KR0131573B1 - Process of copolymer having high heat resistance - Google Patents

Abstract

The heat resistant copolymer having a good processability, impact resistance, latex stability and high solid content, was prepared. 1-30 Parts of a seed latex, 50-75 parts of M-methyl styrene, 10-30 parts of vinyl cyanates, 0.1-10 parts of ethylenic unsaturated amide, 0.1-10 parts of acrylic alkyl ester or methacrylic alkyl ester and 0.1-5 parts of styrene were emulsion-polymerized in the presence of 0.2-0.6 part of molecular weight adjusting agent, 0.2-0.4 part of oxidation-reduction initiator and 4 parts of emulsifier to give the heat resistant copolymer having polymerization transfer rate more than 97%, solid content more than 45%. 75-90 Wt.% of total monomer was put into the seed latex in the initiation process, followed by reaction at 55-75 deg.C for 1-2 hours, 8-22 wt.% of total monomer was put into the seed latex at 65-80 deg.C for 2-5 hours, followed by addition and reaction of residual monomer and initiator for 1-2 hours.

Description

Method of producing a heat resistant copolymer

The present invention relates to a method for producing a heat resistant copolymer having excellent heat resistance, processability, impact resistance, latex stability, and extremely high solid content.

Recently, heat-resistant ABS (acrylonitrile-butadiene-styrene resin) resins having excellent impact resistance, processability, chemical resistance, and surface gloss are widely used for electric, electronic devices such as office equipment, home appliances, and automobiles, and have high functionalization. It is a situation.

In order to manufacture them, a method of manufacturing a heat resistant copolymer used for training is important and many studies have been conducted.

For example, Japanese Patent Laid-Open Nos. 58-206657, 59-135210 and 59-184243 describe a method for producing a heat resistant copolymer including N-phenylmaleimide, which increases the heat resistance of the resin but There is a problem of deterioration of physical properties such as workability and impact strength.

U.S. Patent Nos. 3010936 and 4659790 describe a method for preparing a heat resistant copolymer comprising α-methylstyrene, which also improves the heat resistance of the resin but decreases the polymerization conversion rate, latex stability, moldability, and thermal stability at high temperatures. Indicates a problem.

In addition, the heat-resistant copolymers prepared by the two methods have a low solid content because of poor latex stability.

In order to improve this problem, the present inventors use monomers such as ethylenically unsaturated amides, acrylic acid alkyl esters, or methacrylic acid alkyl esters to α-methylstyrene, styrene and vinylcyanide compounds to achieve polymerization conversion of about 96% or more. The polymers obtained were subjected to emulsion polymerization with the monomers again using these as latexes for seed.

This polymerized polymer is a heat resistant copolymer having a polymerization conversion of about 97% or more and a solid content of about 45% or more and a glass transition temperature of about 135 or more.

Hereinafter, the present invention will be described in detail.

1) Latex for Seed

The method for preparing latex for the seed is an emulsion polymerization method, and the method of adding each component may include a method of batch-administering the total amount of each component, or a method of continuously or sequentially administering the total amount or part of the components. Takes a complex form using a combination of and continuous administration method.

That is, 75 to 90% by weight of the total weight of the monomers used in the preparation of the latex for the seed is administered in a batch after the reaction and reacted at a reaction temperature of 55 to 75 ℃ for 1 to 2 hours and then 8 to 22% by weight of the total weight of the monomers After the continuous administration over 2 to 5 hours at 65 to 80 ℃ to administer the residual monomer and the initiator to the emulsion polymerization reaction for 1 to 2 hours to prepare a latex for the seed.

The monomers used in the method for producing the latex for the seed are prepared by emulsion polymerization using at least two kinds of α-methylstyrene, styrene, vinyl cyanide, ethylenically unsaturated amide, alkyl acrylate or alkyl methacrylate. Specifically, 50 to 80 parts by weight of α-methylstyrene, 15 to 30 parts by weight of vinyl cyanide, 0.1 to 10 parts by weight of ethylenically unsaturated amide, 0.1 to 10 parts by weight of alkyl acrylate ester or 0.1 to 10 parts by weight of alkyl methacrylate Parts and optionally 0.1 to 5 parts by weight of styrene, prepared by emulsion polymerization.

Methyl methacrylate (or any compound of the same kind, similar or substituted (compatible) substitute) is used as alkyl methacrylate ester, and methacrylamide ((or the same kind, similar or substituted with ethylenic unsaturated amide) is used. Compatibility), including all replaceable compounds).

As the emulsifier, sodium salts and potassium salts of rosin acid and higher fatty acids, sodium salts and potassium salts of alkyl benzene sulfonic acid, and the like are used alone or in combination.

Polymerization catalysts include peroxides such as persulfate, diisopropyl benzene hydroperoxide cumene hydroperoxide, sodium formaldehyde sulfoxylate, sodium ethylene dimante tetraacetate, ferrous sulfate, dextrose, sodium pyrolate Oxidation-reduction catalysts in a mixture with a reducing agent such as sodium sulfite and the like are used. When using an oxidation-reduction catalyst, the amount of oxidant therein is 0.2 to 0.4 parts by weight based on 100 parts by weight of the total monomers.

As the molecular weight modifier, tertiary dodecyl mercaptan is used and is used in an amount of 0.01 to 0.6 parts by weight per 100 parts by weight of the total monomers.

The polymerization conversion rate of the latex for the seed prepared by the above method was about 96% or more.

2) Preparation of heat resistant copolymer

1 to 30 parts by weight of the latex for the seed prepared above, 50 to 75 parts by weight of α-methylstyrene, 10 to 30 parts by weight of vinyl cyanide, 0.1 to 10 parts by weight of ethylenically unsaturated amide, parts by weight of alkyl ester of acrylic acid or methacryl Emulsion polymerization is carried out in the presence of 0.1 to 10 parts by weight of the acid alkyl ester and optionally 0.1 to 5 parts by weight of styrene, in the presence of 0.2 to 0.6 parts by weight of the molecular weight regulator, 0.2 to 0.4 parts by weight of the oxidizing agent and 1 to 4 parts by weight of the oxidizing-reducing initiator. A heat resistant copolymer having a polymerization conversion of about 97% or more and a solid content of about 45% or more is prepared.

When described in more detail as follows.

50 to 99% by weight of the total weight of the monomers used in the batch administration of the latex for the seed and the heat-resistant copolymer are combined in a batch and continuous (sequential) administration for a reaction temperature of 50 ° C. to 85 ° C. for 2 hours to 5 hours. After reacting at 1 to 20% by weight of the total weight of the monomers in a batch emulsion polymerization for 1 hour to 2 hours at 70 ℃ to 85 ℃ to prepare a heat-resistant copolymer.

Of the monomers used in the present invention, methyl methacrylate is used as the methacrylic acid alkyl ester and methacrylamide is used as the ethylenically unsaturated amide.

As emulsifiers, single or double compounds such as sodium salts and potassium salts of rosin and higher fatty acids, sodium salts and potassium salts of alkyl benzene sulfonic acid, and the polymerization catalysts are persulfate diisopropyl benzene hydroperoxide and cumene hydroperoxide. Redox catalysts are used which are a mixture of a peroxide such as sodium permaldehyde sulfoxylate, sodium ethylenediamine tetra acetate, ferrous sulfur, dextrose sodium pyrrolate, sodium sulfite and the like.

As the molecular weight regulator, tertiary dodecyl mercaptan is used and is used in an amount of 0.01 to 0.6 parts by weight per 100 parts by weight of the total monomers.

After the completion of the polymerization, the polymerization conversion was about 97% or more, the solid content was about 45% or more, and the latex obtained was coagulated with an aqueous calcium chloride solution at about 120 ° C., dehydrated and dried.

In the examples, the solids content and the weight of the resulting coagulant can be obtained from the following formula.

When the product coagulant weight is about 0.5% or more, the stability of the prepared latex is extremely poor, which is not suitable for the purpose of the present invention.

Example

1: Manufacture of Latex for Seed

[A1]

One step component of composition ratio A1 of Table 1, that is, 110 parts by weight of ion-exchanged water, 2.0 parts by weight of sodium dodecyl benzene sulfonate as an emulsifier, 65 parts by weight of α-methylstyrene, 2 parts by weight of styrene, and 14 parts by weight of acrylonitrile. In addition, an oxidation-reduction catalyst consisting of 0.4 parts by weight of dodecyl mercaptan (TDDM) as a molecular weight regulator, 0.2 parts by weight of potassium persulfate and 0.10 parts by weight of sodium sulfite as a initiator was collectively administered at 45 ° C., and the reaction temperature was 70 ° C. The reaction was carried out for 1 hour and 30 minutes while increasing to.

Then, the two-component components of the composition ratio A1, namely 70 parts by weight of ion-exchanged water, 0.6 parts by weight of an emulsifier, 11 parts by weight of acrylonitrile, 4 parts by weight of methacrylamide, 3 parts by weight of methyl methacrylate and 0.2 parts by weight of TDDM, 0.1 parts by weight of persulfate leaf was mixed as an initiator and continuously administered at 75 ° C. for 3 hours.

After the polymerization temperature was raised to 80 ° C., a three-step component of the composition ratio A1, that is, 5 parts by weight of ion-exchanged water, 0.1 parts by weight of an emulsifier, 1 part by weight of acrylonitrile, and 0.05 parts by weight of persulfate were mixed with an initiator and collectively administered. The reaction was then carried out for 30 minutes and then aged for 1 hour.

After the reaction was completed, the solids content (%) of the latex prepared by using an infrared lamp was measured and the polymerization conversion was measured. And the weight of the resulting coagulum (%) was measured to determine the stability of the latex.

[A2 to A4]

The composition was carried out in the same manner as A1, but the composition ratio of A2 to A4 was performed instead of A1 in Table 1.

The results are shown in Table 1.

1: Preparation of heat resistant copolymer

[B1]

In the reactor, the first stage components of composition ratio B1 in Table 2, namely, 75 parts by weight of ion-exchanged water, 1.0 part by weight of sodium dodecyl benzene sulfonate as an emulsifier, 5 parts by weight of latex [A2] for seed, and 68 parts by weight of α-methylstyrene After the reaction temperature was raised to 77 ° C., an oxidation-reduction catalyst consisting of 0.2 part by weight of sodium persulfate and 0.1 part by weight of sodium sulfite was administered as an initiator.

Thereafter, the second stage component of the composition ratio B1, that is, 40 parts by weight of ion-exchanged water, 1.7 parts by weight of emulsifier, 22 parts by weight of acrylonitrile, 3 parts by weight of methacrylamide, 1 part by weight of methyl methacrylate, 0.55 part by weight of TDDM and emulsification 0.1 parts by weight of persulfate was mixed with the mixture and the initiator and administered continuously (sequentially) at 78 ° C for 4 hours.

After raising the polymerization temperature to 80 ° C., three parts of the composition ratio B1, that is, 5 parts by weight of ion-exchanged water, 0.1 parts by weight of an emulsifier, 1 part by weight of an emulsified mixture, and 0.05 parts by weight of persulfate with an initiator were mixed for 30 minutes. Reaction and aged for 1 hour. After completion of the reaction, the solid content (%) and polymerization conversion rate of the latex prepared by using an infrared lamp were measured, and the weight of the resulting coagulant (%) was measured to determine the stability.

In addition, the prepared latex was coagulated with an aqueous calcium chloride solution at 120 ° C., washed, dried, and the glass transition temperature was measured by DSC (differential scanning heat analyzer).

The results are shown in Table 2.

[B2 to B8]

The same method as in B1 was used, but the composition ratio B2-B8 was used instead of B1 in Table 2, and the results are shown in Table 2.

Example

[C1]

The powder prepared in Example B1 and the graft ABS polymer (Lucky Co., Ltd. DP210) powder were mixed and administered by adding 0.4 part by weight of lubricant, 0.4 part by weight of antioxidant, and 0.2 part by weight of UV stabilizer per 100 parts by weight of the mixed powder. Extruded using a twin-screw trainer at a cylinder temperature of ℃ to 260 ℃ to prepare a pellet form.

Specimens were prepared using this pellet and the physical properties thereof were shown in Table 3.

[C2 to C6]

Using the composition ratio C2 to C6 of Table 3 it was carried out in the same manner as in the use example C1.

The results are shown in Table 3.

Claims (5)

a monomer mixture comprising 50 to 80 parts by weight of α-methylstyrene, 15 to 30 parts by weight of vinyl cyanide, 0.1 to 10 parts by weight of ethylenically unsaturated amide, parts by weight of alkyl acrylate or 0.1 to 10 parts by weight of alkyl methacrylate. To obtain a polymer having a polymerization conversion of 96% or more by emulsion polymerization, and using the obtained polymer as a latex for seed, 1 to 30 parts by weight of this polymer, 50 to 75 parts by weight of α-methylstyrene, and 10 to 30 parts by weight of vinyl cyanide. And emulsification polymerization by adding a monomer mixture containing 0.1 to 10 parts by weight of ethylenically unsaturated amide and 0.1 to 10 parts by weight of alkyl acrylate or alkyl methacrylate. The method of claim 1, wherein the ethylenically unsaturated amide is methacrylamide. The method of producing a heat resistant copolymer according to claim 1, wherein the methacrylic acid alkyl ester is methyl methacrylate. The method of claim 1, wherein 50 to 99% by weight of the total weight of the monomers used in the batch administration of the seed latex and the heat-resistant copolymer is 50 ° C. for 2 to 5 hours in a combination of batch administration and continuous (sequential) administration. And reacting at a temperature of from 85 ° C. to 1 to 20% by weight of the total weight of the monomers, thereby performing emulsion polymerization at 70 ° C. to 85 ° C. for 30 minutes to 2 hours. The method of claim 1, wherein the monomer mixture further comprises 0.1 to 5 parts by weight of styrene.