JPS61101508A - Ethylene copolymer - Google Patents

Abstract

PURPOSE:The titled copolymer which has excellent compatibility with polyphenylene ether and improves its impact resistance, comprising ethylene, a specified ethylenically unsaturated ester and itaconic anhydride. CONSTITUTION:A solution formed by dissolving 1-30wt% itaconic anhydride in 5-50wt% ethylenically unsaturated ester of the formula (wherein R1 is H or CH3, R2 is OCOR3 or COOR4 and R3 and R4 are each a 1-18C alkyl) so that the total amount may be 10-30wt% is mixed with 20-94wt% ethylene. To this solution a solvent (e.g., hexane) in which a catalyst (e.g., t-butyl peroxypivalate) is dissolved at a concentration of 0.5-30wt% and a chain transfer agent (e.g., propylene) are added. The resulting solution is radical- polymerized at a polymerization pressure >=500kg/cm<2>, preferably, 1,000-4,000kg/cm<2> and a polymerization temperature >=120 deg.C, preferably, 150-300 deg.C to obtain an ethylene copolymer of a MFR of 0.01-1,000g/10min.

Description

DETAILED DESCRIPTION OF THE INVENTION (Background) This invention relates to novel ethylene copolymers useful as impact modifiers for polyphenylene ether crystals.

Polyphenylene ether TD, (PPE) has excellent electrical and mechanical properties, high heat distortion temperature and self-extinguishing properties, making it an extremely useful engineering material.
Many applications are being developed as plastic materials. However, PPE has drawbacks such as poor moldability due to its high glass transition temperature and insufficient impact resistance.

In order to eliminate this drawback, various attempts have been made to improve the moldability and impact resistance of PPE.

As a method for improving the moldability of PPE, for example, P
Blending of styrenic polymers such as PEK polystyrene, rubber-modified polystyrene, and styrene-acrylonitrile-butadiene terpolymer has been carried out, and US Pat.
It is introduced in Publication No. 12, etc.

On the other hand, as a method for improving the impact resistance of PPE, it has been proposed, for example, to mix a rubber-like polymer with PPE (Japanese Patent Publication No. 1482/1982).

However, each of these proposals has some drawbacks, so in practice, a method that combines the above two methods, that is, P
A commonly used method is to blend PE with both components, a styrenic polymer and a rubbery polymer.

In this method of blending both components, the particle diameter of the rubbery polymer dispersed in the multi-IJ trap of PPE or a composition consisting of PPE and a styrene polymer is controlled to 2 microns (hereinafter referred to as μ) or less. Therefore, a method has been proposed to further improve the impact strength (Japanese Patent Publication No. 1983).
-28659, Japanese Unexamined Patent Application Publication No. 148838/1983) is a process of vigorously kneading the rubber-like polymer in a mixer until the particle size of the rubber-like polymer becomes 2 μ or less, or a process in which the particle size of the rubber-like polymer is adjusted to 2 μ or less. This requires the selection of a special rubber-modified polystyrene, and there are many practical limitations.

On the other hand, industrial demands for PPE are becoming more and more sophisticated, and conventional products are no longer satisfactory due to the need for more complex shapes and thinner walls. is requested.

(Summary) The present inventors have endeavored to develop a new impact modifier for PPE that can improve the impact resistance of PPE and has fewer practical restrictions. It was discovered that a terpolymer of itaconic acid has excellent compatibility with PPE and can improve impact resistance, leading to the present invention.

By melt blending the copolymer of the present invention into PPE, 1. The disadvantages of PPE, such as processability, impact resistance, and oil resistance, have been improved, and the adhesiveness with inorganic fillers such as glass fiber, calcium carbonate, silica, and TiO2 has been improved.
Deterioration in physical properties when filled with these can be reduced.

The present invention provides: (a) ethylene (b) ethylenically unsaturated ester (comonomer (I)) represented by the following general formula tz [wherein R1 represents H or CH3, R2i represents 0COR
3, or C00R4 (R3 and R4 represent an alkyl group having 1 to 18 carbon atoms). ] (c) It is a terpolymer represented by itaconic anhydride, ethylene, comonomer (1), and itaconic anhydride, the composition of which is (a) 20 to 94% by weight of ethylene (b) comonomer (1) ) is 5 to 50% by weight; and (c) itaconic anhydride is 1 to 30% by weight.

(Detailed description of the invention) (1), copolymer The copolymer of the present invention is defined as follows.

1-1 Type of comonomer (a) Ethylene (b) Comonomer = (1) (c) It is a terpolymer represented by itaconic anhydride, and the comonomer (1) is an ethylenic monomer represented by the following general formula. It is a saturated ester.

[In the formula, R1 represents H or CHj, R2 is 0COR3
, or COOR4 (Ps, R4 represents an alkyl group having 1 to 18 carbon atoms). ] Specifically, vinyl acetate, vinyl propionate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate,
Stearyl methacrylate et al.

1-2 Composition The composition of the terpolymer of the present invention is defined as follows.

(a) 20 to 94% by weight of ethylene (mountain) 5 to 50% by weight of comonomer (1) (c) 1 to 30% by weight of itaconic anhydride (b) + (c) The total amount of the copolymer of the present invention Component (c) is a component that is extremely effective in improving the compatibility with PPE, and the higher the content, the more effective it is, but if it is included in an amount of 30% by weight or more, the molecular weight of the copolymer becomes small. However, combining it with PPE becomes extremely difficult.

1-a MFR The copolymer of the present invention has an MFR of 0.01 to 1000y/
It is a random copolymer of min. Should MFR be 0.01 to improve the processability of PPE? ,”tomi
n or more is desirable, and HlMFR is 1 to improve impact resistance.
0009/10 min or less is desirable.

To improve the impact resistance of composite systems of PPE and polystyrene resin, the MFR of the terpolymer is 0.5 to 10 f/10 m.
In is desirable.

1-4 Applications The copolymer of the present invention is a very special polymer having a carboxyl group or an acetoxy group and an anhydride itacone group in the molecule, so it can be used in various applications.

For example, by utilizing the reactivity of the itaconic anhydride group, PPE
It can be used as an impact-resistance improver for nylon and nylon.

When used as an additive for PPE, add 0 to 80% by weight (based on total amount) to PPE or PPE containing styrenic resin.
, preferably 0.1 to 50% by weight, particularly preferably 1 to 50% by weight
Added at 30% by weight. The ratio of PPE to styrene resin is 80 to 20 parts by weight of PPE and 2 parts by weight of styrene resin.
It is 0 to 80 parts by weight.

In addition, as styrene resin, polystyrene, poly-
α-methylstyrene, polychlorostyrene, styrene・
Acrylonitrile copolymer, styrene/butadiene/acrylonitrile copolymer, styrene/mannic anhydride copolymer, rubber-modified polystyrene, or the like can be used.

In addition, since it has excellent metal adhesion properties, it can be used as a sealant for extrusion lamination, dry lamination, and coextrusion film materials.

Furthermore, it can be formed into a film by a T-die method or an inflation method and used for flexible films, adhesive films, and splittable films.

The copolymer of the present invention can also be used to produce various molded products by blow molding, injection molding, extrusion molding, etc. As one example of extrusion molding, a laminated film can also be obtained by extrusion coating a film made of other plastics or materials other than plastics (metal foil, paper, cloth, etc.).

Since the copolymer of the present invention falls within the category of thermoplastic resins, it can be used with other thermoplastic resins, such as polyethylene, polypropylene ethylene-vinyl acetate copolymers, as commonly used for resin materials of this type. It can also be used in blends with petroleum resins, waxes, stabilizers, antistatic agents, ultraviolet absorbers, synthetic or natural rubber, lubricants, etc.
An inorganic filler or the like may also be mixed therein.

2. Production of copolymer The copolymer of the present invention is produced by subjecting predetermined monomers to copolymerization conditions, and can be produced using a high-pressure polyethylene production apparatus.

1) Catalyst The copolymer of the present invention is produced by radical polymerization. The catalyst used in the preparation of the copolymers of the invention is therefore a free radical generating compound.

For example, oxygen, dialkyl peroxide such as ditertiary butyl peroxide, tertiary butyl cumyl peroxide, diacyl peroxide, diacyl peroxide such as acetyl peroxide, isobutyl peroxide, octanoyl peroxide, diisopropyl peroxydicarbonate, etc. Peroxydicarbonates such as 2-ethylhexyl oxyne dicarbonate, tertiary butyl peroxy isobutyrate, tertiary butyl peroxy pivalate, tertiary butyl peroxylaurate, etc., tuberoxynysdel, methyl ethyl ketone peroxide, cyclohexanone Ketone peroxides such as peroxide, peroxyketals such as 1,1-bistersial butyl peroxycyclohexane, 2,2-bistersial butyl peroxyoctane, hydroperoxides such as ternarybutyl hydroperoxide, cumene hydroperoxide, Azo compounds and substances such as 2,2 azobisisobutyronitrile.

2) Polymerization (1) Polymerization apparatus This polymerization is preferably carried out in a continuous manner. The polymerization equipment can be a continuous stirring seed reactor or a continuous large tube reactor, which are commonly used in high-pressure radical polymerization of ethylene. - Can be implemented as a zone process, using many reactors in series, possibly with condensers, or in a single system with the interior effectively divided into several zones for each zone process. A reactor can also be used. In the zone method, the reaction conditions in each zone are differentiated to control the properties of the polymer obtained in each reactor or reaction zone, and the reaction conditions are different between the two reactors or reaction zones. It is common to adjust the C monomer, composition, catalyst concentration, molecular weight regulator concentration, etc. When using multiple reactors connected in series, in addition to the combination of two or more bite-type reactors or two or more cylindrical reactors, 1. ．． A combination of 15 or more seed reactors and one or more tube reactors can also be used.

The polymer produced in the reactor or reactors can be separated from unreacted monomer and processed as in the production of conventional high pressure polyethylene. The mixture of unreacted monomers is mixed with an additional amount of the same monomers,
Repressurize and circulate to the reactor. The additional amount of monomer added as described above is of a composition that is greater than returning the composition of the mixture to that of the original feed, and generally this additional amount of monomer is added to the polymer separated from the polymerization vessel. It has a composition roughly equivalent to that of the coalescence.

In addition, the reactor is preferably a seed type reactor in order to obtain a copolymer with a uniform composition.

The catalyst is dissolved in a solvent with a small chain transfer effect and directly injected into the reactor using a high-pressure pump. Concentration is 0.5~
Approximately 30 cm/cm is desirable.

Suitable solvents include, for example, hexane, heptane, white spirit, hydrocarbon oils, cyclohexane, toluene, higher branched chain saturated fatty acid hydrocarbons, and mixtures of these liquids.

Since itaconic anhydride is solid at room temperature, it is dissolved in solvent V' and supplied to the reaction system using a high-pressure pump. Suitable solvents include saturated fatty acid esters such as methyl acetate, ethyl acetate, butyl acetate, etc. Hexane, heptane, white spirit, charcoal! lS hydrogen oil, cyclohexane, toluene, higher branched chain saturated fatty acid hydrocarbons, vinyl acetate,
Comonomers such as acrylic ethyl methacrylate and methyl methacrylate (also the ethylenically unsaturated esters already mentioned as D) and mixtures of these liquids can be mentioned.

Among these solvents, it is most desirable to use comonomer (1) as the solvent from the viewpoint of minimizing the chain transfer effect in order to produce a product with a target molecular weight.

In high-pressure radical polymerization, a chain transfer agent is generally used to adjust the molecular weight, except in special cases.

As the chain transfer agent, all those used in ordinary high-pressure radical polymerization can be used.

Alkanes such as ethane, propane, butane, hexane, heptane, alkenes such as propylene, butene, hexene, alcohols such as ethanol, methanol, propatool, ketones such as acetone, methyl ethyl ketone, acetaldehyde, Aldehydes such as propionaldehyde and many other compounds used in high pressure methods can be used.

These gaseous substances are injected into the suction side of the compressor, and the liquid substances are injected into the reaction system by a pump.

(2) Polymerization conditions (a) Polymerization pressure The polymerization pressure employed is a pressure exceeding 50 Kp/-, preferably in the range of 1000 to 4000 Kp/-.

(b) Polymerization temperature The polymerization temperature is at least 120°C, but preferably 15°C.
It is in the range of 0 to 300°C.

(3) In addition, the copolymer of the present invention produced in the reactor is separated from the monomer in a separator according to the conventional method of high-pressure radical polymerization,
It becomes a product as it is.

This product may be used as it is, or may be subjected to various post-treatment steps such as those already used for products obtained by high-pressure radical polymerization.

3. Experimental Example The measuring method used to evaluate the quality of the copolymer of the present invention is as follows.

(11MFR: JIS K6760 (2) Density: JIS K6760 (3) Comonomer content x NMR method (4) Izod impact value: JIS K7110 Example-1 Using a stirred autoclave type continuous reactor with an internal volume of 1.5 liters , ethylene at 35 to 9/hour, a solution prepared by dissolving itaconic anhydride 2942 in ethyl acrylate 7352 at o, s 96 K9/hour, propylene at 6'θ liter/hour, and tertiary butyl panioxyvinyl as a catalyst. A solution dissolved in n-hexane at a ratio of Pareto sy/l was continuously supplied at a rate of 440 ml/hour, a polymerization pressure of 2500 Kf/7% and a polymerization temperature of 200°C.
A copolymer was produced.

The obtained copolymer had an MFR of 5.4 y/1o, an ethyl acrylate content of 10% by weight, and an itaconic anhydride content of 4% by weight.

This copolymer was made into a 100μ film using an inflation molding machine, sandwiched between 0.3m aluminum plates, and heated at 180°C for 50 minutes.
Kg/al, 10 minute hot press to adhere, and adhesive strength was measured in accordance with ASTM D903-49. The adhesive strength was t'120 Kf/251all at a tensile speed of 250 m/rnin and a measurement temperature of 20°C.

10 parts by weight of this copolymer, BoIJ-2.6-cymethyl-1
．． 4-phenylene ether (manufactured by Mitsubishi Yuka Co., Ltd., in chloroform, intrinsic viscosity at 30°C 0.46 > 50 parts by weight and polystyrene (manufactured by Mitsubishi Yuka Co., Ltd., number average molecular weight 55,00
0, weight average molecular weight 200,000) in a super mixer, and then melt-mixed at 250° C. in a twin-screw kneader (PCM-45, manufactured by Kamioki Tekko Co., Ltd.), and pelletized. The pellets were molded into Nippon Steel's new injection molding machine N-
Izot impact was measured using a test piece obtained by injection molding using a model 100. The obtained results are shown in Table 1 along with comparative examples.

Example-2 Vinyl acetate was used in place of ethyl acrylate in Example-1. 35Kq/hour of ethylene, 1 itaconic anhydride
4? 6.34
A copolymer was produced at a polymerization pressure of 2500 Kq/i and a polymerization temperature of 195°C.

The obtained copolymer has an MFR of 6.8? /10 minutes The vinyl acetate content in the polymer was 15% by weight, and the itaconic anhydride content was 2% by weight.

Table 1 shows the Izot impact values of resin compositions obtained in the same manner as in Example 1 except for using the copolymer of this example.
Shown below.

Comparative example Commercially available high-pressure polyethylene, Yucalon NH-s.

(MFR=2.8 ylx o min) and ethylene acetate/acetate compound, -'force:/EVA, V401 H (MFR=
zy/1o min, vinyl acetate content = 15% by weight) and the impact resistance improvement effect of PPE was compared. The results are shown in Table-1.

Examples 3 and 4 Same copolymer as Example 1 and polyphenylene ether (
Manufactured by Mitsubishi Yuka Co., Ltd., intrinsic viscosity at 30°C in chloroform: 0.
46) and 7 at the blending ratio shown in Table 1, respectively.
The mixture was mixed with molten M at 290° C. using a twin-screw kneader (PCM-45, Kamioki Iron Works Co., Ltd.) and pelletized. The pellets were molded in the same manner as in Example 1, and the Izot impact of the resulting test piece was measured. The obtained results are shown in Table 1 along with comparative examples.

(Margin below)

Claims (3)

[Claims] (1), (a) Ethylene (b) Ethylenically unsaturated ester (comonomer (I)) represented by the following general formula ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ [In the formula, R_1 represents H or CH_3 , R_2 is OC
OR_3 or COOR_4 (R_3 and R_4 have 1 carbon number
~18 alkyl groups). ] (c) Itaconic anhydride A terpolymer represented by the above-mentioned ethylene, comonomer (I), and itaconic anhydride, the composition of which is (a) 20 to 94% by weight of ethylene (b) comonomer (I) (c) Itaconic anhydride is 1 to 30% by weight. (2) The copolymer according to claim 1, which has an MFR of 0.01 to 1000 g/10 min. (3) The copolymer according to claim 1, wherein the total amount of the comonomer (I) and itaconic anhydride is 10 to 30% by weight.