JPS60208310A - Alpha-alkylstyrene-nitrile copolymer with good moldability - Google Patents

Abstract

PURPOSE:A mixture of alpha-alkylstyrene with a nitrile monomer is polymerized in the presence of a polymerization initiator and a crosslinking compound to achieve high-conversion production of the titled resin of high polymerization degree and heat resistance in a short time. CONSTITUTION:100pts.wt. of a monomer mixture consisting of (A) 15-80pts.wt. of an alpha-alkylstyrene such as alpha-methylstyrene, (B) 10-45pts.wt. of a nitrile monomer such as acrylonitrile, (C) 0-75pts.wt. of monomers copolymerizable with components A and B are combined with (D) a catalyst amount of polyfunctional peroxide with 10hr half-life temperature of 60-120 deg.C such s peroxyhexahydroisophthalic di-t-butyl ester and/or an azo compound such as 1,1- azobis(cyclohexane-1-carbonitrile) and (E) 0.01-2pts.wt. of a crosslinking compound such as ethylene diacrylate to effect bulk and/or suspension polymerization, thus giving the objective resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal thermoplastic copolymer resin which is excellent in moldability, and more specifically, an α-alkylstyrenic heptamine 15 to 80 parts by weight, preferably 40 to 78 parts by weight. ,
10 to 45 parts of a nitrile monomer, 0 to 75 parts of a nitrile that can be co-merged with these nitrile monomers, and 0.0 parts of a crosslinking compound
It relates to a copolymer resin obtained by 1 to 2 parts by bulk polymerization, suspension polymerization, or a combination of both.

It is well known that by copolymerizing α-alkylstyrene, a product with a high heat distortion temperature can be obtained.

On the other hand, this material has extremely poor polymerizability, especially bulk polymerization,
When attempts were made to obtain this by suspension polymerization, the polymerization conversion rate did not increase, or even if it did increase, the polymerization took a long time, making production difficult. Therefore, in the case of polymerizing α-alkylstyrene, emulsion polymerization has generally been employed.

However, those obtained by emulsion polymerization contain a large amount of impurities such as coagulants and emulsifiers, and problems remain in terms of resin transparency and thermal stability. In addition, as a result of investigating how to efficiently increase the polymerization conversion rate of α-alkylstyrene by suspension polymerization, we found that polyfunctional peroxides (compounds containing multiple -0-0- bonds in the molecule) or Ab-based compounds The time range temperature at lO is 60 to l20'C1 (preferably 70 to 110°0
) was found to be suitable for actual production conditions. However, if such a polymerization initiator is used, the conversion rate of polymerization will increase, but the degree of polymerization of the resulting resin will be low, resulting in molded products breaking during injection molding, and problems in mold release. . In an attempt to solve this problem, in order to raise the degree of polymerization of the obtained polymer, the amount of initiator was reduced, or the polymerization temperature was set low, but the polymerization conversion rate was not sufficient, and the polymerization took a long time. Become something.

As a result of intensive studies to solve the above problems, the present invention has been arrived at. In other words, the inventors have found that it is possible to easily increase the degree of polymerization by using the polymerization initiator and a crosslinkable compound in combination. Here, it is important to use a crosslinkable compound that does not lower the heat distortion temperature of the resulting resin.

Examples of crosslinking compounds used in the present invention include polyfunctional acrylates such as diethylene glycol diacrylate, neopentyl glycol diacrylate, vinyl acrylate, human 1-1 xypivalic acid neopentyl glycol diacrylate, 1, 6 Hexanediol acrylate, 1-limethylolpropane triacrylate, l,4-butanediol diacrylate, tetraethylene glycol diacrylate I, polyethylene glycol-41)0 diacrylate, pentaerythritol triacrylate 1, etc. , polyfunctional methacrylates include ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, vinyl methacrylate-1-, trimethylolbroban trimecrylate, allyl methacrylate-1-, glycidyl methacrylate, l,3-butanediol dimethacrylate. -1., tetraethylene glycol dimethacrylate, glycidyl methacrylate, 2,3-dibromopropyl methacrylate, and the like. In addition, various polyfunctional monomers such as vinyl crotonate, vinyl oleate, vinyl oleate, divinylhenzen, allylgrinnorether, etc. can be used. Particularly preferred is a resin that has a low heat deformation temperature, and dimethacrylate-based resins are effective. Also, if the amount used is too small, there will be no effect, and if it is too large, the degree of crosslinking will be too high, and the moldability will deteriorate. Therefore, the preferred crosslinking agent is 0.01 to 2
parts (based on 100 parts of monomer) are suitable. Further, care must be taken when selecting a crosslinking agent since it may adversely affect the polymerization conversion rate and suspension stability.

Also, the α-alkylstyrene monomer mentioned here is
It refers to α-alkylstyrenes such as α-methylstyrene and their heptad-substituted derivatives. In addition, examples of nitrile monomers include acrylonitrile and methacrylonitrile, and examples of monomers that can be copolymerized with these 7-mers include styrene, t-butylstyrene, and ortho-styrene.
, nuclear substituted styrene such as para-methylstyrene, methacrylic acid, methacrylic ester, acrylic ester, acrylic acid, maleic anhydride, N-methyl-maleimide,
Examples include N-phenylmaleimide.

The amount of α-alkylstyrene monomer used is 15
~80 WL% (based on the total weight) is good, but in order to improve the heat resistance of the resin, it is preferable to use 40 parts or more of the α-alkyl styrene thread. but,
If an α-alkylstyrene thread monomer is used in the equipment, the degree of polymerization will be lowered, the IH resin will have a weaker copper mine impact property, and the moldability of injection will be worse. Therefore, in order to produce a product with good moldability and high heat deformation temperature using α-alkyl styrene yarn monomer, the α-alkyl styrene yarn monomer is preferably 40 to 78-t%, more preferably, 50
~78-t% and 0.01-2 parts of crosslinking compound (
The objective is achieved by the combined use of 100 parts of total monomers).

Next, as polyfunctional peroxides, ditertiary butyl peroxyhexahydroisophthalate,
ditertiary butyl per-1-xyhexahydroterephthalate,
1.1'-ditertiary peroxy 3,3°5trimenal
Cyclohexane, 1lis(ternarybutylbaroxy)tridian, 2.5-dimethyl 2.5 Bis(hendiyl peroxy)hexane, 2.5-dimethylhexane 2,5-bis(perfluorocarbon), 2.5
-dimethylhexane-2,5-bis(perlaure-1.
), etc. On the other hand, as a thread compound, 2.2'
-Azobis-(2,4-dimenalvaleronitrile), dimethyl 2.2--1zobisiso-butylene-1., 1゜1
'-7zobis(cyclohexane-1-carbonitrile)
, 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, abbisisobutyronitrile, etc., but 1llll? It is preferable to use a W-type compound, and 1,1'-azobis(cyclohexane-1-carbonitrile) is particularly preferable.

As a polymerization method for obtaining the co-m polymer in the present invention, known suspension polymerization and/or bulk polymerization are employed.

Particularly in the case of suspension polymerization, known dispersants are used in the aqueous medium. Dispersants include organic dispersants such as polyvinyl alcohol, polyvinylpyrrolidine, and methylcellulose, and inorganic dispersants such as tricalcium phosphate, magnesium phosphate, sodium silicate, zinc oxide, and magnesium carbonate. In some cases, the effect of the dispersing agent can be significantly improved if an anionic surfactant such as sodium dodecylhenzensulfonate or sodium α-hydrogensulfonate is used in combination.

Examples are shown next, and in each table of each example,
The conversion rate of the obtained copolymer is reduced by percentage (weight %),
Regarding the properties of the obtained copolymers, the results are those obtained when molding each copolymer by injection molding, and the heat distortion temperature HD'r (18.6K g / cJ (% city)) indicates the heat resistance. JIS-1-
Indicates the value according to the method of 6871, without south attack strength notch I
ZOD is also based on the method of JIS-6871. In addition, the specific viscosity ηsp uses dimethylformamide as the solvent,
The value measured at 30°C using a 0.2% solution is shown,
This was used as a comparison standard for the degree of polymerization.

In addition, injection moldability was evaluated based on the sample release property during mold release and clogging of the shaft 1 fat supply gate.

Incidentally, it is of course possible to use stabilizers, lubricants, etc. in the copolymer resin obtained in the present invention from the viewpoint of L-addability, etc.
In order to improve the impact resistance, it is of course possible to blend an elastomer such as diene thread rubber, EP rubber, or sulfonated polyethylene, etc. In addition, the resin obtained in the present invention shows good compatibility with chlorinated resins, and can of course be used in blends with polyvinyl chloride, chlorinated polyvinyl chloride, etc. There is no problem. Of course, there is no problem in using it in combination with other various resins.

Example 1 110 parts by weight of water, 0.30 parts of tricalcium phosphate, 0.005 parts of sodium dodenruhenzenesulfonate, and 0.2 parts of sodium chloride were placed in an autoclave equipped with a stirrer, and then stirred in a flit state. 1.1'-azobis(cyclohexane 1 carbonitrile) 0.5 parts, 1.1'-ditertiary baroxy 3.3.5) α-methylstyrene 55 parts dissolved in 01 part of dimethylcyclohexane, 27 parts acrylonitrile , 18 parts of styrene, and the number of parts of dittaacrylic acid ester (1,3-butylene glycol dimethacrylate, referred to as D M li) shown in Table 1 were introduced into the system, and the temperature was raised to 95°C. Polymerization was carried out for 3 hours, and then the temperature was further raised to 115°C and post-polymerization was carried out for 3 hours. Conversion rate, specific viscosity, heat distortion temperature,
(h'1 Strength and moldability were tested. Table 1 shows the results.

Moldability: ◎Extremely good, 0Good, △Poor,
Light yellow coloration △Yellow coloration h & 1 Example 2 In the same manner as in Example 1, 70 parts of α-methylstyrene, 30 parts of acrylonitrile, 1,1′-azobis(Siku I:
Polymerization was carried out in the same manner except that 0.6 part of hexane-1-carbonitrile) was used, and the results shown in Table 2 were obtained.

2 'A Example 3 1,1' Instead of using 0.6 parts of 1,1' Asosis (-7-riL1 hekylin 1-carho'-11. The results shown in Table 3 were obtained in the same manner as in Example 2 except that .6 parts were not used and 5 parts were used.

5 6 Comparison of Example 3 and Example 2 (It can be seen that the colorability of the molded article is improved when the Azu yarn compound is used as an initiator.

Claims (1)

[Scope of Claims] 1. 15 to 80 parts by weight of α-alkylstyrene monomer (hereinafter simply referred to as parts), 10 to 10 parts of nitrile monomer
45 parts, copolymerized with those 7-mers, nJ functional 7-mers 0 to 7
5 parts and 0.01 to 2 parts of a crosslinking compound are bulk polymerized or suspended. i1 An α-furkylstyrene/nitrile copolymer resin with excellent moldability obtained through polymerization. 2. As an initiator, the temperature in the 10 o'clock time range is 60 to 120°.
3. The co-polymerized resin according to claim 1, which uses a polyfunctional peroxide and/or an ab-based compound. 3. The polyfunctional peroxide is peroxo- tertiary butyl, tertiary butyl peroxyhexahydrotylphthalate, l) 1'-tertiary peroxy 3.3.5 trimethylcyclo11 hexane, tris(ternary-so-tylper-A-phthalate)], less (
The copolymer resin according to claim 1, wherein one type of each is selected. 4. Claim 1 in which the azo compound is 1.1' γzobis(inklI hexane-1-carbonitrile)
Copolymer resin described in section. 5. The co-polymer resin according to claim 1, wherein the crosslinkable compound is nisfur dimethacrylate. 6. 40 to 7 copies of α-alkyl styrene thread
The copolymer resin according to item 1, wherein the desired range is R%A# (based on all seven polymers). 7. 50 to 7 copies of α-fulkyl styrene thread
(based on all monomers) The copolymerized resin according to claim 6, which is (relative to all monomers).