JPS60210653A - Transparent, heat-resistant, flame-retardant and impact- resistant resin composition - Google Patents

Abstract

PURPOSE:To provide a resin compsn. having excellent transparency, flame retardance and resistance to heat and impact, consisting of a copolymer obtd. by polymerizing a monomer mixture contg. alpha-methylstyrene and acrylonitrile in the presence of a styrene/butadiene block copolymer, and a chlorine-contg. resin. CONSTITUTION:A graft copolymer (a) obtd. by suspension-polymerizing or bulk- polymerizing a monomer mixture consisting of 30-80pts.wt. alpha-methylstyrene monomer, 15-50pts.wt. acrylonitrile monomer and 0-50pts.wt. other copolymerizable monomer in the presence of 10-40pts.wt. styrene/butadiene block copolymer, is kneaded with a chlorine-contg. resin (b). A polyfunctional peroxide and/ or an azo compd. are/is used as the polymn. initiator. An example of the polyfunctional org. peroxide is di-t-butyl peroxyhexahydroterephthalate. An example of the azo compd. is 1,1'-azobiscyclohexane-1-carbonitrile.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition that is transparent, has excellent heat resistance, flame retardancy, and impact resistance. More specifically, (a) in the presence of 10 to 40 parts by weight of a styrene-butadiene block copolymer, 30 to 80 parts by weight of an alpha methylstyrene monomer, preferably 50 to 80 parts by weight, and 15 to 50 parts by weight of an acrylonitrile monomer. %, preferably 20 to 35 parts by weight, and 0 to 50 parts by weight, preferably 0 to 30 parts by weight of other monomers copolymerizable with these monomers, preferably polyfunctional organic monomers. A transparent, heat-resistant, flame-retardant, impact-resistant resin consisting of a graft copolymer obtained by suspension polymerization or bulk polymerization using a peroxide and/or an azo compound as an initiator, and (b) a chlorine-containing resin. The present invention relates to a composition.

Recently, transparent, heat resistant, flame retardant,
There is a demand for impact-resistant resin.

Conventionally, acrylonitrile-styrene copolymer (generally called AS resin) or polymethyl methacrylate and MBS have been used as transparent, heat-resistant, flame-retardant, and impact-resistant resins.
Although resin compositions consisting of chlorinated polyethylene, polyvinyl chloride, or flame retardants are known, these are insufficient in terms of transparency, heat resistance, or flame retardancy. In addition, instead of A341J]ll, resin compositions made of alpha methylstyrene, acrylonitrile, methyl methacrylic acid, emulsion copolymers made of styrene and polyvinyl chloride or flame retardants are also known, but these also have transparency. was insufficient, and because it was an emulsifier, its thermal stability was also poor.

The present invention provides a resin composition that improves these drawbacks and has excellent transparency, heat resistance, flame retardancy, and impact resistance. More specifically, in the presence of (a) 10 to 40 parts by weight of a styrene-book diene block copolymer, 30 to 80 parts by weight of an alpha methylstyrene monomer and 15 to 50 parts by weight of an acrylonitrile monomer, which can be copolymerized with these. and other monomers in a proportion of 0 to 50 parts by weight, preferably by suspension polymerization or bulk polymerization using a polyfunctional peroxide and/or an azo compound as an initiator. Graft copolymer 30-80 parts by weight, preferably 40-80 parts by weight
The present invention relates to a transparent, heat-resistant, flame-retardant, and impact-resistant resin composition comprising 70 to 20 parts by weight, preferably 60 to 30 parts by weight of (b) a chlorine-containing resin.

In the present invention, alpha methyl styrene includes, in addition to alpha methyl styrene, benzene nucleus-substituted products of alpha methyl styrene, such as alpha methyl styrene derivatives having substituents such as methyl groups, ethyl groups, and halogen groups.

Furthermore, acrylonitrile refers to acrylonitrile, mecrylonitrile, and the like. Monomers copolymerizable with these include styrene, benzene-nucleated products of styrene, styrene derivatives having substituents such as methyl, ethyl, t-butyl, and halogen groups, methacrylic acid,
Known vinyl monomers such as acrylic acid, maleimide compounds such as N-methylmaleimide and N-phenylmaleimide are included. These may be used alone or in combination.

The styrene-butadiene block copolymer used in the present invention is a block copolymer having a butadiene content of 50 to 80i+t%. As the block type, known block type polymers such as single block, radial teleblock, teleblock, and multiblock are used.

The initiator used in obtaining the suspension copolymer of the present invention is a polyfunctional organic peroxide and/or an azo compound,
The time half-life temperature is 60 to 130°C. Compounds corresponding to this include di-t-butylperoxyhexahydrothylephrate, 2.5 dimethyl-2,5
bis(2-ethylhexanoylperoxy)hexane,
1,1'-di-t-butylperoxycyclohexane, 3.5-trimethylcyclohexane, 1,1'-di-t-butylperoxycyclohexane, di-t-butylperoxyazelate, 2,5-dimethyl-2 , 5bis(hensilveroxy)hexane, 2,2'-di-(t-butylperoxy)-butane, 4゜4'-di-L-butylveroxyparellic acid-n-butyl ester, di- Difunctional organic peroxides such as t-butylperoxy-1-limethyl adipate, or trifunctional organic peroxides such as 2.4.6-)-L-butylperoxy-1,3,5-triazine. There are things. Among them, di-t-butylperoxyhexahydrothylephthalate-1. and 1.1'-di-t-butylperoxy-3,3,5-trimethylcyclohexane have a good polymerization time, and 2. 4. 6-
) Li-L-butylbaroxy-1,3,5-)riazine is preferred because processability improves as the degree of polymerization increases.

The azo compounds used in the present invention include azobisisobutyronitrile, dimethyl 2,2-azobisisobutyrate, 1
, 1'-abbisfuclohexane-1-carbonil-1-lyl, 2-cyano-2-propylazoformamide, 2-
There are azo compounds such as phenylazo-2,4-dimethyl-4-methoxyvaleronitrile. Preferably 1.1'-
Azobiscyclohexane-1-carbonitrile is good.

If an azo compound is used, a colorless graft copolymer can be obtained with less coloration than when a polyfunctional organic compound is used, and therefore the molded article of the resin composition of the present invention can be colored well.

The amount of the polyfunctional organic peroxide and/or azo compound used as an initiator for the graft copolymer in the present invention is preferably 0.1 to 2.0 parts by weight based on 100 parts by weight of the monomer mixture. . Further, these initiators may be used in combination. The polymerization temperature for obtaining the graft copolymer of the present invention is preferably 80 to 130°C.

If an initiator other than those mentioned above is used as an initiator, the conversion rate will not increase and this will be extremely disadvantageous industrially. From this point of view,
The present invention has discovered a special polymerization initiator for the reason that suspension polymerization products or bulk polymerization products of alpha methylstyrene-acrylonitrile copolymers containing high alpha methylstyrene cannot be obtained industrially. This is one feature of

Next, regarding the polymerization method, for example, a styrene-butadiene block copolymer (hereinafter referred to as elastomer) may be dissolved in a monomer system and subjected to bulk polymerization or E-turbidity polymerization, or bulk suspension polymerization may be performed. Good too. Furthermore, when the elastomer is in the form of small particles, it is also possible to disperse the elastomer together with a dispersant in an aqueous medium and then charge the heptamer system for polymerization. In this case, it is similar to the seed polymerization method in which the monomer is impregnated into elastomer particles, and is often advantageous in terms of scale, water content, etc. compared to the case of solution suspension polymerization.

Next, when 'FJ polymerization is employed, a known dispersant is used in the aqueous medium. Dispersants include organic dispersants such as polyvinyl alcohol, polyvinylpyrrolidone, and methyl cellulose, and inorganic dispersants such as tricalcium phosphate, magnesium phosphate, sodium silicate, zinc oxide, and magnesium carbonate. The effect of the dispersant is significantly improved when an anionic surfactant such as sodium dodecylbenzenesulfonate or sodium α-olefin sulfonate is used in combination.

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 130°C, more preferably 90 to 120°C. 80°C
If it is less than 130°C, the conversion rate will be extremely low, and if it exceeds 130°C, the molecular weight will decrease, making it difficult to obtain an industrially useful copolymer.

In the present invention, in order to improve transparency, it is necessary to perform bulk and/or suspension polymerization in the presence of an elastomer, and a copolymer consisting of an elastomer and the monomer system described in the present invention is simply Breading alone will only yield a completely opaque material and will not provide sufficient impact strength.

The chlorine-containing resin used in the present invention is a polyvinyl chloride resin and/or a chlorinated polyvinyl chloride resin. Examples of polyvinyl chloride resins include polyvinyl chloride resins and copolymers of vinyl chloride and vinyl monomers copolymerizable therewith. Examples of copolymerizable vinyl monomers include ethylene,
There are known monomers such as propylene, 1-butene, vinylidene chloride, and allyl chloride. The content of these vinyl monomers in the copolymer is 1 to 0 to 10i+t%, preferably θ to
511t% is good. This is because if it exceeds 10 wt%, heat resistance will decrease, which is not preferable.

As the chlorinated polyvinyl chloride resin, a chlorinated polyvinyl chloride resin described above is used. Chlorinated poly or vinyl chloride resins with a chlorine content of 60 wt% to 70 wt% are preferred. This means that if it is less than 60 wt%, the effect of improving heat resistance on polyvinyl chloride resin will be small;
Exceeding Qiit% is not preferable because processability deteriorates.

The chlorine-containing resin used in the present invention is preferably produced by a suspension polymerization method or a bulk polymerization method. This is because they have better transparency and thermal stability than emulsion polymerized products.

In the present invention, it is preferable to use a chlorinated polyvinyl chloride resin as the chlorine-containing resin. This is because the use of chlorinated polyvinyl chloride resin improves heat resistance and thermal stability.

Conventionally, chlorinated polyvinyl chloride resins were said to have poorer thermal stability than polyvinyl chloride resins, but it has been found that according to the present invention, they have better thermal stability.

The reason for this is not clear, but it seems to be due to some kind of synergistic effect with the graft copolymer.

In addition, the average degree of polymerization of the chlorine-containing resin used is 400 to 8.
00 is good. This is because if it is less than 400, it becomes difficult to develop impact strength, and if it exceeds 800, workability becomes poor. In order to significantly improve processability without impairing thermal stability, it is possible to use ethylene-vinyl chloride, allyl chloride-vinyl chloride, propylene-vinyl chloride, l-butene-vinyl chloride copolymers. is good.

In the present invention, known stabilizers for polyvinyl chloride resins such as low molecular weight AS resins, processability improvers such as low molecular weight polyalphamethylstyrene, dibutyltin maleate, mercaptotin maleate, metal soaps, and lead compounds are used. A small amount of known flame retardants such as bromine-based and phosphorus-based flame retardants, and known coloring agents such as dyes and pigments may be used in combination.

The resin composition of the present invention can be formed into molded articles for various uses by extrusion, rolling, molding, etc.

Hereinafter, resin embodiments of the present invention will be disclosed, but these do not limit the present invention in any way.

Reference Examples 1 to 7, Control Examples 1 to 3 120 parts of water, 0.7 parts by weight of tricalcium phosphate, and 0.05 parts by weight of sodium α-olefin sulfonate were charged into a polymerization vessel with an internal volume of 31 and equipped with a stirrer. A solution system consisting of the initiator, monomer, and styrene-butadiene block copolymer in the parts by weight shown in Table 1 was charged and polymerized at 95°C for 7 hours and then at 115°C for 5 hours to obtain a graft copolymer. Ta.

*1 The initiator is as follows; A: tertiary butyl peroxyhexahydroterephthalate B: l,l'-ditertiary peroxy 3,3.5-trimethylcyclohexane C: 2.4.6-trimethylcyclohexane t-butylperoxy-1,3
, 5-) Reazine D: 1,1'-Azobiscyclohexane carbonitrile E: Benzoyl peroxide *2 The evaluation of the colorability of the copolymer is as follows: Second place: Colored a light reddish brown. Young: Colored a slightly light reddish brown. It can be seen from Table 1 that the monomer conversion rate of the present invention is extremely good. It is also found that the use of an azo compound provides good coloring properties.

Examples 1 to 11, Comparative Example 1 The graft copolymers obtained in Reference Examples 1 to 7 were blended with polyvinyl chloride or chlorinated polyvinyl chloride. At this time,
Per 100 parts by weight of this mixture, 3.0 parts by weight of dibutyltin maleate and 2.0 parts by weight of ester wax were mixed.

This mixture was kneaded with a roll at 170° C. for 5 minutes to form a sheet. From this sheet, heat distortion temperature HDT (load capacity 18.6 kg/c+a) is determined according to JIS-7207.
, notched I ZOD according to JIS-7110
Each value was measured. The transparency of the sheet is 170℃, 15
The determination was made from a pressed plate (thickness: 5 mm) made by pressing for 5 minutes under the condition of Q kg/ad. Thermal stability is 18
The blackening time (minutes) of the sample was measured using a 0°C gear open test. The results are shown in Table 2.

Table 2 also shows, as Comparative Example 1, the results of evaluating the physical properties of a resin composition consisting of a styrene-butadiene block copolymer, the copolymer obtained in Comparative Example 1, and a polyvinyl chloride resin.

From Table 2, it can be seen that the blend of styrene-butadiene copolymer is opaque and has poor heat resistance and IZOD value. On the other hand, in the method of the present invention, transparent, heat-resistant, IZO
It can be seen that the D value is excellent.

It is also found that the use of chlorinated polyvinyl chloride provides excellent heat resistance and thermal stability.

Examples 12 to 20, Control Examples 4 to 5 From 50 parts by weight of the graft copolymer obtained in Reference Example 5, 50 parts by weight of chlorine-containing resin, 1.5 parts by weight of dibutyltin maleate, and 1.0 parts by weight of ester lubricant. The formulation becomes 160
The mixture was kneaded for 5 minutes with a roll at ℃ to obtain a sheet. From this sheet, method B flow (nozzle lφx l Q t m/m,
(Load: 170 kg/cJ, temperature: 190°C) Impact strength, thermal stability, transparency, and heat resistance were examined. The results are shown in Table 3.

From Table 3, the average weight of the polyvinyl chloride resin is 400
If it is less than 800, the impact strength will not be developed, and if it exceeds 800, the flow will deteriorate.On the other hand, the use of a specific PVC joint will significantly reduce the flow without deteriorating the thermal stability. It turns out that it can be improved.

Claims (1)

[Claims] 1. (a) Styrene-buccadiene block copolymer 10
In the presence of ~40 parts by weight, 30 to 80 parts by weight of an alpha methylstyrene monomer, 15 to 50 parts by weight of an acrylonitrile monomer, and 0 parts of a carbon monomer copolymerizable with these.
A transparent, heat-resistant, flame-retardant, impact-resistant resin composition consisting of a graft copolymer obtained by suspension polymerization or bulk polymerization of monomers at a usage rate of ~50 parts by weight, and (b) a chlorine-containing resin. thing. 2. The resin according to claim 1, wherein the monomers consist of 50 to 80 parts by weight of alpha methylstyrene, 20 to 35 parts by weight of acrylonitrile, and 0 to 30 parts by weight of other monomers copolymerizable with these. Composition. 3. The resin composition according to claim 1 or 2, wherein the graft copolymer is obtained using a polyfunctional organic peroxide and/or an azo compound as an initiator. 4. A patent in which the polyfunctional organic peroxide is a difunctional organic peroxide of di-t-butylperoxyhexahydroterephthalate and/or di-t-butylperoxy-3,3,5-trimethylcyclohexane. The resin composition according to claim 3. 5. Claim 3, wherein the polyfunctional organic peroxide is a difunctional organic peroxide of 2.4.6-)sort-t-butylperoxy-1,3,5-)riazine. resin composition. 6. The resin composition according to claim 3, wherein the azo compound is 1,17-azopiscyclohexane-1-carbonitrile. 7. The resin composition according to claim 1, wherein the chlorine-containing resin is a polyvinyl chloride resin and/or a chlorinated polyvinyl chloride resin. 8. The resin composition according to claim 7, which uses a chlorine-containing resin having an average degree of polymerization of 400 to 800. 9, ethylene-vinyl chloride, allyl chloride-vinyl chloride,
9. The resin composition according to claim 8, which uses propylene-vinyl chloride and 1-butene-vinyl chloride copolymers.