JPS60203611A - Production of alpha-alkylstyrene based heat-resistant resin - Google Patents

Abstract

PURPOSE:To obtain the titled resin with little coloring in high conversion, by polymerizing a monomeric mixture consisting of an alpha-alkylstyrene, nitrile based monomer, etc. in the presence of a specific azo based initiator. CONSTITUTION:0.1-3pts.wt. azo based initiator, e.g. 1,1'-azobiscyclohexane-1- carbonitrile, having 60-120 deg.C temperature at 10hr half-life is added to 100pts.wt. mixed monomer of (A) 40-85pts.wt. alpha-alkylstyrene based monomer, e.g. alpha-methylstyrene, (B) 10-45pts.wt. nitrile based monomer, e.g. acrylonitrile, and (C) 0- 60pts.wt. monomer copolymerizable with the monomers (A) and (B), and the resultant mixture is block or suspension polymerized preferably at 90-110 deg.C to give the aimed resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses α-alkylsdyrene monomers with 40 to 85 parts (hereinafter referred to as M parts), nitrile monomers with 10 parts
~45 parts and 0~ monomer copolymerizable with these monomers
The present invention relates to a method for obtaining a heat-resistant + sealant by subjecting 60 parts of the above-mentioned resin to polymerization or suspension polymerization using an azo initiator having a temperature in the 10 hour range of 60 to 120°C.

A copolymer consisting of α-alkylstyrene, a nitrile monomer, and other monomers that can be copolymerized with α-alkylstyrene, and has sufficient heat resistance for practical use. Of the total amount of monomers used,
It is necessary to use at least 40% or more, preferably 50% to 80%.

However, based on this point of view, in the past, attempts were made to use large amounts of α-alkylstyrene as described in ``2'' to obtain a copolymer with excellent heat resistance by suspension polymerization or bowl polymerization.
Polymerization is carried out using organic peroxides used in the polymerization method of styrenic monomers, such as t-butylverhenzoate, di-t-butylverhendoate, di-L-butyl peracetate, and henzoyl peroxide. However, regardless of the polymerization temperature, the conversion rate of the polymerization is extremely low, or even if the conversion rate of polymerization is high enough for practical use, a large amount of initiator is required, and the molecules of the resulting resin are Its length was extremely low and its usefulness as a molding material was poor. or,
An example of polymerization using a difunctional peroxide can be found, for example, in US Pat. No. 41G9195, but this requires an extremely long polymerization time, resulting in extremely low productivity from an industrial perspective.

The inventors of the present invention have conducted intensive research in view of these points, and have found that a resin with excellent transparency, heat resistance, and strength can be produced with a high conversion rate in a short time by suspension polymerization or bowl polymerization using an azo initiator. They found that it can be obtained extremely easily by.

Furthermore, the resin obtained according to the present invention is characterized by extremely little coloring during molding due to the use of nitrile monomers.

The α-alkylstyrenic monomers mentioned herein include α-alkylated styrenes such as α-methylstyrene, and those obtained by halogenating or alkylating the phenyl group of the above-mentioned monomers.

Further, the nitrile monomer includes acrylonitrile, methacrylonitrile, and derivatives thereof. Examples of copolymerizable monomers include vinyl acetate, various methacrylates, acrylates, styrene, t-butylstyrene, nuclear-substituted styrenes such as ortho- and para-methylstyrene, methacrylic acid, acrylic acid, N-methylmaleimide, Maleimide compounds such as N-phenylmaleimide,
Known vinyl monomers such as maleic anhydride may be used.

In addition, the amount of these monomers used is α-
The alkylstyrene monomer is used in an amount of 40 to 85 parts, preferably 50 to 80 parts. Furthermore, if the amount of the nitrile monomer used is less than 10 parts, the polymerization rate will be slow and the conversion rate will not be practical.

On the other hand, if the amount exceeds 45 parts, the molded product will have a strong yellowish tinge, which is characteristic of di-lyl, which is disadvantageous. The preferred amount is 15~
There are 35 copies.

Next, the azo initiator used in the present invention has a temperature range of 60 to 120°C, preferably 70 to 110°C.
C is preferable, but considering the actual polymerization system, it is desirable to use an oil-soluble one. Examples of such substances include abbisisobutyronitrile, 2,2-azobis-
(2,4-dimedylhaleronitrile), dimethyl-2,
2'-Azohisisobutyrate, 2-phenylazo-
2,4-dimethyl-4-methyl-4-methoquino-valeronitrile, 1,1'--7zobisune, carbonyl, etc. can be used, and particularly preferred are 1, I'-A'zohydric I: 1-hexane-1-carbonyl is preferred. Of course, it is also effective to use one or more of them.

The amount used is 0.1 per 100 parts by weight of the monomer mixture.
-3% by weight is preferable, and if it is less than 0.1% by weight, a practical conversion rate cannot be obtained or polymerization for an extremely long time is required, which is practically meaningless.

Moreover, if it exceeds 3% by weight, the molecular weight will decrease and the moldability will deteriorate.
decreases to

As a polymerization method for obtaining the copolymer in the present invention, known suspension polymerization or bowl polymerization is employed. Particularly in the case of suspension polymerization, known dispersants are used in the aqueous medium. Dispersants include organic dispersants such as polyvinyl alcohol, polyvinylpyrrolidone, and methylcellulose, and inorganic dispersants such as tricalcium phosphate, magnesium phosphate, sodium silicate, zinc oxide, and magnesium carbonate. Anionic surfactants such as sodium dotesylhenzensulfonate and sodium α-olefin sulfonate (
When used as a dispersant, the effect of the dispersant becomes significantly better.

Furthermore, when using the initiator in the present invention, it is important to select the polymerization temperature. That is, the polymerization temperature is preferably 80 to 120°C, more preferably 90 to 110°C. 80℃
If it is less than 120°C, the conversion rate will be extremely low, and if it exceeds 120°C, the molecular weight will decrease, making it difficult to obtain an industrially useful copolymer.

Examples are shown next, and in each table of each example,
The conversion rate of the obtained copolymer is shown in percentage (wt%),
Regarding the properties of the obtained copolymers, the results are those obtained when molding each copolymer by injection molding, and the heat distortion temperature HDT is measured as an expression of heat resistance and is in accordance with JIS-7207. (The impact strength IZO,D is also based on the method of JIS-7110.

In the present invention, further L-to]-silmercaptan,
Known chain transfer agents such as 2-mercaptoethanol and thiophenol, known crosslinkable intermediates having two or more double bonds in one molecule, etc. can be used as necessary.

The heat-resistant resin obtained in the present invention may be used alone or, if necessary, in combination with other resins, such as polyvinyl chloride, chlorinated polyvinyl chloride, acrylonitrile-styrene copolymer, acrylonitrile-methyl methacrylate copolymer, styrene. −
Methacrylic acid copolymer, styrene-maleic anhydride copolymer, methyl methacrylate-styrene copolymer, styrene-methyl methacrylate-acrylonitrile copolymer,
Styrene-methacrylic acid-acrylonitrile copolymer,
Copolymers such as styrene-imide copolymer, methyl methacrylate-imide copolymer, acrylonitrile-imide copolymer, +1? Polymers such as methyl rimecacrylate, polyacetal, polycarbonate, chlorinated polyethylene, MBS resin, ABS resin, styrene-bucdiene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-carbon oxide copolymer , acrylic rubber,
Known resins such as EPR, EPDM, polyurethane, chlorosulfonated polyethylene, NBR, stabilizers such as Sn stabilizers, lead stabilizers, Ca-Zn stabilizers, phenyl derivatives, di-stearylthiopropionate Antioxidants such as n-flame agents, n-flame agents such as flame retardant aids, coloring agents such as dyes and pigments, low molecular weight polyethylene, low molecular weight As resins, wax, liquid paraffin and other 'tFJt agents are mixed. For processing and molding, known methods such as extrusion, injection, calendering, blowing, foaming, and vacuum forming may be employed.

Embodiments of the present invention are disclosed below, but these are not intended to limit the present invention in any way.

Example 1 110 parts by weight of water, 0.25 parts of tricalcium phosphate, and 6 parts of sodium todecylhenzenesulfonate O,OO were placed in an autoclave equipped with a stirrer, and then 1.1'-
Azohis-Cyclokiman-1-Carbonitrile 0.5
A mixture of 55 parts of α-medylstyrene, 27 parts of acrylonitrile, and 18 parts of Step 1 was added to the aqueous medium, heated to 100° C., and polymerized for 7 hours. Thereafter, the mixture was further heated to 120°C and post-polymerized for 4 hours to form a resin. The polymerization conversion rate for the resin-containing resin, and the HDT and IZOD after molding with 1 indium resin were measured and are listed in Table 1.

Example 2 In Example 1, 0.4 part of azobisisobutyronitrile and 1.1'-azobiscyclohexane-1-carbotrile were used instead of 0.5 part of 1.1'-azobis-cyclohexane-1-carbotrile. Resin B was obtained in the same manner as in Example 1, except that 0.15 part of carbonyl-lyl was used and the polymerization conditions were changed to 90°C for 7 hours instead of 100°C for 7 hours. Table 1 shows the measurement results of the polymerization conversion rate, IDT, and IZOD of this resin.

Example 3 05 parts of 2-cyano-2-propylazoformamide was used instead of 05 parts of 1.1'-azobis-cyclohexane-1-carbonyl-1-lyl in Example 1,
Resin C was obtained in the same manner as in Example 1 except that the polymerization conditions were 110°C for 7 hours and 120°C for 4 hours, and the polymerization conversion rate and
The results of HDT and IZOD measurements are shown in Table 1.

Comparative Example 1 A resin resin was prepared in the same manner as in the example except that 0.5 part of hensyl peroxide was used instead of 0.5 part of 1,1'-azobis-cyclohexane-1-carbotrile. The polymerization conversion rate, HD1', and IZOL) were measured. The measurement results are shown in Table 1.

It can be seen from Table 1 that by using the polymerization initiator of the present invention, a copolymer containing a high α-methylstyrene content can be obtained. or,
The coloration of the injection molded products obtained from the copolymerized 4-part resins A, 13, and C, which were obtained in the 1:1 ratio according to the present invention, was extremely low.

Claims (1)

[Scope of Claims] 1. 40 to 85 parts by weight of an α-alkylstyrene monomer (hereinafter, all parts are indicated by weight), 10 to 45 parts of a nitrile monomer, and 0 monomers copolymerizable with these seven monomers. ~60 parts, at 10 o'clock temperature range 60~120℃
A method for producing an α-alkylstyrene-based silica-resistant resin, which comprises carrying out polymerization or suspension polymerization using an azo-based initiator. 2. The production method according to claim 1, wherein the α-alkylstyrene monomer is one or a mixture of α-methylstyrene and its nuclear-substituted monomers. 3. The manufacturing method according to claim 1, wherein the nitrile monomer is one or a mixture of acrylonitrile and methacrylonitrile. 4. The manufacturing method according to claim 1 or 2, wherein the azo initiator is 1,1'-azobiscyclohexane-1-carbonitrile. 5. The manufacturing method according to claim 1, wherein 50 to 80 parts by weight of the α-alkyl styrene monomer is used.