JPS6241208A - Production of polymer - Google Patents

Abstract

PURPOSE:To obtain a polymer which can give a composition excellent in environmental stress cracking resistance and improved in delamination, by copolymerizing a fatty acid vinyl ester monomer with a long-chain bifunctional monomer to form a polymer of specified properties. CONSTITUTION:100pts.wt. fatty acid vinyl ester monomer or its mixture with other copolymerizable monomers is copolymerized with 0.01-10pts.wt. long-chain bifunctional monomer of formula I to obtain a polymer having a solubility parameter of 8.4-9.8(calml)<1/2>, a glass transition temperature <=20 deg.C and a gel content <=70wt%. In formula I, R<1> and R<2> are each H or CH3 and X is a group of formula II (wherein n>=2, and R<3> is H or CH3). Examples of the monomers of formula I include polymethylene glycol diacrylate long-chain bifunctional monomers and mixed ester long-chain bifunctional monomers.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to the production of a polymer suitable for providing a thermoplastic resin composition that has excellent environmental stress resistance and improved laminar peelability. Regarding the method.

[Conventional technology]

When rubber-containing styrenic resins come into contact with chemicals under stress, cracks occur and, in severe cases, breakage is observed. This phenomenon is called the environmental two-ka crack phenomenon.
It is well known that this phenomenon is significantly observed in chemicals such as alcohols, carboxylic acids, esters, alkanes, and alkenes that do not have high solubility in resins.

Environmental stress cracking phenomenon is caused by the distortion that remains inside the molded product even when no external force is applied to the resin molded product.
Because it occurs when it is released by contact with chemicals, it places many restrictions on the uses of rubber-containing styrenic resins.

The content of the rubber component and the molecular weight of the resin component are known factors that affect the environmental stress cracking properties of rubber-containing styrenic resins. Although it is possible to improve the environmental stress cracking resistance by increasing the ratio, the effect was insufficient for practical use.

Recently, the present inventors have discovered that by mixing a fatty acid vinyl ester polymer with a rubber-containing styrenic resin, the environmental stress cracking resistance of the rubber-containing styrenic resin can be dramatically improved. (%Kai No. 56-147841)
.

However, although the composition of the invention has a remarkable effect of improving the environmental stress cracking resistance, a mica-like layered peeling phenomenon is observed in injection molded products, and therefore improvements have been required. The delamination phenomenon is noticeable in molded products injection molded under high shear rate conditions, and is noticeable near the reeds and gates.

The delamination phenomenon occurs when the fatty acid vinyl ester polymer particles dispersed in the rubber-containing styrene resin are flattened by shear stress during injection molding. In order to prevent flattening of the fatty acid vinyl ester polymer particles, 0 is effective for copolymerizing a polyfunctional vinyl monomer during polymerization of the fatty acid vinyl ester polymer.

[Problem that the invention seeks to solve]

However, fatty acid vinyl ester polymers obtained by copolymerizing polyfunctional vinyl monomers such as divinylbenzene and ethylene glycol dimethacrylate,
Although the delamination phenomenon is improved, the gel content is high and the effect of improving the environmental stress cracking property of rubber-containing styrenic resin is insufficient. Therefore, by using a polyfunctional vinyl monomer and a chain transfer agent in combination to produce a fatty acid vinyl ester polymer with a low gel content and a branched structure, it is possible to prevent delamination and environmental stress resistance. Although it is possible to measure the balance of fission, the effect is unsatisfactory in practical terms.

An object of the present invention is to provide a method for producing a polymer that overcomes the drawbacks of the prior art described above.

[Means for solving problems]

To summarize the present invention, the present invention relates to a method for producing a polymer, and includes 100 parts by weight of a fatty acid vinyl ester monomer or a mixture of a fatty acid vinyl ester monomer and another copolymerizable monomer. , the following general formula I: o O [wherein R1 and Rz are H or a mountain group, X is (-CI(ff
i -CHR''-〇-)7-cut-CHR''- group (n is an integer of 2 or more, R3 are the same or different, H
101 to 10 parts by weight of a long chain bifunctional monomer represented by
, the glass transition temperature is 20°C or less, and the gel content is 7.
It is characterized by obtaining a polymer having a content of 0% by weight or less.

The mixture of the polymer produced by the method of the present invention (hereinafter referred to as fatty acid vinyl ester polymer) and the rubber-containing styrenic resin has excellent environmental stress cracking resistance, and also exhibits the delamination phenomenon at, - b In the method for producing a fatty acid vinyl ester polymer according to the present invention, examples of the fatty acid vinyl ester monomer used as a raw material include vinyl formate,
Vinyl acetate, vinyl propanoate, vinyl butanoate, vinyl pentanoate, vinyl hexanoate, vinyl heptanoate,
Vinyl octoate, vinyl nonanoate, vinyl decanoate,
Examples include vinyl dodecanoate, vinyl tetradecanoate, vinyl hexadecanoate, and vinyl octadecanoate.

On the other hand, examples of other copolymerizable monomers include olefin monomers such as ethylene, propylene, 1-butene, 2-butene, isobutylene, cyclopentene, cyclohexene, norbornene, styrene, α-methylstyrene, t-
Styrenic monomers such as butylstyrene and p-methylstyrene, acrylic acids such as methyl acrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, cyclohexyl acrylate, octyl acrylate, hydroxyethyl acrylate, methoxyethyl acrylate, phenyl acrylate, and glycidyl acrylate Ester monomers, methacrylic acid ester monomers such as methyl methacrylate, butyl methacrylate, glycidyl methacrylate, nitrile monomers such as acrylonitrile, methacrylaterile, methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether,
vinyl ether monomers such as phenyl vinyl ether,
Examples include halogenated olefin monomers such as vinyl chloride and vinylidene chloride.

Examples of the long chain bifunctional monomer represented by the general formula C include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, pentaethylene glycol diacrylate, and nonaethylene glycol diacrylate. polyethylene glycol diacrylate-based long-chain bifunctional monomers such as acrylate, tetradecaethylene glycol diacrylate, and eicosaethylene glycol diacrylate;
Long chain polyethylene glycol dimethacrylates such as diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, pentaethylene glycol dimethacrylate, nonaethylene glycol dimethacrylate, tetradecaethylene glycol dimethacrylate, and eicosaethylene glycol dimethacrylate Bifunctional monomer, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, pentaprobisone glycol diacrylate, nonapropylene glycol diacrylate, tetradecaethylene glycol diacrylate, eicosapropylene glycol diacrylate Polypropylene glycol diacrylate long chain bifunctional monomers such as acrylate, dipropylene glycol dimethacrylate,
Polypropylene glycol dimethacrylate-based long chain bifunctional monomers such as tripropylene glycol dimethacrylate, tetrapropylene glycol dimethacrylate, pentapropylene glycol dimethacrylate, nonapropylene glycol dimethacrylate, tetradecapropylene glycol dimethacrylate, and eicosapropylene glycol dimethacrylate. Examples include mixed ester-based long chain bifunctional monomers such as polyethylene glycol monoacrylate monomethacrylate and polypropylene glycol monoacrylate monomethacrylate.

These long chain bifunctional monomers may be used alone or in combination of two or more.

In addition, when producing the long-chain bifunctional monomer industrially, it is difficult to strictly limit the molecular weight distribution of the raw material polyethylene glycol or polypropylene glycol. For example, industrially produced nonapropylene Glycol dimethacrylates may include octapropylene glycol dimethacrylate, decapropylene glycol dimethacrylate, and the like. therefore,
Although it is industrially difficult to strictly limit the number of n in formula 1 to 1', this fact does not impede the effects of the present invention.

In the present invention, it is particularly preferable that n in the general formula 1 is 5 or more, which has an excellent effect of improving environmental stress dissipation.
Moreover, it provides an h-tongo-a=4=ester polymer in which the layered peeling phenomenon is suppressed and the fatty acid vinyl is controlled.

The amount of the long-chain difunctional monomer used is 101 to 10 parts by weight, and particularly preferably α01 to 7 parts by weight, based on 100 parts by weight of the monomers to be copolymerized as described above. However, if this amount is less than α01 heavy areas, the effect of improving layered peelability will be poor, while if it exceeds 10 parts by weight, the effect will be saturated.

Further, in addition to the long-chain bifunctional monomer, other polyfunctional vinyl monomers may be copolymerized in the fatty acid vinyl ester polymer according to the present invention. Examples of polyfunctional vinyl monomers that can be used include divinylbenzene, ethylene glycol dimethacrylate, 1,5-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate, and propylene glycol dimethacrylate. , triallyl cyanurate, triallyl incyanurate, trimethylolpropane trimethacrylate, allyl acrylate, allyl methacrylate, vinyl acrylate, vinyl methacrylate, and the like.

The fatty acid vinyl ester polymer according to the present invention has a4
It is necessary to have a solubility/parameter of ~9.8 (cat/cc)', and a more preferable numerical range is a6.
~9.6 (cat/cc)%. The solubility parameter referred to herein refers to the Polymer Handbook, edited by J. Brandrup and E. L. Immergut, published in 1975 by John Wiley and Elad Sons, New York City.
) f, 2nd edition f (Using the solubility parameter values described on pages -557 to ■-559, the solubility parameter δT of the copolymer is calculated for each vinyl monomer constituting the copolymer consisting of m types of vinyl monomers. It is calculated from the solubility parameter δ of the monomer homopolymer and its weight fraction Wn using the following formula (2).

δT=Σδn”Il' 乎Wn((cat/cc voice)
・-[11) nmI n votes 1 For example, the solubility parameters of polybutyl acrylate and boria-ethyl acrylate are a a (caz
/cc voice, 9.4 (cat/cc) 3A, the solubility parameter of a copolymer consisting of 70% by weight of butyl polyacrylate and 50% by weight of polyethyl acrylate is 9.
．． It is calculated as 0 (cat/cc)y6.

If the solubility parameter of the fatty acid vinyl ester polymer is less than A4 or exceeds 9.8, the environmental stress cracking resistance of the composition obtained by mixing it with the rubber-containing styrenic resin will be low. Undesirable.

It is necessary that the fatty acid vinyl ester polymer according to the present invention has a glass transition temperature of 20°C or less.
The following are preferred. When the glass transition temperature exceeds 20℃,
The composition obtained by mixing with the rubber-containing styrenic resin has low environmental stress cracking resistance, which is undesirable.

Furthermore, the fatty acid vinyl ester polymer according to the present invention is
It is necessary that the gel content is 70% by weight or less.

The gel content in this specification means that the polymer was tar-precision weighed, placed in a basket made of 400 mesh stainless steel wire mesh, immersed in 100 tons of toluene, and heated at 5°C for 24 hours.
After standing for a period of time, the basket was pulled up and air-dried at room temperature, and the weight (f) of the polymer insoluble matter was measured, and the value was then calculated according to the following formula (2).

[(Polymer insoluble weight)/1)X100 (%)...
-(f [[] If the gel content of the fatty acid vinyl ester polymer exceeds 70% by weight, the environmental stress cracking resistance of the resin obtained by mixing it with the rubber-containing styrene resin will be undesirable).

Although there are no particular limitations on the polymerization method in the present invention,
Production by emulsion polymerization is industrially most advantageous, and any known technique relating to emulsion polymerization can be applied.

In order to mix the fatty acid vinyl ester polymer obtained according to the present invention with the rubber-containing styrene resin, a known mixing technique is applied to blend both components in an emulsified state, a particle state, or a molten state. By melting and kneading the mixture, the desired mixture can be easily obtained. When a fatty acid vinyl ester polymer is produced by emulsion polymerization, the loaded latex is blended with a rubber-containing styrene polymer in an emulsified, particle or molten state, and then subjected to a dehydration process.
Alternatively, it can be melt-kneaded simultaneously with the dehydration step.

Examples of melt-kneading equipment include panburi mixers, intensive mixers, mixtruders, co-kneaders, extruders, rolls, and the like. Also, JP-A-56-13
The manufacturing method disclosed in Japanese Patent No. 1656 can also be applied.

In addition, the rubber-containing styrenic resin as used in the present invention refers to a group of composite thermoplastic resins consisting of a rubber component, a resin component, and a covalent bond of a rubber component and a resin component. Polystyrene, ABS (acrylonitrile-butadiene-styrene) resin, heat-resistant ABS (
Acrylonitrile-butadiene-styrene-α-methylstyrene) resin, AAS (acrylonitrile-acrylic ester-styrene) resin, AES (acrylonitrile-EPDM-styrene) resin, MBA8 (methyl methacrylate-butadiene-acrylonitrile-styrene) resin be.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The invention is not limited to these examples.

In addition, all parts and percentages described in each example are based on weight.

Example 1 and Comparative Example 1 100 parts of pure water, 4 parts of partially saponified polyvinyl alcohol, 11 parts of potassium persulfate, and 0.2 parts of sodium acetate were added to a pressure autoclave.

After the contents were sufficiently purged with nitrogen, the entire amount of ethylene corresponding to the composition shown in Table 1 was injected under pressure. After the contents were heated to 60° C., the entire amount of monomers having the composition shown in Table 1 except for ethylene was continuously added over 10 hours. The total amount of initially injected ethylene and continuously added monomers excluding ethylene is 1
It is 00 copies.

After the addition was completed, the mixture was further stirred at 70° C. for 5 hours to complete the polymerization. Table 2 shows the properties of the obtained fatty acid vinyl ester polymer.

The abbreviations of the long chain bifunctional monomers used in Table 1 are as follows: 9PG: nonapropylene glycol dimethacrylate 5G; triethylene glycol dimethacrylate 4G; tetraethylene glycol dimethacrylate 9G: nonaethylene glycol Dimethacrylate 14G: Tetradecaethylene glycol dimethacrylate 23G:)-Lieicosaethylene glycol dimethacrylate V-9PAG: Nonapropylene glycol diacrylate SAG:) Lyethylene glycol diacrylate 9AG: Nonaethylene glycol diacrylate 14AG; Tetradecaethylene glycol The physical property values of diacrylate were determined using the following method.

(1) Glass transition temperature The solid obtained by pouring fatty acid vinyl ester polymer latex into an aqueous calcium chloride solution is dried and measured using DuPont type measuring instruments, 910 differential scanning calorimeter and 990 thermal analyzer. did.

12) Solubility parameter Solubility parameter value of each polymer used for calculation of solubility parameter on each side [unit: (ca4/cc)%]
The following is the general rule.

Butyl polyacrylate: &8 polyethylene
;a1 polyvinyl acetate
;9.4 Vinyl polydodecanoate ;a8
Polyacrylonitrile: 12.5 (3)
A solid obtained by pouring a gel content fatty acid vinyl ester polymer latex into an aqueous calcium chloride solution was dried. Part 1.
The O2 was accurately weighed, treated and measured as described above, and the amount was calculated.

Application example 1 and reference example 1 Polybutadiene 50%, acryloni) IJ/1715%
, 80 parts of AB8 resin latex (as polymer) consisting of 35% styrene and 2 o parts of fatty acid vinyl ester polymer latex (as polymer) shown in Table 1 were mixed in a latex state, and an aqueous calcium chloride solution was added. The mixture was stirred at 95° C., and the resulting precipitate was exposed to F to recover the polymer. After drying the resulting mixture, 40 parts of the mixture was mixed with 60 parts of acrylonitrile-styrene copolymer resin (acrylonitrile content 30%) powder, 4.4
'-Isopropylidene-bis [monophenyl-dialkyl (C1- to C1M) phosphite] [manufactured by Adeka Argus Chemical, MARK 1500]
The mixture was mixed with 0.5 parts using a Henschel mixer and fed to VC-40 (single-screw extruder with vent) manufactured by Chuo Kikai Seisakusho Co., Ltd. to obtain pellets.

Moldings were made using the obtained pellets and their physical properties were evaluated, and the results are shown in Table 3 Experiment Nos. 1 to 25.

Note that the physical property measurements on each side were determined by the following method.

(1) Tensile) Yield point...A8TM D-658
(2) Izotsu impact strength...A8TM D-2
56(3) Chemical resistance (environmental stress resistant column) ASTM D-638 type! The time taken to break when a dumbbell is given a 50-degree deflection, fixed to a jig, coated with ethylene glycol monoethyl ether, and left at a temperature of 23° C. is expressed in minutes. In the table, >300 indicates that no breakage occurred after 500 minutes.

(4) Layered Peelability Using a 5-ounce injection molding machine, a plate-like molded product measuring 50 x 20 x 2 m with a gate of 5 x 3 x 1 m was molded. In applied example 2 and reference example 2 (experiment numbers 26 to 32) described below, the resin temperature was 240°C, and in applied example 1 and reference example 1, the resin temperature was 200°C, and the injection speed was 90 tram / Sec.
% mold temperature was 40°C.

The layer peelability of the gate portion of the molded product was evaluated as follows in comparison with a standard sample. AB indicates that it is located between A rank and B rank.

A: Not peeled off at all B: Slightly peeled C: Slightly peeled D: Significantly peeled off Numbers 1 to 19 are application examples, and numbers 20 to 25 are reference examples. As is clear from the reference example, if the glass transition temperature, gel content, and solubility parameters of the fatty acid vinyl ester polymer deviate from the range of the present invention, the environmental stress resistance and column formation will be poor, and the long chain bifunctional polymer will be degraded. If the amount of the monomer used is insufficient, the occurrence of delamination phenomenon will be observed.

Application Example 2 and Reference Example 2 The AB8-bound latex and fatty acid vinyl ester polymer latex used in Application Example 1 were mixed with acrylonitrile-
a-methylstyrene copolymer (acrylonitrile 24%
) The mixture was mixed with latex in a latex state, and an aqueous calcium chloride solution was added thereto, followed by stirring at 110°C.

The resulting precipitate was filtered to recover the polymer, and after drying, α3 parts of the stabilizer used in Application Example 1 was added to 100 parts of the mixture, and the mixture was mixed with VC-40 manufactured by Chuo Kikai Seisakusho Co., Ltd. The pellets were obtained by feeding.

A molded article was made using the obtained pellets and the physical properties were evaluated, and the results are shown in Table 4.

In addition, all parts in the table indicate the number of parts as a polymer.

When an acrylonitrile-α-methylstyrene copolymer is used as a matrix resin, the resin has a high melt viscosity and is subjected to high shear stress during injection molding. When an ester polymer is used, a significant delamination phenomenon is observed (Experiment No. 3o, sl in Table 4). However, with the fatty acid vinyl ester polymer according to the present invention, little or no peeling phenomenon was observed, demonstrating the effects of the present invention (
Table 4 Experiment No. 26-29).

〔Effect of the invention〕

As explained above, by mixing the polymer obtained by the production method of the present invention with a thermoplastic resin, the layered peeling phenomenon of molded products is difficult to occur, and the polymer has an excellent effect on environmental stress resistance. It has the remarkable effect of demonstrating.

Claims (1)

[Claims] 1. Fatty acid vinyl ester monomer or mixture of fatty acid vinyl ester monomer and other copolymerizable monomers 10
0 parts by weight, the following general formula 1: ▲There are mathematical formulas, chemical formulas, tables, etc.▼...[1] [In the formula, R^1 and R^2 are H or CH_3 groups, and X is -(
CH_2-CHR^3-O)-_n_-_1CH_2C
0.01 to 10 long-chain bifunctional monomers represented by HR^3- group (n is an integer of 2 or more, R^3 is the same or different, and is H or CH_3 group) Part by weight is copolymerized to give a solubility parameter of 8.4 to 9.8 (cal
/cc)^1^/^2, and the glass transition temperature is 20℃
A method for producing a polymer, characterized in that a polymer having a gel content of 70% by weight or less is obtained.