JPH01210445A - Styrene/maleic anhydride copolymer resin composition - Google Patents

Abstract

PURPOSE:To obtain the title resin composition improved in weather resistance without detriment to its heat resistance, rigidity, etc., by adding a benzotriazole light stabilizer and a hindered amine light stabilizer to a styrene/maleic anhydride copolymer resin in a specified weight ratio. CONSTITUTION:0.01-1 pt.wt. benzotriazole light stabilizer (B) and 0.01-1 pt.wt. hindered amine light stabilizer (C) are added to 100 pts.wt. styrene/maleic anhydride copolymer resin (A) to produce a styrene/maleic anhydride copolymer resin composition of improved weather resistance. Examples of component B include 2-(2'-hydroxy-5'-methyl-phenyl)benzotriazole and 2-(2'-hydroxy-3,5-di-t- butyl-phenyl)-5-chlorobenzotriazole. Examples of component C include compounds of formulas I and II. The obtained resin composition can be suitably used for automobile parts, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel styrene-maleic anhydride copolymer resin composition. More specifically, the present invention is directed to a styrene-maleic anhydride copolymer resin that has excellent heat resistance, rigidity, and significantly improved weather resistance and is suitable as a material for various parts in the automobile field, electrical equipment field, etc. The present invention relates to a composition.

[Conventional technology] Conventionally, styrene-maleic anhydride copolymer resins have excellent heat resistance, rigidity, transparency, etc., have a high refractive index, have good high frequency insulation properties, and have little strength loss at low temperatures. Therefore, it is widely used as an industrial material, especially in the automobile and electrical equipment fields.

However, this styrene-maleic anhydride copolymer resin has the disadvantage of inferior weather resistance compared to olefin resins such as polypropylene and polyethylene.
Improvements were strongly requested in various quarters.

By the way, as weathering (light) stabilizers for thermoplastic resins,
Conventionally, benzotriazole type, benzophenone type,
Various compounds such as aromatic benzoates, hindered amines, and oxalic acid anilides are known, but even when these weather (light) stabilizers are applied to styrene-maleic anhydride copolymer resins, they cause some degree of damage. Although the effect is exhibited, it is not always satisfactory depending on the purpose of use, and there are cases where a layer with excellent weather resistance (light) stability is required. However, even if the amount of the weather (light) stabilizer added is simply increased to meet such demands, there is a limit to the improvement of weather resistance, and satisfactory weather resistance cannot be obtained. This often leads to undesirable situations such as impaired characteristics.

[Problems to be Solved by the Invention] Under these circumstances, the present invention provides a method that sufficiently maintains the excellent mechanical properties such as heat resistance and rigidity inherent in a styrene-maleic anhydride copolymer, The object of this invention is to provide a styrene-maleic anhydride copolymer resin composition which has significantly improved weather resistance.

[Means for Solving the Problems] The present inventors have conducted intensive research to develop a styrene-maleic anhydride copolymer resin composition having the above-mentioned excellent properties. The inventors have discovered that a polymeric resin in which predetermined amounts of a benzotriazole light stabilizer and a hindered amine light stabilizer are added are suitable for the purpose, and based on this knowledge, they have completed the present invention. .

That is, the present invention provides 0.01 to 1.0 parts by weight of (B) a benzotriazole light stabilizer and (C) a hindered amine light stabilizer based on 100 parts by weight of (A) styrene-maleic anhydride copolymer resin. The object of the present invention is to provide a styrene-maleic anhydride copolymer resin composition in which 1.0 parts by weight of the styrene-maleic anhydride copolymer resin composition is added.

The present invention will be explained in detail below.

In the composition of the present invention, the styrene-maleic anhydride copolymer resin used as component (A) is styrene 98-
The preferred polymerization method is to use a resin obtained by copolymerizing 70 mol%, preferably 95 to 80 mol%, and 2 to 30 mol%, preferably 5 to 20 mol% of maleic anhydride. Either the bulk polymerization method or the solution polymerization method may be used, and the polymerization may be carried out in a single polymerization tank, but it is also possible to carry out the polymerization in a continuous multistage system in which multiple stages of polymerization tanks are arranged in series. preferable.

In this continuous multi-stage polymerization method, a fixed amount of a reaction solution containing styrene and a copolymer produced by a certain degree of reaction in the previous stage is sequentially flowed through each stage, and a predetermined amount of maleic anhydride is added at each stage. is used. In this case, the formula (ΔS1 in the formula is the polymerization amount of styrene monomer per unit time in a certain stage, ΔM is the addition amount per unit time of maleic anhydride in a certain stage, and ΔS2 is the polymerization amount per unit time of the other one) It is preferable to control the amount of styrene monomer polymerized per unit time in the step, and 6M2 is the amount of maleic anhydride added per unit time in the step.

ΔM, /ΔS1+ΔM1, ΔM2 in the above formula (1)
/ΔS2+ΔM2 both mean the amount of maleic anhydride reacted with respect to the total amount of copolymer produced in the polymerization tank. In other words, it represents the composition ratio of maleic anhydride units in the copolymer.

Therefore, the difference between the two is the difference in the composition ratio of maleic anhydride units in each copolymer in the two polymerization tanks.

By using a copolymer resin obtained so as to satisfy the above-mentioned relational expression (1), a composition with good transparency can be obtained.

In order to control the value of the formula (1) to 0.045 or less, for example, first, samples are taken from each polymerization tank and the value of ΔS+ΔM is calculated. ΔSSb between each copolymer species
When the 2O difference is larger than 0.045, the method of lowering the temperature 5ΔM of the polymerization tank with the smaller value of ΔS+ΔM or increasing the temperature of the polymerization tank with the larger value of ΔS+ΔM is applied.

The polymerization may be carried out either thermally or in the presence of a catalyst. In the latter case, any catalyst can be selected from those used in ordinary radical polymerization. For example, paysol peroxide,
2.4-dichlorobenzoyl peroxide, di-t-
Butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, diisopropyl peroxydicarbonate, t-butylperoxyisopropyl carbon-1, t-butyloxy Vivalate, stearoyl peroxide, azobisisobutyronitrile, 1,1-bis(t-butylperoxy)-3,3,5-)limethylcyclohexane,
1.1-bis(t-butylperoxy)cyclohexane, 2.2-bis(t-butylperoxy)octane, n
-Butyl-4,4-bis(t-butylperoxy)valerate, 2.2-bis(t-butylperoxy)butane, di-t-butylshiba-oxyisophthalate, 2.5
-dimethyl-2,5-di(bezoylperoxy)hexane, etc. can be used.

In addition, when using a solvent, examples include benzene, toluene, xylene, ethylbenzene, methyl ethyl ketone,
Acetone, tetrahydrofuran, dioxane, dimethylformamide, chlorobenzene, isopropyl alcohol, n-butyl alcohol, and the like can be used.

Polymerization is usually carried out at 70-200°C, preferably at 80-160°C.
It is carried out at a temperature in the range of °C.

In addition, when butadiene rubber, styrene-butadiene rubber, isoprene rubber, butadiene-acrylonitrile rubber, etc. is added to the reaction system during polymerization, or when the above-mentioned rubbers or thermoplastic elastomers are melt-kneaded into the polymerization product, styrene-maleanhydride with improved impact resistance can be obtained. An acid copolymer is obtained, which can also be used in the composition of the invention.

In the composition of the present invention, examples of the benzotriazole light stabilizer used as component (B) include 2-
(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole,
°-Hydroxy-3゛,5°-di-t-isoamylphenyl)benzotriazole, 2-[2'-hydroxy-
3′,5°-bis(α,α-dimethylbenzyl)phenyl]benzotriazole, 2-(2′-hydroxy-
4°-Octoxyphenyl)benzotriazole, 2-
(2°-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2
'-Hydroxy-3'', 5'-di-t-butylphenyl)-5-chlorobenzotriazole, etc.'
. These may be used alone or in combination of two or more.

In the composition of the present invention, the benzotriazole light stabilizer as the component (B) is 0.01 to 1 part by weight per 100 parts by weight of the styrene-maleic anhydride copolymer resin as the component (A).
．． It is necessary to use a proportion of 0 parts by weight, preferably 0.1 to 0.8 parts by weight. If this amount is less than 0.01 parts by weight, the effect of improving weather resistance will not be sufficiently exhibited;
If the amount exceeds 6 parts by weight, the heat resistance tends to decrease.6 In the composition of the present invention, the hindered amine light stabilizer used as component (C) is, for example, Sumisorb TMO61 [Sumitomo Chemical Co., Ltd.] shown by the following structural formula. ), Sanol LS770, LS774, LS944, LS26
26 [manufactured by Sankyo Co., Ltd., trade name], Tinuvin 622 (manufactured by Ciba Geigy, trade name), MARK LA-57 [manufactured by Adeka Argus Chemical Co., Ltd., trade name], but are not necessarily limited to these. It's not something you can do. Among these hindered amine light stabilizers, Sumisorb TMO61 is particularly suitable from the viewpoint of improving weather resistance. In addition, one kind of the above-mentioned hydadoamine light stabilizer may be used,
You may use two or more types in combination.

(Left below), Sumisorb TMO61 [manufactured by Sumitomo Chemical Co., Ltd.] - Sanol LS770 [manufactured by Sankyo Co., Ltd., product name] CH
s CHs・Sanol LS
774 [Manufactured by Sankyo Co., Ltd., product name] H3 CH.

・Sanol LS944 [manufactured by Sankyo Co., Ltd., product name] CH
2C(CH*)i ・Sanol LS2626 [Manufactured by Sankyo Co., Ltd., product name] H
3CH, -C-CH.

CH.

・Tinuvin 622 (manufactured by Ciba Geigy, product name)・M
ARK LA-57 [Manufactured by Adeka Argus Chemical Co., Ltd., trade name] H2-R CH, -R CH, -R CH2-R In the composition of the present invention, the hindered amine light stabilizer as the component (C) is: 0.01 to 1.0 parts by weight per 100 parts by weight of the styrene-maleic anhydride copolymer resin of component (A).
It is necessary to use it in a proportion of 0 parts by weight, preferably 0.1 to 0.08 parts by weight.

If this amount is less than 0.01 part by weight, the effect of improving weather resistance will not be sufficiently exhibited, and if it exceeds 1.0 part by weight, heat resistance tends to decrease.

The composition of the present invention contains various additives conventionally used in styrene-maleic anhydride copolymer resins, such as phenol-based and phosphorus-based antioxidants, lubricants, antistatic agents,
Antifogging agents, coloring agents, etc. may be added as desired.
Furthermore, thermoplastic elastomers and other thermoplastic resins can also be blended.

The composition of the present invention can be prepared by, for example, mixing the (A>component, (B) component, (C) component, and various additives used as necessary using a Henschel mixer or the like, and then melting the mixture using an extruder or the like. It can be prepared by kneading and pelletizing.

[Effects of the Invention] The styrene-maleic anhydride copolymer resin composition of the present invention has good weather resistance (light resistance) without impairing the heat resistance and mechanical properties such as rigidity that the styrene-maleic anhydride copolymer resin inherently has. For example,
It is suitably used as a material for various parts in the automobile field, electrical equipment field, etc.

[Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, each physical property of the composition was determined as follows.

(1) Weather resistant sunshine carbon arc type weather meter [manufactured by Suga Test Instruments Co., Ltd., model WBL-SUN-HCH]
After 600 hours of irradiation under fade conditions of 83℃, JIS
Measure the YI value in accordance with K 7103, and determine the YI value before irradiation.
The difference ΔYI value from the I value was calculated.

(2) Heat distortion temperature determined in accordance with JIS K 6871 ('C/18
．． 67FI/cm2).

(3) Flexural modulus It was determined in accordance with ASTM D790.

(Structure example 1) A reactor with a capacity of 2.32 mm and equipped with a stirrer with double helical blades made of a copolymer resin of slenium and water was used as the first reactor.
A polymerization tank with a capacity of ff12.1 equipped with a Clofford-Russell blade stirrer! The reactor was used as the second polymerization tank, and these were arranged in series. In the first polymerization tank, styrene and maleic anhydride (melted maleic anhydride) were added at 6.395% each.
mol/hr, 0.370 mol/hr, and the polymerization tank temperature was maintained at 128.5 °C. From the bottom of the first polymerization tank, a mixture of partially polymerized copolymer and styrene (styrene conversion rate 38.3%) is continuously fed into the second polymerization tank.
The molten maleic anhydride was fed into a polymerization tank and the molten maleic anhydride was heated to 0.
It was fed at a flow rate of 314 mol/hr.

The temperature of the second polymerization tank was maintained at 141°C. The mixture of copolymer and styrene extracted from the second polymerization tank (styrene conversion rate 66.1%) was treated at 200°C and 30axHg to remove unreacted monomers, and the resulting copolymer ( The maleic anhydride unit content of the copolymer resin was measured and found to be 13.9 mol%.

Also, each ΔM of the first polymerization tank and the second polymerization tank ΔS+ΔM The absolute value of the difference in values was 0.019.

(Manufacturing example 2) Manufacturing example 1
, the amounts of styrene and maleic anhydride supplied to the first polymerization tank were 6.481 mol/hr and 0.3 mol/hr, respectively.
The polymerization temperature was 129° C. and the styrene conversion was 35.8%. Further, maleic anhydride was added to the second polymerization tank at a rate of 0.322 mol/hr, and the polymerization was carried out at a polymerization temperature of 133° C., so that the styrene conversion rate was 59.7%.

Also, ゛ of the 1.2 polymerization tank. ΔM ΔS+ΔM The absolute value of the difference in values was 0.048.

(Examples 1 to 9, Comparative Examples 1 to 6) Styrene-maleic anhydride copolymer resin produced in Production Example 1 (maleic anhydride unit content 13.9 mol%) 100
Predetermined amounts of benzotriazole light stabilizers and hindered amine light stabilizers shown in Table 1 were added to the parts by weight, mixed in a Henschel mixer, and then heated at a temperature of 200°C and rotated using a 4011 single-screw extruder. Pellets were obtained by kneading at several 600 rpm.

Next, a test piece was formed from this pellet using an injection molding machine, and weather resistance and other tests were conducted. The results are shown in Table 1.

(Example 10) Production example 2 as styrene-maleic anhydride copolymer resin
The procedure was carried out in the same manner as in Example 1, except that the sample prepared in Example 1 was used. The results are shown in Table 1.

(Margin below)

Claims (1)

[Claims] (1) (A) Styrene-maleic anhydride copolymer resin 10
Styrene anhydride prepared by adding (B) 0.01 to 1.0 parts by weight of a benzotriazole light stabilizer and (C) 0.01 to 1.0 parts by weight of a hindered amine light stabilizer to 0 parts by weight. Maleic acid copolymer resin composition.