JPH0547583B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Technology] The present invention relates to a whitening-resistant ethylene-propylene copolymer composition. More specifically, the present invention provides specific Ziegler
A highly rigid, whitening-resistant copolymer obtained by block copolymerizing ethylene and propylene in two stages using a Natsuta catalyst, and a mixture of high-density polyethylene and ethylene-propylene copolymer rubber at a predetermined ratio. Regarding the composition. The composition of the present invention has almost no whitening due to impact or bending as a molded product, and has high rigidity, heat resistance, and impact resistance. [Prior Art] Crystalline polypropylene (hereinafter referred to as polypropylene) obtained by polymerizing propylene using a stereoregular catalyst such as a Ziegler-Natsuta catalyst has excellent physical properties such as rigidity and heat resistance. On the other hand, there is a problem in that the impact strength, especially the impact strength at low temperatures, is low, which limits its practical range. In order to improve this drawback, many methods have been proposed in which propylene is block copolymerized with ethylene or other α-olefins. The ethylene (or α-olefin) propylene block copolymer thus obtained has excellent low-temperature impact resistance without significantly impairing the excellent properties of polypropylene, such as rigidity and heat resistance. However, such copolymers have new physical property drawbacks. This disadvantage is that when a molded article made from the above-mentioned block copolymer is used, the loaded portion easily whitens due to the impact or bending force applied to the molded article. The molded product that has become white in this way is
Naturally, the product value is completely lost. As a method for solving these drawbacks of propylene/α-olefin block copolymers (hereinafter referred to as block copolymers) from the viewpoint of polymerization catalysts, the present inventors previously proposed the invention of Japanese Patent Application No. 136349/1983 1986-
No. 28411 and below are referred to as earlier inventions). This invention almost completely solved the problem of whitening of known block copolymers. However, it has been newly discovered that even with molded articles made from the block copolymers of the previous invention, problems different from those described above exist under particularly limited and severe conditions. The problem is that the low-temperature impact strength of sheet canned products used in winter or in cold regions, especially molded products with textured surfaces, is insufficient to meet higher strength requirements. The molded product cracks due to low-temperature impact. In other words, in the field where the block copolymer of the above invention is used in the production of cans with a textured sheet, it is necessary to further improve the low-temperature impact strength in order to prevent damage in winter and in cold regions. ,
It is requested. It is generally known that when a textured pattern is added to a plastic molded article, the low-temperature impact strength of the molded article is significantly reduced due to the notch effect.
By the way, regarding can products made from the block copolymer of the above invention, when the manufactured sheet is first folded and the folded surfaces are folded and bent together at 180°C, the surface smooth finish product has a temperature of 0. Although it did not break at all even at ℃, the textured version cracked at room temperature (23℃). Regarding the previous invention, in addition to the above problems, since the polymerization method is a three-step block copolymerization method,
In terms of production equipment, it is necessary to dedicate a continuous polymerization apparatus using at least three polymerization vessels in series, or if a batch polymerization vessel is used, switching between each stage takes time and is inefficient. [Object of the Invention] The present inventors conducted research to solve the above-mentioned problems related to the previous invention. As a result, we obtained an ethylene-propylene block copolymer with a specific composition obtained by copolymerizing propylene and ethylene in two stages using a specific Ziegler-Natsuta catalyst, high-density polyethylene, and ethylene-propylene copolymer rubber with a specific composition. The present invention was achieved based on the knowledge that a composition in which the above-mentioned components are mixed at a certain composition ratio can solve the above-mentioned problems. That is, a molded article made from the composition of the present invention has excellent heat resistance, rigidity, and low-temperature impact resistance, and
Even when stress such as impact and bending is applied, there is almost no whitening phenomenon, and the appearance of molded products such as sheets is excellent. As is clear from the above description, an object of the present invention is to provide an ethylene-propylene copolymer composition that has excellent low-temperature impact resistance and whitening resistance, particularly for textured molded products. Another object is to provide molded articles produced from the composition. [Configuration and Effects of the Invention] The present invention has the following configuration. (1)○B Ethylene-propylene block copolymer (A) 74~ produced by the method described below
88% by weight, "a solid product obtained by reacting an organoaluminum compound (L) or a reaction product (P) of an organoaluminium compound (L) and an electron donor (A) with titanium tetrachloride (C)" ) is reacted with an electron donor (A) and an electron acceptor (B), and the resulting solid product () is combined with an organoaluminum compound (L ₂ ) and an aromatic carboxylic acid ester (R),
The carboxylic acid ester (R) and the solid product ()
Using a catalyst with a molar ratio R/=0.2 to 10.0, propylene and ethylene were mixed in the following two stages in the presence of hydrogen: In the first stage, the ethylene content was 1.0.
~3.0% by weight of copolymer ~75% of the total polymerization amount
90% by weight, followed by a second step with an ethylene content of 75-85%.
Ethylene is copolymerized to produce 10 to 25% by weight of the total polymerized amount of copolymer.
○B Polyethylene (B) 10 to 20% by weight with a density of 0.955 g/ ^cm3 or more and a melt index of 0.2 to 20 and ○C A melt index of 0.2 to 20 and an ethylene content of 25 to 85 An ethylene/propylene copolymer composition (J) comprising 2 to 5% by weight of ethylene/propylene copolymer rubber (C). (2) The ratio of the melt index (MFR) of the copolymer fraction obtained in the first stage and the copolymer fraction obtained in the second stage is MFR (first stage) / MFR (second stage) = 1.0 ~
10. The composition according to item 1, which uses an ethylene-propylene block copolymer (A) having a composition of 10%. The configuration and effects of the present invention will be explained in detail below. The ethylene-propylene copolymer used in the present invention can be produced by using the catalyst disclosed in the previous invention (Japanese Unexamined Patent Publication No. 60-28411). The specific method is as follows. The block copolymer according to the present invention is produced by a two-step block copolymerization method using a specific Ziegler-Natsuta catalyst as described in (1) above. The purpose of the present invention cannot be achieved even if the following various titanium trichlorides are used in place of the above-mentioned solid product () which is a catalyst component of the above-mentioned catalyst used in the production of the block copolymer according to the present invention. . In other words, these titanium trichlorides are so-called A type, H type, or H type titanium tetrachloride, which is obtained by reducing titanium tetrachloride with metal aluminum or hydrogen, or by pulverizing these reduced products.
It is AA type or HA type titanium trichloride. Furthermore, the object of the present invention cannot be achieved by supporting titanium tetrachloride on a carrier such as magnesium chloride, or by simply heat-treating titanium tetrachloride after reducing it with an organoaluminum compound. The solid product ( ) which is the catalyst component according to the present invention is produced as follows. First, (a) an organoaluminum compound (L) and titanium tetrachloride (C) are reacted, or (b) a reaction product (P) of the former and an electron donor (A) is reacted with the latter to form a solid product (). Manufacture.
The method (b) can ultimately yield a more preferable titanium catalyst component. Regarding method b,
It is described in the specification of JP-A-56-110707 and is as follows. The reaction between the organoaluminum compound (L) and the electron donor (A) is carried out in the solvent (D) at -20°C to 200°C, preferably at -10°C to 100°C for 30 seconds to 5 hours. There is no restriction on the order of addition of (L), (A) and (D), and the ratio of amounts used is as follows:
Electron donor 0.1 to 1 mole of organoaluminum
8 mol, preferably 1-4 mol, solvent 0.5-5,
Preferably, 0.5 to 2 is appropriate. Aliphatic hydrocarbons are preferred as solvents. The reaction product (P) is thus obtained. The reaction product (P) can be subjected to the next reaction in a liquid state after the reaction (sometimes referred to as reaction product liquid (P)) without separation. The reaction between the reaction product (P) and titanium tetrachloride (C) is 0
It is carried out at ~200°C, preferably 10-90°C for 5 minutes to 8 hours. Although it is preferred not to use a solvent, aliphatic or aromatic hydrocarbons can be used. (P), (C)
The mixing of the solvent and the solvent may be performed in any order, and it is preferable that the mixing of the entire amount be completed within 5 hours.
After mixing the entire amount, it is preferable to continue the reaction at 10 to 90° C. within 8 hours. The amount of each used in the reaction is 0 to 3000 ml of the solvent per mol of titanium tetrachloride, and the ratio of the number of Al atoms in the reaction product (P) to the number of Ti atoms in titanium tetrachloride is the reaction product (P). (Al/Ti)
and is 0.05 to 10, preferably 0.06 to 0.2. After the reaction is complete, the liquid portion is separated and removed by filtration or decantation, and the product is washed repeatedly with a solvent, and the obtained solid product (2) is used in the next step while suspended in the solvent. Alternatively, it may be further dried and taken out as a solid for use. The solid product () is then reacted with an electron donor (A) and an electron acceptor (B). Although this reaction can be carried out without using a solvent, preferable results are obtained when an aliphatic hydrocarbon is used. The amount to be used is 10g or more of (A) per 100g of solid product ().
1000g preferably 50g to 200g, (B) 10g to 1000g
Preferably 20g to 500g, 0 to 3000ml of solvent, preferably 100 to 1000ml. These 3 or 4 substances
The substances were mixed for 30 seconds to 60 minutes at -10℃ to 40℃, then heated to 40℃
It is desirable to carry out the reaction at ~200°C, preferably 50°C ~ 100°C for 30 seconds to 5 hours. solid product (),
There is no restriction on the mixing order of (A), (B) and the solvent. (A) and (B) may be reacted with each other before mixing with the solid product (); in this case, (A)
After reacting and (B) at 10 to 100℃ for 30 minutes to 2 hours,
Use one that has been cooled to below 40℃. After the reaction of the solid product () with (A) and (B) is completed, the reaction mixture is filtered or decanted to separate and remove the liquid portion, and then washed repeatedly with a solvent to remove unreacted liquid raw materials. By the solid product ()
is obtained. The obtained solid product (2) can be dried and taken out as a solid, or it can be left suspended in a solvent for the next use. The thus obtained solid product () is used as a catalyst by combining 0.1 to 500 g of an organoaluminum compound and a predetermined amount of an aromatic ester described below with respect to 1 g of the solid product (), or more preferably, by reacting this catalyst with an α-olefin. After preactivation, the ester is added to prepare a catalyst for producing a block copolymer according to the present invention. The organoaluminum compounds (L) and (L ₂ ) used in the catalyst according to the present invention have the general formula
It is expressed as AlRnR'nX ₃ -(n+n'). In the formula, R and R' represent a hydrocarbon group such as an alkyl group, an aryl group, an alkaryl group, or a cycloalkyl group, or an alkoxy group, X represents a halogen such as fluorine, chlorine, bromine, and iodine, and n, n' is 0<
Represents any number n+n'≦3. Specific examples include trimethylaluminum, triethylaluminum, trin-propylaluminum, trin-
Butylaluminum, tri-n-hexylaluminum, tri-i-hexylaluminum, tri-2-
Trialkylaluminums such as methylpentylaluminum, tri-n-octylaluminum, and tri-n-decylaluminum, diethylaluminium monochloride, di-n-propylaluminum monochloride, di-i-butylaluminum monochloride, diethylaluminium monofluoride, diethyl aluminum monobromide,
Diethylaluminum monohalides such as diethylaluminum monoiodide, alkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride, alkylaluminum sesqui- or dihalides such as methylaluminum sesquichloride, ethylaluminum dichloride, i-butylaluminum dichloride, etc. etc.,
In addition, alkoxyalkylaluminums such as monoethoxydiethylaluminum and diethoxymonoethylaluminum can also be used. Two or more types of these organoaluminum compounds can also be used in combination. The organoaluminum compound (L) to obtain the reaction product (P) and the organoaluminum (L ₂ ) combined with the solid product () may be the same or different. As the electron donor (A) used in the present invention, various ones are shown below, but it is preferable to mainly use ethers and to use ethers in combination with other electron donors. Those used as electron donors are organic compounds having oxygen, nitrogen, sulfur, or one or more types of adjacent atoms, such as ethers, alcohols, esters, aldehydes, fatty acids, and ketones. nitriles, amines, amides, ureas or thioureas, isocyanates, azo compounds, phosphines, phosphites, phosphinites, thioethers or thioalcohols.
Specific examples include diethyl ether, di-n-propyl ether, di-n-butyl ether, diisoamyl ether, di-n-pentyl ether, di-n-
Ethers such as hexyl ether, di-i-hexyl ether, di-n-octyl ether, di-i-octyl ether, di-n-dodecyl ether, diphenyl ether, ethylene glycol monomethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, methanol, ethanol, propanol , alcohols such as butanol, pentanol, hexanol, octanol, phenols such as phenol, cresol, xylenol, ethylphenol and naphthol, methyl methacrylate, ethyl acetate, butyl formate, amyl acetate, vinyl butyrate, vinyl acetate, benzoic acid Ethyl, propyl benzoate, butyl benzoate, octyl benzoate, 2-ethylhexyl benzoate, methyl toluate, ethyl toluate, 2-ethylhexyl toluate, methyl anisate,
Esters such as ethyl anisate, propyl anisate, ethyl cinnamate, methyl naphthoate, ethyl naphthoate, propyl naphthoate, butyl naphthoate, 2-ethylhexyl naphthoate, ethyl phenylacetate, acetaldehydes, formic acid, acetic acid, aliphatic carboxylic acids such as propionic acid, butyric acid, oxalic acid, succinic acid, acrylic acid, and maleic acid; aromatic carboxylic acids such as benzoic acid and p-methylbenzoic acid; ketones such as methyl ethyl ketone, methyl isobutyl ketone, and benzophenone; Nitriles such as acetonitrile and butylnitrile, methylamine, diethylamine, tributylamine, triethanolamine, β(N,N-dimethylaminoethanol), pyridine, quinoline, α-picoline, N,N,N′,N′- Amines such as tetramethylhexaethylenediamine, aniline, dimethylaniline, formaldehyde, hexamethylphosphoric acid triamide, N,N,N′,N′,N″-pentamethyl-N′-β-dimethylaminomethylphosphoric acid triamide, octa Amides such as methylpyrophosphoramide, ureas such as N,N,N',N'-tetramethylurea, isocyanates such as phenyl isocyanate and toluyl isocyanate, azo compounds such as azobenzene and azotoluene, ethylphosphine , triethylphosphine, trin
- Phosphines such as butylphosphine, tri-n-octylphosphine, triphenylphosphine, triphenylphosphine oxide, dimethylphosphite, di-n-octylphosphite, triethylphosphite, tri-n-butylphosphite, triph Phosphites such as enyl phosphite, phosphinites such as ethyl diethyl phosphinite, ethyl butyl phosphinite, phenyl diphenyl phosphinite, diethyl thioether, diphenyl thioether, methyl phenyl thioether, ethylene sulfide, propylene sulfide Examples include thioethers such as ido, thioalcohols such as ethylthioalcohol and n-propylthioalcohol, and thiophenols such as thiophenol and methylthiophenol. Two or more types of these electron donors can also be used as a mixture in any ratio. The electron acceptor (B) used in the catalyst according to the present invention is typified by a halide of an element in groups 1 to 10 of the periodic table. Specific examples include anhydrous aluminum chloride, silicon tetrachloride, stannous chloride, stannic chloride, titanium tetrachloride, vanadium tetrachloride, and antimony pentachloride, and these can also be used in combination. Most preferred is titanium tetrachloride. The following are used as the solvent (D). That is, as aliphatic hydrocarbons, n-heptane, n-
Octane or i-octane, etc. are indicated, and halogenated hydrocarbons such as carbon tetrachloride, chloroform, dichloroethane, trichloroethylene,
Tetrachlorethylene etc. can be used.
In addition, aromatic hydrocarbons and their alkyl or phenyl derivatives include benzene, naphthalene, mesitylene, duylene, ethylbenzene, isopropylbenzene, 2-ethyllunaphthalene,
Examples of halogen derivatives include 1-phenylnaphthalene and the like, and monochlorobenzene, orthodichlorobenzene, and the like. The solid product thus obtained ( ) is then combined with the organoaluminum compound (L ₂ ) and the aromatic carboxylic acid ester (R) mentioned above and treated with ethylene as a catalyst according to the process of the earlier invention. Used in propylene copolymerization. but,
More preferably, the catalyst is used as a preactivated catalyst by reacting a small amount of α-olefin.
As the organoaluminum compound (L ₂ ), a dialkyl aluminum monohalide represented by the formula (AlR ₁ R ₂ X) is preferable. In the formula, R ₁ and R ₂ represent a hydrocarbon group such as an alkyl group, an aryl group, an alkaryl group or a cycloalkyl group, or an alkoxy group, and X represents a halogen such as fluorine, chlorine, bromine or iodine. Specific examples are diethylaluminium monochloride, di-n-butylaluminum monochloride, diisobutylaluminum monobromide and diethylaluminium monoiodide. In the slurry polymerization or bulk polymerization of ethylene and propylene according to the previous invention related to the present invention, a catalyst combining the above-mentioned solid product () and an organoaluminum compound (L ₂ ) is also sufficiently effective. When used in phase polymerization, it is desirable to use a catalyst with higher activity, which is preactivated by further reacting this catalyst with an α-olefin. When gas phase polymerization is performed following slurry polymerization or bulk polymerization, even if the catalyst initially used is the former (note: not preactivated), the gas phase polymerization stage has already reacted with propylene and ethylene. Since the reaction is taking place, it is the same as the latter catalyst, and excellent effects can be obtained. Preactivation is carried out for 1 g of solid product ().
Organic aluminum 0.1g to 500g, solvent 0 to 50,
Hydrogen 0~1000ml and α-olefin 0.05g~
5000g, preferably 0.05g to 3000g, 0°C to
React α-olefin at 100°C for 1 to 20 hours,
It is desirable to react 0.01 to 2000 g, preferably 0.05 to 200 g of α-olefin per 1 g of solid product (). The reaction of α-olefin for preactivation is
Liquefied propylene, liquefied butene, in aliphatic or aromatic hydrocarbon solvents or without solvents.
The reaction can be carried out in a liquefied α-olefin such as No. 1, or ethylene, propylene, etc. can be reacted in a gas phase. It is also possible to carry out the reaction in the presence of a pre-produced α-olefin polymer (preferably an ethylene-propylene copolymer) or hydrogen. There are various aspects of the preactivation method. These include, for example, a slurry reaction in which an α-olefin is brought into contact with a catalyst that combines a solid product () and an organoaluminum, a bulk reaction method, and a method in which a solid product () and an organoaluminum are combined in the presence of an α-olefin. Method,
A method in which an α-olefin polymer is coexisting in the method of , or a method in which hydrogen is coexisting in the method of .
An aromatic carboxylic acid ester (R) can also be added in advance during preactivation. The α-olefin used for preactivation is
Ethylene, propylene, butene-1, hexene-
1. Heptene-1 and other linear monoolefins,
In addition to branched monoolefins such as 4-methyl-pentene-1,2-methyl-pentene-1,3-methyl-butene-1, styrene can also be used. These α-olefins may be the same as or different from the α-olefin to be polymerized, that is, ethylene or propylene, and two or more types of α-olefins may be used.
-Olefins may be mixed and used. After completion of preactivation, the solvent, organoaluminum compound and unreacted α-olefin are removed by distillation under reduced pressure, filtration, decantation, etc.
It can be used in the polymerization as a dried granular catalyst, or as a catalyst suspended in a solvent with a concentration not exceeding 80% per gram of solid product. Further, a new organoaluminum compound can also be added during polymerization. Using the preactivated catalyst thus obtained, the copolymerization of propylene and ethylene according to the present invention is carried out in a hydrocarbon solvent such as n-hexane, n-heptane, n-octane, benzene or toluene. Slurry polymerization carried out, bulk polymerization carried out in liquefied propylene and gas phase polymerization can be carried out. However, in order to increase the target stiffness of the ethylene-propylene copolymer, the ratio of aromatic carboxylic acid ester (hereinafter referred to as aromatic ester) (R) to the solid product () is as follows: R/
=0.1 to 10.0 (molar ratio). If the amount of aromatic ester is too small, the improvement in rigidity will be insufficient, and if it is too large, the catalytic activity will decrease, making it impractical. Specific examples of aromatic esters include benzoate, propyl benzoate, butyl benzoate, octyl benzoate, 2-ethylhexyl benzoate, methyl toluate, ethyl toluate, 2-ethylhexyl toluate, methyl anisate,
Ethyl anisate, propyl anisate, ethyl cinnamate, methyl naphthoate, propyl naphthoate,
These include butyl naphthoate, 2-ethylhexyl naphthoate, and ethyl phenyl acetate. The usage ratio of the organoaluminum compound (L ₂ ) and the solid product ( ) is Al/Ti = 0.1 to 100, preferably 1 to 20.
It is. In this case, the number of moles of the solid product () essentially refers to the number of Tig atoms in the solid product (). The polymerization conditions of the first stage of the ethylene-propylene copolymer of the previous invention according to the present invention are as follows. That is, the desired MFR is usually 0.5 to 20
The hydrogen concentration in the gas phase is 0.5 to 20 mol%.
Polymerization temperature is usually 20°C to 80°C, preferably 40°C to 70°C.
It is ℃. If the temperature is lower than 20°C, the catalyst activity will be low, which is not practical, and if the temperature is higher than 80°C, the proportion of polymer soluble in the polymerization catalyst will increase, which is undesirable. Polymerization pressure is 0 to 50
Kg/cm ² G, and is usually carried out for about 30 minutes to 15 hours. The propylene and ethylene block copolymerization format according to the present invention can be any of the following.
That is, for example, slurry polymerization using an inert solvent such as propane, hexane or heptane,
Bulk polymerization carried out in liquid propylene, gas phase polymerization carried out in gaseous propylene, or a combination of two or more thereof. However, in order to improve the stiffness of the desired polymer, it is preferable to carry out the first stage by slurry polymerization, bulk polymerization or gas phase polymerization, and to carry out the second stage by slurry polymerization. In the first stage polymerization according to the invention, a mixed monomer of ethylene and propylene containing 1.2 to 4.0% by weight of ethylene, preferably 1.8 to 3.0% by weight, is fed to the reactor, the ethylene content being 1.0 to 3.0%, preferably 1.5 to 3.0% by weight.
2.5% by weight of the copolymer is produced from 75 to 90% by weight, preferably from 80 to 85% by weight of the final amount of copolymer obtained. If the ethylene content of the first stage polymer is less than 1.0% by weight, the improvement in whitening and low-temperature impact cracking resistance will be insufficient.
If it exceeds 3.0% by weight, rigidity and heat resistance decrease, which is not preferable. Ethylene supplied in the first stage can be uniformly supplied during the polymerization period, but as mentioned above, the ethylene content in the copolymer obtained in the first stage needs to be 1.0 to 3.0% by weight. There is. The amount of polymerization in the first stage is preferably 75 to 90% by weight of the total amount of polymerization, which is the sum of the amount of polymerization in the second stage.
If the content is outside the former range, it will not be possible to obtain a polymer that satisfies all of the desired physical properties. In the second stage polymerization of the method for producing a block copolymer according to the present invention, an ethylene/propylene mixed monomer containing 55 to 75% by weight of ethylene, preferably 59 to 66% by weight, is supplied. Ethylene content as a composition of the copolymer fraction produced
10-25% by weight, preferably 15-20% by weight of the 75-85% by weight copolymer fraction, preferably 78-82% by weight, is polymerized. If the ethylene content of the copolymer fraction is less than 75% by weight, the whitening improvement effect aimed at by the present invention will be insufficient. Moreover, if it exceeds 85% by weight, the strength at low temperatures will be insufficient. The effect when the polymerization amount in the second stage falls outside the above-mentioned range of 10 to 25% by weight is almost the same as that when the ethylene content falls outside the above-mentioned range. That is, if it is less than 10% by weight, the effect of improving impact strength will be insufficient, and if it exceeds 25% by weight, the stiffness of the obtained copolymer will be reduced. of the copolymer fractions obtained in the first and second stages of the copolymerization according to the present invention described above.
The ratio of MFR should preferably be MFR (first stage)/MFR (second stage) = 1.0 to 10. If this ratio is less than 1.0, the impact strength and tensile elongation of the finally obtained copolymer tend to decrease, which is undesirable. At the same time, there is the disadvantage that the polymerization rate is reduced due to the extremely high hydrogen concentration in the gas phase during the first stage polymerization. If the ratio exceeds 10, the whitening improvement effect of molded articles obtained from the copolymer will be slightly reduced, which is not preferable. The gas phase hydrogen concentration in the second stage copolymer of the present invention is, for example, 10 to 60 mol% when the polymerization temperature is 60°C. If the temperature is higher than 60℃, the desired MFR
The hydrogen concentration to obtain can be reduced somewhat. As a result of the above, the obtained ethylene-propylene block copolymer (A) has the following properties based on the total amount of the composition:
74-88% by weight is used, preferably 79-84% by weight. As the polyethylene (B), polyethylene having a density of 0.955 or more and usually called high-density polyethylene (HDPE) can be preferably used. If the density is less than 0.955, the stiffness of molded articles from the composition of the invention is reduced. The amount of polyethylene (B) used is 10 to 20% by weight, preferably 13 to 17% by weight, based on the total amount of the composition. If it is less than 10% by weight, the whitening improvement effect is insufficient, and if it exceeds 20% by weight,
This is undesirable because the strength of the molded product, especially the tear strength in the longitudinal direction when processed into a sheet, is extremely reduced. Melt index (MI) of the polyethylene (B)
is preferably 0.2 to 20. If it is less than 0.2, it will be difficult to mix uniformly and a granulator or the like with a particularly strong kneading force will be required for mixing, and if it exceeds 20, the low-temperature impact strength of the composition will decrease, both of which are undesirable. As the ethylene-propylene copolymer rubber (C), one that is usually called EPR and has an ethylene content of 25 to 85% by weight can be used. If the content is more than 85% by weight or less than 25% by weight, the impact strength of the composition will be low, which is not preferable. In addition, as the rubber (C),
It is also possible to use so-called EPDM obtained by copolymerizing a small amount of a non-conjugated diene such as dicyclopentadiene as a third component in addition to ethylene or propylene. The MI of the copolymer rubber (C) is preferably within the range of 0.2 to 20 for the same reason as the polyethylene (B). The amount of the copolymer rubber (C) used is preferably 2 to 5% by weight, particularly preferably 2.5 to 5% by weight based on the total amount of the composition.
It is 4.0% by weight. When the amount used is less than 2% by weight, the effect of improving low-temperature impact cracking is insufficient, and when it exceeds 5% by weight, the rigidity decreases, which is not preferable. The ethylene-propylene copolymer of the present invention has interrelated limitations (for example, when impact resistance strength is improved, Compared to the control material obtained by a known method, the material maintains the same impact resistance value while achieving a significant improvement in stiffness and whitening resistance. Achieved. Therefore, the product of the present invention can be widely applied to various molding fields, but especially in the sheet field, it can be expected to improve the quality of molded products or expand the amount of use by making the molded products thinner. Furthermore, by creating an ethylene/propylene block copolymer composition in which the copolymer of the present invention is blended with an appropriate amount of a nucleating agent and/or an inorganic filler, it is possible to achieve properties that could never be achieved with known control polypropylene compositions. The following physical properties: high rigidity;
It is possible to produce molded products that have a good balance of whitening resistance and impact resistance. The present invention will be explained below with reference to examples, but these are not intended to limit the invention. The methods for measuring various physical property values in Examples were as follows. ◎MFR: ASTM D-1238 (g/10 minutes), 230℃ 2.16Kg load ◎MI: ASTM D-1238 (g/10 minutes), 190℃ 2.16Kg load ◎Calculation method of MFR at each polymerization stage: MFR ₁ : 1st stage MFR (*1) MFR ₂ : 2nd 〃 MFR ₁₊₂ : Total MFR generated in the 1st stage and 2nd stage (*1) W ₁ : Polymerization ratio in the 1st stage W ₂ : 2nd 〃 W ₁ + W ₂ = 1.0 Note *1: Sampling and actual measurement at each stage. Calculation of MFR ₂ is based on the following relational expression. logMFR ₁₊₂ = (W ₁ /W ₁ +W ₂ )logMFR ₁ + (
W ₂ /W ₁ +W ₂ ) logMFR ₂ ◎Ethylene content: Based on infrared absorption spectroscopy. ◎Ethylene/propylene reaction ratio at each stage: Copolymers with varying ethylene/propylene reaction ratios were prepared in advance, and a calibration curve was created using infrared absorption spectroscopy using this as a standard sample (140℃, A720/A730) , the second stage, and the third stage were determined by the difference spectrum method. ◎Calculation of W ₁ and W ₂ : Calculated from the ethylene content in the copolymer at each stage and the ethylene/propylene reaction ratio at each stage. ◎Method for measuring physical properties of sheet molding (sheet thickness 0.8mm): *Young's modulus: ASTMD882 (Kgf/ ^mm2 ) *Punching impact strength: ASTMD781 (Kgf・cm) *Bending whitening: Chitsuso method (mm); The bending radius at which whitening began to occur was measured. *Impact whitening: Same as injection molding, but the radius of the striking core was 3.2 mm, a 200 g weight was dropped from a height of 50 cm, and the radius of the whitened area was measured. (mm). *Impact cracking: Put a 300 x 300 mm sheet in a constant temperature room, and after 12 hours fold the sheet so that the textured side faces outward and both ends meet, place it on a table, and use work gloves to fold it 180 degrees. The state when bent was observed. ○: No cracking at all. △: Cracks occur in the bent part. ×: Cracks propagated. *Sheet appearance: visual inspection Example 1 (1) Preparation of catalyst 600 ml of n-hexane, 0.50 mol of diethylaluminium monochloride (DEAC), and 1.20 mol of diisoamyl ether were mixed at 25°C for 1 minute.
A reaction product P (molar ratio of diisoamyl ether/DEAC of 2.4) was obtained by reacting for a minute at the same temperature.
4.0 mol of titanium tetrachloride was placed in a reactor purged with nitrogen, heated to 35°C, the entire amount of the reaction product P was added dropwise to this over 180 minutes, and then heated to the same temperature for 30 minutes.
The temperature was raised to 75°C and reacted for an additional hour, cooled to room temperature, the supernatant liquid was removed, and n-hexane was added.
Add 4000 ml and remove the supernatant by decantation four times to obtain a solid product ().
Obtained 190g. While the entire amount of () was suspended in 3000 ml of n-hexane, 160 g of diisoamyl ether and 350 g of titanium tetrachloride were added at 20°C over about 1 minute at room temperature, and the mixture was reacted at 65°C for 1 hour. After the reaction was completed, it was cooled to room temperature (20℃), the supernatant liquid was removed by decantation, and the
ml of n-hexane was added, stirred for 10 minutes, allowed to stand, and removed the supernatant liquid, which was repeated five times, and then dried under reduced pressure to obtain a solid product (). (2) Adjustment of preactivated catalyst After purging a stainless steel reactor with internal volume 20 with inclined blades with nitrogen gas, 15
, 42g of diethylaluminum monochloride,
After adding 30 g of solid product () at room temperature, hydrogen
Add 15N, propylene partial pressure 5Kg/cm ² G to 5
After reacting for a minute, unreacted propylene, hydrogen and n-hexane were removed under reduced pressure to obtain a preactivated catalyst in the form of powder (82.0 g of propylene reacted per 1 g of solid product). (3) First stage polymerization of propylene N-hexane was placed in a stainless steel polymerization vessel with an internal volume of 400 and a turbine-type stirring blade, which was purged with nitrogen.
250 Then, 10 g of diethylaluminum monochloride, 820 g of the preactivated catalyst, and 11.0 g of methyl p-toluate were charged, and hydrogen was added.
50N was added. Then, after raising the liquidus temperature to 60°C, propylene was supplied and the total pressure was raised to 10Kg/cm ² G. After reaching 60℃ and 10Kg/cm ² G, supply propylene containing 2wt% ethylene to 60℃.
The polymerization was continued for 4 hours while maintaining the temperature at 10 Kg/cm ² G. During the polymerization, the hydrogen concentration in the gas phase was added using a gas chromatograph. After continuing the polymerization for 4 hours, the supply of propylene was stopped, unreacted propylene was discharged, and a portion of the slurry in the polymerization vessel was collected, filtered, washed, and dried to obtain polypropylene powder. The MFR of this powder is 3.1 and the ethylene content is 2.1%
It was hot. (4) Second stage polymerization After releasing unreacted propylene, the inside of the polymerization vessel is 60
℃ and 0.1 Kg/cm ² G, and ethylene and propylene were continuously fed at a constant rate for 1.5 hours so that the feed ratio of ethylene was 90% by weight as the second stage polymerization raw material. The total supply of ethylene is
7.5Kg. During the polymerization, hydrogen was supplied so that the gas phase hydrogen concentration was 25 mol%. After polymerization for 1.5 hours, the supply of ethylene and propylene was stopped, and unreacted ethylene and propylene were released. A portion of the slurry in the polymerization vessel was collected, filtered, washed, and dried to obtain a polypropylene copolymer (hereinafter sometimes referred to as polypropylene) powder.
This powder had an MFR of 2.1 and an ethylene content of 14.5% by weight. In addition, the second calculated
The ethylene content in the copolymer fraction produced in the second stage was 80%. Next, 25 methanol was supplied into the polymerization vessel,
The temperature was raised to 75°C. After 30 minutes, add 100g of 20% caustic soda water and stir for 20 minutes to make pure water.
The remaining propylene was continuously added.
After extracting the water layer, add 100% pure water and 10%
Stir for minutes, wash with water, extract the aqueous layer, then extract the polypropylene-n-hexane slurry,
This product was filtered and dried to obtain polypropylene powder. The analysis was carried out in the same manner as in the second stage, and the results are shown in Table 1. (5) Production of granules Polypropylene powder obtained in (4) above 6.56
Kg, polyethylene 1.2Kg with density 0.965, MI=5.0
(Chitsuso Polyethylene M850) and Japan Synthetic Rubber Co., Ltd.
Add 0.008 kg of phenolic heat stabilizer and 0.008 kg of calcium stearate to 0.24 kg of EPR (EP02P), mix at room temperature for 10 minutes with a high-speed stirring mixer (Note: Henschel mixer, trade name), and mix the mixture with a screw diameter Granulation was performed using a 40 mm extrusion granulator. (6) Manufacture of sheet molded product The granules obtained in (5) are molded into a 50mmφ extruder.
A single-sided grained sheet with a width of 60 cm and a thickness of 0.8 mm was prepared at 225°C, and the sheet was conditioned in a room with a humidity of 50% and a room temperature of 23°C for 72 hours. Then, physical properties were measured as shown in Table 1. Comparative Examples 1 and 2 In Example 1, instead of the pre-activated catalyst, 30 g or 45 g of a commercially available catalyst (AA type) obtained by reducing titanium tetrachloride with metal aluminum and pulverizing it to activate it.
g, using 0 g or 22 g of methyl toluate,
Further, the same procedure as in Example 1 was carried out except that the hydrogen charged in the first stage was 25N or 50N, and the hydrogen concentration in the gas phase gas was 1.5 mol% or 3.0 mol%. The manufacturing conditions and results are shown in Table 1. As is clear from these tables, even if titanium trichloride (AA) is used in place of the catalyst component of the present invention, a highly rigid copolymer cannot be obtained. Further, even when MPT is used in combination with titanium trichloride (AA), the large improvement in rigidity as in the present invention is not observed. Comparative Example 3 20 g of anhydrous magnesium chloride, 10.0 ml of ethyl benzoate and 6.0 ml of methylpolysiloxane were ground in a ball mill for 100 hours. 15 g of the solid product obtained were suspended in 200 ml of titanium tetrachloride,
After stirring at 80°C for 2 hours, the liquid was removed by filtration, washed with n-hexane until no titanium tetrachloride was detected in the filtrate, and then dried to obtain a solid catalyst. 7 g of this solid catalyst was used in place of the preactivated catalyst of Example 1, and in place of DEAC,
The same procedure as in Example 1 was conducted except that 10 g of TEA was used and the amount of hydrogen was changed as shown in Table 1. As the production conditions and results are shown in the same table and Table 1, in the supported catalyst,
Highly rigid polypropylene, which is the effect of the present invention, cannot be obtained. Comparative Example 4 In Example 1, 0.5 mol of DEAC was used instead of the reaction product P during the reaction to obtain the solid product (),
After dropping in the same manner as in Example 1 at 0°C instead of 35°C.
The temperature was raised to 75°C, the reaction was stirred for another hour, and then the mixture was refluxed for 4 hours at the boiling temperature of titanium tetrachloride (approximately 136°C) to turn purple. After cooling, it was washed with n-hexane and filtered in the same manner as in Example 1. , and dried to obtain a solid catalyst. The same procedure as in Example 1 was performed except that this solid catalyst was replaced with the preactivated catalyst of Example 1, and the hydrogen at each stage was changed as shown in Table 1, and the results are shown in the same table. The copolymer obtained in this case is also inferior to the copolymer of Example 1 in overall stiffness. Examples 2, 3, 4, Comparative Examples 5, 6, 7 Example 1 was carried out in the same manner as in Example 1 except that the amount of MPT used and therefore the aromatic ester/solid product molar ratio was changed. However, Example 2, Comparative Examples 5 and 6
492g of preactivated catalyst, Comparative Example 7 1640g,
In Example 3, 984 g was used. Also, in the second stage of Example 4 and Comparative Example 7, ethylene,
The amount of propylene supplied is 1/2 of that in Example 1, respectively.
It was set to 1/8. Regarding hydrogen, it was carried out under the conditions shown in Table 2, and the results are shown in Table 2. As is clear from these tables, when the aromatic ester/solid product molar ratio used during polymerization is 0.05 or less, the rigidity of the obtained block copolymer is insufficiently improved. Further, in Comparative Example 7 in which the molar ratio greatly exceeds 10.0, the obtained polymer had high rigidity, but the catalytic activity was greatly reduced, and it was inferior in this aspect. Examples 5 to 10 The same procedures as in Example 1 were carried out except that predetermined amounts of aromatic esters d to i below were used in place of MPT. d; Ethyl p-toluate 12.0 g (Example 8) e; Butyl p-toluate 14.0 g (Example 9) f; Methyl benzoate 10.0 g (Example 10) g; Ethyl benzoate 11.0 g (Example 10) 11) h: Methyl p-anisate 12.0 g (Example 12) i: Ethyl p-anisate 13.0 g (Example 13) Polymerization conditions and results are shown in Table 3. As is clear from the table, in these Examples, almost the same results as Example 1 were obtained in both yield and physical properties. Examples 11 and 12, Comparative Examples 8 and 9 In Example 1, the ethylene supply amount and hydrogen amount in the first stage were changed as shown in Table 4, and the other conditions were the same as in Example 1. However, the amount of monomer fed in the second stage of Comparative Example 8 was 75% of that in Example 1, and the results are shown in the same table. As is clear from the same table, Comparative Example 8, in which ethylene was not added to the first stage, was inferior in whitening improvement effect, and Comparative Example 9 was undesirable because the ethylene content in the first stage was too high, resulting in a large decrease in rigidity. Examples 13 and 14, Comparative Examples 10 and 11 The same procedures as in Example 1 were carried out except that the second stage polymerization conditions were changed as shown in Table 4. The amount of ethylene supplied was 7.0 Kg in Example 13 and Comparative Example 10, and 8.0 Kg in Example 14 and Comparative Example 11. As is clear from the table, when the ethylene content in the second stage copolymer portion is as low as 70% (comparative example
10) The obtained composition is inferior in whitening resistance,
In addition, as in Comparative Example 11, the content is too high (90
%), the composition is inferior in terms of impact cracking. Example 15, Comparative Examples 12 and 13 The same procedures as in Example 1 were carried out except that the polymerization ratios in the first and second stages were changed as shown in Table 4. However, the ethylene supply rate was 5 Kg/hr in each case as in Example 1, and the polymerization time was 1 hour (Example 15) and 0.5 kg/hr, respectively.
time (Comparative Example 12) and 2.5 hours (Comparative Example 13). In the above, when the amount of polymerization in the second stage is small (Comparative Example 12), the resulting composition is inferior in impact strength, and when the amount of polymerization is too large (Comparative Example 13), This composition is inferior in whitening resistance and rigidity, both of which are unfavorable. Examples 16, 17, Comparative Examples 14, 15 The ethylene-propylene copolymer obtained in Example 1, EPR (ethylene 74% by weight, MFR 3.5, trade name EP02P) and polyethylene HDPE (d=
0.965, MI=5, trade name Chitsusopolyech M850)
Compositions were prepared by using the following methods and varying the amount of polyethylene mixed as shown in Table 5. As is clear from the table, when the amount of polyethylene mixed is too small (Comparative Example 14), the low-temperature impact strength and resistance to whitening are inferior, and when it is too large (Comparative Example 15), the physical properties of the formed sheet became non-uniform, and the strength in the vertical direction in particular decreased significantly. Examples 18 and 19, Comparative Examples 16 and 17 The same procedures as in Example 1 were carried out except that the amount of EPR (trade name EP02P) used was changed as shown in Table 5. As is clear from the table, when the amount of EPR mixed is too small (Comparative Example 16), the composition is inferior in terms of impact cracking, and when it is too large (Comparative Example 17), the composition becomes stiff and difficult to whiten. They are inferior in terms of sex and are not desirable in any way. Examples 20, 21, Comparative Examples 17', 18, 19 The same procedures as in Example 1 were carried out, except that polyethylenes with different MI or densities were used. Table 5 shows the mixed composition and the physical properties of the sheet formed from the resulting composition. As a result, if the MI of the polyethylene mixed with the resulting composition is too high (Comparative Example 17),
Inferior to each example in terms of impact cracking, the MI
When the ratio was too low (Comparative Example 18), the mixing became non-uniform, fish eyes were generated in the resulting sheet, and the sheet was inferior to those of the Examples in terms of impact cracking. Furthermore, when the density of the polyethylene used was low (Comparative Example 19), the resulting composition was inferior to that of the example in terms of rigidity. Examples 22, 23, 24 In Example 1, except for changing the type of EPR used (ethylene content weight%, MI),
The same procedure was carried out. The mixing conditions and results are shown in Table 6.

【table】

【table】

【table】

【table】

【table】

【table】

【table】

【table】

【table】

【table】

【table】

Claims (1)

[Scope of Claims] 1 B. Ethylene-propylene block copolymer (A) 74 to 74 produced by the method described below.
88% by weight, "a solid product obtained by reacting an organoaluminum compound (L) or a reaction product (P) of an organoaluminium compound (L) and an electron donor (A) with titanium tetrachloride (C)" ) is reacted with an electron donor (A) and an electron acceptor (B), and the solid product () obtained is combined with an organoaluminium compound (L ₂ ) and an aromatic carboxylic acid ester (R), and the carboxylic acid ester is Molar ratio of (R) and solid product () R/
= 0.2 to 10.0, propylene and ethylene were mixed in the presence of hydrogen in the following two stages: In the first stage, the ethylene content was 1.0 to 1.
A copolymer containing 3.0% by weight is produced in an amount of 75 to 90% by weight of the total amount of polymerization, and then, in the second step, a copolymer with an ethylene content of 75 to 85% by weight is produced in an amount of 10 to 25% by weight of the total amount of polymerization. ○B Density 0.955g/ ^cm3 or more, melt index
Ethylene consisting of 10-20% by weight of polyethylene (B) with a melt index of 0.2-20 and 2-5% by weight of ethylene-propylene copolymer rubber (C) with a melt index of 0.2-20 and an ethylene content of 25-85% by weight.・
Propylene copolymer composition (J). 2 The ratio of the melt index (MFR) of the copolymer fraction obtained in the first stage and the copolymer fraction obtained in the second stage is set as MFR (first stage)/MFR (second stage) = 1.0 to 10. The composition according to claim 1, which uses the ethylene-propylene block copolymer (A).