KR101063712B1 - Method for producing thermoplastic resin having scratch resistance - Google Patents

Abstract

The present invention relates to a resin manufacturing method that can exhibit excellent scratch resistance and moldability as well as impact resistance when added to a composite resin used as a vehicle interior material, and more particularly, a modified poly obtained by grafting maleic anhydride to polypropylene. A method for producing a modified polypropylene-imide resin by reacting propylene with an amine group. In general, polypropylene resin is widely used because of its excellent moldability, low specific gravity, and low cost, and in particular, polypropylene resin is widely used as an interior and exterior material of a vehicle in the form of a composite resin as a material to replace a metal material for weight reduction of a vehicle. However, the polypropylene composite resin molding composition has excellent disadvantages such as impact strength but low scratch resistance, so to solve this problem, aliphatic amide has been added and used during the manufacture of the composite resin. Since the molecular weight is very small compared to the polypropylene resin, the transition to the surface of the molded product occurs quickly, and there is a structural disadvantage of appearance appearance due to volatilization as well as whitening phenomenon after molding at high temperature. In order to improve this, the modified polypropylene-imide resin in which the amine group is directly reacted with the modified polypropylene grafted with maleic anhydride obtained in the present invention has a much higher molecular weight than the aliphatic amide, and thus is used in the production of automotive interior materials. When used in addition to composite resin, it exhibits excellent scratch resistance while maintaining the high impact strength of conventional polypropylene.

Scratch resistance, melt index, polypropylene, modified polypropylene, interior and exterior materials for automobiles

Description

The manufacturing method of scratch resistant thermoplastics resin

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The present invention relates to a method for producing a thermoplastic resin having scratch resistance, and more specifically, to a modified polypropylene obtained by grafting maleic anhydride to polypropylene, an aliphatic amine is reacted to produce a modified polypropylene-imide resin. It is about how to. In general, polypropylene resin is widely used because of its excellent moldability, low specific gravity, and low cost. In particular, polypropylene resin is a material that can replace metal materials for weight reduction of automobiles. . However, the polypropylene composite resin molding composition has excellent disadvantages such as impact strength but low scratch resistance, so to solve this problem, aliphatic amide has been added and used during the manufacture of the composite resin. Since the molecular weight is very small compared to the polypropylene resin, the transition to the surface of the molded product occurs quickly, and there is a structural disadvantage of appearance defects due to volatilization at high temperature molding as well as whitening after molding. Another method to improve the structure is to improve the scratch resistance by introducing an amine group into the copolymer of alpha olefin and unsaturated carboxylic acid, that is, alpha olefin-acrylate copolymer or alpha olefin-maleate copolymer. However, the manufacturing process is complicated, and in order to improve the dispersibility and adhesion as polypropylene and inorganic fillers are not excellent in dispersing polypropylene composite resin, modified carboxylic acid such as maleic anhydride or unsaturated carboxylic acid such as acrylic acid is grafted. There is a disadvantage that the polyolefin must be used separately.

In order to improve this, in the present invention, a modified polypropylene-imide resin is obtained by directly reacting an aliphatic amine with a modified polypropylene grafted with maleic anhydride, and the modified polypropylene-imide resin obtained through the present invention is used as an aliphatic amide. Compared with the polypropylene composite resin used in the manufacture of automobile interior materials, the molecular weight is much higher than that of the polypropylene composite resin, thereby maintaining excellent scratch resistance while maintaining the high impact strength of the existing polypropylene. In the present invention, a modified polypropylene grafted with a maleic anhydride as a polar material to a polypropylene as a nonpolar material is used as a compatibilizer to increase the affinity and dispersibility of the nonpolar material and the polar material in the production of the polypropylene composite resin. The present invention relates to a modified polypropylene-imide resin by further reacting maleic anhydride contained in the modified polypropylene with the aliphatic amine optionally used in the present invention. In this case, the polypropylene composite resin has excellent dispersibility even without a separate compatibilizer, and on the other hand, the image of the modified polypropylene-imide resin obtained by the reaction of the modified polypropylene and aliphatic amines By providing the slip property of the surface while the orientation occurs to the surface improves the friction resistance and wear resistance, and as a result it shows better scratch resistance when using the existing aliphatic amide. Accordingly, the present invention relates to a method for producing a thermoplastic resin that can exhibit scratch resistance when a molded article is added to a polypropylene composite resin used as an automotive interior material.

As is already known, polyolefin resins such as polypropylene are widely used in various fields because of their light weight, good processability, chemical stability, and low cost. In line with the trend toward lighter weight, the demand for automobile materials to replace metal materials has been continuously increasing. However, polypropylene resins have high impact strength but low surface hardness. In particular, in order to prepare polypropylene composite resins, an inorganic filler such as glass fiber or talc is added. As the amount of the inorganic filler increases, heat resistance and bending are increased. Since physical properties such as strength are improved but scratch resistance is deteriorated, a method of improving surface slippage by adding aliphatic amides such as 13-docosenamide and 9-octadeceneamide has been used. come.

However, when the molded article is manufactured by simply adding a low molecular weight aliphatic amide as described above, the aliphatic amide may migrate to the surface of the molded article, thereby providing a slip property of the surface to improve friction and wear resistance. Since aliphatic amides have a very low molecular weight compared to polypropylene used as a matrix resin, the transition to the molded article surface occurs too quickly, and there are structural disadvantages such as poor appearance due to volatilization and whitening after molding.

Accordingly, an object of the present invention is to improve the scratch resistance of the above-described conventional polypropylene composite resin molded article, such as rapid transition to the surface and poor appearance due to whitening or volatilization when simply adding a low molecular weight aliphatic amide. It is an object of the present invention to provide a method for producing a thermoplastic resin having scratch resistance in which disadvantages and the above-mentioned problems are eliminated.

The first technical problem to be achieved in the present invention is that the polypropylene resin has a high impact strength but a low surface hardness, especially when an inorganic filler such as glass fiber or talc is added to prepare a polypropylene composite resin. As the amount of is increased, the physical properties such as heat resistance and flexural strength are improved, but the scratch resistance is deteriorated. Therefore, aliphatic amides such as 13-docosenamide and 9-octadeceneamide are required to prepare polypropylene composite resins requiring scratch resistance. However, the method of imparting the slip property of the surface by adding the compound has been used for a while, but when the molded product is manufactured by simply adding a low molecular weight aliphatic amide, the aliphatic amide is transferred to the surface of the molded product to give the surface slip property. It can play a role in improving the friction and wear resistance However, these aliphatic amides have a very low molecular weight compared to the polypropylene used as the matrix resin, so the transition to the surface of the molded product occurs too quickly, and the appearance defects due to volatilization during high temperature molding, as well as whitening after molding, etc. In order to improve the scratch resistance when the modified polyolefin-imide resin prepared by the production method proposed in the present invention is added and used in the production of polypropylene composite resin, the slip resistance by imide chain is imparted. Of course, since the molecular weight is similar to that of the polypropylene used as the matrix resin, it is possible to improve the appearance defects and whitening phenomena due to the rapid transition and volatilization during processing when the aliphatic amide is used, thereby improving productivity as well as added value. To increase . In addition, the second technical problem to be achieved in the present invention, when the modified polypropylene-imide resin of the present invention is used in the production of polypropylene composite resin, the non-polar part and the polar part of the structurally modified polypropylene-imide resin When the composite resin molding composition is prepared by mixing inorganic fillers such as talc and glass filament with the action of, it is possible to increase the adhesive strength by improving the uniform dispersibility and compatibility not found in the modified polypropylene prepared by the known method. In addition, as the amount of discharge increases with the decrease of friction in the extruder, the working speed can be increased, and when injection molding, the dispersibility is very good, which shows excellent formability without discoloration due to heat. These features represent features that can be used as durable materials Physical properties such as performance and dispersibility and scratch resistance can not be obtained by any existing resin-based molding composition and manufacturing method, which is a great advantage of the present invention, which is a result that can be obtained only through the present invention.

The present invention is a method for improving the disadvantage of inferior scratch resistance against the excellent impact strength of the polypropylene composite resin modified polypropylene produced by a known method, that is, unsaturated to polypropylene in order to give polarity to the polypropylene Carboxylic acid, in particular maleic anhydride, is a modified polypropylene molding composition (Chemco Precision, CHEMS 600PP) having a melt index of 230 to 5 to 200 g / 10 min, obtained by grafting peroxide as a catalyst. Aliphatic amines such as amines, cetylamines, cocoamines, 13-docosenamines and the like can be reacted individually or in combination. In this reaction, the ring-opening reaction of maleic anhydride, which is a hydrophilic functional group of the modified polypropylene, occurs to produce a thermoplastic resin of the modified polypropylene-imide shown in FIG. At this time, the weight average molecular weight of the modified polypropylene-imide thermoplastic resin is in the range of 20,000 to 300,000, and R is C ₁₂ to C _{22, which} is alkyl or alkenyl. When the modified polypropylene-imide thermoplastic resin obtained through the present invention is added to prepare a polypropylene composite resin used for automobile interior materials, the modified polypropylene-imide resin having a molecular weight similar to that of the polypropylene as a matrix resin is formed. Since the surface is oriented to the surface of the surface to give the slip resistance, the friction resistance and wear resistance is improved, the scratch resistance is improved. In particular, since the modified polypropylene-imide thermoplastic resin has a molecular weight similar to that of a polypropylene resin used as a matrix resin, there is no phenomenon that the modified polypropylene-imide thermoplastic resin is not carried out or volatilized to the surface of a molded article which appears when a low molecular weight aliphatic amide is added. It is an advantage that appearance defects due to volatilization or whitening after molding do not appear during high temperature molding. In addition, when the polypropylene composite resin is prepared, when the modified polypropylene-imide resin obtained through the present invention is added, compatibility with polar substances such as glass fiber and talc is improved, thereby showing excellent adhesion and compatibility. It is good for manufacturing polar materials and composite resins, so that the processing conditions are alleviated and the discharge volume is increased. Therefore, the work speed can be increased and problems such as discoloration due to heat can be solved. The economic result is also excellent.

In order to prepare the modified polypropylene-imide resin of the present invention, various conventional additives mixed with the resin-based molding composition may be mixed, including lubricants, stabilizers, antioxidants, ultraviolet absorbers, and the like.

The modified polypropylene-imide resin of the present invention optionally uses maleic anhydride as an unsaturated carboxylic acid with a suitable blender such as a banbari mixer, Henschel mixer, etc., optionally with polypropylene, such as a propylene polymer, optional additives such as lubricants described above, and optional peroxides. By using the modified polypropylene having a melt index of 230 ℃ 5 ~ 200g / 10 minutes obtained by using a single screw or twin screw extruder under the melting conditions can be prepared as a base raw material.

More specifically, the molding composition of the present invention is a modified polypropylene-based molding composition having a polar index of 5 to 200 g / 10 min at a melt index of 0.5 to 5% by weight of polar maleic anhydride having an unsaturated carboxyl group in polypropylene. 0.1 to 25 parts by weight of oleamine, 0.01 to 2 parts by weight of antioxidant, and 0.01 to 5 parts by weight of organic peroxide optionally used in the present invention, and 0.01 to 5 parts by weight of paratoluene sulfamic acid as a catalyst for ring-opening reaction of maleic anhydride. After mixing 5 parts by weight in a Henschel mixer, the resin reactant was charged into a hopper of a single screw or twin screw extruder, fed at a constant rate to an extruder in which the barrel temperature was maintained at 200 to 230 ° C., and reacted in a molten state. The modified polypropylene-imide resin which gives a scratch resistance at the time of manufacture was produced. At this time, the barrel in the extruder is composed of five stages, the temperature distribution is maintained at 200 ℃, 210 ℃, 220 ℃, 230 ℃ and 230 ℃ respectively. In addition, the aliphatic amine selectively used in the present invention may be used in addition to or in combination with oleylamine, laurylamine, stearylamine, tallowamine, cetylamine, cocoamine, 13-docosenamine and the like.

In the present invention, as described above, the peroxide and the acid catalyst selected in the present invention are used as a reforming promoter for improving ring opening efficiency of modified polypropylene grafted with maleic anhydride, that is, modified polypropylene having a melt index of 5 to 200 g / 10 minutes. At this time, the peroxide is used in 0.01 to 5 parts by weight, preferably 0.02 to 2 parts by weight to 100 parts by weight of the modified polypropylene-based molding composition, and does not exhibit sufficient modification effect at 0.01 parts by weight or less and unreacted at 2.5 parts by weight or more. This is because peroxide may remain. As another modifier, the acid catalyst is used in an amount of 0.01 to 5 parts by weight, preferably 0.03 to 0.1 parts by weight, based on 100 parts by weight of the modified polypropylene-based molding composition, and at 0.02 parts by weight or less, the effect of ring opening of maleic anhydride is not significant. This is because at least 0.1 part by weight can cause a reverse reaction of the reacted modified polypropylene-imide resin. On the other hand, in order to suppress oxidation that may occur due to heat and pressure generated in the extrusion reaction, pentaerythritol tetrakis-3- (3,5-di-tert.-butyl-4-hydroxyphenyl as a phenolic antioxidant 0.01 to 2 parts by weight of propionate and tris (2,4-di-tert.butylphenyl) phosphite, a phosphite-based antioxidant, alone or in combination with 100 parts by weight of the modified polypropylene-based molding composition It is possible to use a mixture of the same amount, but preferably synergistically to give a good result. At this time, the peroxide may be dicetyl peroxydicarbonate, dimyristyl peroxydicarbonate, dilauryl peroxide, didecanoyl peroxide, di- (2-tert-butyl peroxyisopropyl) -benzene, 2,5-dimethyl- Any commercially available products such as 2,5-di- (tert-butylperoxy) -hexane and 2,3-dimethyl-2,3-diphenylbutane may be used, but generally gel formation during melt extrusion of the resin, etc. In order to prevent this, it is preferable to use a relatively high molecular weight. In addition, the acid catalyst may be sulfuric acid, nitric acid, phosphoric acid and paratoluene sulfamic acid, but it is more preferable to use paratoluene sulfamic acid which is an organic acid and a solid.

The characteristics of the present invention are as described above, 100 parts by weight of a modified polypropylene having a maleic anhydride as a main component grafted to polypropylene, that is, a melt index of 230 ° C from 5 to 200 g / 10 minutes, and the oleamine described above as a modified base. , 0.1 to 25 parts by weight of aliphatic amines such as laurylamine, stearylamine, tallowamine, cetylamine, cocoamine, docosenamine, 0.01 to 2 parts by weight of antioxidant and the organic use optionally used in the present invention. 0.01 to 5 parts by weight of peroxide and 0.01 to 5 parts by weight of paratoluene sulfamic acid as a catalyst for ring-opening reaction of maleic anhydride are mixed in a Henschel mixer, and the resin reactant is charged into a hopper of a single or twin screw extruder, and the barrel temperature is Polypropylene composites used as automobile interior materials by being supplied at a constant rate to an extruder maintained at 200 to 230 ° C and reacted in a molten state. Modified polypropylene to impart scratch resistance to the resin during manufacture - to already prepared the imide resin.

In this case, the modified polypropylene has a density of 0.9 g / cm 3 to 0.95 g / cm 3 and a melt index of 5 to 200 g / 10 minutes at 230 ° C., wherein the modified polypropylene is described above with respect to 100 parts by weight of the modified polypropylene. It is preferable to use 0.1 to 25 parts by weight of aliphatic amines such as oleamine, laurylamine, stearylamine, tallowamine, cetylamine, cocoamine, docoseneamine, etc. This is because it does not appear sufficiently, and at 25 parts by weight or more, unresponsive aliphatic amine remains, resulting in a decrease in performance.

A thermoplastic resin having a scratch resistance, that is, a modified polypropylene-imide resin, produced by any of the above methods is within the scope of the present invention when the conditions described in the following claims are satisfied.

The modified polypropylene-imide resin of the present invention is a matrix resin when an aliphatic amide such as 13-docosenamide, 9-octadeceneamide, or the like, which is a low molecular weight aliphatic amide that is used separately to improve scratch resistance, is added. Compared with the polypropylene used in the present invention, the structural defects such as deterioration of scratch resistance due to rapid transition to the surface of the molded product, which is a disadvantage due to the extremely low molecular weight, poor appearance due to volatilization at high temperatures, and whitening after molding As the modified polyolefin-imide resin produced by the production method proposed in the present invention is used in addition to the polypropylene composite resin, slip resistance is given by imide chain to improve the scratch resistance as well as the matrix resin. Molecular weight similar to polypropylene used as Because such a poor appearance and a whitening phenomenon due to rapid implementation and volatilization during processing shown when using the above-described aliphatic amides appear because Entrance can be increased as well as the added value is greater productivity. The application field can be widely used in composite resin for automobile interior materials, building interior materials, home appliances and mobile phone exterior materials requiring scratch resistance, and its utilization is very high.

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

Example 1

1) Preparation of Resin Reactant

a) 15 parts by weight of oleamine and peroxide (pergansa, PEROXAN HX) with respect to 100 parts by weight of modified polypropylene (Chemco Precision, CHEMS 600PP) having a melt index of 230 ° C. 105 g / 10 minutes in which polypropylene is grafted with maleic anhydride. 1.5 parts by weight, 0.15 parts by weight of an antioxidant (Shiba-Geigi, a mixture of IG-1010 and IF-168), and 0.05 parts by weight of paratoluene sulfamic acid as an acid catalyst for 5 minutes at 1,000 rpm in a 500 L Henschel mixer. The resin reactant mixed by operation was prepared.

2) Preparation of Modified Polypropylene-Imide Resin

The resin reactant prepared in 1) was charged to a hopper, and fed at a constant rate into a 90 kW twin screw extruder maintained at an extrusion rate of 300 kg / hr and a barrel temperature of 200 to 230 ° C. to react in a molten state to prepare a polypropylene composite resin. The modified polypropylene-imide resin which gives a scratch resistance was produced.

3) Polypropylene Composite Resin

5 parts by weight of the modified polypropylene-imide resin prepared in 2) and 60 parts by weight of the polypropylene resin used as the base resin, 10 parts by weight of ethylene / propylene rubber having an ethylene content of 70% by weight, and 25 parts by weight of talc at 500 L capacity. After mixing in a supermixer and compounding in a twin screw extruder to form a pellet, the molded pellet was injection-molded by a known method using a injection molding machine 3mm thick sheet.

Examples 2-8

The same procedure as in Example 1 was conducted except that 0.05, 0.1, 5, 10, 20, 25, and 30 parts by weight of oleamine were used instead of 15 parts by weight of oleamine.

Examples 9-16

The same procedure as in Example 1 was conducted except that 0.05, 0.1, 5, 10, 15, 20, 25, and 30 parts by weight of laurylamine were used instead of 15 parts by weight of oleamine.

Examples 17-24

Stearylamine 0.05, 0.1, 5, 10, 15, 20, 25, 30 parts by weight instead of 15 parts by weight of oleamine was carried out in the same manner as in Example 1.

Examples 25-32

The same procedure as in Example 1 was conducted except that 0.05, 0.1, 5, 10, 15, 20, 25, and 30 parts by weight of tallowamine were used instead of 15 parts by weight of oleamine.

Examples 33-40

Cetylamine 0.05, 0.1, 5, 10, 15, 20, 25, 30 parts by weight instead of 15 parts by weight of oleamine was carried out in the same manner as in Example 1.

Examples 41-48

The same procedure as in Example 1 was conducted except that 0.05, 0.1, 5, 10, 15, 20, 25, and 30 parts by weight of cocoamine were used instead of 15 parts by weight of oleamine.

Examples 49-56

The procedure was carried out in the same manner as in Example 1, except that 0.05, 0.1, 5, 10, 15, 20, 25, and 30 parts by weight of 13-docosenamine were used instead of 15 parts by weight of oleamine.

Examples 57-64

The same method as in Example 1, except that 0.05, 0.1, 5, 10, 15, 20, 25, 30 parts by weight of a mixture of equal amounts of oleamine and 13-docosenamine in a weight ratio instead of 15 parts by weight of oleamine were used, respectively. It was performed by.

Comparative Example 1

2 parts by weight of 13-docosenamide, 5 parts by weight of modified polypropylene and 60 parts by weight of polypropylene resin used as the base resin, 10 parts by weight of ethylene / propylene rubber having an ethylene content of 70% by weight, and 25 parts by weight of talc at 500 L After mixing in a supermixer and compounding in a twin screw extruder to form a pellet, the molded pellet was injection-molded by a known method using a injection molding machine 3mm thick sheet.

Comparative Example 2

The same procedure as in Comparative Example 1 was conducted except that 5 parts by weight of an alpha olefin-acrylate copolymer having an amine group introduced therein instead of 13-docosenamide was used.

Comparative Example 3

The same procedure as in Comparative Example 1 was conducted except that 13-docosenamide was not used.

Experimental Example 1

Table 2 shows the results of measuring the scratch resistance and physical properties of the polypropylene composite resin sheets obtained in Examples and Comparative Examples according to a known test method.

1) Melt Flow Index: measured according to ASTM D1238

2) Density: measured according to ASTM D1505

3) Flexural Modulus: measured according to ASTM D790

4) Tensile strength: measured according to ASTM D 683

5) Izod Impact Strength: measured according to ASTM D256

6) Scratch Resistant: Visually determine the scratched surface under the conditions of Table 1 using a scratcher on the surface of the test piece.

◎: Almost no surface damage. ○: fine surface damage. △: obvious surface damage

●: Severe surface damage.

[Table 1] Scratch resistant condition

[Table 2] Comparison of Properties of Injection Molded Polypropylene Composite Resin

Based on the results of Table 2, when the modified polypropylene-imide resin exhibiting scratch resistance obtained through the present invention is used when the polypropylene composite resin for automobile interior is added and used, the additive used to improve the scratch resistance The scratch resistance is remarkably improved without any difference in the basic physical properties of the polypropylene composite resin molding composition prepared by using.

The modified polypropylene-imide thermoplastic resin prepared through the present invention not only improves scratch resistance but also has good compatibility with polar materials such as glass fibers and talc, and thus exhibits excellent adhesive strength and good compatibility. In the case of manufacturing composite resins, the processing conditions are alleviated and the discharge amount is increased. Therefore, the work speed can be increased, and problems such as discoloration due to heat can be solved. It shows excellent results and increases compatibility with polar materials such as nylon, polyester, aluminum, iron, wood, etc., and non-national polypropylene. It can be said to be an excellent thermoplastic resin.

Claims (3)

In the method for producing a thermoplastic resin having scratch resistance, a) 0.01 to 2 parts by weight of antioxidant, 0.01 to 5 parts by weight of organic peroxide, 0.01 to 5 parts by weight of paratoluenesulfonic acid as ring-opening catalyst and oleic acid based on 100 parts by weight of modified polypropylene grafted with maleic anhydride to polypropylene Preparing a resin reactant by mixing 0.1 to 25 parts by weight of an amine selected from any one of amine, stearylamine, tallowamine, cetylamine, cocoamine, 13-dococeneamine, and laurylamine; b) The method of producing a thermoplastic resin having scratch resistance, characterized in that the reaction of the resin in step a) in a single or twin screw extruder maintained at a temperature of 200 ℃ to 230 ℃. In the method for producing a thermoplastic resin having scratch resistance, a) 0.01 to 2 parts by weight of antioxidant, 0.01 to 5 parts by weight of organic peroxide, 0.01 to 5 parts by weight of paratoluenesulfonic acid as ring-opening catalyst and oleic acid based on 100 parts by weight of modified polypropylene grafted with maleic anhydride to polypropylene Preparing a resin reactant by mixing 0.1 to 25 parts by weight of an amine and 13-docosenamine mixed in the same weight ratio; b) The method of producing a thermoplastic resin having scratch resistance, characterized in that the reaction of the resin of step a) in a single or twin screw extruder maintained at a temperature of 200 ℃ to 230 ℃. The method according to claim 1 or 2, The modified polypropylene has a density of 0.9 g / cm 3 to 0.95 g / cm 3 and a melt index of 5 to 200 g / 10 minutes at 230 ° C. The method for producing a thermoplastic resin having scratch resistance.

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