KR930002705B1 - Process for preparing a thermoplastic resin having a good impact resistance and mechanical strength - Google Patents

Abstract

The thermoplastic resin is prepared by (1) mixing gamma-latex (A) (weight average particle diameter = 0.03-0.2 μm) and rubber latex (B) (weight average particle diameter = 0.03-0.2 μm), (2) enlarging the mixture to form the latex (C) having weight average particle diameter of 0.25-0.5 μm, (3) adding a monomer mixture consisting of above 60 wt.% of aroamatic vinyl monomer (D) and below 40 wt.% of vinyl compound (E) copolymerizable with (D), initiator and chain transfer agents into the latex (C) obtained in (2), and (4) emulsion graft polymerizing it. The resin has an excellent impact resistance and mechanical strength.

Description

Manufacturing method of thermoplastic resin excellent in impact resistance and mechanical strength

The present invention relates to a method for producing a novel thermoplastic resin with improved impact resistance and mechanical strength (tensile strength, flexural strength).

Conventionally, diene-based rubbery materials such as polybutadiene, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer and the like are hard and brittle thermoplastic resins such as polystyrene, polymethyl methacrylate and styrene-acrylonitrile copolymers. Was added to obtain an impact resistant resin. However, when rubber is added, impact strength is improved, but mechanical strength is inferior. Thus, the present inventors completed the present invention by searching for a method capable of simultaneously improving the impact strength and the mechanical strength.

In addition, the impact resistance of the final composition is largely affected by the diameter of the rubber particles dispersed in the matrix resin. Therefore, much effort has been made to increase the diameter of the rubber particles. However, the present invention has the advantage of producing a resin that can meet the object of the present invention even if the diameter of the rubber particles as small as possible. In the copolymer of impact-resistant acrylonitrile-butadiene-styrene commercially available, rubber having a particle size of 0.3 to 0.5 µm is dispersed. In fact, when the graft reaction is carried out by emulsion polymerization using a large amount of such large-diameter rubber particles, a large amount of coagulum is produced and there are many separation points. Therefore, large diameter particles can be used only about 40 to 80% of the total rubber content.

If less than this, impact resistance cannot be improved. However, using the present invention can exhibit high impact resistance and excellent workability even if the average particle size is slightly smaller than 0.25 ~ 0.35㎛.

Hereinafter, the present invention will be described in detail.

The present invention is a conventional emulsion polymerization method by inserting or adsorbing such a substance in the soft rubber particles when the rubber particle diameter is increased by mixing hydrophobic and hard latex with rubber latex prepared by conventional emulsion polymerization and hard latex. The graft was made to produce a thermoplastic resin which simultaneously improved impact resistance and mechanical strength. The process is summarized as follows.

1) It is a small-diameter rubber latex. The average particle size is 0.03 ~ 0.2㎛, and the gel content is 40 ~ 95%.

-라텍스라 칭함)2) Manufacture of latex material to be mixed with rubber latex

-Called latex)

-라텍스는 방향족 비닐단량체 단독 또는 방향족 비닐단량체와 이와 공중합 가능한 비닐단량체 혼합물이고, 혼합물중 방향족 비닐단량체가 50중량%이상임.A latex material having a weight average molecular weight of 300 to 40,000, more preferably 500 to 10,000 and an average particle diameter of 0.03 to 0.2 µm. Also,

The latex is an aromatic vinyl monomer alone or a mixture of aromatic vinyl monomers and vinyl monomers copolymerizable with the aromatic vinyl monomer, and the aromatic vinyl monomer in the mixture is 50% by weight or more.

-라텍스의 혼합 및 비대화공정.3) with rubbery latex

-Mixing and non-conversation process of latex.

-라텍스의 혼합비는 고무질 라텍스 100중량부당 0.01~20.0중량부가 적절하며, 보다 적합하게는 0.1~10중량부가 좋다. 또 비대화된 고무질 라텍스의 크기는 0.25~0.35㎛이 적절하다.1) Protest with rubbery latex

-The mixing ratio of latex is 0.01 to 20.0 parts by weight per 100 parts by weight of rubber latex, more preferably 0.1 to 10 parts by weight. In addition, the size of the rubberized latex is preferably 0.25 ~ 0.35㎛.

4) Preparation of Graft Copolymer

5 to 80 parts by weight is appropriate for the rubber material enlarged in paragraph 3, and a mixture ratio of aromatic vinyl monomer and vinyl monomer is 60 to 99.25 / 40 to 0.75 as a graft monomer.

The thermoplastic resin produced by the above process is excellent in impact resistance and mechanical strength.

The process is described in more detail as follows.

1) Manufacture of small-diameter rubber latex

The preparation of graft copolymers is already well known and generally the latex form of the graft copolymer is to prepare a high portion and to graft monomers compatible with the matrix thereon.

Suitable rubber bases are conjugated diene rubbers, ethylene-propylene-diene terpolymers, acrylate-diene copolymers and mixtures thereof, and more suitable rubber bases are inexpensive, versatile in use, and exhibit excellent physical properties. It is made from 1,3-butadiene.

In the present invention, rubber containing 1,3-butadiene alone or 4 to 15% by weight of hydrophilic monomers is also very useful. Typically acrylonitrile, methacrylonitrile, methacrylonitrile and mixtures thereof can be used. Conjugated diene rubber includes the following. That is, 1,3-butadiene, 2-methyl-1,3-butadiene, 1,3-dimethyl-1,3-butadiene, pentadiene, 2-neopentyl-1,3-butadiene and 1,3-butadiene Substituents such as hydrocarbon analogs, 2-chloro-1,3-butadiene, 2-cyano-1,3-butadiene, and the like.

Representative anionic emulsifiers may be used alkylallylsulfonates, alkali metalalkylsulfates, sulfonated alkylesters, soaps of fatty acids. Specific examples include sodium dodecylbenzenesulfonate, sodium butylnaphthylenesulfonate, sodium laurylsulfate, dioctylsodium sulfosuccinate, disodium dodecyl diphenylisodisulfonate, N-octadecyl disodium sulfosoxy Nate and the like. Moreover, it is appropriate that the alkali salt of fatty acid has 16 to 18 carbon atoms, and typical examples thereof include stearic acid and oleic acid. In addition, an alkali salt of rosin acid is used. The amount of emulsifier used is suitably within 0.1 to 5 parts by weight per 100 parts by weight of monomer. As a suitable initiator or catalyst, a water-soluble persulfate or a peroxy compound can be used, and a water-soluble redox can also be used.

Most suitable water-soluble persulfates are sodium or calcium persulfate, and fat-soluble initiators include cumene hydroperoxide, azobisisobutyronitrile, tertiary butyl hydroperoxide, paramethane hydroperoxide and benzoyl peroxide. . The amount used is within 0.02 to 1% by weight relative to the polymerized monomer. As the molecular weight regulator, mutantan type is used, and 0.01 to 1.0 parts by weight per 100 parts by weight of the monomer is suitable. The polymerization of the rubber gas is usually carried out at 50 to 80 DEG C for 10 to 20 hours so that the polymerization conversion is 90 to 95%.

In order to be suitable for the present invention, a rubber particle diameter of about 0.03 to 0.2 탆 is appropriate, and a gel content of 40 to 95% is suitable.

2) Manufacturing process of latex material inserted or adsorbed on rubber latex

The feature of the present invention is that the material inserted or adsorbed is very important because graft copolymerization is performed by adding a hydrophobic material stronger than rubber in the rubber substrate. In this case, the present invention can be used as long as it can be mixed with rubbery latex by polymerizing a hydrophobic strong monomer.

-메틸스티렌,

-에틸스티렌,

-메틸비닐톨루엔,

-메틸디알킬스티렌, o-,m-,p-비닐톨루엔, o-에틸스티렌, p-에틸스티렌, 2,4-디메틸스티렌, p-터셔리부틸스티렌, 그리고 이들의 혼합물도 본 발명에서는 적합하다. 그 제조법은 통상의 유화중합법에 의해서도 가능하고, 기타 다른 방법(괴상중합, 현탁중합등)에 의해 제조된 후 라텍스화 한 것도 가능하다.However, the inserted material should be smaller in size than the enlarged rubber particles and have a harder property than rubber. Therefore, an aromatic vinyl monomer is preferable as a monomer suitable for this property. Representative examples are as follows. Styrene,

Methyl styrene,

Ethyl styrene,

Methylvinyltoluene,

-Methyldialkylstyrene, o-, m-, p-vinyltoluene, o-ethylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tertiarybutylstyrene, and mixtures thereof are also suitable in the present invention. Do. The production method can be made by a conventional emulsion polymerization method, or can be latexed after being produced by other methods (block polymerization, suspension polymerization, etc.).

In addition, the present invention can be easily achieved in a form in which a graft reaction can be performed after dissolving in a solvent and swelling in a rubber latex without latexing. The latex produced at this time can achieve the object of the present invention when the following properties are satisfied. The weight average particle diameter is 0.03-0.2 micrometer, More preferably, it is 0.03-0.15 micrometer. The molecular weight should be in the range of 300 to 40,000 weight average molecular weights (200 to 35,000 number average molecular weights and 1.0 to 5.0 ratios of weight average molecular weights to number average molecular weights). More suitably, the weight average molecular weight is 500 ~ 10,000.

-라텍스와의 혼합공정3) Rubber Latex to be inserted

Mixing process with latex

-라텍스 0.01~20.0중량부(고형분)가 적절하며, 보다 적합하기로는 0.05~10중량부가 좋다.To suit the purpose of the present invention per 100 parts by weight of rubber latex (solid content)

-0.01 to 20.0 parts by weight (solid content) of latex is appropriate, and 0.05 to 10 parts by weight is more preferable.

4) Enlargement process of mixed latex

-라텍스의 양이 각각의 비대화 고무입자내에 거의 동일하게 삽입 또는 흡착이 가능하기 때문이다.As the method for enlarging the particles, any method such as an acid method, a shearing method, a solvent method, a polymer electrolyte method or a freeze-thaw method can be used. However, the most suitable thing for the purpose of the present invention is that the average particle size of the particles is 0.25 to 0.5 mu m, and the narrowest possible particle distribution is suitable. Because when the enlarged particle size is uniform,

This is because the amount of latex can be inserted or adsorbed almost equally in each of the enlarged rubber particles.

5) Preparation of Graft Copolymer

Although it is carried out by the conventional emulsion polymerization method, 5 to 80% of the rubber content is suitable for the purpose of the present invention.

The monomer used at this time can use the mixture of 1 type, or 2 or more types of an aromatic vinyl compound and the other vinyl compound monomer copolymerizable with an aromatic vinyl compound. Examples of vinyl monomers copolymerizable with vinylaromatic compounds include vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, acrylic acid and methacrylic acid, and unsaturated carboxylic acids and lower esters thereof, such as methacrylate, butyl acrylate, and methyl methacrylate. Acrylates and the like.

In addition, since the processability of the final thermoplastic resin is greatly influenced by the molecular weight of the matrix resin, it is very important to control the molecular weight of the matrix portion and the grafted copolymer produced during the grafting reaction. The amount of the molecular weight modifier used is appropriately 0.01 to 1.5 parts by weight per 100 parts by weight of the monomer. Examples thereof include mercaptans, allyl bromide, carbon tetrachloride, bromotrichloromethane, β-bromostyrene, and the like. On the other hand, the initiator used in the grafting reaction is the same as can be used in the production of rubber latex. The emulsifier may be used alternatively or mixed among those used for rubber latex polymerization, and the amount of the emulsifier is suitably 0.3 to 3.0 parts by weight per 100 parts by weight of the monomer.

In this case, the monomer, the initiator, the molecular weight regulator, the emulsifier and the like may be added in a batch or dividedly added in the presence of rubbery latex, or may be added continuously, and the addition time in the continuous addition is preferably about 3 hours to 4 hours. In addition, when the reaction temperature is usually 40 ° C to 80 ° C, there is no problem in carrying out the present invention.

6) washing and drying process

The coagulation step is performed by adding 30 parts by weight of 5% sulfuric acid per 100 parts by weight of the graft copolymer (solid content) for about 30 minutes at 70 ° C. to 90 ° C., followed by washing with deionized water sufficiently for 10 minutes by centrifugation. After drying for 1 hour at 70 ℃ in a fluid bed dryer to obtain a white powder.

7) Mixing with Matrix Resin

In the present invention, a copolymer of styrene-acrylonitrile is mixed with a matrix resin, and a lubricant, a heat stabilizer, and the like are added to dilute the rubber content to 15%, 250%, and 25%, followed by extrusion to make pellets. After drying for a time, it was injected and a specimen for measuring the physical properties was prepared.

Hereinafter, it demonstrates as an Example as follows.

[Production Example 1.]

Manufacture of rubber latex (PBL-1)

100 parts by weight of 1,3-butadiene, 2.0 parts by weight of potassium oleate, 0.3 part by weight of an initiator (potassium peroxydisulfate), 0.4 part by weight of tertidodecylmercaptan (t-DDM) with a molecular weight regulator and 120 parts by weight of deionized water It put in the reactor and after 16 hours reaction at 60 degreeC, the polybutadiene latex of 0.08 micrometer of average particle diameters, and 42% of solid content was obtained.

[Production Example 2.]

-1 라텍스의 제조

Preparation of -1 Latex

-1 라텍스를 얻었다. 이 라텍스를 응고시켜 분말을 수득한 후 겔퍼미에아션 크로마토그래피(GPC)로 분자량을 측정한 결과 무게 평균분자량이 6,700이었다.100 parts by weight of styrene, 4.0 parts by weight of potassium oleate, 0.5 parts by weight of initiator (K ₂ S ₂ O), 6 parts by weight of molecular weight modifier (t-DDM), and 205.6 parts by weight of deionized water were reacted at 80 ° C. for 5 hours. 33.4%, the average particle diameter is 0.05㎛

-1 latex was obtained. The latex was solidified to obtain a powder, and then the molecular weight was measured by gel permeation chromatography (GPC). As a result, the weight average molecular weight was 6,700.

[Production Example 3.]

-2 라텍스의 제조

Preparation of -2 Latex

-라텍스 제조에서 분자량 조절제 3중량부를 줄여 중합한 결과, 평균입자경은 동일하였고 무게 평균분자량이 12,000이었다.Of Preparation Example 1

-After the polymerization of 3 parts by weight of the molecular weight regulator in the latex production, the average particle diameter was the same and the weight average molecular weight was 12,000.

[Production Example 4.]

-3 라텍스의 제조

Preparation of -3 Latex

-1 라텍스 제조에서 분자량 조절제 5중량부를 줄여 중합한 결과, 평균입자경은 동일하였고 무게 평균분자량이 35,100이었다.Of Preparation Example 1

Polymerization was carried out by reducing 5 parts by weight of the molecular weight modifier in -1 latex production, and the average particle diameter was the same, and the weight average molecular weight was 35,100.

[Manufacture example 5.]

-4 라텍스의 제조

Preparation of -4 Latex

-1 라텍스 제조에서 분자량 조절제를 0.5중량부 투입하여 동일하게 중합한 결과, 평균입자경은 동일하였고 무게 평균분자량이 66,100이었다.Of Preparation Example 1

In the preparation of -1 latex, 0.5 parts by weight of a molecular weight modifier was added to polymerize the same.

[Production Example 6.]

-5 라텍스의 제조

-5 Preparation of Latex

100 parts by weight of styrene, 2.0 parts by weight of potassium oleate, 0.5 part by weight of an initiator (KPS), 6 parts by weight of t-DDM, and 205.6 parts by weight of deionized water were added and reacted at 80 ° C. for 5 hours to obtain a polystyrene latex. At this time, the average particle diameter was 0.15㎛ and the molecular weight was 6,200.

Example 1.

-1 라텍스와의 혼합 및 응집공정1) with PBL-1 latex

-1 mixing and flocculation with latex

-1라텍스 3중량부(고형분)를 혼합한 후로진산칼륨 0.2중량부를 넣고 교반을 시작하였다. 이때 교반속도는 20rpm이다. 30분 후 5% 초산 수용액 50중량부를 1시간동안에 걸쳐 투입한다. 이때 교반속도는 15rpm으로 줄였다. 초산 수용액의 투입이 완료되면 10%의 수산화칼륨 23중량부를 투입하고 라텍스의 pH를 측정하였다. 이때 pH가 10.2였다. 응집된 고무입자의 크기는 0.32㎛이었다. 또한 입경분포는 매우 좁았다.100 parts by weight (solid content) of PBL-1 latex of Preparation Example 1 and Preparation Example 2

After mixing 3 parts by weight of -1 latex (solid content), 0.2 parts by weight of potassium rosinate was added and stirring was started. At this time, the stirring speed is 20rpm. After 30 minutes, 50 parts by weight of an aqueous 5% acetic acid solution was added over 1 hour. At this time, the stirring speed was reduced to 15 rpm. After the addition of the acetic acid aqueous solution was added 23 parts by weight of 10% potassium hydroxide and the pH of the latex was measured. PH was 10.2 at this time. The size of the aggregated rubber particles was 0.32 mu m. In addition, the particle size distribution was very narrow.

2) Graft Copolymer Preparation

34 parts by weight of agglomerated rubber latex (solid content) having an average particle diameter of 0.32 μm and 6 parts by weight of a rubber latex (solid content) having a particle diameter of 0.08 μm before agglomeration were mixed into a reaction tank, and 45 parts by weight of styrene, 15 parts by weight of acrylonitrile, and t 0.5 parts by weight of DDM, 1.5 parts by weight of potassium rosinate and 170 parts by weight of deionized water were added continuously for 4 hours. At this time, the initiator is composed of 0.15 parts by weight of cumene hydroperoxide, 10 parts by weight of deionized water, 0.25 parts by weight of pyrophosphate, 0.3 parts by weight of dextrose, and 0.005 parts by weight of ferrous sulfate salt. The reaction temperature was maintained at 65 ° C. for 4 hours, and aged at 70 ° C. for 1 hour after the completion of the monomer emulsion addition. Final reaction conversion was 98%.

The graft copolymer latex obtained above was coagulated with a dilute sulfuric acid solution and washed with water and dried to obtain a white powder.

The rubbery content of this powder is about 38.8 parts by weight. The weight molecular weight of the styrene-acrylonitrile copolymer to be mixed with this was 180,000, and the content of acrylonitrile was 24%. After mixing the SAN resin, the rubber content in the final ABS resin was adjusted to 15%, 20%, and 25%, followed by injection to obtain a specimen for measurement of physical properties. The measurement results are shown in Table 1 below.

Example 2.

-1 라텍스 대신

-2 라텍스를 사용하였다.It carried out similarly to Example 1,

-1 instead of latex

-2 latex was used.

Example 3.

-1 라텍스 대신

-2 라텍스를 사용하였다.In the same manner as in Example 1

-1 instead of latex

-2 latex was used.

Example 4.

-5 라텍스 6중량부를 혼합한 후 실시예 1과 동일하게 응집공정을 거치고 그라프트 중합을 실시하였다.100 parts by weight of PBL-1 latex of Preparation Example 1 and Preparation Example 6

After mixing 6 parts by weight of -5 latex was subjected to the coagulation process in the same manner as in Example 1 and subjected to graft polymerization.

TABLE 1

[Comparative Example 1.]

-1 라텍스를 넣지 않고 동일한 방법으로 그라프트 중합을 실시하여 고무질 함량이 40%인 ABS 수지를 얻었다. 이를 동일한 SAN 수지로 혼합하여 고무함량을 각각 15,20,25%로 희석시켜 사출 후 물성측정용 시편을 얻었다. 그 측정물성은 표 2와 같다.Used in Example 1

Graft polymerization was carried out in the same manner without adding -1 latex, thereby obtaining an ABS resin having a rubbery content of 40%. This was mixed with the same SAN resin to dilute the rubber content to 15, 20, 25%, respectively, to obtain a specimen for measurement of physical properties after injection. The measured physical properties are shown in Table 2.

Comparative Example 2.

-1 라텍스 대신에 제조예 4의

-4 라텍스를 사용하여 실시예 1과 동일하게 중합하였다. 그 측정물성은 표 2와 같다.

-1 instead of latex of Preparation Example 4

The polymerization was carried out in the same manner as in Example 1 using -4 latex. The measured physical properties are shown in Table 2.

TABLE 2

-라텍스를 사용치 않은 것은 충격강도는 비교적 우수하지만 기계적 강도가

-라텍스를 사용한 것보다 작다. 특히

-라텍스의 분자량이 40,000이상 될때는 충격강도의 향상을 기대할 수 없다.Looking at the above Examples and Comparative Examples,

-Latex is not used, the impact strength is relatively good, but the mechanical strength is

-Smaller than using latex Especially

-When the molecular weight of latex is over 40,000, the improvement of impact strength cannot be expected.

Claims (3)

The weight average particle diameter is 0.03 to 0.2 µm, the weight average molecular weight is 300 to 40,000, and the ratio of the weight average molecular weight to the number average molecular weight is 1.0 to 5.0

Latexes having a weight average particle diameter of 0.25-0.5 μm were prepared by enlarging a latex containing a latex and a rubber-containing latex having a weight average particle diameter of 0.03 to 0.2 μm and a gel content of 40 to 95%. 20 to 95% by weight of a mixed monomer consisting of 80% by weight and at least 60% by weight of an aromatic vinyl compound monomer and 40% by weight or less of an aromatic vinyl compound and a copolymerizable vinyl compound is added together with an initiator and a chain transfer agent to graf by emulsion polymerization. A method for producing a thermoplastic resin, characterized in that the polymerization is carried out. The method of claim 1,

The mixing ratio of latex and rubber latex is 0.01 to 20 parts by weight per 100 parts by weight of rubber latex. The method of claim 1,

The latex is an aromatic vinyl monomer alone or a mixture of aromatic vinyl monomers and vinyl monomers copolymerizable therewith, wherein the aromatic vinyl monomer is 50% by weight or more in the mixture.