JP2695971B2 - Ethylene copolymer and method for producing the same - Google Patents

Description

The present invention relates to a novel ethylene copolymer and a method for producing the same. The ethylene copolymer of the present invention has excellent light stability.

[Conventional technology]

A homopolymer of a vinyl compound having a hindered amine in the side chain and a copolymer comprising a compound containing at least one polymerizable double bond are disclosed in JP-A-54-21489. Analogous substances of vinyl compounds and ethylene copolymers are disclosed in
No. 80616 discloses this. The copolymer disclosed in JP-A-54-21489 is prepared by charging a vinyl compound having a hindered amine group in a side chain alone or a monomer copolymerizable therewith in an organic solvent such as benzene or toluene;
A free radical generating initiator such as α'-azoisobutyronitrile is added and polymerization is carried out without applying pressure. In the case of a copolymer, at least one polymerizable double bond under polymerization conditions is added. The difference between the polymerization rate of the compound containing one and the vinyl compound having a hindered amine group in the side chain,
A so-called block structure, in which two or more vinyl compounds having a hindered amine group in the side chain are continuously bonded in the molecular chain of the polymer, often occurs, and the copolymer may be used alone or other polymers such as polyolefin. When a blend is used for the material, there is a problem that the light stability performance is not sufficiently exhibited.

On the other hand, JP-A-57-180616 discloses an ethylene / ethyl acrylate copolymer, a compound having a hindered amine group in a side chain by a transesterification reaction between the ethylene / methyl acrylate copolymer and an alcohol having a hindered amine group. However, since the transesterification reaction is a reversible reaction, a small amount of acrylate residue remains, and its light stabilizing effect is limited.

[Problems to be solved by the invention]

The present inventors have conducted various studies in view of such a current situation, and found that, in particular, a block structure in which two or more vinyl compounds having a hindered amine group in the side chain are continuously bonded or unreacted without reacting It was found that the light stability and compatibility of the copolymer were reduced due to the presence of the ester group remaining as it was, and ethylene and a vinyl group having a hindered amine group in the side chain were polymerized by a high-pressure radical polymerization method. In this case, it was surprisingly found that an ethylene copolymer having a very small block structure in which two or more vinyl monomers having a hindered amine group in a side chain were continuously bonded was obtained, and the present invention was accomplished.

[Means for solving the problem]

The present invention relates to: 1. Ethylene (A) and the following general formula: (Wherein, R ₁ and R ₂ are a hydrogen atom or a methyl group, R ₃
Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) and a vinyl compound (B),
The ratio of (B) to the sum of (A) and (B) is 0.0005-
0.85 mol%, and the proportion of (B) in the copolymer that is not continuous two or more and is present in isolation is based on the total amount of (B).
An ethylene copolymer characterized by having an MFR of at least 83% and an MFR of 0.1 to 200 g / 10 minutes, and 2. ethylene (A) and the following general formula: (Wherein, R ₁ and R ₂ are a hydrogen atom or a methyl group, R ₃
Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), and radically polymerizes the vinyl compound (B) at a pressure of 1000 to 5000 kg / cm ² at a temperature of 100 to 400 ° C. The proportion of (B) to the sum of (B) is 0.0005 to 0.85 mol%, and the proportion of (B) that is isolated and not continuous two or more is 83% or more with respect to the total amount of (B). And MFR is
A method for producing an ethylene copolymer, characterized in that a copolymer having a viscosity of 0.1 to 200 g / 10 minutes is obtained.

[Specific description of the invention]

[1] Ethylene copolymer The ethylene copolymer of the present invention comprises ethylene (A) and the following general formula: (Wherein R ₁ , R ₂ and R ₃ are the same as above) and are obtained by copolymerization with the vinyl compound (B).

The most important feature of the copolymer of the present invention is that the ratio of two or more vinyl compounds (B) that are isolated and not isolated in the copolymer is 83% or more with respect to the total amount of (B). That is. The presence of the vinyl compound (B) is confirmed as follows.

¹³ C NMF (for example, JNM-GSX270 Spectromete manufactured by JEOL)
r) according to a method known in the art [for example, see Kagaku Dojin's "Equipment for Instrumental Analysis (1)", pp. 53-56 (1986)], and polyethyl acrylate described in the literature [Polymer Analysis Handbook published by Asakura Shoten Co., Ltd.] 969 (1985)] and ethylene-hydroxyethyl acrylate copolymer [Eur. Poly. J.2
Vol. 5, No. 4, pp. 411-418 (1989)], a peak at 32.9 ppm based on TMS was added to a methylene group at the α-position from the branch point of the isolated vinyl monomer (B) by 35.7 ppm. The peak in ppm was attributed to the methylene group sandwiched between the branch points of two consecutive vinyl monomers (B). Using these two signals, ethylene (A)
The proportion of the vinyl monomer (B) in the copolymer of the vinyl monomer (B) and the vinyl monomer (B) can be calculated by the following formula.

The ratio of two or more vinyl monomers having a hindered amine group in the side chain, which is estimated as described above, is not isolated and is present in an isolated manner is 83% or more based on the total amount of the vinyl monomers (B) in the copolymer. is required. If the ratio of two or more vinyl monomers having a hindered amine group in the side chain is not continuous and less than 83%, the light stability is high even though the content of the vinyl monomer having a hindered amine group in the side chain is small. Is not exhibited.

The ethylene copolymer of the present invention needs to have an MFR (by the measuring method described in JIS-K-6760) in the range of 0.1 to 200 g / 10 minutes. A preferred range is 0.5-20, more preferably 1-5. When the MFR is less than 0.1 g / 10 minutes, the compatibility with a commercially available polyolefin resin or the like is poor, and when a blend is used, it causes visible defects in film applications such as fish eyes and butter. Also, if the MFR exceeds 200, it can be said that the copolymer has a large molecular weight, but bleeding and blooming due to diffusion loss occur, and when blended with other polymer materials such as polyolefin, the strength of the blend decreases. Cause.

Regarding the concentration of the vinyl compound (B) having a hindered amine group in the side chain in the present ethylene copolymer (the concentration is determined by a known nitrogen analysis), ethylene (A) and the vinyl compound ( 0.0005 to 0.85 mol%, preferably 0.005 mol%, of the vinyl compound (B) based on the sum of
1 to 0.55 mol%.

Since this copolymer is excellent in light stabilizing effect, when used alone, a sufficient content of 0.001 mol% with respect to all structural units of the copolymer (that is, ethylene and a vinyl compound having a hindered amine group in a side chain) is sufficient. Exhibits a light stabilizing effect.

On the other hand, even in the case of a blend, since the high-pressure radically polymerized ethylene copolymer of the present invention has excellent light stability, the concentration of the vinyl compound having a hindered amine group in the side chain is a concentration corresponding to 0.001 mol% when used alone. Is enough. In the case of using a blend, since the addition accuracy is poor at a dilution ratio of 1000 times or more by weight, the maximum concentration of the vinyl compound having a hindered amine group in the side chain in the present copolymer at the time of using the blend is 1 mol. %. Use of an ethylene copolymer containing a vinyl compound having a hindered amine group in a side chain thereof is substantially uneconomical.

Furthermore, the ethylene copolymer of the present invention uses GPC,
At monodisperse polystyrene was prepared to determine the calibration curve, it is displayed with a ratio of weight average molecular weight to number average molecular weight M _W
/ M _N (Q value) is preferably in the range of 3 to 120.
A particularly preferred range is from 5 to 20.

[2] Production of Copolymer 1. Copolymerization Monomer The monomer used for production of the ethylene copolymer of the present invention is ethylene and a vinyl compound represented by the following general formula.

(Wherein, R ₁ and R ₂ are a hydrogen atom or a methyl group, R ₃
Represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).

The monomers of the above formula (I) are known and are known in the art,
For example, it can be synthesized by the methods described in JP-B-47-8539 and JP-A-48-65180.

Representative examples of the monomer of the formula (I) are as follows.

4-acryloyloxy-2,2,6,6-tetramethylpiperidine 4-acryloyloxy-1,2,2,6,6-pentamethylpiperidine 4-acryloyloxy-1-ethyl-2,2,6,6 -Tetramethylpiperidine 4-acryloyloxy-1-propyl-2,2,6,6-tetramethylpiperidine 4-acryloyloxy-1-butyl-2,2,6,6-tetramethylpiperidine 4-methacryloyloxy-2 , 2,6,6-tetramethylpiperidine 4-methacryloyloxy-1,2,2,6,6-tetramethylpiperidine 4-methacryloyloxy-1-ethyl-2,2,6,6-tetramethylpiperidine 4- Methacryloyloxy-1-butyl-2,2,6,6-tetramethylpiperidine 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine 4-crotonoyloxy-1-propyl-2,2,6 , 6-tetramethylpipe Lysine 2. Copolymerization The copolymer of the present invention is produced by subjecting required monomers to copolymerization conditions, but can be produced by a high-pressure method and a low-density polyethylene production apparatus.

(1) Catalyst The copolymer of the present invention is produced by radical polymerization. Therefore, the catalyst used in the production of the copolymer of the present invention is a free radical generating initiator.

For example, oxygen, ditertiary butyl peroxide,
Dialkyl peroxides and derivatives such as tertiary butyl cumyl peroxide and dicumyl peroxide, diacyl peroxides such as diacetyl peroxide and dioctanoyl peroxide, diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxide Peroxydicarbonates such as carbonate, tertiary butyl peroxyisobutyrate,
Peroxyesters such as tert-butyl peroxypivalate and tert-butyl peroxylaurate; ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide; 2,2
-Bicesterary butyl peroxyoctane, 1,1-
Peroxy ketals such as bis (tert-butylperoxy) cyclohexane, hydroperoxides such as tert-butyl hydroperoxide and cumene hydroperoxide, and azo compounds such as α, α'-azoisobutyronitrile Useful.

(2) Polymerization apparatus In this polymerization method, polymerization is preferably performed continuously. As the polymerization apparatus, a continuous stirred tank reactor or a continuous tube reactor generally used in a high-pressure radical polymerization method of ethylene can be used.

The polymerization can be carried out as a single zone process using these single reactors, but many reactors can be used in series, optionally connected with a cooler, or the interior can be multi-zone processes. It is also possible to use a single reactor effectively divided into several zones. In the multi-zone method, the reaction conditions in each zone are made different to control the properties of the polymer obtained in each reactor or each reaction zone. It is common to adjust body composition, catalyst concentration, molecular weight regulator concentration, and the like. When using a plurality of reactors connected in series, in addition to a combination of two or more tank reactors or two or more tube reactors, one or more tank reactors and one or more Can also be used.

The polymer formed in one or more reactors is
This can be separated from unreacted monomers and processed as in normal high pressure polyethylene production. The unreacted monomer mixture is mixed with an additional amount of the same monomer, repressurized and recycled to the reactor. The additional amount of monomer added as described above is of a composition that returns the composition of the mixture to that of the original feed. Generally, this additional amount of monomer is separated from the polymerization vessel by weight. It has a composition that approximately corresponds to the composition of the coalescence.

In order to obtain a copolymer having a uniform composition, a tank reactor is preferable.

The catalyst is usually dissolved in a solvent having a small chain transfer effect, and is directly injected into the reactor by a high-pressure pump.

Examples of suitable solvents are hexane, heptane, white spirit, hydrocarbon oil, cyclohexane, toluene, fatty acid esters and mixtures thereof.

Examples of the solvent for the vinyl compound include alcohols such as ethanol, methanol, and propanol, in addition to the above solvents having a small chain transfer effect. Among them, fatty acid esters such as ethyl acetate, alcohols such as methanol, and mixtures thereof are suitable as those having a small chain transfer effect and excellent solubility with vinyl compounds. The solution in which the vinyl compound is dissolved in these solvents can be directly injected into the reactor with a high-pressure pump or supplied to a place where the pressure level does not separate with ethylene, such as unreacted gas separated by a high-pressure separator. Is possible.
But mixed with ethylene under a low pressure of 50 kg / cm ² or less, an attempt to boost up the reaction pressure becomes the ethylene gas compatibility is poor uneven fluid solvents, to avoid since the boosted by stable compression becomes difficult preferable.

(3) Polymerization pressure The pressure employed is 1000 to 5000 kg / cm ² , preferably 1500
~4000kg / cm ^2, more preferably in the range of 2000~4000kg / cm ^2.

(4) Polymerization temperature The polymerization temperature is from 100 to 400 ° C, preferably from 150 to 300 ° C.
° C, more preferably in the range of 150 to 250 ° C.

The higher the polymerization temperature, the higher the productivity, but the lower the molecular weight of the copolymer, the more difficult it is to obtain a high molecular weight polymer, and the higher the polymer density in the polymerization system, the more likely the polymerization reaction becomes unstable, Basically a low temperature reaction is preferred.

(5) Method for Separating Unreacted Gas The copolymer of the present invention is polymerized by a high-pressure radical reaction in a reactor, and is separated from monomers in each of the subsequent separators to be a product as it is. On the other hand, vinyl compounds are solids or liquids at room temperature. When a solid vinyl compound is used in the separation of the reaction product and the unreacted gas, the following situations are likely to occur.

In the separation of the reaction product and the unreacted gas in the high-pressure separator and the low-pressure separator, the solution of the vinyl compound in the unreacted gas depends on the difference in the physical properties (molecular weight, boiling point, melting point, etc.) of the compound and the solvent, The solubility in the polymer differs, and the solution concentration of the vinyl compound increases each time the product is separated, and depending on the initial dilution concentration setting conditions to be supplied to the reactor, the concentration may exceed the saturation concentration, and the vinyl compound precipitates out. The reaction gas line is easily blocked.

The unreacted gas in the high pressure separator has a pressure of 150 to 500 kg / cm ²
There is no problem because it is completely dissolved with ethylene gas because it is at the level, but unreacted gas in the low pressure separator has a pressure of
Since it is as low as about 10 kg / cm ² or less, it is phase-separated from ethylene, and the above phenomenon is likely to occur.

In order to avoid this phenomenon, when a solid vinyl compound is used, in the process of separating the gas and liquid in the unreacted gas, the compound should be separated from the other unreacted gas at a temperature equal to or higher than the melting point of the vinyl compound. is important.

[3] Usefulness of copolymer The present ethylene copolymer is used alone or blended with other polymer materials to form a polymer material or a stabilizer for the polymer material against deterioration by the action of oxygen, heat and light. Can be used as Examples of the polymer material to be blended for imparting stabilization of the copolymer of the present invention include α-olefin homopolymers such as polyethylene, polypropylene, polybutene, poly-3-methylbutene, and poly-3-methylpentene-1. Or ethylene-propylene copolymer, or ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, ethylene-3-methyl-pentene-1 copolymer, etc.
α-olefin copolymer, ethylene-vinyl acetate copolymer,
Ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-2-ethylhexyl acrylate Copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-ethyl methacrylate 2-ethylhexyl copolymer, ethylene-vinyl trimethoxysilane copolymer Coalesce, ethylene-γ acryloyloxypropyl trimethoxysilane copolymer, ethylene-γ acryloyloxypropyl trimethoxysilane copolymer, ethylene-γ methacryloyloxypropyl trimethoxysilane copolymer, polyvinyl chloride, polyvinyl bromide, Polyfluoride Nyl, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, polyvinylidene fluoride, brominated polyethylene, chlorinated rubber, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, Vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer,
Butyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride terpolymer, vinyl chloride-styrene-acrylonitrile terpolymer, vinyl chloride butadiene copolymer, vinyl isobrene copolymer, Vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinylidene chloride, vinyl acetate terpolymer, vinyl chloride
Halogen-containing synthetic resins such as acrylic acid ester copolymer, vinyl chloride-maleic acid ester copolymer, vinyl chloride-methacrylic acid ester copolymer, vinyl chloride-acrylonitrile copolymer, internally plasticized polyvinyl chloride, and petroleum resin , Coumarone resin, polystyrene, polyvinyl acetate,
Acrylic resins, copolymers of styrene with other monomers (eg, maleic anhydride, butadiene, acrylonitrile, etc.), acrylonitrile-butadiene-styrene copolymer, acrylate-butadiene-styrene copolymer, methacrylic ester -Butadiene-styrene copolymer, methacrylate resin such as polymethyl methacrylate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, linear polyester, polyphenylene oxide, polyamide, polycarbonate, polyacetal, polyurethane, cellulose resin, or phenol resin, urea Resin, melamine resin, epoxy resin,
Examples thereof include unsaturated polyester resins and silicone resins. Further, rubbers such as isoprene rubber, butadiene rubber, acrylonitrile-butadiene copolymer rubber, and styrene-butadiene copolymer rubber, and blends of these resins may be used. Further, a foamed polymer such as a crosslinked polymer such as polyethylene crosslinked by a peroxide or radiation or a foamed polyethylene foamed with a foaming agent is also included.

When the ethylene copolymer of the present invention is used alone, phenol-based, sulfur-based, phosphorus-based stabilizers, amide-based, metallic soap-based lubricants, silica, and inorganic compounds such as talc may be blended. .

Further, an antistatic agent, a dropping agent, a neutralizing agent, a nucleating agent, other light stabilizers, and the like can also be blended.

When the ethylene copolymer of the present invention is used by blending it with another polymer material, it may be used in combination with the above-mentioned additives.

〔Example〕

 Next, the present invention will be specifically described with reference to examples.

Example 1 Using a stirred autoclave-type continuous reactor having an internal volume of 1.5 liters, ethylene was added at a rate of 40 kg / hour and 4-acryloyloxy-2,2,6,6-tetramethylpiperidine at a rate of 300 g / liter. Ethyl acetate dissolved in ethyl 1.26 l / h, separate from ethyl acetate contained in the above solution, ethyl acetate 7.0 l / h as a chain transfer agent, tertiary butyl peroxypivalate 5 g / l as a catalyst And continuously supply the solution dissolved in normal hexane at a rate of 0.59 liter / hour at a polymerization pressure of 2000 kg / c.
A copolymer was produced at m ² and a polymerization temperature of 200 ° C. The MFR of the obtained copolymer was 2.7 g / 10 min, 4-acryloyloxy 2,2,
The content of 6,6-tetramethylpiperidine is 0.5 mol%, the molecular weight distribution represented by the ratio of the weight average molecular weight to the number average molecular weight is 8.2, and 4-acryloyloxy-2,2,6,6-tetramethylpiperidine is used. The ratio of two or more that are not continuous and exist in isolation is determined by ¹³ C NMR (solvent ODCB / C ₆ D ₆ : 4/1, measurement temperature 130
C) was 89%.

Examples 2 to 5 Using the same apparatus and method as in Example 1, the injection amount of ethyl acetate solution of 4-acryloyloxy-2,2,6,6-tetramethylpiperidine and ethyl acetate used as a chain transfer agent Was appropriately increased or decreased to produce a copolymer.

The polymerization pressure and temperature during the production are about
The temperature was maintained at 2000 kg / cm ² and about 200 ° C. Table 1 shows the properties of the obtained ethylene copolymer.

Example -6 Using the same apparatus and method as in Example 1, the same weight of 4-acryloyloxy-1,2,2,2 was used instead of 4-acryloyloxy-2,2,6,6-tetramethylpiperidine. 6,6-
An ethylene copolymer was produced using pentamethylpiperidine. Table 1 shows the properties of the copolymer.

Example-7 As in Example-6, 4-acryloyloxy-2,2,6,6-tetramethylpiperidine of Example-1 was replaced with the same weight of 4-acryloyloxy-1-butyl-2,2,6. Was replaced with 1,6-tetramethylpiperidine to produce an ethylene copolymer. The injection amount of the comonomer in the ethyl acetate solution was finely adjusted so that the comonomer content was 0.4 mol%. Table 1 shows the properties of the ethylene copolymer.

Examples -8 to 10 In the same manner as in Example 7, using 4-methacryloyloxy-2,2,6,6-tetramethylpiperidine (Example-8), and using 4-methacryloyloxy- 1,2,2,
Using 6,6-pentamethylpiperidine (Example-
9) Further, an ethylene copolymer was produced using 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine (Example-10). Table 1 shows the properties of these copolymers.

Comparative Examples 1-2 As in Examples -2-5, 4-acryloyloxy-
The injection amount of the 2,2,6,6-tetramethylpiperidine in ethyl acetate solution and the amount of ethyl acetate used as the chain transfer agent were appropriately increased or decreased to produce an ethylene copolymer.

 Table 2 shows the properties of the obtained copolymer.

Comparative Example-3 (Production by Low-pressure Radical Polymerization) Using a 50-liter stainless steel autoclave having a stirrer, 10 liters of pure anhydrous toluene was charged, and extremely pure toluene 25 was stirred under a pure ethylene atmosphere. 4-acryloyloxy-2, in liter
While injecting a solution of 2.1 kg of 2,6,6-tetramethylpiperidine and 20 g of α, α'-azoisobutyronitrile over 110 minutes, the pressure was increased to 250 kg / cm ² and polymerization was carried out. After completion of the pressure increase, the polymerization mixture is further stirred at 110 ° C to 112 ° C.
Hold for 70 minutes.

Thereafter, the pressure was released, nitrogen was introduced, the temperature was lowered to room temperature under a nitrogen atmosphere, and then the mixture was poured into 800 liter of methanol, washed, dried and the product was collected.

 Table 2 shows the properties of the obtained copolymer.

Comparative Example-4 As in Comparative Example-3, 4-acryloyloxy-2,2,
The charge of 6,6-tetramethylpiperidine was increased from 2.1 kg to 14
The amount was changed to 0 g, and ethylene copolymerization was performed. Table 2 shows the properties of the copolymer.

Comparative Example-5 (Transesterification Reaction of Ethylene / Acrylic Ester Copolymer) A 500-ml four-necked round bottom equipped with a stirrer, a reflux concentrator, a thermometer, a nitrogen injection tube and an oil bath was provided with an MFR6.
2. A mixture of 14.5 g of an ethylene-ethyl acrylate copolymer having an ethyl acrylate content of 7.5 mol%, 15.7 g of 2,2,6,6-tetramethylpiperidin-4-ol, and 0.3 g of tetrabutyl titanate was charged. The mixture was heated at 175 ° C. for 20 hours with gentle stirring under a nitrogen atmosphere. The obtained copolymer product was then dissolved in 150 ml of anhydrous toluene, and the toluene solution was dropped into an excess amount of anhydrous hexane to precipitate the copolymer. The copolymer was separated and suspended in acetone that had been separated and refluxed.
2,6,6-Tetramethylpiperidin-4-ol was extracted. After passing through the copolymer after extraction, it was separated under 0.2 mmHg pressure and 5
Dry at 0 ° C. for 7 hours.

 Table 2 shows the properties of the copolymer after transesterification.

Comparative Example-6 Similarly to Comparative Example-5, a transesterification reaction was performed using 2,2,6,6-tetramethylpiperidin-4-ol. The copolymer used in the reaction was an ethylene-methyl acrylate copolymer having an MFR of 4.0 and a methyl acrylate content of 0.82 mol%. Table 2 shows the properties of the copolymer.

For the above Examples 1 to 10 and Comparative Examples 1 to 7, physical properties tests described below were performed.

(1) Film forming properties of the ethylene copolymer alone and resin pressure at the time of extraction: an extrusion film extruder with a cylinder diameter of 20 mmφ and an annular film die with a 50 mmφ ring die (slit width 0.8 mm) At a screw rotation speed of 70 rpm and a blow ratio of 1.5
A 100 micron thick film was formed. The film forming property was visually determined, and the resin pressure was read with a pressure gauge attached to the extruder cylinder head.

(2) Blend experiment when using a blend: MFR1.0, density 0.920 (JIS-K
-6760), and blending was performed so that the number of moles of the comonomer having a hindered amine group in the side chain in 28 g of the blend resin was 1 × 10 ^-5 . The blending was performed by shaking the copolymer pellets and polyethylene pellets in a bag for 2 minutes. After blending, an inflation film was formed in the same manner as in (1).

(3) Film appearance: The appearance of the film formed in (1) or (2) was visually judged.

(4) Haze: In accordance with JIS-K-7105, the haze of the film formed in (1) and (2) was measured using an integrating sphere light transmittance measuring device.

(5) Tensile strength and elongation: The tensile strength and elongation of the film formed in (1) and (2) were determined according to JIS-Z-1702 by a method perpendicular to the mechanical axis.

(6) Presence or absence of bleed: The film formed in (1) and (2) was visually observed after one month to make a judgment.

(7) Light stability of film: According to ASTM-D-2565, the film formed in (1) and (2) above was exposed to a xenon arc lamp, and
In accordance with the above, a tensile test was performed, and the time when the elongation reached 200% was defined as the life of light deterioration.

The structures of the vinyl compounds in Tables 1 and 2 are as follows.

g: ethylene-ethyl acrylate copolymer and 2,2,6,6
Transesterification reaction product with tetramethylpiperidin-4-ol h: ethylene-methyl acrylate copolymer, 2,2,6,6
-Transesterification reaction product with tetramethylpiperidin-4-ol [Effect of the Invention] The novel ethylene polymer of the present invention is a polymer having a specific structure having a hindered amine group in a molecular side chain, and has a light stabilizing effect when blended with itself or the copolymer and another polymer material. And, for example, the transparency, film formability and appearance when formed into a film are extremely good.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshikazu Higaki 1, Toho-cho, Yokkaichi-shi, Mie, Mitsubishi Yuka Co., Ltd. Inside Yokkaichi Research Institute, Inc. (72) Inventor Yasufumi Matsubara 1, Toho-cho, Yokkaichi, Mie, Japan Mitsubishi Yuka Stock (72) Inventor Kenichi Nakamura 17-1 Higashiwada, Kamisu-cho, Kashima-gun, Ibaraki Pref., Japan Kashima Plant (56) References JP-A-2-53804 (JP, A) JP-A Sho 57-180616 (JP, A) JP-A-55-54312 (JP, A) JP-A-58-79033 (JP, A) JP-A-58-38708 (JP, A) JP-A-55-157612 (JP, A) A) JP-A-54-71185 (JP, A)

Claims (2)

(57) [Claims] (1) Ethylene (A) and the following general formula: (Wherein R ₁ and R ₂ represent a hydrogen atom or a methyl group, and R ₃ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) with a vinyl compound (B) ,
The ratio of (B) to the sum of (A) and (B) is 0.0005-
0.85 mol%, and the proportion of (B) in the copolymer that is not continuous two or more and is present in isolation is based on the total amount of (B).
An ethylene copolymer having an MFR of at least 83% and an MFR of 0.1 to 200 g / 10 minutes. 2. An ethylene (A) having the following general formula: (Wherein R ₁ and R ₂ represent a hydrogen atom or a methyl group, R ₃ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms) and a vinyl compound (B) represented by the formula: 1000 to 5000 kg / cm Radical polymerization at a pressure of 100 to 400 ° C. at a pressure of ² ; the ratio of (B) to the sum of (A) and (B) is 0.0005 to 0.85 mol% with respect to the total amount of (B); ) Are isolated and not isolated more than 2 times, and the MFR is
A method for producing an ethylene copolymer, which comprises obtaining a copolymer of 0.1 to 200 g / 10 minutes.