JPH0267308A - Manufacture of graft copolymer - Google Patents

Abstract

PURPOSE:To stably produce a graft copolymer excellent in impact resistance, heat stability, etc. and suitable for automobile parts, etc., by graft-polymerizing a vinyl monomer onto an ethylene-alpha-olefin copolymer rubber, which is crystalline and powdery, by the aqueous suspension method. CONSTITUTION:An ethylene-alpha-olefin copolymer rubber which is crystalline and powdery and has preferably an ethylene content of 40-90wt.% and a crystalinity of polyethylene of 1-20% measured by DSC (e.g. ethylene-propylene copolymer rubber) in prepared. A vinyl monomer (e.g. styrene or acrylonitrile) is graft-polymerized onto the ethylene-alpha-olefin copolymer rubber by the aqueous suspension method, thereby producing a graft copolymer. The graft polymerization reaction is preferably effected above the melting temperature of the ethylene-alpha-olefin copolymer rubber crystal.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a graft copolymer having excellent impact resistance and heat resistance stability, and a method for producing the same.

<Prior Art> Impact resistant resins (ABS resins) have been known in which diene rubber is copolymerized with styrene and acrylonitrile. Weather-resistant and impact-resistant resins (AES resins) using ethylene-propylene-diene copolymer rubber (EPDM) as a rubber component are also known.

Among these resins, ABS resins are generally manufactured by emulsion polymerization, and AES resins are manufactured by solution polymerization.

<Problem to be Solved by the Invention> In recent years, there has been a strong demand for improving the heat resistance of these resins, and methods using polymer alloys or various copolymerization techniques are being investigated.

However, since ABS resin uses diene-based rubber as a rubber component, its thermal stability is low, and its application range is narrow due to phenomena such as burning (coloring) and deterioration of physical properties during high-temperature molding. It has become.

On the other hand, ABS resin uses ethylene-propylene-diene copolymer rubber (EPDM) as a rubber component, so it has high heat resistance and heat resistance stability. Since the polymerization method for AES is generally considered to be a solution polymerization method (Japanese Patent Publications No. 48-18118, No. 52-18751, No. 52-30549, No. 5)
No. 2-30994, No. 52-30995, Japanese Unexamined Patent Publication No. 1973
-61492, 54-94596, 56-50
No. 906). However, the solution polymerization method is economically disadvantageous because it requires separation and recovery of the produced polymer from the solution, purification and recycling of the melt. Also, EPD
Since M is completely amorphous, its strength is low, and impact resistance cannot be achieved unless the degree of crosslinking of the rubber part is increased, and for this purpose it is necessary to introduce a large amount of diene component as a comonomer. This will lead to an increase in economic costs.

Regarding the polymerization method of AES, bulk polymerization (Special Publication
6-33571), bulk suspension polymerization (Japanese Patent Publication No. 48-32
No. 434, No. 49-14874, No. 49-25189
No.), suspension polymerization (Japanese Patent Publication No. 49-10831, Japanese Unexamined Patent Publication No. 4
8-80189), emulsion polymerization (Japanese Patent Publication No. 1639-1989),
Although attempts have been made to find economically more advantageous methods such as EPDM (No. 4, No. 48-35718), because of the low solubility of EPDM in monomers, the rubber concentration is low when performing bulk polymerization. There are problems in that it is impossible to increase the polymerization rate, or the viscosity increases during bulk polymerization, making it difficult to remove heat and making it difficult to polymerize stably. Regarding suspension polymerization, pulverizing completely non-quality EPDM is a major factor in increasing costs, and completely amorphous EPDM cannot be obtained in powder form without mutual adhesion. In order to create a uniform dispersion state, complicated steps such as suspending the solution (Japanese Patent Application Laid-Open No. 17895/1982) have to be taken, and this has not been successful.

Means for Solving the Problems> Under these circumstances, the present inventors have developed an ethylene-α olefin copolymer rubber that is a raw material for a graft copolymer, which has crystallinity and is in powder form. It has been discovered that a graft copolymer with excellent properties can be obtained by using the ethylene-α-olefin copolymer rubber shown in FIG. The inventors have also discovered that it is possible to stably carry out suspension polymerization by carrying out aqueous suspension polymerization in the presence of a dispersant, and have arrived at the present invention.

That is, the present invention is a graft copolymer having an ethylene-α-olefin copolymer rubber as a backbone polymer, and the ethylene-α-olefin copolymer rubber used as a raw material has crystallinity and is in powder form. A method for producing a graft copolymer is provided.

Here, in graft polymerization, it is difficult to bond all of the monomers to the ethylene-α-olefin copolymer rubber by a graft reaction, and an ungrafted copolymer is produced as a by-product. Not only true graft copolymers from which ungrafted copolymers have been actively separated, but also those that still contain ungrafted copolymers are treated as graft copolymers.

(Structure of the Invention) a) Ethylene-α-olefin copolymer rubber The ethylene-α-olefin copolymer rubber used in the present invention is obtained by copolymerizing ethylene and α-olefin, and has crystallinity. Moreover, it is an ethylene-α olefin copolymer rubber that has powder properties.

Here, α-olefins used in the production of ethylene-α-olefin copolymer rubber include α-monoolefins having at most 12 carbon atoms, such as propylene, butene-1,4-methylpentene- Examples include 1, hexene-1 and octene-1, but propylene and phthene-1 are preferably used.

The ethylene-α-olefin copolymer rubber used in the present invention is a crystalline ethylene-α-olefin copolymer rubber, and because it has crystallinity, it is difficult to maintain powder properties without mutual adhesion. In addition, it is easy to exhibit the high strength and impact resistance of rubber. Furthermore, it is preferable to use a material having polyethylene crystals. Here, the ethylene-α-olefin copolymer rubber that has polyethylene crystals has good crosslinking properties during graft polymerization, even though it is an ethylene-α-olefin copolymer rubber that does not have a diene component. The gel fraction of the graft copolymer is quite high, making it possible to obtain a graft copolymer with high impact resistance.

The ethylene content in the ethylene-α olefin copolymer rubber is usually 40 to 90% by weight, more preferably 55 to 85% by weight. If the ethylene content is less than 40% by weight, there will be no polyethylene crystals, resulting in a sticky copolymer that sticks together and becomes lumpy, making it impossible to obtain a copolymerized rubber in powder form. Therefore, the workability and economical efficiency during production of the graft copolymer are lowered, and at the same time, the degree of crosslinking of the graft copolymer is lowered. In addition, when the ethylene content exceeds 90% by weight, the obtained ethylene
The α-olefin copolymer rubber becomes hard, and as a result, the resistance of the graft copolymer finally obtained is high! It will no longer be a sufficient impact force.

Another important factor is the ratio of polyethylene crystals in the ethylene-α-olefin copolymer rubber. This polyethylene crystallinity is determined by the heat of fusion of polyethylene crystals ((al/g) measured by DSC (scanning differential calorimetry), and the heat of fusion of 100% polyethylene crystals is 68.5 (cal/g). ).Here, the crystallinity of the polyethylene in the ethylene-α olefin copolymer rubber is preferably 1 to 20%, preferably less than 1%. As a result, it becomes a sticky copolymer, which makes it impossible to maintain a slurry state during the 1-polymerization reaction, and it sticks to each other and forms a lump.
Since it is no longer possible to obtain copolymerized rubber in powder form, the workability and economic efficiency during the production of graft copolymers are reduced.

The degree of crosslinking of the graft copolymer will be reduced. 20
If the degree of crystallinity exceeds 10%, the obtained copolymer rubber becomes hard and the impact resistance of the finally obtained graft copolymer is no longer sufficient.

Here, the term "powder-like" refers to a powdery state with an average particle size of 1000 gm or less. It is preferable to use polymerized rubber as it is.

Crystalline and powdery ethylene-α olefin J (
JP-A-57-1792 as a suitable method for producing polymerized rubber
An example shown in Publication No. 07 can be cited. According to this method, ethylene and α-olefin are copolymerized in a slurry state in a saturated or unsaturated hydrocarbon having carbon atoms of 4 or less at a reaction temperature of 50°C or less in the presence of a Ziegler type catalyst. Unlike conventional solution polymerization methods, the present invention makes it possible to easily produce a copolymer rubber containing polyethylene crystalline parts by polymerizing in a slurry state. Become.

Furthermore, it becomes easy to increase the molecular weight of the J(ff! rubber), which is advantageous for improving impact resistance.

A catalyst system suitable for such a method includes at least Ti.
A catalyst system consisting of a solid component containing , Mg, and CI and an organic AI is desirable.

The well-known V-containing catalyst system is difficult to form ethylenic blocks and is not suitable.
Publication No. 34478, No. 51-28189, No. 52-1
51691 or 56-11909, a solid component containing titanium, chlorine, and optionally magnesium, an organoaluminum compound such as an aluminum trialkyl, and optionally a third component. or JP-A-56-151707,
Compounds containing at least Ti, Mg, and halogen, as proposed in No. 57-141410, No. 58-45209, or No. 59-215304, are combined with a cyclic compound containing oxygen or nitrogen, or with an organoaluminum compound. A catalyst system consisting of a solid component treated with and an organoaluminum compound or a cyclic compound containing this and oxygen is suitable. Preferably JP-A-56-15170
7 or No. 59-215304, more preferably the catalyst system proposed in No. 59-215304.

In addition, the melt flow index (MFI) of ethylene-α-olefin copolymer rubber measured at 230°C
is usually 0.005 to log/10 minutes, preferably 0.01 to 8 g/10 minutes. If the MFI is less than 0.005, the dispersion of the ethylene-α olefin copolymer comb in the graft polymer will be poor, which is not preferable. Also, MF
When I exceeds 8, the impact strength of the graft polymer decreases, which is not preferable. In addition, the HLMFI/MFI measured at 230°C for the ethylene-α-olefin copolymer comb
is usually 10 or more, or preferably 35 or more. IILM
If FI/MF is less than 1 or 10, the impact strength decreases, which is not preferable.

Does the present invention reveal that a graft copolymer using an ethylene-α-olefin copolymer rubber that is crystalline and powder-like exhibits excellent physical properties? The aqueous suspension polymerization method best expresses the characteristics of rubber.

b) Structure of monomers to be grafted Monomers used in the production of the graft copolymer of the present invention include aromatic vinyl compounds, unsaturated nitrile compounds,
One or more monomers selected from the group consisting of unsaturated carboxylic acid (ester) compounds and maleimide compounds.

Examples of aromatic vinyl compounds include styrene, α-methylstyrene, and their nuclear-substituted derivatives, p-methylstyrene and O-methylstyrene as nuclear alkyl-substituted styrene, and p-chloro as nuclear alkyl-substituted styrene. Examples include styrene and p-bromostyrene, among which styrene, α-methylstyrene, and p-methylstyrene are preferred.

Examples of the unsaturated nitrile compound used in the production of the graft copolymer of the present invention include acrylonitrile, methacrylonitrile, etc. Among them, acrylonitrile is preferred.

Examples of the unsaturated carboxylic acid (ester) used in the production of the graft copolymer of the present invention include acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, etc. However, methyl acrylate and methyl methacrylate are preferred.

Maleimide compounds used in the production of the graft copolymer of the present invention include maleimide and N? Converted mamaleimides, specifically maleimide, N-phenylmaleimide, N-methylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-2
-methylphenylmaleimide, N-2-ethylphenylmaleimide, N-2-chlorophenylmaleimide, etc., and N-phenylmaleimide and N-cyclohexylmaleimide are preferred.

These monomers can be used alone or in combination of two or more, depending on the properties required for the graft copolymer. However, when producing the graft copolymer of the present invention by a suspension polymerization method, in order to obtain a homogeneous or raft copolymer, the monomer (mixture) or ethylene-α-olefin copolymer rubber is mixed under polymerization temperature conditions. It is hoped that this will penetrate to some extent. For this purpose, it is desirable that the monomer to be grafted exhibits a liquid state under polymerization conditions.

C) Polymerization Conditions The method for producing the graft copolymer of the present invention is characterized by the use of a powdery ethylene-α olefin copolymer rubber having crystallinity. 5J of the graft copolymer of the present invention
Is it possible to use any method such as solution polymerization method, bulk polymerization method, bulk suspension polymerization method, or emulsion polymerization method to produce the rubber? Considering this, the most advantageous polymerization method is suspension polymerization.

By using the ethylene-α-olefin copolymer rubber as a raw material in the present invention, it is possible to manufacture a graft copolymer by a suspension polymerization process, which has been extremely difficult in the past, in a very simplified process. Surprisingly, even in such a method, contrary to expectations,
This method has made it possible to produce a graft copolymer that exhibits high performance.

The amount of the ethylene-α olefin copolymer rubber used in the production of the graft copolymer of the present invention is 5 to 80 parts by weight per 100 parts by weight of the mixture of the ethylene-α olefin copolymer rubber and the monomer to be grafted. It is preferably 10 to 60 parts by weight. If it is less than 5 parts by weight, the effect of improving impact resistance will be low, which is not preferable. If the amount exceeds 80 parts by weight, the ethylene-α-olefin copolymer rubber will be crosslinked as large particles, making it impossible to obtain a graft copolymer with good performance.

Furthermore, the monomer to be grafted used in the production of the graft copolymer of the present invention is selected from the group consisting of aromatic vinyl compounds, unsaturated nitrile compounds, unsaturated carboxylic acid (ester) compounds, and maleimide compounds. In addition, one type or two or more types of monomers are used, and the type of monomers used, their combination, and the amount used can be selected depending on the performance required for the graft copolymer. For example, the following combinations and usage amounts can be exemplified. However, the present invention is not limited to these examples.

An example of grafting only one type of monomer is IS, which exemplifies the use of only one type of aromatic vinyl compound. Further, it is possible to exemplify the use of only one type of unsaturated carboxylic acid (ester) compounds.

An example of a combination of two or more monomers is a combination of 40 parts by weight or more of an aromatic vinyl compound and 60 parts by weight or less of an unsaturated nitrile compound as the monomers to be grafted. Preferably, the aromatic vinyl compound is 60 to 8
Examples include combinations of 0 parts by weight and 20 to 40 parts by weight of unsaturated nitrile compounds. If the amount of the aromatic vinyl compound is less than 40 parts by weight, the graft copolymer will become colored, which is undesirable.A suitable example thereof is a combination of styrene and acrylonitrile.

Another example is a combination of 40 parts by weight or more of an aromatic vinyl compound, 60 parts by weight or less of an unsaturated nitrile compound, and 70 parts by weight or less of a maleimide compound as monomers to be grafted. Preferably, the aromatic vinyl compound is 50 to 8011! parts, 20 to 40 ffiffi parts of unsaturated nitrile compound, lθ of maleimide compound
A combination of ~40 parts by weight can be exemplified. Here, if the rI content of the aromatic vinyl compound is less than 40@1 part, it is not preferable because the graft copolymer will be colored. Moreover, if the amount of the maleimide compound exceeds 70 parts by weight, the performance of the graft copolymer will deteriorate, which is not preferable. Suitable examples of these include combinations of styrene, acrylonitrile, and phenylmaleimide.

In the suspension graft polymerization method, which is a typical example of the method for producing the graft copolymer of the present invention, both the ethylene-α olefin copolymer rubber and the monomer mixture to be grafted are suspended in water to carry out the polymerization. However, the amount of water used at this time is 0.8 to 1 in heavy water based on the total of both the ethylene-α olefin copolymer rubber and the #A polymer mixture to be grafted.
O times the amount, Ilf or the same amount to 5 times the amount. If the amount of water used is less than 0.8 times the amount, the suspended state will become unstable, the dispersion will be broken, and the system will coagulate, making polymerization difficult. Also, 1
If the amount exceeds 0 times, the amount of graft copolymer produced in one polymerization will decrease, which is not preferable because productivity will decrease.

As a dispersant used to maintain a suspended state in the production of a graft copolymer, a dispersant generally used in suspension polymerization can be used. in particular,
Water-soluble polymers include gelatin, starch, polyvinyl alcohol, polyacrylates, etc., and sparingly soluble inorganic compounds include barium sulfate, calcium phosphate, calcium carbonate, calcium sulfate, etc., and it is also possible to use these in combination. Among these, polyvinyl alcohol,
Calcium phosphate is preferred. The amount used is preferably from 0.01 to 10 parts by weight, more preferably from 0.1 to 7 parts by weight, per 100 parts by weight of water. Moreover, these dispersants can also be used in combination with cationic, anionic, or nonionic surfactants. When used together, the amount of surfactant used is 1/1/1 by weight of the dispersant.
1011~]/1000 or preferably l/200~11
500 is more preferred.

In the suspension graft polymerization method, both the ethylene-α-olefin copolymer rubber and the monomer mixture to be grafted are suspended in water and heated in the presence of a radical generator that is easily soluble in the intermediate. When a polymerization reaction is carried out, it is desirable that the inside of the polymerization system be purged with an inert gas such as nitrogen gas. The presence of oxygen active against radical polymerization is undesirable because it exhibits a polymerization inhibiting effect. As for the polymerization temperature,
The temperature is preferably from 50 to 200°C, and more preferably from the melting temperature of the crystal component contained in the ethylene-α olefin copolymer rubber to 180°C. If the polymerization temperature is lower than 50°C, the polymerization reaction progresses slowly and is not economical.
If the temperature exceeds 00°C, the performance of the resulting graft copolymer will deteriorate, which is undesirable. Polymerization time is 1 to 20
The time is preferably 2 to 10 hours, and more preferably 2 to 10 hours. A polymerization time of less than 1 hour is undesirable because it is difficult to proceed with the polymerization reaction at a sufficient conversion rate, and a polymerization time of more than 20 hours is not economical and undesirable. The monomer-easily soluble radical generator used should generate radicals at an appropriate rate within the above-mentioned polymerization temperature and polymerization time ranges, and should have a conversion rate of at least 70% under the polymerization conditions. % or more, you can choose from among radical generators. Specifically, among organic peroxides, diacyl peroxides include lauroyl peroxide, benzoyl peroxide; sialkyl peroxides include dicumyl peroxide, 1.3-bis-(t-butylperoxy-isopropyl); )-benzene, di-t-phthyl peroxide; as alkyl peresters, t-butyl peroxypiparate, di-t-butyl peroxyazelate.

t-phthyl peroxybenzoate, etc., and azo compounds such as 2-2'-azobisisobutyronitrile, asobisisophthanol diacetate, 1,1-asobiscyclohexanecarbonitrile, etc., and use of these alone , it is possible to use a combination of two or more types E. In addition, the amount of radical generator used is 10% of the monomer mixture.
0.05 to 10 parts by weight, and 0.05 to 10 parts by weight.
1 to 3 parts is preferred. The amount of radical generator used is 0.
．． If it is less than 0.5 parts by weight, the polymerization rate will be slow and uneconomical, and if it exceeds 10 parts by weight, the polymerization rate will be too fast and there is a risk of runaway polymerization reaction, which is not preferred.

It is also possible to use mercaptans which are commonly used for the purpose of controlling molecular weight in suspension graft polymerization. Specific examples include primary, secondary and tertiary mercaptans having an alkyl group or a 22-substituted alkyl group, such as n-
Butyl mercaptan, isobutyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, 5e
Examples include mercaptans such as c-dodecylmercaptan, tert-dodecylmercaptan, aromatic mercaptans such as phenylmercaptan, thiocresol; thioglycolic acid and its esters: thiocricol. These can be used alone or in combination of two or more. The amount used is monomer (mixed ej) 1
00 parts by weight or less, preferably 3 parts by weight or less.

If the amount exceeds 5 parts, the polymerization chain of the monomer will be shortened and the strength will be lowered, which is not preferable.

After the suspension graft polymerization reaction described above, the resulting graft copolymer is dispersed in water as particles and is therefore very easy to separate from water. The particles obtained by separation are subjected to a treatment and washing step for the purpose of removing the dispersant or unreacted U-unit as necessary, and then are dried and smoked.

d) Graft Copolymer The graft copolymer of the present invention has crystallinity and is produced by graft copolymerization using a powdery ethylene-α olefin copolymer rubber as a raw material.

The graft copolymer thus obtained has a graft ratio of 20 to 150%, preferably 50 to 100%, as defined below. Further, the gel fraction, which is also defined below, is 40 to 250%, preferably 80 to 200%.

If the grafting ratio is less than 20%, the impact resistance will not be sufficient.
If it exceeds 150%, the fluidity becomes poor. Also, if the gel fraction is less than 40%, the #i impact resistance is not sufficient;
If it exceeds %, the fluidity becomes poor.

The graft copolymer (1'<ff1W1, weight fraction of ethylene-α olefin copolymerized in the graft copolymer or F1) was subjected to Soxhlet extraction using MEK (methyl ethyl ketone) for 7 hours. Value calculated from the resulting insoluble amount (weight W2) using the following formula: Gel fraction: Graft copolymer (IT!1ilW1. The ethylene-α olefin copolymer rubber copolymerized in the graft copolymer is F1. It is also possible to use a value calculated by the following formula from the amount of insoluble matter (weight W3) obtained as a result of time Soxhlet extraction with toluene.

<Examples> The present invention will be explained below using examples. It should be noted that the present invention is not limited to the following examples unless the scope thereof is exceeded.

As described above, the graft copolymer of the present invention and its production method have been described. The graft copolymer produced by the present invention itself has high impact strength, high thermal stability, and weather resistance, and is a molding material. It can be used as is, or it can be mixed with various thermoplastic resins such as polystyrene, various styrene copolymers, acrylic resins, polyamide resins, and polycarbonate resins to form a composition with a balance of physical properties that matches the purpose of use. It is also possible to obtain

Furthermore, the graft copolymer of the present invention or a composition containing the graft copolymer as one component may further contain stabilizers, flame retardants, plasticizers, lubricants, glass fibers, inorganic fillers, colorants, and ultraviolet rays. Anhydrous magnesium chloride (commercially available anhydrous magnesium chloride was heated at about 500°C in a dry nitrogen stream for 15 hours) (obtained by drying) 2.1Kg and 0.9Kg of AA type titanium trichloride (manufactured by Toyo Stofa Co., Ltd.)
Co-pulverized for 8 hours in a vibrating ball mill to obtain a homogeneous co-pulverized product (Titanium raw content: 7.2% by weight, chlorine atom content: 73.7%, magnesium atom content: 17.7%)
% by weight, referred to as "solid component (F)") was produced.

Of the solid component (F) thus obtained, 600 g was placed in a 100 ml glass-lined container, and 40 ml of n-
Hexane was added and stirred to form a uniform suspension.

Loog's γ-crisitoxypropyltrimethoxysilane was added to this suspension, and the mixture was thoroughly stirred at room temperature for 1 hour. Thereafter, the mixture was allowed to stand still, the supernatant liquid was removed, and 20 liters of toluene was added. Then, 2 kg of tetrahydrofuran was added, and the mixture was thoroughly stirred at room temperature for 1 hour. The treatment system was cooled to room temperature, and the product was thoroughly washed with n-hexane (until almost no titanium atoms were observed in the washing solution) to obtain a solid catalyst component (A).

A 290-liter tubular loop continuous reactor was filled with liquid propylene, and the propylene was kept at 60 Kg/H, the ethylene concentration in the liquid layer was kept at lOmole%, and the hydrogen was kept at the water concentration in the liquid layer or 0.02IIole%. , 360 mmol of triethylaluminum (hexane solution)
e/H, 180 mmole of tetrahydrofuran
/H1 3.2 g/H1 of solid catalyst component (A) was supplied to this reactor, and polymerization was carried out at a reaction temperature of 30°C. The polymer is intermittently discharged into a flash hopper in the form of a slurry, and the polymer is taken out from the bottom and passed through a hot N2 stream.
It was dried at 0°C to obtain a polymer powder. These were in the form of a smooth powder without sticking together, and the yield was 6 kg/h. Therefore, the average polymerization activity per solid catalyst (A) is 49
．． It was 3Kg/g-Ti.

The ethylene content of this is 61% by weight, MFI is 0.02 g/10 min, HLMFI/MFI is 40, M
w/M n is 5.3, the degree of crystallinity calculated from the heat of fusion of the crystal by DSC measurement is 7.0%, the melting point is 110°C by DSC measurement, and the intrinsic viscosity at 135°C in decalin is 5.4 dl/ It was there. This ethylene-propylene copolymer rubber is referred to as rubber (A).

Furthermore, ethylene-propylene copolymer rubber with a small molecular weight was added to the liquid layer at a concentration of 0.2 m.

Production was carried out under exactly the same polymerization conditions and method as for rubber (A), except that the amount was 1 m%. It has an ethylene content of 61% by weight and an MFI of 1.

Og/10 min, HLMFI/MFI is 37, M w /
Mn is 5, O, the degree of crystallinity calculated from the heat of fusion of the crystal by DSC measurement is 6.8%, the melting point is 108°C by DSC measurement, and the intrinsic viscosity at 135°C in decalin is 2.
It was 2 dl/g. This ethylene-propylene copolymer rubber is referred to as rubber (B).

Furthermore, as a comparison, we used an ethylene-propylene copolymer rubber with a smaller molecular weight, and the hydrogen concentration in the liquid layer was 0.6.
It was produced under exactly the same polymerization conditions and method as rubber (A), except that the mole% was adjusted. The ethylene content of this is 65% by weight and the MFI is 9.0g/1
0 minutes, HLMFI/MFI is 38, M w / M n
is 4.9, the crystallinity calculated from the heat of fusion of the crystal by DSC measurement is 6.6%, the same < the melting point by DSC measurement is 1
The intrinsic viscosity at 07°C and 135°C in decalin is 2.0 dl.
/g was there.

This ethylene-propylene copolymer rubber is referred to as rubber (C).

Furthermore, among the polymerization conditions for rubber (A), the heat of fusion of the crystals was determined by DSC measurement under polymerization conditions such that the concentration of hydrogen in the liquid layer was kept at 0.3 mol% and the ethylene concentration in the liquid layer was kept at 0.3 mol%. Crystallinity calculated from 0.5%
The rubber (D) was synthesized, and the extracted polymer was stuck to each other and could not be obtained in powder form. In addition, the ethylene concentration in the liquid layer is 22Ilo
A rubber (E) with a crystallinity of 25% calculated from the heat of fusion of the crystals measured by DSC was synthesized under polymerization conditions such that the rubber was maintained at le%.

(b) Production of graft copolymer In a pressurized reactor with a capacity of 2 liters and equipped with a stirrer, 42.0 g of rubber (^) as an ethylene-α olefin copolymer rubber and the monomer to be grafted were added. As a mixture of polymerization initiators, 178.5 g of styrene, 59.5 g of acrylonitrile, and 0.6 g of t-phthyl baroxybenzoate.
7 g of a mixture, 560 g of a water slurry with a concentration of 10% by weight of tricalcium phosphate as a dispersant, and 0.1 g of sodium dodecylbenzenesulfonate.
The operation of increasing the pressure to a pressure of am' and then removing the pressure was repeated five times, and the inside of the reactor system was sufficiently nitrogen-exchanged to make it substantially free of oxygen.

After that, the reactor was heated to 135°C over about 40 minutes.
The polymerization reaction was continued at that temperature for 4 hours. After 4 hours of coagulation, the reactor was cooled to room temperature and the contents were taken out. The graft copolymer was dispersed in water as fine particles with uniform particle size. The obtained graft copolymer was washed with hydrochloric acid water for the purpose of removing tertiary calcium phosphate, which is a dispersant, and washed with water for the purpose of removing sodium dodecylbenzene sulfonate, and then dried in a hot air dryer at 80°C. dried. The amount of the obtained graft copolymer was 267.4 g, and the yield was 95.5%. In addition, the graft rate and Kell fraction obtained as a result of Soxhlet extraction are: graft rate = 92%, gel official residence i! = 191%.

The dried graft copolymer was heated at 200°C using a Laboplastomill (Toyo Seiki Co., Ltd. Laboplastomill ME type).
Knead for 10 minutes for homogenization, then knead for 2 minutes.
Test pieces were prepared by hot press molding at 30°C. The physical properties of the test pieces were measured according to the following methods and conditions. The measured physical property values are also shown in Table 1.

Melt flow rate JIS K6970 (230°
g load on C5) Int impact strength: JIS K6871 (with notch) Bending strength, elastic modulus: JIS K7203 [Example 2
~6] Polymerization was carried out in the same manner as in Example 1 using the charged composition ratio, polymerization temperature, and time shown in Table 1 to obtain a graft copolymer. Table 1 also shows the graft ratio and gel fraction of the obtained graft copolymer.

In addition, test pieces were prepared for these graft copolymers according to the same procedure as in Example 1, and their physical properties were measured. The measured physical properties (1 m are also shown in Table 1).

[Examples 7 to 10] Polymerization was carried out in the same manner as in Example 1 using the charged composition ratio, polymerization temperature, and time shown in Table 1 to obtain graft copolymers. Table 1 also shows the graft ratio and gel fraction of the obtained graft copolymer.

In addition, these graft copolymers were prepared at 200"C (250"C when SMI was used as the thermoplastic resin) using the thermoufq resin shown in Table 1 and Laboplastomill (Toyo Seiki Co., Ltd. Laboplastomill ME type). ℃) for 10 minutes, and then hot press molded at 230°C (250°C when SMI was used as the thermoplastic resin) to create a test piece.The measured physical properties are also shown in Table 1. It shows.

The thermoplastic resin used here was manufactured based on the method shown below as a reference example.

[Reference Example 1] The AS (styrene-acrylonitrile copolymer) used as the thermoplastic resin was composed of styrene and acrylonitrile in a weight ratio of 75/25, and lauroyl peroxide and t-phthyl peroxylaurate as polymerization initiators. 0.25 parts by weight per 10 parts by weight of the polymer mixture,
0.35 parts by weight and 0.2 parts by weight of t-dodecyl mercaptan as a chain transfer agent were added to 100 parts by weight of the solid mixture, and the suspension polymerization was carried out at 80°C for 14 hours and at 120°C for 12 hours. It is obtained by polymerization. Its molecular weight is [η]0176d at 30°C in chloroform.
It was l/g.

[Reference Example 2] SMI (styrene-acrylonitrile-N-phenylmaleimide) used as a thermoplastic resin is styrene, acrylonitrile, and N-phenylmaleimide! I! This was obtained in the same manner as in Reference Example 1 except that the quantitative ratio was 60/20/20. Its molecular weight was 0.82 dl/g [η] at 30°C in chloroform.

[Example 10] Rubber (C) as ethylene-α olefin copolymer rubber
Table 1 The procedure was similar to that shown in Example 1 except that
Polymerization was carried out at the charging composition ratio, polymerization temperature, and time shown in , to obtain a graft copolymer. Table 1 also shows the graft ratio and gel fraction of the obtained graft copolymer.

In addition, test pieces were prepared for these graft copolymers according to the same procedure as in Example 1, and their physical properties were measured. The measured physical property values are also shown in Table 1.

[Example 11.12] Polymerization was carried out in the same manner as in Example 1 using the charged composition ratio, polymerization temperature, and time shown in Table 1 to obtain a graft copolymer.

Table 1 also shows the graft ratio and gel fraction of the obtained graft copolymer.

In addition, test pieces were prepared for these graft copolymers according to the same procedure as in Example 1, and their physical properties were measured. The measured physical property values are also shown in Table 1.

[Comparative Example 1] As a commercially available bale-shaped ethylene-α olefin copolymer rubber, EPT0045 manufactured by Mitsui Petrochemicals was pulverized by a Willey mill type pulverizer and then passed through a 10-mesh sieve. Polymerization was carried out in the same manner as in Example 1 using the charged composition ratio, polymerization temperature, and time shown in Table 1. However, the dispersion during polymerization was unstable and the resin often adhered to the stirring blade, the wall of the polymerization vessel, etc., and the properties of the obtained graft copolymer were poor. Table 1 shows the graft ratio and gel fraction of the graft copolymer obtained in barely granular form.

In addition, test pieces were prepared for these graft copolymers according to the same procedure as in Example 1, and their physical properties were measured. The measured physical property values are also shown in Table 1.

(The following is a blank space) <Effects of the Invention> According to the production method of the present invention, by using a crystalline and powdered ethylene-α-olefin copolymer rubber as a starting material, a stable and easily suspended Graft copolymers can be produced by polymerization methods.

In addition, the graft copolymer of the present invention and the composition containing the graft copolymer as one component have excellent heat resistance stability, weather resistance, and impact resistance, so that they can be used, for example, in automobile parts, electrical/electronic parts, household use, etc. It can be preferably used for electrical equipment, office electrical equipment, etc.

Claims (1)

[Scope of Claims] 1) In a method of graft polymerizing a vinyl monomer to an ethylene-α-olefin copolymer rubber, an ethylene-α-olefin copolymer rubber having crystallinity and in the form of powder is used. A method for producing a graft copolymer, characterized by carrying out graft polymerization by a suspension method. 2) The method for producing a graft copolymer according to claim 1, wherein the ethylene-α olefin copolymer rubber has the following characteristics. (a) Ethylene content is 40 to 90% by weight. (b) The degree of crystallinity of polyethylene as determined by DSC measurement is 1 or more.
20%. 3) One or two vinyl monomers selected from the group consisting of aromatic vinyl compounds, unsaturated nitrile compounds, unsaturated carboxylic acid (ester) compounds, and maleimide compounds.
The method for producing a graft copolymer according to claim (1) or (2), which comprises at least one species of monomer. 4) The method for producing a graft copolymer according to claim (1), (2) or (3), wherein the graft polymerization reaction is carried out at a temperature equal to or higher than the melting temperature of crystals of the ethylene-α-olefin copolymer rubber.