KR20210050180A - Thermoplastic resin composition - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition comprising an olefinic copolymer as an additive, wherein the thermoplastic resin composition of the present invention has good basic physical properties such as impact resistance and moldability during injection molding, and is particularly suitable for use as exterior materials for home appliances such as washing machines because of excellent chemical resistance to laundry detergents.

Description

Thermoplastic resin composition {THERMOPLASTIC RESIN COMPOSITION}

The present invention relates to a thermoplastic resin composition, wherein the thermoplastic resin composition of the present invention has good mechanical properties and moldability, and has excellent chemical resistance to laundry detergents and the like.

ABS resins including an ABS copolymer in which acrylonitrile, butadiene and styrene are copolymerized are used as exterior materials for various home appliances due to excellent processability, moldability, impact resistance, strength and gloss.

On the other hand, among various product groups of home appliances, in the case of home appliances such as washing machines, chemical components that can be used for washing and the exterior material can be easily contacted. In particular, when the chemical component having a strong reactivity and the exterior material of the home appliance are in contact with each other. , Cracks may occur on the surface of the exterior material. Since cracks generated in this way deteriorate the durability of the exterior material and prevent the home appliance from functioning properly, excellent chemical resistance to withstand strong chemical components is also a characteristic that should be considered for ABS resin.

Accordingly, there are various attempts to impart strong chemical resistance to ABS resins, but there are many cases in which the physical properties of the basic resin are deteriorated or insufficient chemical resistance is exhibited. It is still necessary to develop ABS resins that meet basic physical property standards and have excellent chemical resistance.

KR 2017-0067318

The present invention is to solve the problems of the prior art described above, it is to provide a thermoplastic resin composition having excellent chemical resistance of a molded article manufactured from a thermoplastic resin composition, and having good basic physical properties such as impact resistance and moldability.

In order to solve the above problems, the present invention A) a base resin comprising the following i) to iii); And

i) a diene rubber-based graft copolymer;

ii) acrylic rubber-based graft copolymer;

iii) styrenic copolymer;

It provides a thermoplastic resin composition comprising; B) an olefin-based copolymer having at least one functional group selected from an alkyl acetate group or an alkyl acrylate group.

The thermoplastic resin composition provided by the present invention has good basic physical properties including impact resistance during injection molding, and has excellent chemical resistance, and is particularly suitable for application in the field of home appliances such as washing machines.

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

The terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

In the present invention, the "derived unit" refers to a unit derived from the compound, and specifically, may refer to the compound itself or a substituent from which some atoms of the compound have been removed.

Thermoplastic resin composition

The thermoplastic resin composition of the present invention largely includes A) a base resin and B) an olefin-based copolymer. Hereinafter, A) base resin and B) olefin-based copolymer will be separately described.

A) Base resin

The thermoplastic resin composition of the present invention includes three types of copolymers as the base resin, and specifically, the base resin includes the following copolymers i) to iii).

i) Diene rubber graft copolymer

ii) Acrylic rubber graft copolymer

iii) styrenic copolymer

i) Diene rubber graft copolymer

The diene rubber-based graft copolymer of the present invention is prepared by graft polymerization of an aromatic vinyl-based monomer and a vinyl cyan-based monomer on a conjugated diene-based polymer, and the conjugated diene-based polymer is prepared by emulsion polymerization of a conjugated diene-based monomer. It may be in the form of latex, and the conjugated diene-based monomer may be at least one selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, and piperylene, of which 1,3-butadiene may be used.

In the diene rubber-based graft copolymer, the unit derived from the conjugated diene-based polymer may be included in 40 to 80% by weight, preferably 50 to 70% by weight, based on the total weight of the diene rubber-based graft copolymer. When the conjugated diene-based polymer-derived unit is included in this range, not only the grafting rate is high, but also the impact strength and chemical resistance of the molded article manufactured from the thermoplastic resin composition of the present invention may be excellent.

In the diene rubber-based graft copolymer of the present invention, the unit derived from the aromatic vinyl-based monomer is preferably contained in an amount of 20 to 65% by weight based on the total weight of the diene rubber-based graft copolymer. In addition, the unit derived from the vinyl cyan-based monomer is preferably contained in an amount of 5 to 30% by weight based on the total weight of the diene rubber-based graft copolymer. When the content of the unit derived from the aromatic vinyl-based monomer and the unit derived from the vinyl cyan-based monomer is within such a range, grafting polymerization between the conjugated diene-based polymer and the aromatic vinyl-based monomer or the vinyl cyan-based monomer may be more efficient.

In the present invention, the aromatic vinyl-based monomer may be at least one selected from the group consisting of styrene, α-methyl styrene, α-ethyl styrene, and p-methyl styrene, among which styrene may be used.

In the present invention, the vinyl cyan-based monomer may be one or more selected from the group consisting of acrylonitrile, methacrylonitrile, ethacrylonitrile, phenylacrylonitrile, and α-chloroacrylonitrile, of which acrylonitrile Can be used.

ii) Acrylic rubber graft copolymer

In the present invention, the acrylic rubber-based graft copolymer is prepared by graft polymerization of an aromatic vinyl-based monomer and a vinyl cyan-based monomer on an acrylic rubber-based polymer, and the acrylic rubber-based polymer is prepared by emulsion polymerization of an alkyl (meth)acrylate-based monomer. It may be in the form of latex, and the alkyl (meth)acrylate-based monomer may be an alkyl (meth)acrylate substituted with an alkyl group having 1 to 10 carbon atoms, and more specifically, methyl (meth)acrylate, ethyl ( It may be one or more selected from the group consisting of meth)acrylate, propyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, and lauryl (meth)acrylate.

In the acrylic rubber-based graft copolymer of the present invention, the acrylic rubber-based polymer may be included in an amount of 30 to 70% by weight, preferably 40 to 60%, based on the total weight of the acrylic rubber-based graft copolymer. When the acrylic rubber-based polymer-derived unit is included in such a range, the impact resistance of the acrylic rubber-based graft copolymer may be excellent.

In the acrylic rubber-based graft copolymer of the present invention, the aromatic vinyl-based monomer and the vinyl cyanogen monomer are the same as those described in the foregoing diene rubber-based graft copolymer. In the acrylic rubber-based graft copolymer, the unit derived from the aromatic vinyl-based monomer is preferably contained in an amount of 30 to 55% by weight based on the total weight of the acrylic rubber-based graft copolymer, and the unit derived from the vinyl cyan-based monomer is an acrylic rubber-based graft. It is preferably included in 5 to 30% by weight based on the total weight of the copolymer. When the unit derived from the aromatic vinyl-based monomer and the unit derived from the vinyl cyan-based monomer are included in such a range, the shell formation of the acrylic rubber-based graft copolymer from the aromatic vinyl-based monomer and the vinyl cyan-based monomer may be more efficient.

iii) styrenic copolymer

The styrenic copolymer contains units derived from an aromatic vinyl-based monomer and units derived from a vinyl cyan-based monomer, and is obtained by copolymerization of an aromatic vinyl-based monomer and a vinyl cyan-based monomer.

In the styrene-based copolymer, the unit derived from the aromatic vinyl-based monomer may be included in an amount of 60 to 85% by weight, preferably 65 to 74% by weight, based on the total weight of the styrene-based copolymer, and the unit derived from the vinyl cyano-based monomer is It may be included in 15 to 40% by weight, preferably 26 to 35% by weight. When the unit derived from the aromatic vinyl-based monomer and the unit derived from the vinyl cyan-based monomer are included in such a range, the mixed compatibility of the prepared styrene-based copolymer, the diene rubber-based graft copolymer, and the acrylic rubber-based graft copolymer may be higher.

The base resin of the present invention may include 5 to 40% by weight of a diene rubber-based graft copolymer, 5 to 17% by weight of an acrylic rubber-based graft copolymer, and 55 to 80% by weight of a styrene-based copolymer. When the content of each copolymer in the base resin is the same, the balance of physical properties of the molded article manufactured from the thermoplastic resin composition is excellent.

Preparation of the diene rubber-based graft copolymer, the acrylic rubber-based graft copolymer, and the styrene-based copolymer may be performed using one or more methods selected from the group consisting of emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization. , In the case of a diene rubber-based graft copolymer and an acrylic rubber-based graft copolymer, it is particularly preferable to prepare by emulsion polymerization, and in the case of a styrene-based copolymer, by bulk polymerization. In addition, the polymerization may be carried out in the presence of an emulsifier, a polymerization initiator, an activator or a molecular weight modifier, as known in the art.

The emulsifiers are sodium dicyclohexyl sulfosuccinate, sodium dihexyl sulfosuccinate, sodium di-2-ethylhexyl sulfosuccinate, potassium di-2-ethylhexyl sulfosuccinate, sodium dioctyl sulfosuccinate Sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium octadecyl sulfate, sodium oleic sulfate sodium salt, sodium dodecyl sulfate, potassium octadecyl sulfate, potassium loginate, and sodium loginate. It may be more than one, of which sodium dodecyl benzene sulfonate is preferred.

The emulsifier may be added in an amount of 0.1 to 2 parts by weight or 0.3 to 0.7 parts by weight, based on 100 parts by weight of the monomer mixture to be polymerized, of which it is preferably added in an amount of 0.3 to 0.7 parts by weight. If the above-described range is satisfied, the polymerization reaction can proceed stably, and thus the formation of a coagulum can be suppressed.

The kind of polymerization initiator is sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, hydrogen peroxide, t-butyl peroxide, cumene hydroperoxide, p-mentane hydroperoxide, di-t-butyl peroxide, t- Butylcumyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide, 3,5,5-trimethylhexanol peroxide, t-butyl peroxy isobutylate, azobis isobutyro It may be one or more selected from the group consisting of nitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, and azobisisobutyric acid (butyric acid) methyl, of which t-butyl hydroperoxide Is preferred. The initiator may be added in an amount of 0.01 to 1 parts by weight or 0.05 to 0.5 parts by weight based on 100 parts by weight of the monomer mixture to be polymerized, of which 0.05 to 0.5 parts by weight is preferably added. If the above-described range is satisfied, the resulting polymer may have more excellent impact resistance.

The activating agent may be at least one selected from the group consisting of sodium formaldehyde sulfoxylate, disodium ethylenediamine tetraacetate, ferrous sulfate, dextrose, sodium pyrophosphate, sodium pyrophosphate anhydirose, and sodium sulfate, Among these, at least one selected from the group consisting of dextrose, ferrous sulfate and sodium pyrophosphate is preferred. The activator may be added in an amount of 0.01 to 1 parts by weight or 0.1 to 0.5 parts by weight, of which 0.1 to 0.5 parts by weight, based on 100 parts by weight of the monomer mixture to be polymerized. If the above-described range is satisfied, the flow index, impact resistance, and color characteristics of the polymer to be produced may be excellent.

The molecular weight modifier is α-methylstyrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan, n-octyl mercaptan, carbon tetrachloride, methylene chloride, methylene bromide, tetra ethyl thiuram disulfide, dipentamethylene thiuram It may be one or more selected from the group consisting of disulfide and diisopropylxanthogen disulfide, of which t-dodecyl mercaptan is preferred. The molecular weight modifier may be added in an amount of 0.01 to 1.5 parts by weight or 0.1 to 1 part by weight based on 100 parts by weight of the monomer mixture to be polymerized, of which 0.1 to 1 part by weight is preferably added. If the above-described range is satisfied, the balance between the flow index and the impact resistance in the produced polymer may be excellent.

B) Olefin copolymer

The thermoplastic resin composition of the present invention includes an olefin-based copolymer having at least one functional group selected from an alkyl acetate group or an alkyl acrylate group as an additive for improving chemical resistance. When such an olefin-based copolymer is used as an additive for a thermoplastic resin composition, chemical resistance can be greatly improved.

Specifically, the olefin-based copolymer may be represented by the following Formula 1 or 2:

[Formula 1]

[Formula 2]

In the formula, n and z are each independently an integer of 2 to 100,000,

R ₁ and R _{3 are} each independently hydrogen or an alkyl group having 1 to 4 carbon atoms,

R ₂ and R ₄ are each independently an alkyl group having 1 to 4 carbon atoms.

In the present invention, the olefin-based copolymer represented by Formula 1 or 2 may be a block copolymer or a random copolymer.

In addition, the content of at least one functional group selected from the alkyl acetate group or the alkyl acrylate group included in the olefin-based copolymer may be 10 to 40% by weight, preferably 20 to 30% by weight. When the functional group content in the olefin-based copolymer is within the above-described range, the compatibility and chemical resistance of the thermoplastic resin composition may be improved.

At least one functional group selected from the alkyl acetate group or the alkyl acrylate group contained in the olefin-based copolymer is 0.05 to 1.5 by weight, preferably 0.1 to 1.5, based on the unit derived from the acrylic rubber-based polymer contained in the acrylic rubber-based graft copolymer. It may be included in a weight ratio of 1.0, particularly preferably in a weight ratio of 0.1 to 0.5. When the functional group is included within the above-described range compared to the unit derived from the acrylic rubber-based polymer, the compatibility of the thermoplastic resin composition may be improved.

In the thermoplastic resin composition of the present invention, the olefin-based copolymer may be included in an amount of 1 to 10 parts by weight, preferably 1 to 7 parts by weight, based on 100 parts by weight of the base resin. If the olefin-based copolymer is contained less than this, the effect of improving chemical resistance is insignificant, and if it is contained more than this, the compatibility in the thermoplastic resin composition is poor, and the physical properties and quality of the final product may be deteriorated.

Meanwhile, the thermoplastic resin composition of the present invention may further include a thermoplastic polyester elastomer in addition to the olefin-based copolymer described above as an additive. The thermoplastic polyester elastomer plays a role of improving chemical resistance like the olefin-based copolymer, and when the olefin-based copolymer and the thermoplastic polyester elastomer are included at the same time, the chemical resistance may be further improved.

The shore strength (Shore D) of the thermoplastic polyester elastomer may be 30 to 70, preferably 40 to 60. When using a thermoplastic polyester elastomer that satisfies such a shore strength range, not only chemical resistance but also impact resistance It can be improved as well.

The thermoplastic polyester elastomer may be added in an amount of 1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the base resin. In addition, when a thermoplastic polyester elastomer is additionally included, it is preferable that the thermoplastic polyester elastomer and the olefin-based copolymer are added and included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the base resin. If less than this thermoplastic polyester elastomer is included, the effect of improving chemical resistance and impact resistance resulting therefrom is insignificant, and if more than this, it acts as an impurity in the thermoplastic resin composition, so that compatibility may be deteriorated.

The thermoplastic resin composition of the present invention is an antibacterial agent, heat stabilizer, antioxidant, release agent, light stabilizer, surfactant, coupling agent, plasticizer, admixture, colorant, stabilizer, lubricant, antistatic agent, colorant, flame retardant, It may further include additives such as a weathering agent, an ultraviolet absorber, a sunscreen agent, a nucleating agent, an adhesion aid or an adhesive.

The additive may be appropriately included within a range that does not impair the physical properties of the thermoplastic resin composition, and specifically, may be included in an amount of 40 parts by weight or less based on 100 parts by weight of the thermoplastic resin composition, and more specifically 0.1 to 30 parts by weight. It can be included as a wealth.

Hereinafter, a preferred embodiment is presented to aid the understanding of the present invention. However, the following examples are only illustrative of the present invention and are not intended to limit the scope of the present invention.

material

A diene rubber-based graft copolymer, comprising 60 parts by weight of a butadiene polymer having an average particle size of 0.3 µm, 25 parts by weight of styrene, and 15 parts by weight of acrylonitrile, and having a core-shell form of an acrylonitrile-butadiene-styrene copolymer ( In the following, "(1)") was used.

An acrylic rubber graft copolymer comprising 50 parts by weight of a butyl acrylate rubber polymer having an average particle size of 0.3 µm, 32 parts by weight of styrene, and 18 parts by weight of acrylonitrile, and having a core-shell form of acrylate-styrene-acrylic A ronitrile copolymer (hereinafter referred to as "(2)") was used.

A styrene-based copolymer comprising 70 parts by weight of styrene and 30 parts by weight of acrylonitrile, and a styrene-acrylonitrile polymer having a molecular weight of 130,000 (hereinafter referred to as "(3)-1"), or 73 parts by weight of styrene and acrylic A styrene-acrylonitrile polymer (hereinafter referred to as "(3)-2") containing 27 parts by weight of ronnitrile and having a molecular weight of 120,000 was used.

As an olefin-based copolymer as an additive, polyethylene-methyl acrylate copolymer (methyl acrylate content 24%, hereinafter referred to as "(4)-1") or polyethylene-vinyl acetate copolymer (vinyl acetate content 28%, or less) (Indicated as "(4)-2") was used, and a thermoplastic polyester elastomer (TPC-ET, Shore strength 40, hereinafter referred to as "(5)") was used as an additional additive.

Examples and Comparative Examples-Confirmation of physical properties and appearance characteristics of injection specimens

A total of eight thermoplastic resin compositions (Example 5) were mixed with a diene rubber-based graft copolymer, an acrylic rubber-based graft copolymer, a styrene-based copolymer, an olefin-based copolymer, and a thermoplastic polyester elastomer as an additional additive in the ratio of Table 1 below (Example 5 , Comparative Example 3) was prepared, and a specimen was prepared by injecting the prepared thermoplastic resin composition through an injection molding machine.

A) Base resin B) additive Weight ratio of functional group monomer in additive to butyl acrylate polymer (One) (2) (3)-1 (3)-2 (4)-1 (4)-2 (5) Example 1 20 10 70 - 7 - 2 0.34 Example 2 20 12 - 68 5 - 4 0.2 Example 3 20 5 - 75 - 2 - 0.22 Example 4 20 7 73 - One One - 0.17 Example 5 20 7 73 - - 2 One 0.19 Comparative Example 1 25 - 75 - - - - - Comparative Example 2 20 7 73 - - - - - Comparative Example 3 25 - - 75 3 - 4 -

Experimental Example 1. Measurement of physical properties of injection specimens

For the injection specimens prepared in the above Examples and Comparative Examples, physical properties were measured using the following method.

* Izod impact strength (IMP, kgfcm/cm): In accordance with ASTM D256, a notch was made in a pellet specimen having a thickness of 1/4 inch and measured.

* Flow Index (Melt Index, g/min): Measured according to ASTM D1238

The measured physical properties are summarized in Table 2 below.

Impact strength (kgfcm/cm) Flow index (g/min) Example 1 25 20 Example 2 26 19.8 Example 3 23 24.5 Example 4 24 23.9 Example 5 24 24.1 Comparative Example 1 24.7 23.2 Comparative Example 2 23.8 24.0 Comparative Example 3 24.5 23.5

From Table 2, in the case of the molded article injected with the thermoplastic resin composition according to the embodiment of the present invention, it was confirmed that the impact strength and flow index were similar to those of the comparative example, so that the impact resistance and moldability were good.

Experimental Example 2. Confirmation of compatibility and chemical resistance of injection specimens

Compatibility and chemical resistance were confirmed with respect to the specimens prepared in Examples and Comparative Examples. Specifically, the compatibility was evaluated as O if it was good and X if it was not by checking the appearance of the injection specimen after performing a treatment such as breaking the injection specimen or scribing with a knife.

In addition, in the chemical resistance evaluation, a tensile specimen was placed on a 1% jig, and the time until cracks were generated by applying a detergent widely was measured, and evaluated according to the following criteria.

-O: Excellent chemical resistance, more than 100 hours until cracking occurs

-△: Excellent chemical resistance, more than 50 hours until cracking occurs

-X: Poor chemical resistance, less than 10 hours until cracking occurs

Meanwhile, in the case of chemical resistance evaluation, two different types of detergents (chemical resistance evaluation 1: ester ethoxylate + alcohol ethoxylate high concentration detergent, chemical resistance evaluation 2: air conditioner refrigerant oil PVE (polyvinylether) oil) were used. It was performed twice, and the results are shown in Table 3 below.

Compatibility Chemical resistance evaluation 1 Chemical resistance evaluation 2 Example 1 O O O Example 2 O O O Example 3 O △ O Example 4 O △ O Example 5 O △ O Comparative Example 1 O X X Comparative Example 2 O X △ Comparative Example 3 X O O

From the above results, it was confirmed that the thermoplastic resin composition according to the embodiment of the present invention exhibits excellent compatibility and superior chemical resistance and compatibility compared to the comparative example.

Claims (11)

A) a base resin comprising the following i) to iii); And
i) a diene rubber-based graft copolymer;
ii) acrylic rubber-based graft copolymer;
iii) styrenic copolymer;
B) an olefin-based copolymer having at least one functional group selected from an alkyl acetate group or an alkyl acrylate group; a thermoplastic resin composition comprising.
The method of claim 1,
The base resin is
Diene rubber-based graft copolymer 5 to 40% by weight;
5 to 17% by weight of an acrylic rubber graft copolymer; And
A thermoplastic resin composition comprising: 55 to 80% by weight of a styrene-based copolymer.
The method of claim 1,
The diene rubber-based copolymer has a unit content derived from a diene rubber-based polymer of 40 to 80% by weight of the thermoplastic resin composition.
The method of claim 1,
The acrylic rubber-based copolymer has a unit content of 30 to 70% by weight of the acrylic rubber-based polymer.
The method of claim 1,
The olefin-based copolymer is a thermoplastic resin composition represented by the following Formula 1 or 2:
[Formula 1]

[Formula 2]

In the formula, n and z are each independently an integer of 2 to 100,000,
R ₁ and R 3 _are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms,
R ₂ and R ₄ are each independently an alkyl group having 1 to 4 carbon atoms.
The method of claim 1,
The thermoplastic resin composition in which the content of at least one functional group selected from the alkyl acetate group or the alkyl acrylate group contained in the olefin-based copolymer is 10 to 40% by weight.
The method of claim 1,
At least one functional group selected from the alkyl acetate group or the alkyl acrylate group included in the olefin-based copolymer is contained in a weight ratio of 0.05 to 1.5 based on the unit derived from the acrylic rubber-based polymer included in the acrylic rubber-based graft copolymer. Composition.
The method of claim 1,
The olefin-based copolymer is a thermoplastic resin composition that is contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the base resin.
The method of claim 1,
The thermoplastic resin composition further comprising a thermoplastic polyester elastomer.
The method of claim 9,
The thermoplastic polyester elastomer has a shore strength (Shore D) of 30 to 70.
The method of claim 9,
The thermoplastic polyester elastomer is contained in an amount of 1 to 10 parts by weight based on 100 parts by weight of the base resin.