KR100506754B1 - Thermoplastic resin composition for excellent female vacuum thermoforming sheet and method for preparing the same - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition for a plastic sheet and a method for manufacturing the same, and more particularly, to low-density linear polyethylene (EMBOSS) transfer force to a partially crosslinked polypropylene resin having excellent melt strength (EMBOSS). It contains a suitable amount of stabilizer together with Polyethylene) and Branched Polypropylenen, and it has a wide working range in the rolling process, and has excellent vacuum forming. It is about.

Description

Thermoplastic resin composition for excellent female vacuum thermoforming sheet and method for preparing the same

The present invention relates to a thermoplastic resin composition for a plastic sheet and a method for manufacturing the same, and more particularly, to low-density linear polyethylene (EMBOSS) transfer force to a partially crosslinked polypropylene resin having excellent melt strength (EMBOSS). It contains a suitable amount of stabilizer together with Polyethylene) and Branched Polypropylenen, and it has a wide working range in the rolling process, and has excellent vacuum forming. It is about.

Conventionally, automotive interior materials such as instrument panels, door trim panels, headlinings, and the like, include PVC (Polyvinylchloride) or PVC / ABS alloy (Alloy) calendering sheets (SHEET). ) Has been widely used, but in recent years, the replacement of olefin thermoplastic elastomer sheet (hereinafter referred to as “TPO SHEET”), which is advantageous in environmental friendliness, recycling, light weight, fogging and odor, etc. Research is actively underway. However, in the case of the olefinic thermoplastic elastomer resin, calender processability is remarkably inferior due to the inclusion of processing oil to assist the processing of EPDM and secondary processability such as vacuum thermoforming due to low melt strength. As a result, parts with large depth ratios have difficulty in application. In addition, in order to improve the calenderability in the prior art, when the amount of process oil is relatively small and the degree of crosslinking of the EPDM having a crosslinked structure is improved, the surface of the fabric becomes rough, and when the degree of crosslinking of the EPDM having a crosslinked structure is low, the roll during calendering is rolled. Adhesion to the surface caused a problem that the processing was impossible.

The workability in secondary processing such as the degree of crosslinking and vacuum forming of EPDM affecting the calendering process is closely related. In other words, if a resin having a polar group is introduced to ensure vacuum forming, sufficient vacuum forming is ensured, but also causes adhesion problems on the roll surface during calendering.

A related art is a method of diluting a pre-crosslinked EPDM rubber in a polypropylene resin having good fluidity (US Pat. No. 4,247,645). However, this method is not suitable for forming complex shaped structures such as instrument panels and door trim panels due to the inability to sufficiently increase the crosslinking density and deterioration of elasticity and mechanical properties. It can be a problem. In particular, there is a disadvantage in that an excellent facility for kneading is required in the dilution process. In addition, Japanese Patent Application Laid-Open No. 48-26835 proposes a heat treatment method using peroxide after completely melt kneading a polypropylene resin and an EPDM rubber in advance. However, in this case, it is difficult to obtain sufficient crosslinking degree and viscosity in the calendering process due to overdegradation of polypropylene resin and partial crosslinking of EPDM, resulting in inferior calenderability. U.S. Patent No. 4,311,528 discloses a method for fully crosslinking EPDM rubber using a phenol crosslinking agent. However, this method has excellent elasticity and mechanical properties as crosslinking reaction using peroxide crosslinking agent and crosslinking rubber particles are formed, but the problem of crosslinking process that increases crosslinking reaction time and the reason why the crosslinking agent is expensive is the final product. There is a problem that the price increases and the solubility of the solvent is lowered paintability. U.S. Patent No. 4,212,787 proposes non-crosslinked rubber components, polyisobutylene (PIB) and butyl rubber (BR), in order to give higher shear force effect in the crosslinking reaction step by peroxide in EPDM / polypropylene composition. have. However, this method also shows some uniform EPDM crosslinking density, but there is a problem that calendering is not performed because the crosslinking density of the final product is not sufficient.

In addition, the conventionally used composition can secure the depth ratio necessary for the secondary processing such as vacuum molding by introducing a polar salt, but it is adhered to the roll surface when calendering by polar group There is a drawback that it is limited to only processing by extrusion, so it is difficult to secure sufficient productivity.

Therefore, in order to solve the problems of the prior art as described above, the present invention introduces an olefin-based resin capable of improving the degree of crosslinking while being compatible with high crosslinked polypropylene and partially crosslinked polypropylene, and the EPDM in the partially crosslinked polypropylene. Induces crosslinking reaction by using a crosslinking agent that partially crosslinks the olefin-based thermoplastic that can greatly improve calender processability, and secure the depth ratio required for molding by the vacuum molding method used to mold large parts such as instrument panels. It is an object to provide a stormer resin composition and a method for producing the same.

(A) 35 parts by weight of a high crosslinked polypropylene resin; (B) 9 parts by weight of a partially crosslinked polypropylene resin; (C) 9 parts by weight of a reactive polypropylene resin; (D) 3 parts by weight of a high crosslinked thermoplastic olefin resin. (E) 7 parts by weight of homo polypropylene resin; (F) 5 parts by weight of branched polypropylene resin; And (G) 20 parts by weight of a linear low density polyethylene resin.

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In another aspect, the present invention includes a plastic sheet produced by recessing the thermoplastic resin composition.

Hereinafter, the present invention will be described in more detail.

The olefinic thermoplastic resin composition of the present invention is partially crosslinked polypropylene resin, reactive polypropylene resin, high-crosslinked thermoplastic olefine, homo polypropylene, branched polypropylene resin (Branched Polypropylene) and Linear Low Density Polyethylene (LLDPE) are used in the rolling process (CALENDER) to have excellent processability and melt strength, so vacuum forming is good, so the depth ratio required for concave molding can be secured. And it can improve the emboss holding force.

Referring to each component constituting the olefinic thermoplastic resin composition of the present invention in more detail as follows.

The high crosslinked polypropylene-based resin (A) is made of a block or random copolymer of propylene and an ethylene propylene diene monomer, and has a melt index (230 ° C., 5000 g) of 0.1 to 30 g /. 10 minutes are used, Preferably it is good to use 2.6-3.4 g / 10min.

The content of the high crosslinked polypropylene resin is used in an amount of 15 to 80 parts by weight based on 100 parts by weight of the total composition, and if the content is less than 15 parts by weight, there is a problem in high temperature elongation. There is a problem of slipping when pinging.

It is preferable that the (B) partially crosslinked polypropylene resin uses an olefin copolymer rubber copolymerized with ethylene and propylene as main components. This uses a melt index (230 ℃, 2160g) is 0.1 to 2 g / 10min, more preferably from 0.6 to 1 g / 10min. For example, an ethylene-propylene-diene terpolymer copolymer rubber of the partially crosslinked polypropylene resin may be used, and in addition to the copolymer rubber, another olefin copolymer rubber may be used. Such olefin copolymer rubbers include ethylene-propylene copolymer rubber, ethylene-octene copolymer, ethylene-butene copolymer, styrene ethylene butyrene styrene (SEBS), and among these, ethylene-propylene copolymer (EPM) or ethylene Preference is given to using -octene copolymers and ethylene-butene copolymers. In the case of the ethylene-propylene copolymer (EPM), the melt index (230 ° C., 2160 g) is 1 or less, and in the case of the ethylene-octene copolymer and the ethylene-butene copolymer, the melt index (230 ° C., 2160 g) is 5 or more.

The partially crosslinked polypropylene resin is used in an amount of 3 to 30 parts by weight with respect to 100 parts by weight of the total composition, and if the content is less than 3 parts by weight, there is a problem in low temperature impact, and if it exceeds 30 parts by weight, the flowability becomes worse due to rolling. There is a problem with molding.

In addition, the (C) reactive polypropylene resin is a soft polypropylene resin, when the hardness is tested according to ASTM D2240, 85 ~ 89A and melt index (230 ℃, 2160g) is preferably 0.5 ~ 8 g / 10min. More preferably, it is 1-2 g / 10min.

The content of the reactive polypropylene resin is used in 3 to 30 parts by weight with respect to 100 parts by weight of the total composition, wherein the content is less than 3 parts by weight when the high temperature tension is lowered, if it exceeds 30 parts by weight roll adhesion occurs there is a problem.

The high-crosslinked thermoplastic olefin resin (D) is preferably a resin obtained by dispersing ethylene propylene rubber in an olefin resin matrix in order to improve grain characteristics. The hardness is 92 to 96 A according to ISO 868, and a melt index (230 ° C., 2160 g). ) Is 0.1 to 1 g / 10 min, preferably 0.4 to 0.6 g / 10 min.

The content of the high-crosslinked thermoplastic olefin resin is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the total composition, and if the content is less than 1 part by weight, there is a problem of sag during thermoforming. There is a problem that bursting occurs.

Moreover, it is preferable that the said (E) homo polypropylene resin uses the polypropylene which has a block structure in a polypropylene resin structure. The hardness of the Sykes homopolypropylene resin is 75-85R as evaluated by ASTM D0785, and melt index (230 degreeC, 5000g) is 0.5-2 g / 10min, Preferably it is 1.2-1.6 g / 10min.

The content of the homo polypropylene resin is used in an amount of 1 to 30 parts by weight based on 100 parts by weight of the total composition, and if the content is less than 1 part by weight, there is a problem that the heat resistance is lowered. There is.

The branched polypropylene resin (F) is used to maintain a constant tension during vacuum molding because of its low heat distribution due to the side branch structure. The branched polypropylene resin is preferably a Heimmelting Strength polypropylene resin, and the melt index (230 ° C., 2160 g) is 0.6 to 1.5 g / 10 min, and more preferably 1 g / 10 min. .

The content of the branched polypropylene resin is used in an amount of 1 to 30 parts by weight based on 100 parts by weight of the total composition, and when the content is less than 1 part by weight, the rolling molding is not good. There is a problem.

The linear low density polyethylene (G) is used to improve cold resistance properties. As the linear low density polyethylene resin, a copolymer of ethylene and a comonomer is used, and the usable melt index (230 ° C. 2160 g) is in the range of 10 g / 10 min or less, and preferably 1 g / 10 min or less. In this case, if the melt index is out of the above range and the fluidity is increased, the surface characteristics such as surface roughness in the calendar processing is improved, but the melt tension is lowered during the secondary processing such as vacuum forming, so that the fabric is torn in the case of a mold having a high depth ratio. Cannot occur or maintain a constant thickness retention and the emboss disappears seriously. As the comonomer, 1-butene, 1-pentene or 1-hexene may be used.

The content of the linear low density polyethylene resin is used in an amount of 3 to 50 parts by weight based on 100 parts by weight of the total composition, and if the content is less than 3 parts by weight, there is a whitening problem. have.

In addition, the olefinic thermoplastic resin composition of the present invention, if necessary, the general additives such as antioxidants, UV stabilizers, heat stabilizers, colorants, inorganic fillers mainly used in the general polymer processing industry does not significantly affect the thermal decomposition of the peroxide. Can be used within. Preferably, the resin composition may further contain 0.1 to 3 parts by weight of UV stabilizer, 0.01 to 10 parts by weight of lubricant, and 1 to 5 parts by weight of pigment based on 100 parts by weight of the total composition.

As a kneading extrusion apparatus that can be used to prepare the thermoplastic resin composition in the present invention, a facility having a relatively excellent kneading effect such as a Banbury Kneader, a Twin Screw Extruder, a buss kneader, etc. may be used. However, it is preferable to use a continuous extrusion facility rather than a batch type kneading device because the effect of the continuous manufacturing method on the final product is very large. In particular, in the present invention, the desired properties and uniformity can be obtained by kneading and heat-treating the above components under high shear stress such as a single or twin screw extruder or bus kneader heated to about 130 to 280 ° C., preferably within 190 to 250 ° C. It is desirable to adjust the temperature so that the reaction can occur completely in consideration of the residence time.

In the process of manufacturing the plastic sheet using the thermoplastic resin composition, the composition may be blended with a roll mixing and a short-barrier mixer, or may be blended using an extruder.

Thereafter, upper and lower limbs and lower limbs are produced through a rolling process, and then the surface layer is treated with corona and primers. Upper, middle, and lower limbs produced through the laminating process can be produced through plywood or embossing. After the corona and primer surface treatment on the back layer (base layer) again, separate back surface treatment is performed, and the surface coating treatment agent that finally determines the color is first applied to the low gloss, and the final gloss and the touch of the surface are determined. Car surface treatment can be performed to produce sheets. Such plastic sheets can be used as automotive interior skin materials.

In this case, it is preferable to use the surface treatment agent having a solid content of 3 to 4% by weight, 5 to 6% by weight during the first and second treatment, respectively. According to the present invention, the same amount can be processed regardless of the solid content by using the thermoplastic resin composition having excellent physical properties.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by Examples.

Examples and Comparative Examples

Test piece preparation and evaluation of various compositions adopted in the following Examples and Comparative Examples were carried out by the following method.

1) Test piece preparation: After manufacturing the sheet (SHEET) in 8 inch roll mill at 200 ℃ to produce a test standard.

2) Tensile strength at break and elongation at break: According to JIS K6301 Clause 3, the test piece was measured as dumbbell No. 1 and the test speed was 500 mm / min.

3) Roll mill formability: The roll adhesive sheet was processed at 200 degreeC, and the roll adhesiveness of the sheet was measured.

4) Embo holding force: After forming the sheet, vacuum forming was performed and the holding force was observed.

5) Vacuum formability: After the vacuum molding with embossed sheet, the crack, tear, and thickness change rate of each part were observed.

6) Initial adhesiveness: According to KS M 5918, 11 parallel lines, each vertical and horizontal, perpendicular to the center of the coated surface were drawn at intervals of 1 mm to make 100 square scales. Next, the cellophane tape was brought into close contact with each other and pulled off at once in the vertical direction of the test piece.

7) Initial gloss: 60 mirror gloss was measured according to test method 3312 of KS M 5000.

8) Moisture resistance: After holding for 240 hours in saturated steam at 50 ± 2 ℃, 98 ± 2% RH conditions, the resultant was allowed to stand at room temperature for 1 hour, and the appearance change was observed according to the above 2).

9) Heat aging resistance: After holding for 168 hours in a thermostat maintained at 110 ± 2 ℃, it was left for 1 hour at room temperature and observed the appearance change according to the above 2).

10) Light resistance: FADE-0-METER (UV carbon arc 1 class, black panel temperature 88 ± 3 ℃ specified in 5.5 of JIS D 0205, irradiated for 300 hours) and observe the appearance change according to 2) above. The difference in fading was determined by the gray scale for fading of KS K 0911 to obtain a grade.

11) Alkali Resistance: After dipping in 0.1N NaOH solution, it was left at 55 ± 2 ℃ for 6 hours, then taken out, washed with water and air blown. Next, it was left to stand at room temperature for 1 hour and the appearance change was observed according to the above 2).

12) Acid resistance: After dipping in 0.1N H2SO4 solution, it was left at 55 ± 2 ℃ for 6 hours, then taken out, washed with water and air blow. Next, it was left to stand at room temperature for 1 hour and the appearance change was observed according to the above 2).

Example 1 and Comparative Examples 1-9

Using the following components to prepare a resin composition in the content of Table 1 and then measured physical properties by the above method is shown in Tables 1 to 3.

(A) Component: Highly partially crosslinked polypropylene resin (melt index 2.9g / 5kg, 230 ° C)

(B) Component: partially crosslinked polypropylene resin (melt index 0.8g / 2.16 kg, 230 ℃)

(C) Component: Responsive Polypropylene Resin (melt index is 1g / 2.16 kg, 230 ° C)

(D) Component: partially crosslinked thermoplastic resin (melting index of 0.5g / 2.16 kg, 230 ° C)

(E) Component: Homo polypropylene resin (melt index 1.5g / 5kg, 230 ℃)

(F) Component: Branched polypropylene resin (melt index 1g / 2.16kg, 230 ° C, MONTELL)

(G) Component: linear low density polyethylene resin (melt index 1.0g / 10min)

In addition to the above components, UV-3346 of CIBA GEIGY as a UV stabilizer was added in an amount of 1 to 2 parts by weight based on the total weight of the components, and 2 to 4 parts by weight of stearin oxides and 3 to 7 pigments as lubricants. Parts by weight were added.

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Note) ◎: Very good ○: Good △: Medium ×: Bad

As shown in Tables 1 to 3, it can be seen that all the physical properties of the embodiments of the present invention are very excellent.

Example 2

In the process of manufacturing the plastic sheet using the thermoplastic resin composition of Example 1, the composition was blended by a roll mixing and a short-barrier mixer, or blended using an extruder.

Upper and lower limbs and lower limbs were produced through a calender followed by corona and primer treatment. The upper limbs, middle limbs, and lower limbs produced through the laminating process were manufactured through plywood or embossing. The back layer (base layer) was subjected to corona and primer surface treatments again, followed by a separate back treatment. The surface coating treatment agent which finally determines the color was first subjected to the low gloss treatment, and the secondary surface treatment which determined the final gloss and the touch of the surface was performed.

The surface treatment agent used was the content of the solid content of 3% by weight, 5% by weight in the first and second treatment, respectively. The throughput was the same amount regardless of the solid content.

As described above, the olefinic thermoplastic resin composition for plastic sheet of the present invention is a suitable amount of low-density linear polyethylene and branched polypropylene to increase the emboss (EMBOSS) transfer force to the partially cross-linked polypropylene resin excellent in melt strength It has a wide working range in the rolling process and excellent vacuum forming, making it suitable for use as an automotive interior skin material.

Claims (13)

(A) 35 parts by weight of a high crosslinked polypropylene resin; (B) 9 parts by weight of partially crosslinked polypropylene resin; (C) 9 parts by weight of reactive polypropylene resin; (D) 3 parts by weight of a high crosslinked thermoplastic olefin resin; (E) 7 parts by weight of homo polypropylene resin; (F) 5 parts by weight of branched polypropylene resin; And (G) 20 parts by weight of linear low density polyethylene resin Thermoplastic resin composition for plastic sheet comprising a. The partially crosslinked polypropylene resin is an olefin copolymer rubber copolymerized with ethylene and propylene as a main component, and has a melt index (230 ° C., 2160 g) of 0.1 to 2 g / 10 min. Thermoplastic resin composition. 3. The thermoplastic resin composition according to claim 2, wherein the olefin copolymer rubber is selected from ethylene-propylene-diene terpolymer copolymer rubber, ethylene-propylene, ethylene-butene, and ethylene-octene copolymer rubber. The method of claim 1, wherein the high-crosslinked polypropylene resin is a block or random copolymer of propylene and ethylene propylene diene monomer monomer, the melt index (230 ℃, 5000g) of 2.6 ~ 3.4 g / 10 minutes, characterized in that the thermoplastic resin composition. The method of claim 1, wherein the reactive polypropylene resin is a soft polypropylene resin, the hardness is 85 to 89A when tested according to ASTM D2240, characterized in that the melt index (230 ℃, 2160g) is 1 ~ 2 g / 10min Thermoplastic resin composition. The method of claim 1, wherein the high-crosslinked thermoplastic olefin resin is a resin obtained by dispersing ethylene propylene rubber in an olefin resin matrix, the hardness is 92 ~ 96A by evaluation according to ISO 868 and the melt index (230 ℃, 2160g) is 0.4 ~ 0.6 It is g / 10min, The thermoplastic resin composition characterized by the above-mentioned. The method of claim 1, wherein the homo polypropylene resin is a polypropylene resin having a block-like structure in the polypropylene resin structure, the hardness is 75 ~ 85R and the melt index (230 ℃, 5000g) 1.2 to 1.6 as evaluated by ASTM D0785 It is g / 10min, The thermoplastic resin composition characterized by the above-mentioned. The thermoplastic resin composition according to claim 1, wherein the branched polypropylene resin is a Haimelting strength polypropylene resin, and a melt index (230 DEG C, 2160 g) is 1 g / 10 min or less. The thermoplastic resin composition of claim 1, wherein the linear low density polyethylene is a copolymer of ethylene and a comonomer, and has a melt index (230 ° C. 2160 g) of 1 g / 10 min or less. 10. The thermoplastic resin composition of claim 9, wherein the comonomer is 1-butene, 1-pentene or 1-hexene. The resin composition according to claim 1, wherein the composition further contains 0.1 to 3 parts by weight of UV stabilizer, 0.01 to 10 parts by weight of lubricant, and 1 to 5 parts by weight of pigment, based on 100 parts by weight of the total composition. A plastic sheet produced by recessing the resin composition of claim 1. The plastic sheet according to claim 12, wherein the sheet is first and second surface treated with a surface treating agent having a solid content of 3 to 4% by weight and 5 to 6% by weight, respectively.