JPS627752A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a composition having excellent weather resistance and keeping high transparency after thermal history, by adding bis(tetra methylpiperidyl) sebacate and a specific benzotriazole compound to an MMA- styrene copolymer resin. CONSTITUTION:(A) 100pts.(wt.) of a methyl methacrylate-styrene copolymer composed of 30-70wt% methyl methacrylate unit and 70-30wt% styrene unit is compounded with (B) 0.02-0.5pts. of bis(2,2,6,6-tetramethylpiperidyl) sebacate and (C) 0.02-0.5pt. of a benzotriazole compound of formula (R1 is H or tert- amyl; R2 is tert-amyl or tert-octyl). The component A is a polymer produced by using tert-butyl peroxy ester, etc., as a polymerization initiator and an unsaturated dimer of alpha-methylstyrene as a chain transfer agent.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a methyl methacrylate (hereinafter referred to as MMA)-styrene copolymer resin (hereinafter referred to as M8 resin) composition that has excellent weather resistance and transparency. More specifically, it relates to an MS resin composition that has excellent weather resistance and transparency after heat history.

(Prior art) Methyl methacrylic resin (hereinafter referred to as PMMA) has been well-known as a resin with excellent transparency and weather resistance, and has been used in large quantities as a material for automobile tail lamp lenses, lighting equipment, signboards, etc. Ta.

However, PMMA has drawbacks such as being expensive, easily eroded by alcohol, and having poor moldability.

On the other hand, styrene resin (
(hereinafter referred to as PS) is known, but its weather resistance is PMM.
It has the disadvantage that it is far inferior to A.

Copolymerization of methyl methacrylate and styrene may be considered as a means of solving the drawback of stiffness, but the copolymer resins obtained in this way generally have weather resistance that is not much better than that of PS. , is still considerably inferior to PMMA, and to date, no MS resin has existed that has weather resistance comparable to that of PMMA.

In addition, as a means to improve the weather resistance of MS resin, %KOKAI Publication No. 133240/1987 describes that MS resin has bis(2,
It has been proposed to add 2,6,6-titramethylbiperidyl) sebaqueto and/or 4-benzoyloxy-2,2,6,6-titramethylbiveridine Z, but The effect of improving properties is not sufficient and the transparency after heat history is poor.

On the other hand, as a means to improve the weather resistance of styrene, MS resins, etc., 2-(5-methyl-2-hydroxyphenyl)benzotriazole-1P2- Although it has been proposed to add hydroxyphenyl-5-chlorobenzotriazole, etc., the effect of improving weather resistance is not sufficient, and furthermore, there is a fatal drawback that transparency is impaired after heat history.

(Problems to be Solved by the Invention) The present invention improves such conventional technology and converts MS resin into PM resin.
As a result of extensive research in order to improve the material to have weather resistance equivalent to or more than 70% as MA and excellent transparency after heat history,
Through the synergistic effect of various specific requirements described below, we have discovered an MS resin composition that has weather resistance equal to or better than that of PMMA in terms of appearance deterioration and good transparency after heat history, and has completed the present invention.

(Means for Solving the Problems) In other words, the present invention is based on 100 parts by weight of a methyl methacrylate-styrene copolymer consisting of 3% to 70% by weight of methyl methacrylate units and 70 to 30% by weight of styrene units. Bis(2,2,6,6-titramethylpipedylyl)
An MS resin resin containing 0.02 parts by weight or more and 0.5 parts by weight or less of sebacate, and 0.02 parts by weight or more and 0.5 parts by weight or less of a benzotriazole compound represented by the following formula CI+. It is a product.

Formula (1) R1: Hydrogen or tart-amyl R2: Tert-amyl or tart-octyl By the way, in MS resin, as the content ratio of MMA increases, the weather resistance and mechanical strength improve ( On the other hand, the moldability and alcohol resistance deteriorate, and the price also increases.If the MMA content ratio exceeds 70% by weight, MS resin is superior to PMMA in terms of moldability, alcohol resistance, and price. On the other hand, as the styrene content ratio Z increases, the moldability and alcohol resistance improve, and the price decreases, but the weather resistance decreases. From the azeodorope composition (MMA ratio - 50 to 55 ft - child%, styrene ratio: 50 to 45 wt%),
Since the transparency of the MS resin decreases, considering these points comprehensively, the ratio of the MMA content is preferably 30 to 70% by weight.

Bis(2,2,6,6-titramethylbiperidyl) sebacate and the benzotriazole compound of formula (I) used in the present invention need to be used in combination. Bis(2,2,6,6-titramethel♂beridyl) sebacate alone has insufficient weather resistance, and the benzotriazole compound of formula (1) alone also has unsatisfactory weather resistance.

The amounts added are as follows, per 100 parts by weight of MS resin.
A ratio of 0.02 to 0.51 is appropriate. If it is less than 0.02 parts by weight, weather resistance will not be imparted sufficiently, and if it is more than 0.5 parts by weight, the effect will be saturated. As for the addition method, conventional means such as kneading into the resin in an extrusion manner and addition in the first finishing step are used.

Examples of compounds represented by formula (1) of the present invention include 2-
(5'-tart octyl-2hydroxyphenyl)
Benzotriazole, 2-(3',5'-tert-
Examples include amyl-7-hydroxyphenyl)benzotriazole and 2-(3'-tertamyl-5'-t-octyl-7-hydroxyphenyl)penztriazole.

Bis(2,2°6.6
-Titramethylbiperidyl) sebacate and the benzotriazole compound of formula (I) are superior not only in their outstanding weather resistance imparting effect, but also in their thermal stability without impairing the transparency of the resin after thermal history. It is important not to reduce the

In this way, the combined use of bis(2,2,6,6-titramethylbiperidyl)sebacate and the benzotriazole compound of formula (1) can be used without reducing the transparency and thermal stability of the MS resin. These are excellent in the effect of imparting weather resistance to MS resin! When added, weather resistance is significantly improved, and PMM
It is possible to obtain MS resin compositions that have the same level of weather resistance as A6.Additionally, when added to a combined MS resin under certain conditions as described below, surprisingly, the appearance It is possible to obtain an Mf3 resin composition that exhibits weather resistance higher than that of PMMA when degraded than YfT.

That is, MS resin combined under specific conditions is MMA
tert-butyl peroxyesters and/or di-t-butylperoxyesters are used as a polymerization initiator, or a monomer mixture consisting of 33 to 703 m% of styrene and 70 to 30 violet styrene, or as a chain transfer agent. It is a resin composition obtained by polymerizing an unsaturated dimer of α-methylstyrene. It is most preferable that the reaction is carried out in the presence of both the polymerization initiator and the chain transfer agent.

It is known that the weather resistance of a resin is greatly affected by trace components present in the resin, and the decomposition products of the initiator and chain transfer agent ultimately remain in the resin as a residue.
Promotes weather resistance deterioration of resin.

The success of the present invention is largely due to the invention of an initiator and a chain transfer agent Z that do not accelerate the weathering deterioration of MI3 resin. In addition, heat 1 using a polymerization initiator is performed and M
Although it is possible to produce S resin, it is industrially disadvantageous because the polymerization rate is slow and the first reaction time is extremely long. Furthermore, if the reaction is carried out without using a chain transfer agent, the molecular weight will increase, making it very difficult to mold the MS resin.

As tart-butyl peroxyester, tert
-butylperoxybivalate, tert-butylperoxy-2-ethylhexanoate, tart-butylperoxyisobuterate, tert-butylperoxy-3,5,5-)limethylhexanoate), tart
-butylperoxyacetate-), tert-butylperoxybenzoate, and the like. Also, Jeter
As t-butyl peroxy ester, g-tert
-butylperoxyhexahydroterephthalate, g-tert -butylperoxyazenate, g-tert
Examples include t-butylperoxytrimethyl adipate.

As an unsaturated dimer of α-methylstyrene,
diphenyl-4-methyl-1-pentene and 1 or 2
- 4-diphenyl-4-methyl-2-pentene, etc.

(Examples) Hereinafter, the present invention will be further explained with reference to Examples, Comparative Examples, and Examples. However, the present invention is not limited by these examples, and there are various embodiments within the scope of the claims. This should be understood.

Note that both parts and percentages are expressed on a weight basis.

Examples, Comparative Examples, and Reference Examples 5 Suspension polymerization was carried out using an isol autoclave under the conditions shown above the first coating.

After 1 cup, cool, take out the polymerization reaction product, and follow the usual method.
The mixture was neutralized, washed with water, dehydrated, and dried to obtain granular compound 1.

To 100 parts of the MS resin obtained in this way, screws (2, 2,
6,6-tetramethyl-4-bilysyl) sebacate (
Sankyo Co., Ltd., Sanol LS770) 0.1 part (Example 1. 2. 3. 6. 7 Comparative Examples 1, 4.5),
0.05 Juice ((Cod Example 4), 0.5 Juice (Examples 5, 8)
), 0.01 part (Comparative Example 2), and as the compound of formula (I), 2-(5'-tert octyl-2' hydroxyphenyl)benzotriazole (Sumithorpe 340 manufactured by Sumitomo Chemical Co., Ltd.) 'Y0 .1 part (Example 1.6.
7, Comparative Examples 2 and 6), 0.05 part (Example 2), 0.
5 parts (Example 4), 0.01 part (Comparative Example 1), 2-(3
0.1 part of ',5'-tertamyl-2'-hydroxyphenyl)penztriazole (Sumisorb 650, manufactured by Sumitomo Chemical Co., Ltd.) (Example 3.5.8).

Also, 2-(5'-methyl-2-hydroxyphenyl)
Benzotriazole (Ciba Gayer Co., Ltd. Ryotinuvin P) 'Y Di part kneaded pellets (Comparative Example 4),
And, pellets without the addition of stabilizer (Comparative Example 6) were prepared.

Pelletization requires a certain amount of stabilizer after tri-blending.
This was carried out using an extrusion model of 43 mmφ.

Next is the Kowara pellets, and for reference, Asahi Kasei stock molding machine 5N.
-51B'4, thickness: 6 mm, height: 3 [1 mm].

A test piece was formed into a flat plate with a width of 50 mm.

These test pieces are manufactured by Sunshine Carbon Weather Meter WEL-SUN-H.
At C, the blank was soaked at 66°C for 120 minutes.
Weather resistance was evaluated by artificially accelerated exposure for 1500 hours under the condition of an 8 minute water shower. Evaluation was performed using the amount of change in yellowness as an index. In other words, the yellowness before exposure is YX
. If the yellowness after 1500 hours of exposure is 1500, then the change in yellowness is △Y=Y=15Qo
Calculated as −Y engineering 0.

The poorer the weather resistance, the larger the value t of ΔY.

After exposure, the test pieces were washed with pure water to avoid scratches on the surface, and then the chromaticity was measured.

Yellowness is measured using a color tone and color difference meter manufactured by Nippon Denshoku Industries Co., Ltd. (C0LORAND 0OLORD FPERFiNO
EMKIR) Model (MODEL) BID-1Q
i Measured using DC.

At the same time, colors were observed with the naked eye. Furthermore, the evaluation results were divided into four levels: A, B, C, and D.

That is, △Y-work≦0.6 beggar A % 0.6ku△Y-work≦1.0 B% 1.0<ΔY-work≦3.0
I assumed that OS5.0<△Y was a beggar. A is P
A load-bearing material with superior weather resistance than MMA. B is a seven-gun type with almost the same resistance to PMIAA. C has poorer weather resistance than PMMA, and is slightly yellowed to the naked eye. D has yellowing that is clearly visible to the naked eye, and A and B can be substituted for PMMA, but O and D
It's impossible (・.

Next, when molding a test piece using the injection bottom molding machine mentioned above, the resin was heated at a cylinder temperature of 230°C for 15 minutes, and then a flat plate was prepared. Molded. The haze of the test piece was measured with and without retention. Measurement is A8TMD
- According to IDO3.

(Effects of the Invention) As explained above, the present invention improves the transparency after heat history when used alone by using two weathering agents in combination with 100 parts of methyl methacrylate-styrene copolymer. It has excellent weather resistance and transparency, with no deterioration, no yellowing, and no synergistic effects.

Patent Applicant Denki Kagaku Kogyo Co., Ltd. Procedural Amendment July 16, 1955 Director General of the Patent Office Michibe Uga 2 Name of the invention Resin composition 3 Person making the amendment Relationship to the case Patent applicant address 1-4-1 Yurakucho, Chiyoda-ku, Tokyo, Claims column and Detailed Description of the Invention column 5, Contents of amendment 1) Percentage of claims The entire scope of the claims will be corrected as shown in the appendix.

2) “Ramethylbipezolyl)sebacate jt-r,ymethylbiperidel)sebacate” on page 5, line 5 of the specification
And, again, on the 10th line, ``Formula ([1 ``Formula (1) Correct.

3) “Stabilizer (2)” on page 14 of the specification, table 1, bottom 2nd line
: ``benzotriazole compound of formula (1)'' is replaced with ``stabilizer (
2) benzotriazole compound of formula (1).''

7-H,l, - Claims [(1) Methyl methacrylate unit 30-70% by weight
and 0.02 to 0.5 parts by weight of bis(2,2,6,6-titramethylbiperidyl) sebacate, per 100 to 100 parts by weight of the methyl methacrylate-stin copolymer containing 70 to 30% by weight of styrene units, and A methyl-styrene methacrylate copolymer resin composition comprising 0.02 to 0.5 parts by weight of a benzotriazole compound represented by the following formula (1).

Formula (1) R1: hydrogen or tert-amyl R2: tert-amyl or tert-octyl (2
) Methyl methacrylate-styrene copolymer is ter
t-Butyl peroxyesters and/or tert
The resin composition according to claim 1, which is obtained by polymerizing t-butyl peroxyesters as a polymerization initiator.

Claims (1)

Scope of Claims: (1) Bis(2,
2,6,6-tetramethylpiperidyl) sebacate 0.
A methyl methacrylate-styrene copolymer resin composition, characterized in that it contains 0.02 to 0.5 parts by weight and 0.02 to 0.5 parts by weight of a benzotriazole compound represented by the following formula (I). Formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ R_1: Hydrogen or tert-amyl R_2: tert-amyl or tert-octyl (2
) Methyl methacrylate-styrene copolymer is tert-
Butyl peroxyesters and/or di-tert-
The resin composition according to claim 1, which is obtained by polymerizing butyl peroxyesters as a polymerization initiator. (3) The resin according to claim 1 or 2, wherein the methyl methacrylate-styrene copolymer is obtained by polymerizing an unsaturated dimer of α-methylstyrene as a chain transfer agent. Composition.