block copolymer is mixed preferably comprises 100 parts by weight of the olefin block copolymer and 2 to 8 parts by weight of the ethylene propylene diene monomer.

The olefin block copolymers (OBC) are prepared by synthesizing a block polymer of a polyolefin and a polar polymer, and exhibit excellent thermoplasticity and elasticity because they exhibit superior thermoplastic behavior compared to conventional random copolymers and blends.

The olefin block copolymer is preferably an alpha-olefin copolymer. The alpha-olefin copolymer may be a conventional ethylene copolymer having a comonomer distribution of random or block structure, Characterized by having a uniform comonomer distribution and a lower density at the same comonomer content.

The Ethylene Propylene Diene Monomer (EPDM) is a thermoplastic elastomer containing polypropylene as a resin component. It lowers the possibility of occurrence of cracking in the production of a foam composition, has excellent durability and elasticity, and is applicable to various industrial fields This excellent thermoplastic elastomer is provided. If the content of the ethylene propylene diene monomer is less than 2 parts by weight, the flexibility at low temperatures is reduced and the improvement in impact resistance becomes insufficient. When the content of ethylene propylene diene monomer is more than 8 parts by weight, the hardness is excessively increased.

The resin mixture in which the olefin block copolymer is mixed preferably further comprises 13 to 100 parts by weight of ethylene vinyl acetate relative to 100 parts by weight of the olefin block copolymer.

Ethylene-Vinyl Acetate (EVA) has strong adhesive force and flexibility and is easy to mold, and exhibits impact absorption and impact prevention. If the content of ethylene vinyl acetate is less than 13 parts by weight, the impact resistance is not improved. If the content of ethylene vinyl acetate exceeds 100 parts by weight, the improvement of impact resistance becomes insignificant and the manufacturing cost is increased.

The resin mixture in which the olefin block copolymer is mixed preferably further comprises 20 to 100 parts by weight of the polyolefin elastomer relative to 100 parts by weight of the olefin block copolymer.

The polyolefin elastomer (POE) has excellent rigidity, flexibility, and excellent elasticity, and is effective for shock absorption. When the content of the polyolefin elastomer is less than 20 parts by weight, the impact resistance is not improved. When the content of the polyolefin elastomer is more than 100 parts by weight, the improvement of the impact resistance is insignificant and the manufacturing cost is increased.

The resin mixture in which the olefin block copolymer is mixed preferably further contains 50 to 100 parts by weight of other polymer relative to 100 parts by weight of the olefin block copolymer.

If the content of the other polymer is less than 50 parts by weight, the heat resistance and the elasticity do not improve. When the content of the other polymer exceeds 100 parts by weight, the improvement of the impact resistance becomes insignificant and the manufacturing cost is increased.

At this time, the other polymer is polyethylene. It is preferably made of at least one selected from the group consisting of polyvinyl chloride, polyamide, polycarbonate, polyethylene terephthalate, polyoxymethylene, and polystyrene, and most preferably made of polyethylene.

The foaming agent is contained in an amount of 14 to 22 parts by weight and serves to foam the product produced by reacting the resin mixture, crosslinking agent, crosslinking aid, processing aid, and additives mixed with the olefin block copolymer. The foaming agent can be made lighter in weight by lengthening the number of pores formed during the foaming process.

When the content of the foaming agent is less than 14 parts by weight, the foaming efficiency is decreased. When the content of the foaming agent is more than 22 parts by weight, the foaming effect is not improved and the manufacturing cost is increased.

If the expansion ratio is less than 8 times, the number of pores is too small, the weight is heavy, sound absorption and sound insulation performance are lowered, and the expansion ratio is 18 times , The weight is lighter, but mechanical properties are deteriorated.

The foaming agent used in the present invention is preferably a chemical foaming agent. Examples of the foaming agent include organic thermally decomposable foaming agents such as azodicarbonamide, N, N'-dinitrosopentamethylenetetramine and benzenesulfonylhydrazide, And an inorganic pyrolytic foaming agent such as sodium hydrogen carbonate, ammonium hydrogen carbonate, ammonium carbonate, and the like. Of these, azodicarbonamide is most preferably used .

The cross-linking agent is contained in an amount of 0.5 to 1 part by weight, and is selected from the group consisting of dicumyl peroxide, t-butylperoxy diisopropylbenzene, di-t-butyl peroxide, trimethylcyclohexane, t- Butyl peroxy isopropyl carbonate, t-butyl peroxylaurate, t-butyl peroxyacetate, t-dibutyl peroxymaleic acid, cyclohexanone peroxide, t-butyl hydroperoxide, Bis (t-butylperoxy) valerate, and a, a-butylperoxy- And bis (t-butylperoxy) diisopropylbenzene. When the amount of the crosslinking agent is less than 0.5 parts by weight, the crosslinking rate is slow and the crosslinking ratio is low, When the content of the cross-linking agent exceeds 1 part by weight, the formed foot The molecular weight of the porous body is excessively increased and the workability is lowered.

The crosslinking aid is contained in an amount of 0.1 to 0.5 parts by weight, and serves to control the crosslinking speed and improve the mechanical strength of the foam.

In addition, when a foam is manufactured using a crosslinking aid, the viscosity of the foam is lowered during the production process, so that the workability is improved, the volatile gas generation is suppressed, the working environment is improved, and the stability against the scorch .

When the amount of the crosslinking aid is less than 0.1 parts by weight, the crosslinking efficiency is lowered. When the amount is more than 0.5 parts by weight, the mechanical strength is not further improved, and the crosslinking is unbalanced and the appearance of the foam is lowered.

At this time, the crosslinking assistant may contain a small amount of sulfur, triallyl isocyanurate, triallyl isocyanurate, trimethylol, propane trimethacrylate, butylene glycol dimethacrylate and metal-acrylate, metal-methacrylate May be used alone or in combination of two or more.

The processing aid is contained in an amount of 0.5 to 1.5 parts by weight, and improves the crosslinking and foaming properties and improves the processability, thereby improving the appearance quality of the foam.

When the content of the processing aid is less than 0.5 parts by weight, the workability is not improved. When the amount is more than 1.5 parts by weight, the improvement of the workability is insignificant and the manufacturing cost is increased.

The processing aid may be one or more selected from the group consisting of palm stearine based hydrogenated fatty acid, dibutyl ammonium oleate, unsaturated fatty acid amide, and octadecanamide. .

The additive is contained in an amount of 3 to 7 parts by weight and significantly improves the mechanical, chemical and electrical properties for the purpose of reducing the compounding cost due to the increase in volume, improving the quality characteristics and imparting special functions.

If the amount of the additive is less than 3 parts by weight, the foaming property with the foam is insignificant, and the mechanical, chemical and electrical properties are not improved. If the additive is more than 7 parts by weight, the effect of improving the chemical, electrical and mechanical properties It does not show any further increasing effect and increases the manufacturing cost.

The additives include metal oxides such as cadmium oxide, zinc oxide, magnesium oxide, silver oxide, tin oxide, lead oxide, aluminum silicate, clay, talc, carbon black, graphene, glass fiber, PP fiber, silica block, Calcium oxide, and titanium oxide.

In addition to the disclosed components, commonly used additives such as foaming aids, fillers and fillers may be added.

Also, the method for producing a foam for an automobile interior material using the disclosed olefin block copolymer includes a first mixing step (S101) of mixing a resin mixture, a processing aid, and an additive in which an olefin block copolymer is mixed, a first mixing step (S101) (S103) mixing the foaming agent, the cross-linking agent and the crosslinking aid to the mixed mixture through the second mixing step (S103); an extrusion molding step (S105) of extruding the mixed mixture through the second mixing step (S103) A pellet processing step S107 for processing the extruded molded product through step S105 into a pellet form and a foam injection step S109 for foaming and injecting the processed pellet through the pellet processing step S107.

The first mixing step (S101) is a step of mixing the resin mixture, processing aid, and additives mixed with the olefin block copolymer, and kneaded in a kneader at a temperature of 100 to 125 ° C for 10 to 12 minutes.

The second mixing step (S103) is a step of mixing the foaming agent, the crosslinking agent and the crosslinking aid to the mixed mixture through the first mixing step (S101). The mixing step is carried out in a kneader at a temperature of 100 to 125 ° C for 3 to 5 minutes Lt; / RTI >

At this time, the components and roles of the resin mixture, the foam, the crosslinking agent, the crosslinking agent, the processing aid, and the additive mixed with the olefin block copolymer are the same as those described in the foam composition for an automobile interior material using an olefin block copolymer. Is omitted.

The temperature of the extruder, the temperature of the extruding screw, and the temperature of the extrusion die may be adjusted by adjusting the temperature of the extruder, which is necessary for the extrusion, in the extrusion molding step (S105) And the temperature is set, but is not particularly limited.

The pellet processing step (S107) is a step of processing the extruded molded product through the extrusion molding step (S105) into a pellet shape. More specifically, the extruded molded product through the extrusion molding step (S105) It is preferable that the cooling water is cooled by passing through a cooling water bath, and the cooled cooling water is cut into pellets having a length of 2 to 3 mm by using a pelletizing machine.

The foam injection step S109 is a step of foaming the processed pellets through the pellet processing step S107 and then molding the pellets processed through the pellet processing step S107 into a foam injection molding machine (Injection Mold Type) into a foaming mold and injecting and foaming the foams in an appropriate pressure.

If such a foam injection molding machine as described above is used, it is possible to produce a complicated and small-shaped foam which is difficult to produce by the foam press method.

The foam injected and foamed through the foam injection step (S109) is preferably cooled through a stabilization process after the foaming is completed, and the foam obtained through the stabilization process as described above has improved morphological stability.

The method for producing a foam for an automobile interior material using the disclosed olefin block copolymer includes a first mixing step (S201) of mixing a resin mixture, processing aid and additives mixed with an olefin block copolymer (S201), a first mixing step (S201) A second mixing step S203 of mixing the foaming agent, the crosslinking agent and the crosslinking aid to the mixed mixture through the second mixing step S203, an extrusion molding step S205 of extruding the mixed mixture through the second mixing step S203, And a press foaming step (S207) of processing the extruded molded product through a step S205 into a sheet form and foaming the processed sheet with a foaming press.

The first mixing step (S201) is a step of mixing the resin mixture, the processing aid, and the additives mixed with the olefin block copolymer, and kneaded in a kneader at a temperature of 100 to 125 ° C for 10 to 12 minutes.

The second mixing step (S203) is a step of mixing the foaming agent, the crosslinking agent and the crosslinking aid into the mixed mixture through the first mixing step (S201). The mixing is carried out in a kneader at a temperature of 100 to 125 ° C for 3 to 5 minutes Lt; / RTI >

At this time, the components and roles of the resin mixture, the foam, the crosslinking agent, the crosslinking agent, the processing aid, and the additive mixed with the olefin block copolymer are the same as those described in the foam composition for an automobile interior material using an olefin block copolymer. Is omitted.

The temperature of the extruder, the temperature of the extruder screw, and the temperature of the extruder die may be adjusted by adjusting the temperature of the extruder, which is necessary for the extrusion, in the extrusion molding step (S205) And the temperature is set, but is not particularly limited.

The press foaming step S207 is a press foaming step S207 of cutting the molded product extruded through the extrusion molding step S205 into a sheet form and foaming the foamed product into a foam press, And the foamed material is foamed in a state in which an appropriate pressure is applied to form the foam.

Using such a foam press machine, it is possible to manufacture a foam suitable for a large-sized product.

The foams foamed and injected through the press foaming step (S207) are preferably cooled through a stabilization process after the foaming is completed, and the foam obtained through the stabilization process as described above has improved morphological stability.

In addition, the foam made from the foam composition for an automobile interior material using the olefin block copolymer according to the disclosure may be used as a sheet, a crash pad, a headliner, a built-in trim pillar, an instrument panel, a sheet foam, a door interior finishing material, And a head cushioning material, a sun visor, a sound absorbing pad and a floor pad, and the like.

Hereinafter, the physical properties of the foam composition for an automobile interior material according to the disclosure will be described with reference to examples.

≪ Example 1 >

Olefin block copolymer (25 parts by weight of an olefin block copolymer, 25 parts by weight of ethylene vinyl acetate, 24 parts by weight of a polyolefin elastomer, 24 parts by weight of polyethylene and 2 parts by weight of ethylene propylene diene monomer) were mixed with 100 parts by weight of stearic acid 1 3 parts by weight of zinc oxide and 2 parts by weight of titanium oxide were mixed in a kneader at 112.5 DEG C for 11 minutes, and 14 parts by weight of azodicarbonamide, 0.8 parts by weight of dicumyl peroxide and 0.25 parts by weight of triallyl isocyanurate The mixture was further extruded in an extruder and charged into a foam injection molding machine set at a mold temperature of 170 占 폚, a vulcanization time of 420 seconds, an injection pressure of 125 bar and a polymer melt temperature of 130 占 폚 A foam for automobile interior using an olefin block copolymer was prepared.

≪ Example 2 >

, 1 part by weight of stearic acid, 10 parts by weight of zinc oxide (hereinafter referred to as " polyvinyl alcohol "), 100 parts by weight of a resin mixture containing an olefin block copolymer (37.5 parts by weight of an olefin block copolymer, 50 parts by weight of ethylene vinyl acetate, 10.5 parts by weight of a polyolefin elastomer and 2 parts by weight of ethylene propylene diene monomer) And 2 parts by weight of titanium oxide were mixed in a kneader at 112.5 DEG C for 11 minutes, and further added with 14 parts by weight of azodicarbonamide, 0.8 part by weight of dicumyl peroxide and 0.25 part by weight of triallyl isocyanurate to obtain 112.5 The mixture was extruded in an extruder and charged into a foam injection molding machine set at a mold temperature of 170 DEG C, a vulcanization time of 420 seconds, an injection pressure of 125 bar and a polymer melt temperature of 130 DEG C to obtain an olefin block copolymer To prepare a foam for automobile interior material.

≪ Example 3 >

100 parts by weight of a resin mixture containing an olefin block copolymer (50 parts by weight of an olefin block copolymer, 37.5 parts by weight of ethylene vinyl acetate, 10.5 parts by weight of a polyolefin elastomer, and 3 parts by weight of ethylene propylene diene monomer, 1 part by weight of stearic acid, And 2 parts by weight of titanium oxide were mixed for 11 minutes at a temperature of 112.5 DEG C, and then 14 parts by weight of azodicarbonamide, 0.8 part by weight of dicumyl peroxide and 0.25 part by weight of triallyl isocyanurate were further added thereto, The mixture was extruded in an extruder and charged into a foam injection molding machine set at a mold temperature of 160 DEG C, a vulcanization time of 450 seconds, an injection pressure of 125 bar and a polymer melt temperature of 130 DEG C to obtain an automobile using an olefin block copolymer To prepare a foam for an interior material.

<Example 4>

1 part by weight of stearic acid, 3 parts by weight of zinc oxide and 2 parts by weight of titanium oxide were kneaded at 112.5 DEG C in 100 parts by weight of a resin mixture (olefin block copolymer: 98 parts by weight and ethylene propylene diene monomer: 2 parts by weight) 14 parts by weight of azodicarbonamide, 0.8 parts by weight of dicumyl peroxide and 0.25 part by weight of triallyl isocyanurate were further added and mixed for 4 minutes in a kneader at 112.5 DEG C, Extruded and injected into a foam injection molding machine set at a mold temperature of 170 占 폚, a vulcanization time of 420 seconds, an injection pressure of 125 bar and a polymer melt temperature of 130 占 폚 to prepare an automotive interior foam using an olefin block copolymer.

&Lt; Example 5 >

Olefin block copolymer (30 parts by weight of an olefin block copolymer, 25 parts by weight of ethylene vinyl acetate, 25 parts by weight of a polyolefin elastomer, 18 parts by weight of polyethylene and 2 parts by weight of an ethylene propylene diene monomer) were mixed with 100 parts by weight of stearic acid 1 3 parts by weight of zinc oxide and 2 parts by weight of titanium oxide were mixed in a kneader at 112.5 DEG C for 11 minutes, and 18 parts by weight of azodicarbonamide, 0.8 part by weight of dicumyl peroxide and 0.25 part by weight of triallyl isocyanurate The mixture was further extruded in an extruder and charged into a foam injection molding machine set at a mold temperature of 170 占 폚, a vulcanization time of 420 seconds, an injection pressure of 125 bar and a polymer melt temperature of 130 占 폚 A foam for automobile interior using an olefin block copolymer was prepared.

&Lt; Example 6 >

Olefin block copolymer (30 parts by weight of an olefin block copolymer, 25 parts by weight of ethylene vinyl acetate, 25 parts by weight of a polyolefin elastomer, 18 parts by weight of polyethylene and 2 parts by weight of an ethylene propylene diene monomer) were mixed with 100 parts by weight of stearic acid 1 3 parts by weight of zinc oxide and 2 parts by weight of titanium oxide were mixed in a kneader at 112.5 DEG C for 11 minutes, and 20 parts by weight of azodicarbonamide, 0.8 parts by weight of dicumyl peroxide and 0.25 parts by weight of triallyl isocyanurate The mixture was further extruded in an extruder and charged into a foam injection molding machine set at a mold temperature of 170 占 폚, a vulcanization time of 420 seconds, an injection pressure of 125 bar and a polymer melt temperature of 130 占 폚 A foam for automobile interior using an olefin block copolymer was prepared.

&Lt; Comparative Example 1 &

1 part by weight of stearic acid, 3 parts by weight of zinc oxide and 2 parts by weight of titanium oxide were mixed in a kneader at 112.5 DEG C for 11 minutes, 14 parts by weight of azodicarbonamide, 0.8 parts by weight of dicumyl peroxide and 0.25 part by weight of triallyl isocyanurate were further added and mixed in a kneader at 112.5 DEG C for 4 minutes, extruded in an extruder, , A vulcanization time of 420 seconds, an injection pressure of 125 bar and a polymer melt temperature of 130 캜 to prepare a foam for an automobile interior using an olefin block copolymer.

The specific gravity, tensile strength, hardness, rebound resilience and foaming ratio of the foam for automobile interior using the olefin block copolymer prepared in Examples 1 to 6 and Comparative Example 1 were measured as follows and shown in Table 1 below.

1) Specific gravity: KS M 6660 or ASTM D 296-13

Specific gravity is measured by the following formula using the mass of the specimen underwater and the mass of the specimen outside the water using an automatic gravity meter while sampling a sample of the foam by the specified standard.

Sg: specific gravity (t / 4)

W: Mass of the specimen in air (g)

W: Mass of the specimen in water (g)

W: Mass of the weight to which the specimen is fixed in water (g)

d: Specific gravity of water at t

At this time, the values deviating by more than 20% are excluded, and the average value is obtained by measuring 5 times for each test piece.

2) Tensile strength: KS M 6518 or ASTM D 412-06a

Test specimens were prepared with a dumbbell No. 1 cutter according to KS M 6518, and tensile strength and elongation were measured at a tensile speed of 200 mm / min. At this time, three pieces per each test piece are measured by the following equations and the average value is obtained.

3) Hardness: KS M 6518 or ASTM D 2240

The hardness is measured with Acker C type hardness meter according to ASTM D2240 in the smooth middle part with the skin layer on one side of the foam removed with a skiving machine. The thickness of the test specimen shall be 10mm and the distance between measuring points shall be 6mm or more.

4) Ball rebound Resilience: KS M ISO 8307 or ASTM D 3574-11

The prepared foam is made into a cylindrical shape with a diameter of 29 mm and a thickness of 1 mm, and ball rebound resilience is measured.

The elasticity of the foam is measured by a ball drop method using a sheet having a thickness of 10 mm or more and repeating the same experiment three times to calculate the average by discarding the maximum and minimum values.

As shown in Table 1, the foam for an automobile interior material using the olefin block copolymer prepared in Examples 1 to 6 had a specific gravity of at least 7% (volume 10% increase) as compared with the foam composition for automobile interior material of Comparative Example 1, The rebound resilience increases or decreases by up to 10%, even though it decreases by up to 34% (volume 50% increase). The tensile strength and hardness properties decreased with decreasing specific gravity. However, it can be confirmed that the variation of property decrease is not larger than that of lower specific gravity.

In addition, the present invention is applied to the inside of a vehicle to mitigate external impact, thereby providing a driver with a sense of security and comfort during driving.

Accordingly, the foam for automobile interior materials using the disclosed olefin block copolymer has a low specific gravity and can be made lighter, maintains hardness, tensile strength and rebound resilience, and has excellent durability and mechanical properties. A method for producing a foam is provided.

S101; The first mixing step
S103; The second mixing step
S105; Extrusion step
S107; Pellet processing step
S109; Foam injection stage
S201; The first mixing step
S203; The second mixing step
S205; Extrusion step
S207; Press Foaming Phase

Claims (16)

Olefin block copolymer, 14 to 22 parts by weight of a blowing agent, 0.5 to 1 part by weight of a crosslinking agent, 0.1 to 0.5 parts by weight of a crosslinking auxiliary, 0.5 to 1.5 parts by weight of a processing aid and 3 to 7 parts by weight of an additive In addition,
Wherein the resin mixture in which the olefin block copolymer is mixed comprises 100 parts by weight of an olefin block copolymer, 2 to 8 parts by weight of ethylene propylene diene monomer, and 13 to 100 parts by weight of ethylene vinyl acetate. Lt; / RTI &gt;
delete delete delete The method according to claim 1,
Wherein the resin mixture in which the olefin block copolymer is mixed further comprises 20 to 100 parts by weight of a polyolefin elastomer relative to 100 parts by weight of the olefin block copolymer.
The method according to claim 1,
Wherein the resin mixture in which the olefin block copolymer is mixed further contains 50 to 100 parts by weight of other polymer relative to 100 parts by weight of the olefin block copolymer.
The method of claim 6,
The other polymer is polyethylene. Wherein the foam composition comprises at least one selected from the group consisting of polyvinyl chloride, polyamide, polycarbonate, polyethylene terephthalate, polyoxymethylene, and polystyrene.
The method according to claim 1,
The foaming agent may be an organic pyrolytic foaming agent such as azodicarbonamide, N, N'-dinitrosopentamethylenetetramine or benzenesulfonylhydrazide, and an inorganic pyrolytic foaming agent such as sodium hydrogencarbonate, ammonium hydrogencarbonate or ammonium carbonate. Wherein the olefin block copolymer is one or two or more selected from the group consisting of ethylene, propylene, and propylene.
The method according to claim 1,
The crosslinking agent may be at least one selected from the group consisting of dicumylperoxide, luperox, di-t-butylperoxide, trimethylcyclohexane, t-butylcumylperoxide, t-butylperoxyisopropylcarbonate, t-butylperoxylaurate, Peroxyacetate, t-dibutylperoxymaleic acid, cyclohexanone peroxide, t-butyl hydroperoxide, methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) n-butyl-4,4-bis (t-butylperoxy) valerate, and a, a-bis (t-butylperoxy) diisopropylbenzene. Wherein the olefin block copolymer is an olefin block copolymer.
The method according to claim 1,
Wherein the crosslinking aid is selected from the group consisting of sulfur, triallyl cyanurate, triallyl isocyanurate, trimethylol, propane trimethacrylate, butylene glycol dimethacrylate, metal-acrylate and metal-methacrylate Wherein the foam composition comprises one or more selected from the group consisting of olefin block copolymers.
The method according to claim 1,
Wherein the processing aid is one or more selected from the group consisting of stearic acid, dibutylammonium-oleate, unsaturated fatty acid amide and octadecanamide.
The method according to claim 1,
The additive is selected from the group consisting of cadmium oxide, zinc oxide, magnesium oxide, silver oxide, tin oxide, lead oxide, aluminum silicate, clay, talc, carbon black, graphene, glass fiber, PP fiber, silica block, calcium oxide and titanium oxide Based on the weight of the olefin block copolymer. &Lt; Desc / Clms Page number 15 &gt;
A first mixing step of mixing a resin mixture, processing aid, and additives mixed with an olefin block copolymer;
A second mixing step of mixing the foaming agent, the crosslinking agent and the crosslinking aid into the mixed mixture through the first mixing step;
An extrusion molding step of extruding the mixed mixture through the second mixing step;
A pellet processing step of processing the extruded molded product through the extrusion molding step into a pellet form; And
And a foaming and injecting step of foaming and injecting the processed pellets through the pellet processing step,
Wherein the resin mixture in which the olefin block copolymer is mixed comprises 100 parts by weight of an olefin block copolymer, 2 to 8 parts by weight of ethylene propylene diene monomer, and 13 to 100 parts by weight of ethylene vinyl acetate. Gt;
A first mixing step of mixing a resin mixture, processing aid, and additives mixed with an olefin block copolymer;
A second mixing step of mixing the foaming agent, the crosslinking agent and the crosslinking aid into the mixed mixture through the first mixing step;
An extrusion molding step of extruding the mixed mixture through the second mixing step; And
And a press foaming step of processing the extruded molded product through the extrusion molding step into a sheet form and foaming the processed sheet with a foaming press,
Wherein the resin mixture in which the olefin block copolymer is mixed comprises 100 parts by weight of an olefin block copolymer, 2 to 8 parts by weight of ethylene propylene diene monomer, and 13 to 100 parts by weight of ethylene vinyl acetate. Gt;
14. The method according to claim 13 or 14,
Wherein the first mixing step is performed in a kneader at a temperature of 100 to 125 ° C. for 10 to 12 minutes.
14. The method according to claim 13 or 14,
Wherein the second mixing step is performed in a kneader at a temperature of 100 to 125 DEG C for 3 to 5 minutes. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt;

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