JPH0247145A - Weather resistant impact resistant resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin compsn. having good molding processability and excellent luster, weatherability and impact resistance by compounding a mixture consisting of a styrene resin and a specified oil-extended rubber and a specified hydrogenated diblock copolymer. CONSTITUTION:100 pts.wt. component I an and 7-15 pts.wt. component II are compounded. The component I consists of 10-40wt.% oil-extended rubber obtd. by compounding 90-60wt.% styrene resin (A), 100wt.% ethylene-propylene- nonconjugated copolymer rubber (B) having a Mooney viscosity of 85ML1+4(100 deg.C) or larger and 5-100 pts.wt. process oil (C). The component II consists of a hydrogenated diblock copolymer contg. 60-30wt.% arom. vinyl polymer chains and 40-70wt.% conjugated diene polymer chains wherein 70% or more of the double bonds are hydrogenated and having a number-average MW of 10,000 or larger.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to weather-resistant impact-resistant resin compositions.

More specifically, it has excellent weather resistance and impact resistance, consisting of styrene resin, ethylene propylene non-conjugated diene copolymer rubber (hereinafter abbreviated as EPDM), processing oil, and hydrogenated knob block copolymer. The present invention relates to a resin composition from which molded articles with properties can be obtained.

[Prior Art] Styrenic resin is a non-crystalline general-purpose 744 resin and has many characteristics such as poor moldability and easy coloring. Styrene 1? Molded products obtained from resin have excellent rigidity, mechanical strength, dimensional accuracy, dimensional stability, etc., and are used as housings for electrical equipment, daily necessities, etc. Among these, styrenic resins reinforced with rubber with diene polymers such as polybutadiene, commonly known as high impact polystyrene (hereinafter abbreviated as HIPS), are widely used.

However, HIPS has limitations in its 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 glazing method. For example, it is difficult to sufficiently increase impact resistance. However, when the impact resistance is increased, mechanical properties such as rigidity, tensile strength, and gloss, as well as moldability of the molded product are severely deteriorated.

In addition, the reinforcing rubber used for HIPS production is mainly a diene polymer that has many chemically unstable double bonds in its main chain. is easily deteriorated by ultraviolet rays, ozone, etc.
Deterioration of physical properties and discoloration of appearance may occur.

In order to improve these drawbacks of HIPS, attempts have been made to blend EPDM into styrenic resins. However, styrenic resin and EPDM have poor compatibility, so even if an apparently homogeneous mixture is obtained by simply melting and kneading the two mechanically, this mixture is generally brittle and has low impact resistance, resulting in practical use. It has been difficult to obtain molded products with high commercial value.

For this reason, styrene? 3 (+frt and a of EPDM etc.
- It has been proposed that a specific hydrogenated styrene/conjugated diene block copolymer be blended as a third component as a method to improve compatibility with olefin polymers (
For example, JP-A-46-635, JP-A-54-53
(Refer to Publication No. 159 and Japanese Patent Application Laid-open No. 133544/1983)
. By blending such a third component, it is true that a resin composition in which the styrene resin and the a-olefin polymer are physically dispersed can be obtained. The improvement in impact resistance of the resin composition is still small and insufficient.

In addition, as the applications of molded products using such styrene resin compositions expand and molding technology advances, thinner molded products, that is, molding materials that have both excellent rigidity and impact resistance, are becoming more and more popular. It's starting to be sought after.

As mentioned above, until now, resin compositions of styrene resin and EPDM have combined the excellent properties of both,
Furthermore, at present, no resin material has been obtained that has better mechanical properties such as weather resistance and impact resistance, and moldability than HIPS.

"Problems to be Solved by the Invention" The present inventors have discovered that the above-mentioned intermittency that has conventionally existed in resin compositions of styrene resin and EPDM, 1. The present invention was arrived at as a result of extensive research aimed at solving 'K.

In other words, by blending a specific hydrogenated noblock copolymer with a mixture of styrene resin, specific EPDM, and processing oil, it has good moldability and excellent gloss, weather resistance, and mechanical properties. The object of the present invention is to provide a resin IL composition from which a molded article can be obtained which has significantly improved Izot impact strength and tensile elongation.

[Means for Solving the Problems 1] The gist of the present invention is that styrene-based fat (A)
Ethylene-propylene-nonconjugated diene copolymer rubber (
100 parts by weight of a mixture consisting of 10 to 40% by weight of oil-extended rubber in which the amount of B) is 100 parts by weight and the amount of processing oil (C) is 5-uloO! ! : part, and the content of aromatic vinyl polymer chains is 60 to 30% by weight, and the content of conjugated diene polymer chains in which 70% or more of double bonds are hydrogenated is 40 to 70% by weight. , and 7 to 15 parts by weight of a hydrogenated diblock copolymer (D) having a number average molecular mechanical strength flO,000 or more.
Exists in fat compositions.

The present invention will be explained in detail below.

Styrenic resin (A
) refers to a known styrene-based thermoplastic resin that can be injection molded, and styrene fruit tree* (A) is blended as a resin composition component to improve moldability and rigidity of the resin composition according to the present invention. let

Specific examples of the styrene resin (A) include styrene, a
-Methylstyrene, 1) -1 of aromatic lit'nyl monomers such as methylstyrene, vinyltoluene, vinylnaphthalene, etc.
A polymer obtained by polymerizing a species or two or more monomers,
and a copolymer obtained by polymerizing the above monomers in a ratio of 50% by weight or more and maleic anhydride in a ratio of 50% by weight or less. Among these examples, polystyrene, styrene/a-methylstyrene copolymer, or styrene/maleic anhydride copolymer is particularly preferred.The specific viscosity ηsp of the styrenic resin (A) is In order to improve the impact resistance of objects, it is preferably in the range of 0.1 or more, and particularly preferably in the range of 0.14 or more.

The styrene fruit tree Jflt(A) can be produced by emulsion polymerization, suspension polymerization,
It can be produced by appropriately selecting a method such as a solution polymerization method or a bulk polymerization method from a quarter-part method or a continuous method.

Ethylene-propylene-nonconjugated diene copolymer rubber (B) (hereinafter referred to as EPDM) constituting the resin composition according to the present invention
It is abbreviated as (B). ) means coordination 7 by appropriately combining each component such as ethylene, propylene, and non-conjugated diene.
Manufactured by ionic polymerization with a Mooney viscosity of 85 M
Refers to rubber with a temperature of L++4 (100°C) or higher. This EPDM (B) has the effect of imparting excellent impact resistance when blended into the resin composition according to the present invention.

In order for EPDM (B) to effectively function as an impact resistance imparting material in the resin composition according to the present invention, it is necessary to
The Mooney viscosity of (B) is 85ML.

(100° C.) or above; outside this range, the effect of improving physical properties such as impact resistance of the resulting resin composition will be reduced.

In the present invention, Mooney viscosity refers to JISK6300
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, dicyclopentanoene, and the like. These non-conjugated diene components are usually 0 in EPDM (B).
．． It is preferable to select it so that it is contained 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 manufacturing technology, the solution-type coordination-anion polymerization method may be appropriately selected from batch or continuous methods.

The processing oil (C) constituting the resin composition according to the present invention is:
A petroleum-based softener manufactured by extracting or washing and refining petroleum fractions. By including this processing oil (C) in the resin composition according to the present invention, it has the effect of imparting excellent tensile elongation and impact resistance and improving molding processability.

In order to effectively improve mechanical properties such as tensile elongation and moldability in the mu4 fat composition according to the present invention, the processing oil (C) must contain 6 paraffin carbon atoms.
0 to 80%, naphthene carbon atoms 2O-u40% and aromatic carbon atoms θ to 20%, and at 100°C
Preferably, the viscosity is selected from the range of 1 to 20 centistokes.

In addition, when the resin composition of the present invention is used for food containers, etc., it is preferable to select liquid paraffin for food additives having a composition and viscosity within the above range.6 Oil constituting the resin composition of the present invention Expanded rubber is based on 100 parts by weight of the above EPDM (B) and 5 to 100 parts by weight of processing oil (C).
It refers to a product that is blended in a proportion within the range of parts by weight. Outside this range, the processing properties as an oil-extended rubber will be impaired.
The desired physical properties of the 01 fat composition according to the present invention cannot be obtained.

The mixture constituting the resin composition according to the present invention is a mixture of the above styrene resin (A) in a range of 90 to 60% by weight and the above oil extended rubber in a ratio of 40% by weight. say something The proportions of the above-mentioned components constituting the mixture are preferably 65 to 75% by weight for the styrene resin (A) and 15% to 25% by weight for the oil extended rubber.

If the blending ratio for 2 t1 is out of the above range,
This is undesirable because the physical properties of the resulting resin composition, such as rigidity, impact resistance, and moldability, and the balance of these physical properties are deteriorated.

Each component of the mixture consisting of the above styrene resin (A), EPDM (B) and processing oil (C) is kneaded separately prior to blending with the hydrogenated noblock copolymer (D) described later. However, it is not necessary to knead it in advance, and it is sufficient that it is finally contained in the above-mentioned range in the fat composition according to the present invention.

The hydrogenated diblock copolymer (D) constituting the resin composition of the present invention has an aromatic vinyl polymer chain content of 60 to 30% by weight, and a double bond content of 70% or more. The content of hydrogenated conjugated diene polymer chains is 4O-u70
6-hydrogenated diblock copolymer (D) which is % by weight and has a number average molecular weight of io, ooo or more
exhibits an effect as a compatibilizer that improves the compatibility and oxidation properties of Moeki styrene fruit tree WI (A) and the oil-extended rubber according to the present invention (by incorporating it into the fat composition) do.

The hydrogenated diblock copolymer (D) contains two types of polymer chains, one each in the molecule: an aromatic vinyl polymer chain and a conjugated diene polymer chain.
It is obtained by hydrogenating a block copolymer of type B.

A specific example of the aromatic vinyl polymer chain is a polymer formed by polymerizing one or two types of aromatic vinyl monomers -1- exemplified as the raw material monomers for the styrenic mW(A). An example is a combined chain. Among these, styrene polymer chains are particularly preferred.

Specific examples of the above conjugated diene polymer chain include 1.3-
butadiene, isoprene, 1,3-pentadiene, 2,
3-dimethyl-1,3-butanoene, 3-butyl-1,
Polymer chains formed by polymerizing one or more conjugated dienes such as 3-octanoene and 4-ethyl-1,3-hexanoene, or a mixture of the above conjugated dienes and the above aromatic vinyl monomers. Examples include polymer chains made of Among these, isoprene polymer chains are preferred.

An A-B type block copolymer having both the above-mentioned aromatic vinyl polymer chain and the above-mentioned conjugated diene polymer chain is prepared by appropriately combining an aromatic vinyl monomer and a conjugated diene, and using a known glueing anion method. By continuously copolymerizing! ! can be built.

The hydrogenated block copolymer (D) is a hydrogenated block copolymer (D) in which the conjugated diene polymer chain portion constituting the A-B type block copolymer is suitably selected from known hydrogenation methods and hydrogenation conditions. , can be produced by adding hydrogen. Specifically, for example, there is a method of hydrogenating an AB type block copolymer in a solution state under hydrogen pressure at a reaction temperature of 50 to 250° C. using a metal catalyst.

The hydrogenated diblock copolymer (D) is a conjugated diene polymer in which the content of aromatic vinyl polymer chains is in the range of 60 to 30% by weight, and 70% or more of the double bonds are hydrogenated. The chain content 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 diblock copolymer (D) constituting the resin composition according to the present invention must be in the range of 10,000 or more. If it is out of this range, the compatibility and impact resistance of the resulting resin composition will decrease, so it is preferable -1. In the present invention, the number average molecular weight means , copolymer (D)
It refers to the number average molecular weight of polystyrene dissolved in tetrahydrofane (THF) and measured.

The resin composition according to the present invention comprises the styrene resin (A>
The copolymer is preferably produced by mixing and kneading 100 parts by weight of the mixture consisting of the oil-extended rubber and the hydrogenated diblock copolymer (D) in the range of 7 to 15 parts by weight. If the content of the coalesce (D) is too low outside the above range, the compatibility and impact resistance of the resin composition will tend to decrease, and if it is too high, the rigidity, gloss, etc. of the resin composition will decrease. , have an unfavorable effect on the appearance of the molded product, etc.
+Since the manufacturing cost of the HIM composition increases, it is preferable to keep it within the above range.

Styrenic resin (A), EPDM (B), processing oil (C)
A known mixing method may be used to blend and mix and knead the components of the hydrogenated monoblock co-mallium (D).

For example, these components (A), (B) in powder, bead, seven lake, pellet, block, or liquid form,
A mixture of one or more of (C) and (D) is mixed using an extruder such as Tsumugi Extrusion Iso, Nitsumugi Extrusion Iso, or a kneading machine such as Banbury Mixer-1 Pressurized Neegoo or two rolls. Accordingly, a resin composition can be obtained. In some cases, i'Mi or 2 of these components after polymerization may be
It is also possible to adopt a method in which two or more components are mixed in a liquid or molten state, devolatilized, and kneaded.

The order of this mixing and kneading is that four types of components may be mixed and kneaded at the same time, or one or more of the components may be mixed and kneaded first, and one or more of the components may be mixed and kneaded separately. The desired resin Jl can be mixed and mixed later.
You may grow up.

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

The resin composition according to the present invention includes M class and amounts of lubricants, plasticizers, mold release agents, colorants, ultraviolet absorbers, light resistance stabilizers, heat resistance stabilizers, and flame retardants that do not inhibit the properties of the resin. , fillers, and other various resin hot machining agents 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 impact resistance. can do.

[Effects of the Invention] The present invention has been explained above, and has particularly remarkable effects as described below, and its industrial utility value is extremely large.

(1) The resin composition according to the present invention is a styrenic tH resin (
Since it contains A), EPDM (B), processing oil (C), and hydrogenated diblock copolymer (D), it has excellent weather resistance, impact resistance, and tensile elongation.

(2) The resin composition according to the present invention has good moldability and can yield molded products with excellent gloss and appearance.

(3) The molded article obtained from the resin composition according to the present invention is
It has an excellent balance of impact resistance, tensile elongation, and rigidity.

[Examples] Hereinafter, the present invention will be described in detail 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 and viscosity of the processing oil (C), the composition and hydrogenation rate of the hydrogenated diblock copolymer (D>) , and the weather resistance of the obtained mu (fat composition) is
It was measured by the following method.

Specific viscosity r/sp of styrene resin (A): Prepare a toluene solution (concentration 0.2 g/1001) of resin (A),
The specific viscosity ηs1) 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 (wt%) of the non-conjugated diene component was measured by infrared spectroscopy (IR).

Composition and viscosity of processed oil (C): The composition was measured in accordance with ASTM D-2140 (N, D, M, method). Kinematic viscosity at 100°C was measured in accordance with JIS K-2283.

Composition and hydrogenation rate of hydrogenated diblock copolymer (D): The content of styrene polymer chains (wt%) and the content of hydrogenated isoprene polymer chains (wt%) were determined by infrared spectroscopy ( IR). The hydrogenation rate (%) of hydrogenated isoprene polymer chains was determined by infrared spectroscopy (IR).
It was measured by

Weather resistance: Using a Sunshine Weathermeter (manufactured by Sushi 9 Iso Co., Ltd.), a molded specimen was subjected to a weather resistance test for 400 hours at 43°C, 12 minutes of rainfall, and RF conditions of 60 minutes per cycle. I did it.

As weather resistance, the retention rate (%) of Izot impact strength and the retention rate (%) of 1 tensile elongation before and after the weather resistance test were measured.

In addition, among the constituent components used in the following examples, styrene fruit tree jilt (A) is shown in table fjS1, and EPDM (B
) is in the m2 table, processing oil (C) is in the fIS3 table, and the above EP
The oil-extended rubber (R) obtained by blending DM (El) with the processing oil (C) described in 1. is shown in Table 4, and the hydrogenated diblock copolymer (D> is shown in Table m5). Described.

Example 1-u14, Comparative Examples 1 to 12 Styrenic resin (A) listed in Table 1, oil extended rubber (R) listed in Table 4 (E PDM (B), processing oil (C) ) and the hydrogenated noblock copolymer (D) listed in Table 5 were weighed according to the formulation (heavy weight part) listed in Table 6, mixed in a tumbler, and the resulting mixture was mixed. Nitsumugi extruded rock (manufactured by Plastic Engineering Research Institute, BT-40)
Schilling temperature: 180°C, rotation speed: 150
It was extruded under the conditions of rpm and pelletized.

A test piece for measuring physical properties was molded from a pellet of this resin composition by injection molding under conditions of a Schilling temperature of 210°C and a mold temperature of 40°C. Izot impact strength, tensile elongation, flexural modulus, gloss (reflectance), and weather resistance (retention rate) were measured for each molded test piece.

The results are shown in Table 6.

Table Note: Ning G Measured in accordance with JIS K6300.

Table 3 Kitamoto 2: N, D, as described in ASTM D-2140
M, Measured in accordance with the law.

Kyo 3: Compliant with JIS K 2283, 10
0°C fi, 7) Measurement of kinematic viscosity.

Table Comparative Example 13 HI PS (containing about 7% by weight of polybutadiene rubber: Mitsubishi Monsanto Chemical Co., Ltd., Dialex" I-I
T-88D) was molded into a test piece for measuring physical properties by injection molding according to the same procedure as described in Example 1. Regarding the molded test pieces, Izot impact strength, tensile elongation, flexural modulus, gloss (reflectance), and V weather resistance (
retention rate) was measured.

The results are shown in Table 6. Book 4: Book 5: The hydrogenation rate measured by infrared spectroscopy was 98% by weight.
That's all.

It is a polystyrene conversion number average molecular weight measured using GPC.

As shown in Table 6, the following becomes clear.

(1) The resin composition according to the present invention has excellent weather resistance (see Example 1.2), tensile elongation and impact resistance (Example 1-2).
(see Li 14).

On the other hand, HIPS which is outside the scope of the present invention (see Comparative Example 13) has poor weather resistance, and resin compositions which are outside the scope of the present invention have low impact resistance (Comparative Example 1.2.4.5. 6.7.9
．． (see 12.13).

(2) Molded articles obtained from the +31 fat composition according to the present invention have excellent gloss (see Example 1.2).

(3) Molded articles obtained from the Ju-111 composition according to the present invention have an excellent balance between impact resistance and rigidity (see Examples 1 to 14).

On the other hand, resin compositions obtained outside the scope of the present invention are significantly inferior in impact resistance, tensile elongation, or rigidity (see Comparative Example 1'u13).

Claims (1)

[Scope of Claims] Styrenic resin (A) 90 to 60% by weight and ethylene-propylene-nonconjugated diene copolymer rubber (B) having a Mooney viscosity of 85ML_1_+_4 (100°C) or more
100 parts by weight of a mixture consisting of 10 to 40 parts by weight of oil-extended rubber, containing 100 parts by weight of (100 parts by weight) and 5 to 100 parts by weight of processing oil (C), and containing 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 to 70% by weight, and the number average molecular weight is 10,000 or more. A weather-resistant and impact-resistant resin composition comprising 7 to 15 parts by weight of a hydrogenated diblock copolymer (D).