KR910003870B1 - Thermosetting resin having good heat-resistant inpact-proof - Google Patents

Abstract

forming the rubbric latex of 0.2-1.0μ particle size, of particle formable core-shell form, by continuous inputting 70-99 wt. pts of rubbric forming monomer, 0.1-1 wt. pts of emulsifier, 0.1-5 wt. pts of crosslinking agent, 0.01-2 wt. pts of polymn. initiator and ion-exchange water; graft polymerizing, as continuous in putting of, 30-60 wt. pts of the obtd. rubbric latex, 15-40 wt. pts of monovinyl idene aromatic hydrocarbon, 5-25 wt. pts of unsatd. nitrile, 0.1-5 wt. pts of emulsifier, 0.01-2 wt. pts of initiator and ion-exchange water; removing the unreacted monomer by inputting monovinyliden aromatic hydrocarbon, unsatd. nitrile, etc.

Description

Manufacturing method of thermoplastic resin excellent in impact resistance, weather resistance and heat resistance

The present invention relates to a method for producing a thermoplastic resin excellent in impact resistance, weather resistance and heat resistance. As the thermoplastic resin having impact resistance, rubber-modified thermoplastic resins such as ABS (Acrylonitrile-Butadine-Styrene copolymer: hereinafter called ABS resin) resin and high-fill polystyrene are widely used.

However, these resins have been subject to many restrictions on the use of electrical, electronic products, advertising signs, automobile parts, and the like, which require weather resistance and heat resistance.

In general, in order for the resin to exhibit excellent weather resistance, it is possible when the molecular structure of the rubber component is not a diene type. Representative weather resistance resins include ASA (Acrylonitrile-Styrene-Acrylate copolymer) resin, AES (Acrylonotrile-EPDM-Styrene copolymer) resin, ACS (Acrylonitrile-CPE-Styrene copolymer) resin and the like. It is also used most often because of its excellent color and luster.

In addition, these resins are therefore wake up the thermal deformation by the long time exposure at high temperature during the injection process by replacing a portion of the monomer as a method for improving the heat resistance as α- methylstyrene excellent glass transition temperature (T _g) of the heat resistance is 165 ℃ Since the content of α-methylstyrene in the resin phase is increased by polymerization, there is a method of increasing heat resistance and a method of mixing these resins with α-methylstyrene-acrylonitrile copolymer.

The present invention relates to a method of improving the heat resistance by replacing a portion of the monomer with α-methylstyrene in preparing the ASA resin used in the thermoplastic resin having excellent impact resistance, heat resistance and weather resistance.

However, in this method, the higher the content of α-methylstyrene in the ASA resin, the better the heat resistance. However, the higher the content of α-methylstyrene in the reactant, the more unreacted monomers are present in the reactants. There are many difficulties in increasing the heat resistance of the.

In the present invention, as a result of solving the above problems to prepare an ASA resin with improved weather resistance, impact resistance and other physical properties as well as heat resistance, a graph containing a proper amount of α-methylstyrene but little unreacted monomer is present It was found that a thermoplastic resin having excellent impact resistance, weather resistance and heat resistance can be obtained by preparing a resin resin by a three-step emulsion polymerization method and mixing it with a conventional α-methylstyrene-acrylonitrile copolymer having excellent workability. The present invention has been completed.

In the present invention, a three-step polymerization process is performed to produce graft ASA. In the first step, the rubber particle diameter and the particle shape are modified, and the graft site is provided, and the second step is α-methylstyrene. It is characterized in that it is added to give the heat resistance, in the third step is characterized in that the addition of a small amount of α-methylstyrene compared to the monomer to remove the unreacted monomer.

The method of the present invention is described in detail as follows. 70-99 parts by weight of rubbery polymer monomer, 0.1-1 part by weight of emulsifier, 0.1-5 parts by weight of crosslinking agent, 0.01-10 parts by weight of graft agent, 0.01-2 parts by weight of polymerization initiator and ion-exchanged water to form a particle-forming core -Rubbery latex obtained in the first step reaction to form a rubbery latex with a particle diameter of about 0.2-1.0μ, forming a shell (Core-Shell), to change the shape of the rubber particles and to give a graft site. 30-60 parts by weight, 15-40 parts by weight of monovinylidene aromatic hydrocarbon, 5-25 parts by weight of unsaturated nitrile, 0.1-5 parts by weight of emulsifier, 0.01-2 parts by weight of comprehensive initiator and ion exchanged water In the second step of the reaction to impart heat resistance and 5-10 parts by weight of monovinylidene aromatic hydrocarbon, 5-15 parts by weight of unsaturated nitrile, 0.1-5 parts by weight of emulsifier, molecular weight regulator and ion-exchanged water, Dosing method, dosing time, Depending on whether dimer absorption controlling the viscosity and particle size of the graft and a method of manufacturing a thermoplastic resin consisting of the reaction step 3 to remove the unreacted monomers.

The first step is a gum monomer used to prepare rubbery latex having excellent weather resistance, such as alkyl ester having 1 to 8 carbon atoms and alkyl ester having 1 to 4 carbon atoms, specifically methyl ester and acrylic acid. Ethyl ester, acrylic propyl ester, acrylic butyl ester, acrylic acid 2-ethyl hexyl ester, methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid butyl ester, and the like. One or two or more homopolymers or copolymers selected from acrylic acid 2-ethyl hexyl ester, acrylic acid butyl ester and acrylic acid ethyl ester having a relatively low T _g ) are preferred.

In order for the rubber component to exhibit elasticity, proper crosslinking is required, so in the case of acrylate rubber, use of a crosslinking agent is inevitable.

Examples of the crosslinking agent include 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, divinylbenzene, trialkylsaanurate, tetraethylene glycol diacrylate, 1,4-butanediol dimethacrylate, and the like. The use amount is 0.1-5 weight part.

If less than the above range is used, the degree of crosslinking is low, making processing difficult.

A graft agent is also used to bond the matrix and the rubber particles in the dispersed phase. The graft agent is triarylcyanurate, triarylisocyanurate, diarylsuccinate, aryl methacrylate, diarylphthalate, and diarylmaleate. And aryl methacrylates are most preferred.

The adjustment of graft viscosity is the most important factor for improving heat resistance, impact strength and mechanical properties. When the amount of graft agent is less than 0.01 part by weight, the effect of graft is hardly affected, and thus the improvement of heat resistance, impact strength and mechanical properties is achieved. Not contributing

The second and third reactions are polymerization reactions in which unsaturated nitrile and monovinylidene aromatics are grafted to rubbery latex, and a representative example of the monovinylidene aromatic compound in the above step is α-methylstyrene.

Examples of the unsaturated nitrile include one or two homopolymers or copolymers of acrylonitrile, methacrylonitrile and ethacrylonitrile, of which acrylonitrile is most preferred. α-methylstyrene is low in reactivity, so there are many unreacted monomers in the final polymer. In order to remove such unreacted monomer, in the two-stage reaction, α-methylstyrene and a small amount of acrylonitrile are polymerized. In the three-stage polymerization, a small amount of α-methylstyrene and an excess of acrylonitrile are polymerized. It removes and gives structure of resin excellent in heat resistance.

As a method of adding a monomer to the reactor, a method of adding a monomer compound, an emulsifier, ion-exchanged water, an initiator, and the like at a time, a method of dividingly adding a constant amount, and a method of continuously adding a predetermined amount are most preferred. It is a way.

In the second step, the polymerization is continuously introduced into the reactor while stirring the emulsifier, ion-exchanged water, polymerization initiator, 15-40 parts by weight of monovinylidene aromatic hydrocarbon and 5-25 parts by weight of unsaturated nitrile in a stirred vessel. The ratio of the injected amount of the second stage and the third stage of the monovinylidene aromatic hydrocarbon is preferably 6: 4-9: 1, and the ratio of the injected amount of the second and third stages of the unsaturated nitrile is 4: 6-1: 5. Do.

In the third stage polymerization, an emulsifier, a molecular weight modifier, ion-exchanged water, 5-10 parts by weight of monovinylidene aromatic hydrocarbon, and 5-15 parts by weight of unsaturated nitrile are continuously added to the reactor while stirring in a stirred vessel.

In the three-stage polymerization, the internal temperature of the reactor is increased by the heat of polymerization, and thus the inside of the reactor needs to be cooled.

Emulsifiers used in the present invention include sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium oleate sulfate, potassium dodecyl sulfate, potassium dodecyl benzene sulfate, potassium octadecyl sulfate, potassium oleate sulfate, etc. Its usage amount is 0.1-1 parts by weight in the first stage reaction, 0.1-5 parts by weight in the second stage reaction, 0.1-5 parts by weight in the three stage reaction. It is economical and excessive use than the above amount causes new particle formation, which makes it difficult to control the particle shape.

As the polymerization initiator used in the present invention, benzool peroxide, aluminum peroxide, potassium peroxide, azobis butyltonitrile, and the like are used, and molecular weight regulators include n-dodecyl methane, t-dodecyl methethane, t It is preferable to use hexadecylmerethane, and the amount of use is 0.001-0.5 parts by weight in three steps. Excessive use in excess of the above range rapidly decreases the molecular weight, leading to a decrease in impact strength and mechanical properties.

The graft polymer according to the present invention requires latex blending or mechanical mixing with a copolymer of α-methylstyrene and acrylonitrile to control physical properties.

In the case of mechanical mixing, specimens are obtained after mixing by various machines such as an extruder, a Banbury mixer or heating rolls after passing through a Henschel mixer.

Hereinafter, the present invention will be described by way of examples.

Example 1

In the first stage polymerization reaction, 80 parts of ion-exchanged water, 0.2 parts of sodium oleate, 8 parts of butyl acrylate, 0.5 parts of divinylbenzene were added, and when the inside of the reactor reached 80 ° C, 0.2 parts of calcium persulfate dissolved in water was added and reacted for 30 minutes. Then, 87 parts of butyl acrylate, 0.1 part of sodium oleate, 0.5 part of aryl methacrylate, and 3.0 parts of divinylbenzene were continuously added to the reactor with stirring for 2 hours, followed by polymerization for 1 hour. Subsequently, rubbery latex having a particle diameter of 0.5 mu is obtained.

Subsequently, in the two-step synthesis reaction, 40 parts of rubbery latex obtained from the first step reaction, 40 parts of ion-exchanged water, 0.4 parts of sodium lauryl sulfate, 35 parts of α-methylstyrene, 5 parts of acrylonitrile and 0.2 parts of potassium persulfate were added to the stirring vessel. Into an emulsion and then continuously pumped into the reactor over 2 hours. Subsequently, in a three-step polymerization reaction, 30 parts of ion-exchanged water, 0.4 part of sodium lauryl sulfate, 0.5 part of n-dodecyl merethane, 0.5 part, 7 parts of α-methylstyrene, and 13 parts of acrylonitrile were injected and stirred, After making the melt state, the mixture was continuously introduced into the reactor over 2 hours, and after 1 hour, the reaction was stopped to obtain a graft ASA resin.

Example 2

The graft agent used in Example 1 was prepared in the same manner as in Example 1 except that triaryl isocyanurate was used instead of aryl methacrylate, and the physical properties thereof are shown in Table 1 below.

Comparative Example 1

10 parts of α-methylstyrene and 19 parts of acrylonitrile were prepared in the second step of Example 1, except that 21 parts of α-methylstyrene and 10 parts of acrylonitrile were used in the third step. The physical property results are shown in Table 1 below.

Comparative Example 2

In a one-stage reaction of rubbery latex production, 99 parts of butyl acrylate, 0.7 parts of divinylbenzene, 0.3 parts of aryl methacrylate, 1.0 part of emulsifier and 300 parts of ion-exchanged water were added, and 0.2 parts of initiator was added at 80 ° C. In order to increase the particle size after the reaction for 4 hours, HCl (2% solution) was added in an amount of 0.15 parts, except that high-rich latex was prepared.

Comparative Example 3

The physical properties of the graft polymerization were prepared by the same method as in Example 1, except that polybutadiene latex was used instead of the rubbery latex obtained in the first stage of polymerization in Example 2, and the physical properties are shown in Table 1.

TABLE 1

* 1. Color change of specimen after 500 hours curing under xenon lamp conditions

Claims (4)

70-99 parts by weight of a rubber forming monomer, 0.1-1 part by weight of an emulsifier, 0.1-5 part by weight of a crosslinking agent, 0.01-2 part by weight of a polymerization initiator and ion-exchanged water were added continuously to form a core-shell form. First step reaction to form a rubbery latex having a particle size of about 0.2-1.0μ, 30-60 parts by weight of the rubbery latex obtained in the first step, 15-40 parts by weight of monovinylidene aromatic hydrocarbon, 5-25 parts by weight of unsaturated nitrile Part, a second stage reaction in which a grafting reaction is carried out by continuously adding 0.1-5 parts by weight of an emulsifier, 0.01-2 parts by weight of a polymerization initiator and ion-exchanged water, and 5-10 parts by weight of a monovinylidene aromatic hydrocarbon, and an unsaturated nitrile 5- 15 parts by weight, an emulsifier 0.1-5 parts by weight, a molecular weight control agent and ion-exchanged water by adding a three-stage reaction to remove the unreacted monomers. The method for producing a thermoplastic resin according to claim 1, wherein the rubber forming monomer is one or two or more homopolymers or copolymers selected from acrylic acid 2-ethylhexyl ester, acrylic acid butyl ester and acrylic acid ethyl ester. The method for producing a thermoplastic resin according to claim 1, wherein the graft agent is triarylcyanurate, triarylisocyanurate, diarylsuccinate, arylmethacrylate, diarylphthalate, and diarylmaleate. The method for producing a thermoplastic resin according to claim 1, wherein the unsaturated nitrile is one or two or more homopolymers or copolymers selected from acrylonitrile, methacrylonitrile and methacrylonitrile.