JPH032244A - Weather resistant impact resistant resin composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition, composed of a styrene-based resin, crosslinked ethylene.propylene.nonconjugated diene terpolymer rubber and hydrogenated diblock copolymer, having excellent weather and impact resistance and capable of providing molded products excellent in physical properties of welded parts. CONSTITUTION:The objective composition containing (A) 100 pts.wt. mixture composed of (i) 90-60wt.% styrene-based resin and (ii) 10-40wt.% rubber blend composed of 74-99.5 pts.wt. ethylene.propylene.nonconjugated diene terpolymer rubber having >=50ML1+4 Mooney viscosity (100 deg.C), 0.5-6 pts.wt. organic peroxide and 0-20 pts.wt. polyfunctional monomer and (B) 5-15 pts.wt. hydrogenated diblock copolymer having 60-30wt.% content of aromatic vinyl polymers, 40-70wt.% content of conjugated diene-based polymer chain with hydrogenated >=70wt.% double bonds and >=10000 number-average molecular weight.

Description

[Detailed description of the invention] [Industrial Application Field J The present invention relates to weather-resistant impact-resistant resin compositions.

More specifically, styrene resin, cross-linked ethylene/propylene-nonconjugated diene copolymer rubber (hereinafter referred to as EP
It is abbreviated as DM. ) and a hydrogenated diblock copolymer, the present invention relates to a resin composition from which a molded article having excellent weather resistance and impact resistance and excellent physical properties in the weld area can be obtained.

``Prior art'' Styrenic resin 1 is an amorphous general-purpose resin with many characteristics such as excellent moldability and easy coloring. Molded products have excellent rigidity, mechanical strength, dimensional accuracy, dimensional stability, etc., and are used as hatchings for electric Wi-Fi appliances, daily miscellaneous goods, etc.In particular, molded products are reinforced with rubber using diene polymers such as polybutanoene. Styrenic resin, commonly known as high impact polystyrene (hereinafter abbreviated as HIPS), is widely used.

However, HIPS has limitations in physical properties such as mechanical strength due to its physical structure such as the amount of rubber compounded and the dispersed rubber particle size, as well as its manufacturing method.For example, it is difficult to sufficiently increase impact resistance. Moreover, when impact resistance is evaluated, the rigidity, tensile strength, and gloss of the molded product are significantly reduced.

In addition, the reinforcing rubber used for HIPS production is
Since it is mainly a diene polymer that has many chemically unstable double bonds in its main chain, I (IPS) using a diene polymer is It is easily deteriorated, resulting in deterioration of physical properties and discoloration of appearance.

In order to improve these drawbacks of HIPS, attempts have been made to blend EPDM with styrene 1A1 (fat). However, since styrene resin and EPDM have poor compatibility, it is difficult to simply melt them together mechanically. Appearance after kneading
F Even if a homogeneous mixture was obtained, this mixture was generally brittle and had low resistance**, making it difficult to obtain a molded article with high practical value.

Therefore, as a method to improve the compatibility between styrenic resins and a-olefin polymers such as EP[)M, a specific hydrogenated styrene/conjugated diene block copolymer is used as a third component. It has been proposed to mix (for example, JP-A-46-635, JP-A-54-5315
9, Japanese Patent Application Laid-open No. 133544/1983). If such fjS3 component is blended, the styrene resin and α-olefin polymer will certainly be physically dispersed.
(Although a resin composition can now be obtained, even with such a method, the improvement in WJw resistance of a resin composition composed of these three components is still small and insufficient. For this reason, styrene, (By blending a specific hydrogenated diblock copolymer with a mixture consisting of fat and specific EPDM, it has good moldability, excellent gloss, weather resistance, and 1l111 mechanical properties, including notched It is known that a four-fat composition with improved Ni1 strength can be obtained (see Japanese Patent Application No. 63-14845).

However, when molding such a resin composition,
A weld is formed inside the molded product when the resin in a fluid state joins together (a weld line is formed on the surface of the molded product).
In this weld area, each compounded component separates or becomes oriented, resulting in a significant decrease in mechanical properties, which may cause practical problems.

In addition, with the expansion of applications for molded products using such styrene IA resin compositions and the advancement of molding technology, it is possible to create thinner molded products that have both excellent rigidity and impact resistance, and that have a thinner weld area. There is an increasing demand for molding materials with excellent physical properties.

As mentioned above, until now, styrenic resins and EPDM II (TIIt compositions) have been developed that combine the excellent properties of both, but also have superior weather resistance and impact resistance compared to IP S. At present, no resin material has been obtained.

[Problem to be Solved by the Invention 1] The present inventors aimed to solve the following drawbacks that have conventionally existed in 01 resin compositions of styrene resin and EP[)M. As a result of extensive research, we have arrived at the present invention.

In other words, styrene-based 0 (fat, a rubber compound made by blending a specific EPDM, an organic peroxide, and a polyfunctional monomer,
and a specific hydrogenated Novronc copolymer to provide a resin composition that provides a molded article with excellent gloss, weather resistance, and mechanical properties, and with improved physical properties in the weld area. .

[Means for Solving the Problems] The gist of the present invention is that styrene-based 0 (fat (A)
Ethylene-propylene-non-conjugated diene copolymer rubber (86-60% by weight and Mooney viscosity of 50ML1+4 (100°C) or higher)
B) 74-99.5 parts by weight, organic peroxide (C) 0.
5-56 Ft parts and polyfunctional monomer (D) 0.\-
Rubber compound (R) 10-. 4
100 parts by weight of a mixture consisting of 0% by weight, and the content of aromatic vinyl polymer chains is 60-=, 30% by weight, containing a conjugated diene polymer chain in which 70% or more of the double bonds are hydrogenated. hydrogenated diblock copolymer (E) having a weight ratio of 40.570% by weight and a number average molecular weight of 10,000 or more 1-, 5-=, 15rn parts. A weather-resistant and impact-resistant resin composition characterized by:

The present invention will be explained in detail below.

Styrenic resin (A
) refers to a known styrenic thermoplastic resin that can be injection molded. The styrene resin (A) is blended as a component of the 01 resin composition to improve moldability and rigidity of the resin composition of the present invention.

Styrene M? Examples of JF resins (A) include polymers of one or more monomers of M group vinyl monomers such as styrene, a-7 tylstyrene, p-methylstyrene, vinyltoluene, and vinylnaphthalene. and (2) a copolymer obtained by polymerizing the monoelectric material described above in a ratio of 50 weight % or more and maleic anhydride in a ratio of 50 weight % or less. Among these examples, polystyrene, styrene α-methylsnarene polymer, styrene, styrene, and maleic anhydride copolymer are particularly preferred (1° specific viscosity of styrene resin (A) η31). is the present invention +j
In order to improve the impact resistance of the 1-fat composition, it is preferably in the range of 0.1 or more, and particularly preferably in the range of 0.14 or more.

For example, the styrene resin (A>) is produced by selecting an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, a bulk polymerization method, etc., as appropriate from batch or continuous methods, in accordance with known styrenic resin manufacturing techniques. can be manufactured.

In the present invention, ethylene, which constitutes the rubber compound (R),
Propylene/non-conjugated diene copolymer rubber (B) (hereinafter referred to as
It is abbreviated as EPDM(B). , ) is manufactured by appropriately combining each component such as ethylene, propylene, and a non-conjugated diene, and is produced by distribution anionic polymerization, and has a Mooney viscosity of 50 M 1. , 1+-(100°C) or higher. This EP[)M(B) is based on the present invention 0 (EPDM(B), which has the effect of dispersing to form rubber particles and imparting excellent impact resistance by blending it with a fat composition). In order for the resin set according to the invention to effectively function as an impact resistance imparting material in cloth +41, it is necessary to
The Mooney viscosity of PDM (B) is 50 ML, ÷
The Mooney viscosity of EPDM (B) must be selected from a range of 100" C) or higher. If it is outside this range, the effect of improving physical properties such as impact resistance of the fat composition will be reduced. The Mooney viscosity of EPDM (B) is 85・Su150ML, Ya.

(100°C) is preferable from the viewpoint of improving physical properties.

In the present invention, Mooney viscosity refers to JIS KG300
Mooney viscosity of unvulcanized rubber measured in accordance with

Specific examples of the nonconjugated diene that is a component of the EPDM (B) include ethylidene norbornene, 1,4-hexanoene, nonclopentanoene, and the like. These non-conjugated diene components are usually 0 in EPDM (B).
．． Preferably, the content is selected to be in the range of 1"-20% by weight.

The polymerization method and polymerization conditions for EPDM (B) are the well-known E
Depending on the PDM production technology, the solution-type distributed anionic polymerization method may be appropriately selected from batch or continuous methods.

In the present invention, the peroxide (C) that constitutes the rubber compound (R) refers to 7-syl peroxide, alkyl peroxide, peroxide ester, and hydroperoxide used as a polymerization initiator or crosslinking agent. refers to organic peroxides such as

This organic peroxide (C) crosslinks the EPDM (r3) rubber particles dispersed in the resin composition of the present invention, stabilizes the dispersion, and improves the physical properties of the weld part of the molded article obtained from the resin composition. The organic peroxide (C) in the present invention is preferably one having a half-life of 1 minute and a decomposition temperature in the range of 150'=230°C. Outside this range, the E in the resin composition
PDM (B) may cause a crosslinking reaction while being poorly dispersed, or the crosslinking reaction may not be sufficiently developed.

Specific examples of the organic peroxide (C) include di-t-butyl peroxide, t-butylcumyl peroxide, 1-dicumyl peroxide, 2.5-methyl-2,5
-no(t-butylperoxy)hexane, t-butylperoxy3.5.5-)tumethylhexanoate, L
-butylperoxylaurate, t-butylperoxyacetate, 2,2-bis(t-butylperoxy)octane, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, and the like.

These may be used alone or in combination of two or more.

In the present invention, the polyfunctional monomer (D) constituting the rubber compound (R) refers to a monomer that has two or more 1-vinyl bonds in the molecule and can chemically bond with EPDM (B). say. This polyfunctional monomer (D), together with the organic peroxide (C), crosslinks the rubber dipper of EPDM (B), improves the dispersibility of rubber particles, and improves the molded product obtained from the resin composition. This has the effect of improving the physical properties of the weld portion.

Specific examples of the polyfunctional monomer (D) include divinylbenzene, noaryl 7-thalet, 1,4-butanol diacrylate, 1,6-hexaneol no acrylate, polyethylene glycol no methacrylate, 1
．． Examples include 3-butylene glycol no methacrylate, triallyl isocyanurate, triallyl trimellitate, and the like.

These may be used alone or in combination of two or more.

The rubber compound (R) constituting the resin composition according to the present invention includes 74 to 799.5 parts by weight of the above EPDM (B),
The above organic peroxide (C) is placed in 0.5 parts, (The total amount of D> is io.

It refers to a product that is blended within the range of 6) expressed as parts by weight.

If the blending ratio of these three components is out of the above range, the rubber particles of EPDM (B) in the resulting resin composition will not be sufficiently crosslinked, and the physical properties or molding processability of the weld part of the resin composition will deteriorate. This is not preferable because it lowers the temperature.

The above three components are preferably kneaded in advance before being blended with the styrene-based fat (A) and the hydrogenated diblock copolymer (E) described later, but they do not necessarily need to be kneaded. , in the resin composition of the present invention, finally.
- It is sufficient if it is contained in the range shown below to cause the rubber particles to undergo a crosslinking reaction.

The mixture constituting the resin composition of the present invention includes 9 ()...60% by weight of the styrenic resin (A) listed in (1) and 10'40% by weight of the rubber compound (R) listed in (1). It refers to a product that is blended in a proportion within the range of. Preferably, the ratio of each component listed in I-1 constituting the mixture is 8 to 8 styrenic 01 fat (A).
Rubber compound (R) with a range of 5 to 775% heavy European 15 to 2
The range is 5%.

If the blending ratio of the two components is out of the range specified in 1-1, it is not preferable because the physical properties such as the stiffness, impact resistance, or moldability of the obtained resin composition, and the balance of these physical properties will deteriorate.

The hydrogenated diblock copolymer (E) constituting the O (fat composition) according to the present invention refers to the content of M aromatic vinyl polymer, which has a content of 60 to 30% and a double bond content of 70%. 1] has a hydrogenated conjugated diene-based combined chain content of 40-
It is 770 double phrases, and the number average molecular door is 10,00.
Refers to something that is 0 or more. The hydrogenated diblock copolymer (E) can be added to the present invention O (by blending it into the fat composition,
It is effective as a compatibilizer that improves the compatibility between the styrene-based O (fat (A)) and the rubber compound (R) and the dividing property.

The above hydrogenated Nopronk copolymer (E) is an A-B type containing two types of polymer chains consisting of a yfh group bivinyl polymer chain and a conjugated diene lrf< polymer chain, one each in the molecule. It can be obtained by hydrogenating the bronc copolymerization.

Specific examples of the aromatic vinyl polymer chain include polymer chains obtained by polymerizing one or more of the aromatic vinyl monomers exemplified as single raw materials for the styrenic resin (A). It will be done. Among these, styrene polymer chains are particularly preferred.

Specific examples of the conjugated diene polymer chain described in l are 1.3-
Butanoene, isoprene, 1,3-pentadiene, 2.
3-methyl-1,3-butadiene, 3-butyl-1,
One type of conjugated diene such as 3-octadiene, 4-ethyl-ll3-hexanoene or 2M! Examples include a polymer chain formed by polymerizing the following, or a polymer chain formed by polymerizing a mixture of the conjugated noene described in I and the above-mentioned aromatic vinyl monomer. Among these, isoprene polymer chains are preferred.

The AB type block copolymer having both the above aromatic vinyl polymer chain and the above conjugated diene polymer chain is obtained by appropriately combining an aromatic vinyl monomer and a conjugated diene,
It can be produced by successive copolymerization using a well-known laminating anion vehicle method.

The hydrogenated Novlonc copolymer (E) is obtained by adding a hydrogenation method and hydrogenation conditions appropriately selected from known hydrogenation methods and hydrogenation conditions to the conjugated diene polymer chain portion constituting the A-B type block copolymer described in 1-. It can be produced by adding hydrogen. Specifically, for example, an A-B type block copolymer is prepared in a solution state under hydrogen pressure at a reaction temperature of 50 to 250°C.
An example of this is a method of hydrogenation using a metal catalyst.

The hydrogenated block copolymer (E) has an aromatic vinyl polymer chain content in the range of 60...30%, and 70% or more of the double bonds are hydrogenated. The content of the conjugated diene polymer chains is in the range of 40 to 70% by weight. If it is outside these ranges, the physical properties of the resulting resin composition will deteriorate, which is not preferable. The number average molecular weight of the hydrogenated knobloc copolymer (E) constituting the resin composition of the present invention must be in the range of 10.000 or more. Outside this range, the compatibility and impact resistance of the resulting O(fat composition) decreases, which is not preferable.

In the present invention, the number average molecular weight refers to the polystyrene conversion number average measured by dissolving the copolymer (E) in tetrahydro 7 run (TtlF) using (iPC (150-C, manufactured by Water Taisha)). It refers to molecular clearness.

The resin composition according to the present invention includes the styrene u+A4II
Mixture 100 consisting of W (A) and the rubber compound (R)
It is preferable to produce by mixing and kneading parts by weight of the above-mentioned hydrogenated diblock monomer (E) within the range of 5.sup.15-fold single crystal. If the content of the copolymer (IE) is too small outside the above range, the compatibility and impact resistance of the 31 fat composition tend to decrease; if it is too high, the stiffness of the fat composition It is preferable to keep the amount within the above range since the gloss level etc. will be lowered and this will have an unfavorable effect on the appearance of the molded product.

Blending each component of styrenic O (fat (A), EPDM (B), organic peroxide (C), polyfunctional monomer (D), and hydrogenated diblock copolymer (E), For mixing and kneading, it is preferable to use the following mixing method.

That is, first, these MII component components (B),
A mixture of the two types 1- of (C) and (D) is produced in a -axial extruder,
Extruders such as twin-screw extruder, Makoha, Banbury mixer
A rubber compound (R) is prepared using a kneading machine such as a pressurized kneading machine or a two-roll kneading machine. At this time, the mixing and kneading temperature is preferably the decomposition temperature of the organic peroxide (D) for one half-life, specifically about 130°C or less. -1- When the crosstalk temperature is higher than this decomposition temperature, EP[
3M (r'3) is crosslinked, I (EPDM in the fat composition)
It becomes difficult to disperse (B) well as rubber particles.

Styrenic rubber (fat (A), rubber compound (R),
The hydrogenated noblock copolymer (E) may be blended and a known mixing method may be used. During this mixing and kneading, in order to disperse and crosslink the rubber compound (R) well in the resin composition, it is preferable to mix and knead at a mixing temperature in the range of 150 to 7270°C. By repeating this mixing process, EPDM (B) is dispersed in the rubber ladle and cross-linked at the same time, while the organic peroxide (C) and polyfunctional monomer (D) undergo a decomposition reaction. and virtually disappear.

The O(fat composition) according to the present invention can be used as it is for molding, etc. In addition, other thermoplastic resins, such as
It can be mixed and kneaded with polymethyl methacrylate, polycarbonate, polyamide, polybutylene terephthalate, polyphenylene oxide, thermoplastic polyurethane, etc., and used as a weather-resistant, WJ impact-resistant resin.

The O(fatty composition) according to the present invention includes lubricants, plasticizers, mold release agents, colorants, ultraviolet absorbers, light resistance stabilizers, heat resistance stabilizers, and hardening agents in types and amounts that do not impair the properties of the resin. Various additives such as fuel agents and fillers can be added in appropriate combinations.

The O(fat composition) according to the present invention is made into a desired molded product by various processing methods such as injection molding, extrusion molding, and compression molding, and is used in applications that require excellent weather resistance and 11g7 impact resistance. can do.

[Effects of the Invention] The present invention is as described in 1-1 below, and has the following particularly remarkable effects, and its utility value in industry 1- is extremely large.

(1) The O (fat introduction product) according to the present invention is a styrene resin (
A), crosslinked EPDM, t; and hydrogenated noblock copolymer (E), so it has excellent weather resistance and impact resistance.

(2) The resin composition according to the present invention has good molding processability, has excellent gloss and appearance, and can yield a molded article with improved physical properties in the weld area.

(3) The molded article obtained from the resin composition according to the present invention is
It has an extremely good balance between impact resistance and rigidity.

[Example-1 Hereinafter, the present invention will be specifically explained based on Examples and Comparative Examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

In addition, in the following examples, the specific viscosity of the styrenic resin (A), the composition of EPDM (B), the composition of the hydrogenated knob-tsuku copolymer (E), the hydrogenation rate, and the resulting mussel (fat composition) The tensile strength and weather resistance of the weld part of the product were measured by the following method.

Styrenic rubber (specific viscosity of fat (A) ηSp: 01 fat (A)
toluene solution (a degree 0.2 [1/10 (11)
was prepared, and the specific viscosity ηSll was measured using a Cannon-Fenske type capillary viscometer in a constant temperature bath at 25°C.

Composition of EPDM (B): Content of ethylene component and propylene component (wt%)
was measured by nuclear magnetic resonance (NMR), and the content (% by weight) of the non-conjugated diene component was measured by infrared spectroscopy (IR).

Composition and hydrogenation rate of hydrogenated block copolymer (E): The content of styrene polymer chains (%) and the content of hydrogenated isoprene polymer chains (% by weight) were determined by infrared spectroscopic analysis. It was measured by the method (IR). The hydrogenation rate (%) for aqueous added isoprene weight bodies was determined using infrared spectroscopy (IR).
It was measured by

Tensile strength of weld part: Injection molding was performed by providing two dates at both ends of the test piece mold so that the weld line was at the center of the test piece. The tensile strength of the weld portion of the obtained test piece was measured in accordance with JIS K7113.

In addition, in accordance with JIS K7113, for test pieces made by injection molding υ (fat composition with one date),
Tensile strength was measured.

The ratio of these two tensile strengths was defined as the specific strength in the tensile test of the weld portion.

Weather resistance: Sunshine Weather, Meter (Sushikeniso Co., Ltd.)
43°C, 12 minutes of rain, 1 cycle of 60
The molded specimens were subjected to a 100 hour weathering test under conditions of 100 minutes.

As for weather resistance, Aijino fl) before and after weather resistance test
i! The strength retention rate (%) was measured.

In addition, among the constituent components used in the following examples, styrene O (fat (A) is listed in Table 1 (E P r) M
(B) is in Table 2, organic peroxide (C) is in Table 3, polyfunctional monoelectric material (D) is in fjS4 table,
13), the above organic peroxide (C), and the polyfunctional toner (D) described above, the rubber compound (R) is shown in Table 5.
The names, compositions, properties, etc. of the hydrogenated noblock copolymers (E) are listed in Table 6.

Example 1' 10, Comparative Example 5 The combined (E) was weighed at the composition ratio (critical part) listed in Table 7, mixed in a tumbler, and the resulting mixture was subjected to twin screw extrusion 81 (manufactured by Plastic Engineering Research Institute, model BT-40). Schilling-temperature 12;0° using
It was extruded and pelletized at a C1 rotation speed of 15 (1 rlon). The B-iso peroxide (C) in the pellet was reacted and decomposed during this pelletizing process.

A test piece for measuring physical properties was molded from this resin composition by injection molding under conditions of Schilling temperature of 215°C and mold temperature of 40°C. Regarding the molded test piece, Izot impact strength, tensile strength, tensile strength of 11 wells, and weather resistance (retention rate) were measured.

The results are shown in Table 7.

Book 1: l5 Measured according to K6300.

PISl Table Table 7 makes it clear about dogs.

(1) Since the resin composition according to the present invention crosslinks EPDM (B), it exhibits excellent specific strength of the weld portion (see Example 10).

On the other hand, resin compositions outside the scope of the present invention have low specific strength at the weld portion (see Comparative Example 5).

(2) The resin composition according to the present invention has an excellent balance of physical properties such as impact resistance, physical properties of the weld part, weather resistance, and moldability (see Example 1 to 10).

Applicant: Misara Monsanto Kasei Co., Ltd.

Claims (1)

[Claims] Styrenic resin (A) 90 to 60% by weight and ethylene/propylene/non-conjugated diene copolymer rubber (
B) 74 to 99.5 parts by weight, organic peroxide (C) 0.5
100 parts by weight of a mixture consisting of 10 to 40 parts by weight of a rubber compound (R) formed by blending ~6 parts by weight and 0 to 20 parts by weight of a polyfunctional monomer (D), and an aromatic vinyl polymer chain The content of conjugated diene polymer chains in which 70% or more of the double bonds are hydrogenated is 40% by weight.
~70% by weight, and the number average molecular weight is 10,00
0 or more hydrogenated diblock copolymer (E) 5-1
5 parts by weight of a weather-resistant and impact-resistant resin composition.