JPS60203619A - Production of thermoplastic resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin having improved impact resistance, by suspension polymerizing an aqueous latex containing an elastomer and a monomeric system containing an alpha-alkylstyrene based monomer, nitrile based monomer and monomer copolymerizable therewith in a specific proportion. CONSTITUTION:(A) An aqueous latex containing an elastomer, preferably a diene based rubber latex or an alkyl ester based rubber latex and (B) a monomeric system consisting of (i) 40-80wt% alpha-alkylstyrene based monomer, (ii) 20-50wt% nitrile based monomer and (iii) 0-30wt% monomer copolymerizable with the components (i) and (ii), preferably styrene or vinyltoluene are subjected to suspension polymerization in the presence of preferably a coagulating agent and suspending agent using a polyfunctional organic peroxide, e.g. di-tert-butyl peroxyhexahydroterephthalate, and azo based compound polymerization initiator, e.g. 1,1'-azobis-cyclohexane-1-carbonitrile, to give the aimed resin. The polyfunctional organic peroxide and azo based compound have preferably 60-120 deg.C temperature at 10hr half-life.

Description

Detailed Description of the Invention The present invention comprises an aqueous latex containing an elastomer, 40 to 80 wt% of α-alkylstyrene yarn monomer, 20 to 50 wt% of nitrile yarn monomer, and 0 to 30 wt% of a monomer copolymerizable with these. A method of suspension polymerization with monomers in a proportion of The present invention relates to a method for producing a thermoplastic resin with a high conversion rate and excellent heat deformation resistance and impact resistance in a short polymerization time.

In general, a high proportion of α-furkylstyrene is used to obtain nidistomer-reinforced thermoplastic resins with excellent heat deformation resistance by suspension polymerization. -/It is possible to use organic peroxides such as liver oxide as the main initiator, but in methods using these initiators, regardless of the polymerization temperature,
It is necessary to use a very large amount, and therefore the degree of polymerization of the matrix II phase of the thermoplastic resin obtained is extremely low, making it less useful as a molding material. Furthermore, if the amount of initiator is reduced to increase the degree of polymerization using these initiators, so-called dead 'end polymerization will occur.
It is not possible to obtain a high conversion rate that is expected industrially, or an extremely long polymerization time is required to obtain a high conversion rate, resulting in extremely poor productivity. Furthermore, if an organic peroxide such as pen soy flavor oxide is used, even if an appropriate polymerization temperature is used, a thermoplastic resin with a high conversion rate that can be used industrially cannot be obtained at all.

As mentioned above, the error 1- for conventional emulsification/suspension polymerization
In the production method of mer-reinforced α-fulkyl nitrile thermoplastic resin, it is difficult to obtain a technology for producing a copolymer that can be used industrially as a molding material, or it is extremely difficult to obtain from an industrial perspective. It is bad for productivity.

The present invention was developed as a result of intensive research in view of the strength and strength of the elastomer reinforced α-alkylstyrene, which has excellent heat deformation resistance and impact resistance, with a high conversion rate in a short time and by suspension polymerization.
We have discovered a method for producing J-type mature thermoplastic resin, and have completed the present invention.

The present invention uses an aqueous latex containing an elastomer, 40 to 80 wt% of α-alkyl styrene thread monomer, 20 to 50 wt% of nitrile thread monomer, and 0 to 50 wt% of copolymerizable monomer.
The monomers at a usage rate of 3Qwt% are preferably polymerized at a polymerization temperature of 3Qwt% using a polyfunctional organic peroxide and/or an azo thread compound as an initiator in the presence of a suspension stabilizer and a coagulant. 8
To provide a manufacturing method for obtaining a nydistomer-reinforced α-alkylstyrene/nitrile thermoplastic resin with a high conversion rate and excellent heat deformation resistance and impact resistance in a short time by suspension polymerization at 0 to 130°C. It is.

The polyfunctional organic peroxide used in the suspension polymerization of the present invention has a 10-hour half-life temperature of 60 to 20°C, and a corresponding compound includes di-t-butyl Peroxyhexahydroterephthalate, 2,5dimethyl-2,5bis(2-ethylhexanoylperoxy)hexane, 1,1'-dipropylene rubberoxy 3
, 3°5-trimethylcyclohexane, 1. l-di-butylperoxycyclohexane, di-t-butylperoxyamole-1-12,5-dimer-2,5-bis(penzoylperoxy)hexane, 2,2-dibutylperoxycyclohexane ciparelic acid-n-butyl ester,
Examples include di-t-butylperoxytrimethyladibate and tris(t-butylperoxy)triazine. Among these, particularly preferred are di-t-1-rubberoxyhexahydroterephthalate, 1.1'-di-t-7''-rubberoxy-8,8,5-trimethylcyclohexane, and tris(t-butylperoxy)triazine.

In addition, as the azo yarn initiator, 1,1'-azobis-cyclohexane-1-carbonitrile, 2-phenylazo-2
, 4-dimethyl-4-methoxyvaleronitrile, azobisisobutyronide 1j, 2'-azobis-(2,
Particularly preferred is 1'-azobis-cyclohexane-1-carbonitrile.

The amount of initiator used is 0.1 to 2.0% by weight, more preferably 0.2 to 1.5% by weight, based on the total monomers. O
If the amount is less than 1% by weight, no industrially practical conversion rate can be obtained at all, or it will take an extremely long time, which will seriously impair productivity.

On the other hand, if it exceeds 2.0% by weight, a high conversion rate can be obtained in a short time, but the molecular weight will be significantly reduced, and only products with significantly reduced strength will be obtained when molded (1.0% by weight).

As described above, by using a polyfunctional organic peroxide and/or an azo thread compound, elastomer reinforcement α is achieved through suspension polymerization.
- The ability to obtain high-quality Alkyls handmade nitrile thermoplastic resins in a short period of time could not have been expected based on conventional technology and knowledge, but the mechanism is now available. is unknown.

When using the initiator in the present invention, it is important to select the polymerization temperature. That is, the polymerization temperature is 80 to 130°
C is good, more preferably 90 to 110°C.

Below 80°C, the conversion rate is extremely low (or 130°C).
If the temperature exceeds °C, the molecular weight decreases, making it difficult to obtain an industrially useful copolymer.

Examples of the aqueous latex containing the elastomer used in the present invention include diene thread rubber latex such as butadiene rubber latex, styrene butadiene rubber latex, Ac+10 nitrile butadiene rubber latex, isoprene rubber latex, chloroprene rubber latex, and ethyl acrylenide. Alkyl ester rubber latex such as rubber latex, propyl acrylate rubber latex, butyl acrylate rubber latex, butyl thread rubber latex such as isobutylene rubber latex, inbutylene isoprene rubber latex, and aromatic vinyl monomers in these latexes. It is a graft elastomer latex etc. in which one or more monomers selected from vinyl cyanide monomers, acrylic esters, and methacrylic esters are graft-polymerized.

Elastomer latex and whisker raft elastomer latex can be used alone or in combination.

The monomer to be graft-polymerized to the elastomer latex includes aromatic vinyl monomers such as styrene, α-methylstyrene, vinyltoluene, and monochlorostyrene.

Examples of nitrile monomers include acrylonitrile and metaa.
There are Rironito 11 Ru, etc. Examples of acrylic esters include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate.

Examples of methacrylic acid esters include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and 2-ethylhexyl acrylate. The above monomers can be used alone or in combination.

There are no particular limitations on the composition ratio of the elastomer and monomer in the grafted elastomer latex.

The elastomer content in the finally obtained thermoplastic resin (excluding the grafted portion in the case of grafted elanuttomer) is preferably 5 to 30% by weight. If the elastomer content is less than 5% by weight, impact resistance will decrease. On the other hand, when the content exceeds 80 M%, the 111 thermal shape property decreases.

In the presence of an aqueous latex containing an elastomer, α-diylstyrene monomers are copolymerized with Nido 1 full yarn monomers and monomers that can be copolymerized with these to achieve excellent heat deformation resistance sufficient for practical use. In order to obtain a thermoplastic resin, α-alkylstyrene should be used in an amount of at least 40% by weight, preferably 5% by weight, of the total monomers used.
It is necessary to use 0% by weight or more.

In the present invention, the α-alkyl monomer is α-
α-alkylstyrene such as methylstyrene and nuclear substituted derivatives of these monomers, e.g. t-butylstyrene,
It refers to ortho-, para-methylstyrene, etc., and is used to raise the heat distortion temperature of resin. Therefore, it is preferable to use a large amount of α-alkylstyrene, but the above-mentioned range is preferable in terms of polymerization rate and conversion rate. Next, the nitrile monomers include acrylonitrile, metha-7-acrylonitrile, etc., which are used to increase the reaction rate and conversion rate. If a large amount of nitrile monomer is used, it may cause coloring during molding, which is not preferable. Next, copolymerizable monomers [7] include styrene, vinyltoluene, butylstyrene, methacrylic ester, acrylic ester, methacrylic acid, acrylic acid, maleic anhydride, N-methyl simalimide-N-
Examples include monomers such as phenylmaleimide. However, if a large amount of acrylic ester is used, the heat deformation resistance of the resin will decrease, which is not preferable.

A method of suspension polymerizing the above monomers in the presence of an aqueous latex containing a nidistomer is to stir and mix them together with a suspension stabilizer and a coagulant to form a stable dispersed phase, and then polymerize. A method of elongating and polymerizing is preferred from the viewpoint of polymerization stability.

Suspension stabilizers include organic suspension stabilizers such as polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, and methylcellulose, or inorganic suspension stabilizers such as tricalcium phosphate, magnesium phosphate, sodium silicate, zinc oxide, and magnesium carbonate. In the case of an inorganic suspension stabilizer, the effect of the suspension stabilizer is significantly improved when sodium dodecylbenzenefluoride and an α-surfactant are used in combination.

As a coagulant, any of the acids and/or water-soluble inorganic salts used for coagulating ordinary emulsion polymers can be used. Also, water-soluble organic compounds such as methanol can be used. Typical acids are inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid, and organic acids such as acetic acid. As water-soluble inorganic salts, sulfates, chlorides, acetates, etc. of various metals such as sodium sulfate and magnesium sulfate can be used.

The type and amount of the coagulant can be arbitrarily selected depending on the stability of the aqueous nidistomer latex.

In addition, from the viewpoint of processability etc., stabilizers,
It goes without saying that a lubricant or the like may be used. Furthermore, the resin obtained in the present invention exhibits good compatibility with chlorine-based resins, and may of course be used in blends with, for example, polyvinyl chloride, chlorinated polyvinyl chloride, and the like. Of course, it may also be used in combination with other various resins.

Next, examples will be shown, but the scope of the present invention is not limited in any way. In addition, in Table 1, the conversion rate of the copolymer obtained in each example is expressed as a percentage (wt%) (7mer content wt
The properties of the obtained copolymers are the results obtained when each copolymer was molded by injection molding, and the heat strain temperature indicates the heat resistance. The values were measured according to the JIS-6871 method, and the impact strength was also according to the JIS-6871 method.

Example 1 (2) Graft polymerization Using a conventional emulsion polymerization method, graft polymerization was carried out using hand sanitizer and hyacrylonitrile in the following proportions to polybutadiene latex.

Polybutadiene 70 parts by weight (solid content) Styrene 20
〃 Acrylonitrile 10 〃 The solid content of the obtained grafted elastomer latex is 2
It was 8%.

(To) Charge the following raw materials into an autoclave equipped with a suspension polymerization stirrer, and
Polymerization was carried out for 12 hours while maintaining the temperature at C.

Water 240 Parts by weight Polyvinyl alcohol 0.3 Parts by weight Anhydrous calcium chloride 3.0 Parts by weight Raft elastomer latex (hard paste) '25
Itα-Methylsin 53 γ〃Sronitrile 22 〃 G-Moichibu Rubber Oxyhexahydrothyrephthalate) Q, 4 // Table 1 shows the conversion rate, heat distortion temperature, and impact strength of the obtained resin. It was shown to.

Example 2 Instead of using 0.4 parts by weight of di-t-1 mole peroxyhexahydroterephthalate in Example 1, 1,
Using 0.5 parts by weight of 1'-dibutyloxy-8,3,5-trimethylcyclol\xane, the polymerization temperature was 9.
A resin was obtained in the same manner as in Example 1 except that the temperature was 100°C instead of 5°C.

Table 1 shows the conversion rate, heat strain temperature, and impact strength.

Example 3 Polymerization was carried out in the same manner as in Example 1 using the following recipe.

Water 240 parts by weight Polyvinyl alcohol 0.3 Anhydrous calcium chloride 3. o Alkylaryl sulfonate thread surfactant 0.01 Graft elastomer latex (Shield m) 2'5
〃α-Metal Rubber Oxyhexahydroterephthalate 43 〃 Acrylonitrile 22 〃 Stainless Steel 5'' Methyl methacrylate 5 〃 G-T-P Rubber Oxyhexahydroterephthalate 0.4〃 Conversion rate and thermal deformation of the obtained resin The temperature and impact strength are shown in Table 1.

Comparative Example 1 In Example 1, 0.4 parts by weight of benzoyl peroxide was used instead of 0.4 parts by weight of di-t-1 mole peroxyhexahydroterephthalate, and polymerization was carried out in the same manner. did. The conversion rates are shown in Table 1.

Claims (1)

[Scope of Claims] 1. A monomer consisting of an aqueous latex containing a nystomer, 40 to 5 wt% of an α-alkyl styrene monomer, 20 to 5 gwt% of a nitrile thread monomer, and 0 to awt% of a monomer copolymerizable with these. A method for producing a thermoplastic resin, comprising suspension polymerization of threads. 2. The production method according to claim 1, wherein suspension polymerization is carried out in the presence of a coagulant and a suspension stabilizer. 3. The manufacturing method according to claim 1 or 2, wherein a polyfunctional organic peroxide and/or an azo compound is used as an initiator. 4. The manufacturing method according to claim 3, wherein the polyfunctional organic peroxide and the azo compound have a 10-hour half-life temperature of 60 to 120°C. 5. The polyfunctional organic peroxides include di-t-butylperoxyhexahydroterephthalate, di-t-1-rubberoxy-8,8,5-1J-mer cyclohexane, and tris(t-butyl). The manufacturing method according to claim 3 or 4, wherein at least one kind is selected from (-oxy)triazine. 6. The manufacturing method according to claim 3 or 4, wherein the azo compound is 1,1'-azobis-cyclohexane-1-carbonitrile. 7. Copolymerizable monomers, styrene, vinyletluene, t-butylstyrene, methacrylic acid ester, acrylic acid ester, maleic anhydride, methacrylic acid, acrylic acid, N-metal maleimide, N-phenyl maleimide, etc. The manufacturing method according to claim 1, wherein at least one type is selected. 8. The aqueous latex containing elastomer is diene thread rubber latex, alkyl ester thread rubber latex,
Butyl rubber latex and their latexes contain one or two selected from the following: aromatic vinyl monomers, vinyl cyanide monomers - acrylic acid esters, meta/7 II acid esters) Claim 1 is a graft elastomer latex obtained by graft polymerizing the above monomers.
Manufacturing method described in section. 9 α-alkyl styrene monomer 50-8 Uwt
% of the manufacturing method according to claim 1.