KR100760457B1 - ABS resin composition excellent in vacuum forming - Google Patents

Abstract

The present invention relates to an ABS resin composition having excellent vacuum formability, and includes a graft copolymer, a styrene-acrylonitrile copolymer (SAN copolymer), an ultra high molecular weight SAN copolymer, and a high-tension polypropylene. According to the present invention, it is possible to provide an ABS resin composition having excellent vacuum formability and a molded article which is lightweight without thermal discoloration by improving the stretching property by increasing the high temperature tensile strength in accordance with the present invention.

Vacuum Forming, Ultra High Molecular Weight SAN Copolymer, High Melt Strength Polypropylene, Elongation Properties

Description

ABS resin composition with good vacuum-forming ability {ABS (Acrylonitrile butadiene styrene) resin composition with good vacuum-forming ability}

The present invention relates to an ABS resin composition, and more particularly, by adding a high melt strength polypropylene (HMS PP) to a resin composition composed of a graft copolymer, a SAN copolymer, and an ultra high molecular weight SAN copolymer, It relates to an ABS resin composition having.

In general, ABS resin has excellent impact resistance, rigidity and chemical resistance, high gloss, good appearance, and excellent moldability, and is widely used in OA devices, sundries, and home appliances. Particularly, in the case of the refrigerator, ABS resin having good mechanical properties and appearance is used, and a resin having excellent stretching characteristics is required according to an increase in the capacity of the refrigerator.

In general, a refrigerator manufactures a sheet by an extruder, and then vacuum forms the sheet to obtain an inner wall surface and a door having a desired shape. The molded article manufactured as described above and the iron plate housing outside the refrigerator are assembled, and a urethane is injected between the internal molded article and the iron plate housing, and then foamed and solidified to manufacture a refrigerator cabinet. That is, a refrigerator molded product is obtained through a vacuum molding process, and as the stretching property is excellent, a uniform molded product without thickness deviation is obtained.

The stretching property of the resin refers to the degree of resistance when the resin is stretched or expanded by an external force at as high a temperature as possible. In general, the stretching property of the resin is related to the chemical structure, and the use of a good vacuum forming resin is easy to mold and the thickness of the resin is thinner, it is possible to reduce the weight, and therefore, there is an advantage that the molding of a large refrigerator is also easy.

In the case of the conventional general ABS resin, when applied to the vacuum molding of a large molding, there is a problem that a thin portion occurs due to a large thickness deviation and a lot of appearance defects accordingly. To solve this problem, SAN copolymers with large molecular weight and molecular weight distribution can be used to reduce thickness deviations.However, fluidity decreases, extruder overload occurs during sheet production, resulting in reduced productivity, thermal discoloration of sheets and poor appearance of molded products. There is still much to be improved, so much research is being done.

The present invention has been made to solve such a conventional problem, to provide an ABS resin composition excellent in vacuum formability by adding a high melt strength polypropylene to improve the stretching characteristics of the ABS resin composition.

Another object of the present invention is to provide a molded article having no heat denaturation and weight reduction made of the ABS resin composition.

The above and other objects of the present invention can be achieved by the present invention described below.

One aspect of the present invention for achieving the above object is (A) 20 to 40 parts by weight of graft copolymer, (B) 20 to 40 parts by weight of SAN copolymer, (C) 20 to 40 weight of ultra high molecular weight SAN copolymer And (D) 1 to 15 parts by weight of a high melt strength polypropylene, and relates to an ABS resin composition having excellent vacuum formability.

Another aspect of the present invention for achieving the above object relates to a molded article made of the ABS resin composition.

Hereinafter, each component of the resin composition of the present invention will be described in detail.

(A) Graft  Copolymer

The graft copolymer resin used in the present invention is prepared by adding an aromatic vinyl monomer capable of graft copolymerization and a monomer copolymerizable with the aromatic vinyl monomer to the following rubbery polymer and graft polymerizing it.

Butadiene rubber is suitable for the rubbery polymer used in the graft copolymer resin, and its content is suitably 30 to 70% by weight based on the graft copolymer resin. The size of the butadiene rubber particles is preferably 90% or more and 2500 to 3500 kPa, the gel content is 50% by weight or more.

As the aromatic vinyl monomer capable of graft copolymerization to the rubber, styrene, α-methyl styrene, nuclear substituted styrene, and the like are preferable, and among these, styrene is more preferable, and as the monomer copolymerizable with the aromatic vinyl monomer, acrylonitrile, Preference is given to unsaturated nitrile monomers such as methyl methacrylonitrile.

The content of the aromatic vinyl monomer and the monomer copolymerizable therewith is preferably applied so that the sum of one aromatic vinyl monomer and one unsaturated nitrile monomer is 30 to 70% by weight based on the graft copolymer resin. .

The graft copolymer is a polymer having a graft ratio of 50 to 70% and a weight average molecular weight of 50,000 to 60,000 of the grafted resin, and is preferably used at about 20 to 40 parts by weight in the final resin composition.

(B) SAN  Copolymer

The SAN copolymer according to the present invention is formed by copolymerizing 50 to 90% by weight of the aromatic vinyl monomer and 10 to 50% by weight of the unsaturated nitrile monomer, and more preferably 60 to 80% by weight of the aromatic vinyl monomer and the unsaturated nitrile monomer 20 It is preferably prepared by copolymerizing from 40% by weight to 40% by weight, and the content thereof is suitably used in 20 to 40 parts by weight of the final resin composition. As said aromatic vinylic monomer, styrene, (alpha) -methylstyrene, nuclear substituted styrene, etc. are preferable, Among these, styrene is more preferable.

As the unsaturated nitrile monomer, unsaturated nitrile monomers such as acrylonitrile and methyl methacrylonitrile are preferable, and 20-40% by weight of acrylonitrile is particularly preferable.

(C) ultra high molecular weight SAN  Copolymer

Ultra high molecular weight SAN copolymer according to the present invention is 0.01-5 parts by weight of polyfunctional mercaptan and 0.005 to 100 parts by weight of the monomer mixture consisting of 50 to 90% by weight of the aromatic vinyl monomer and 10 to 50% by weight of the unsaturated nitrile monomer. It refers to a copolymer having an ultra-high molecular weight of a non-molded structure prepared by adding -5 parts by weight of a polyfunctional acrylic monomer, particularly preferably 20 to 40% by weight of acrylonitrile as the unsaturated nitrile monomer.

The polyfunctional mercaptans include trimethylpropane tri (3-mulstoppropionate), trimethylpropane tri (3-mulsottoacetate), trimethylpropane tri (4-multigaptobutanate), and trimethylpropane tree (5-multi Gaptopentanate), trimethylpropane tri (6-mercaptohexaonate) and pentaerythryl tetrakis (2-mercaptoacetate), pentaerythryl tetrakis (3-mercaptopropionate), pentaerythryl tetra Kiss (4-MultoTobutanate), Pentaerythryl Tedirakis (5-Meltotophantanate), Pentaerythryl Tedirakis (6-Mercaptorexanate), and the like.

As polyfunctional acryl-type monomer, ethylene dimethacrylate, diethylene glycol methacrylate, trimethylene propane trimethacrylate, 1, 3- butanediol methacrylate, 1, 6- hexanediol dimethacrylate, allyl acryl The rate etc. are mentioned.

The ultra high molecular weight SAN copolymer is an ultra high molecular weight having a PS reduction weight average molecular weight of 1,000,000 to 5,000,000, preferably 20 to 40 parts by weight based on the final resin composition.

(D) Employment  Polypropylene

The high melt strength polypropylene according to the present invention has a higher melt tension than the existing polypropylene to increase the viscosity at the time of melt elongation, thereby providing excellent moldability of the final resin composition. Melt tension of general polypropylene is not measured at 150 degrees, 25 cN for high density polypropylene, and 32 cN for high melt polypropylene. The content is suitably 1 to 15 parts by weight, more preferably 3 to 7 parts by weight based on the final resin composition. If it is less than 1 part by weight, the vacuum forming property is lowered, and if it is more than 15 parts by weight, impact resistance may be lowered.

(E) Compatibilizer

When heterogeneous polymers are mixed, many compatibilizers are used as a method of controlling the compatibility state. The compatibilizer used in the present invention may be optionally used as needed, and when used, it is preferable to use about 0.1 to 1 part by weight, more preferably about 0.4 part by weight, based on 100 parts by weight of the final resin composition. Although it does not specifically limit as a compatibilizer used for this invention, The polymer in which polypropylene is grafted to SAN can be used.

The resin composition prepared by the present invention may be a heat stabilizer, an antioxidant, a lubricant, a lubricant, a release agent, a light and ultraviolet stabilizer, a flame retardant, an antistatic agent, a colorant, a filler, an impact modifier, as necessary, without departing from the object of the present invention. It is also possible to add other additives such as, it is also possible to use other resins or other rubber components together. The content is preferably 0.1 to 30 parts by weight.

The invention can be better illustrated by the following examples which are intended to illustrate the invention and are not intended to limit the appended claims.

Example

(A) graft copolymer, (B) SAN copolymer, (C) ultra high molecular weight SAN copolymer, (D) high melt strength polypropylene, and (E) compatibilizer used in the following Examples and Comparative Examples The manufacture and specifications are as follows.

(A) graft copolymer

30 to 70% by weight of one aromatic vinyl monomer and one unsaturated nitrile monomer are present in the presence of 30 to 70% by weight of butadiene rubber having a size of 90% or more of the rubber particles of 2500 to 3500 ~ and a gel content of 50% or more. It injected | thrown-in, these were graft copolymerized and the said graft copolymer was obtained. The graft copolymer was used such that the graft ratio was 50 to 70%, the weight average molecular weight of the grafted resin was 50,000 to 60,000, and 34 wt% of the final resin composition.

(B) SAN copolymer

Cheil Industries, Ltd. SAN HR-5330 was used.

(C) Ultra High Molecular Weight SAN Copolymer

Styrene monomer 71% by weight, acrylonitrile monomer 29% by weight, ion-exchanged water 150 parts by weight, tricalcium phosphate 0.4 parts by weight, 0.3 parts by weight of trimethylpropane tri (3-mulcetopropionate) with polyfunctional multanane, 0.15 parts by weight of the multifunctional acrylate monomer and 0.3 parts by weight of 2,2'-azobisisobutylonitrile as an initiator were mixed and added, and the reactor was completely sealed.

Thereafter, the mixture was sufficiently stirred and dispersed, and then the temperature of the reactor was raised, polymerization was performed at 70 ° C. for 5 hours, and then the interior of the reactor was cooled to room temperature to terminate the reaction. The resulting polymer was washed, dehydrated and dried to obtain A copolymer was obtained. An acrylonitrile-styrene copolymer resin having an acrylonitrile content of 24% by weight and a weight average molecular weight of 3,000,000 was used.

(D) High melt strength polypropylene

WB130HMS manufactured by Borealis was used.

(E) Compatibilizer

Modifer A3400 grade manufactured by NOF was used.

[ Example  1-4]

The components (A), (B), (C), (D) and (E) were uniformly mixed with a tumbler mixer and then extruded with a 45 mm twin screw extruder into pellets. At this time, the cylinder temperature of the extruder was maintained at an average of 220 ℃ and screw RPM was adjusted to 300. The prepared pellets for measuring the physical properties were prepared. The impact strength, flow index, tensile strength, high temperature tensile strength / elongation were measured for the test pieces of the prepared resin composition. The contents of components (A), (B), (C), (D) and (E) according to the present invention are shown in Table 1.

[ Example  5]

The content of each component of the resin composition except the component (E) was used as shown in Table 1, and was carried out in the same manner as in Example 1.

[ Comparative Example  1-3]

In order to compare with the resin composition according to the present invention except for (D) component or (D) and (E) component, the content of the remaining components were carried out in the same manner as in Example 1 as in Table 1.

(Units of components (A), (B), (C) and (D) are parts by weight, and (E) is 100 parts by weight of a composition consisting of (A), (B), (C) and (D). It is weight part on the basis.)

Tensile strength: measured according to ASTM D638. (23 ° C., 5 mm / min, kg / cm 2)

Impact strength: measured according to ASTM D256. (23 ° C./-30° C., 1/8 ”, kg · cm / cm)

Fluidity Index: Measured according to ASTM D1238. (220 ° C / 10kg, g / 10min)

Tensile strength / elongation at high temperature was measured at 150 ° C. for 3 minutes according to ASTM D638, and then tensile strength was measured. High tensile strength at 150 ° C. indicates good vacuum forming. (150 ° C., 150 mm / min, kg / cm 2)

In the thermoplastic resin composition of Examples 1, 3, and 5 containing 5 parts by weight of a high melt strength polypropylene component from the results of Table 1, the tensile strength and impact strength of the thermoplastic resin composition of Comparative Examples 1, 2, and 3 were not maintained. Melt index decreases, 1.0㎏ / ㎠ It can be seen that the difference in the difference between the excellent high temperature tensile strength and the high temperature elongation of the car by more than 500% indicates a much improved vacuum formation. In Examples 2 and 4 containing 15 parts by weight of a high melt strength polypropylene component, tensile strength and impact strength were slightly reduced compared to Comparative Examples 1, 2 and 3, but high tensile elongation was maintained and melt index was decreased. At the same time 6.5㎏ / ㎠ This difference makes it possible to identify excellent high temperature tensile strength.

Accordingly, the present invention can provide a molded article that satisfies the weight reduction and the solidification essential for the enlargement of a product, such as a refrigerator, while providing an ABS resin composition having better vacuum formability through excellent high temperature tensile strength and reduced melt index.

The present invention can confirm that the high-temperature tensile strength is improved by adding a high melt strength polypropylene, thereby improving the stretching characteristics to improve the ABS resin composition excellent in vacuum formability and lightweight molded article with uniform thickness and no heat discoloration Can provide. In particular, it is possible to provide a composition suitable for internal molded articles such as home appliances, which require both light weight and robustness, such as sheets of large refrigerators.

Simple modifications and variations of the present invention can be readily made by those skilled in the art, and all such modifications or changes can be seen to be included within the scope of the present invention.

Claims (5)

(A) 20 to 40 parts by weight of a graft copolymer comprising 30 to 70% by weight of a butadiene rubber, a total of 30 to 70% by weight of one aromatic vinyl monomer and one unsaturated nitrile monomer; (B) 20 to 40 parts by weight of a SAN copolymer having an acrylonitrile content of 20 to 40% by weight; (C) 20 to 40 parts by weight of an ultra high molecular weight SAN copolymer having an acrylonitrile content of 20 to 40% by weight and a weight average molecular weight of 1,000,000 to 5,000,000; And (D) ABS resin composition with excellent vacuum formability, characterized in that the melt tension comprises 1 to 15 parts by weight of high melt strength polypropylene ranging from 150 ° C to 32 cN. delete The ABS resin composition as claimed in claim 1, wherein 0.1 to 1 part by weight of the (E) compatibilizer is further added to 100 parts by weight of the ABS resin composition. The method of claim 1, wherein the ABS resin composition is a heat stabilizer, antioxidant, lubricant, lubricant, release agent, light and ultraviolet stabilizer, flame retardant, antistatic agent, colorant, filler, impact modifier, pigment, dye or a mixture of two or more thereof ABS resin composition excellent in vacuum forming, characterized in that the composition is further added by being selected from the group consisting of. Claims 1, 3 and 4, wherein the molded article for the interior of the refrigerator characterized in that it is made of the ABS resin composition according to any one of claims.