JPH04279617A - Propylene block polymer - Google Patents

Abstract

PURPOSE:To provide the subject polymer consisting of polypropylene copolymer blocks and propylene.ethylene random copolymer blocks, having a specific side copolymer composition distribution and giving molded products having excellent balanced rigidity and impact resistance. CONSTITUTION:The objective polymer having an MFR of 0.1-100g/10min comprises (A) 50-95wt.% of blocks consisting of a propylene homopolymer or a random copolymer of propylene with 2-5C olefin having an MFR of 1-200g/min and an isotactic index of >=95% [in the case of the copolymer, the content of the alpha-olefin is <=3wt.% based on the total weight of the copolymer] and (B) 5-70wt.% of blocks consisting of propylene-ethylene random copolymer having an ethylene content of 20-90wt.%, a copolymer composition distribution index (C) of >=300 determined by the measurement of NMR and an MFR of 0.01-5g/10min.

Description

[Detailed description of the invention]

[Background of the invention]

[Industrial Application Field] The present invention relates to a propylene block copolymer which has an excellent balance between rigidity and impact resistance and is particularly useful as an injection molding resin, as well as an essential constituent unit (block (B)) of this propylene block copolymer. )), and relates to a propylene-ethylene random copolymer that achieves the properties described above.

0002

BACKGROUND OF THE INVENTION In recent years, there has been a demand for thinner and lighter injection molded products from the viewpoint of resource and energy conservation. By improving the balance between polypropylene's rigidity and impact resistance, we are able to make molded products thinner and lighter.
Various proposals have been made for the purpose of improving the physical properties of polypropylene. For example, JP-A-54-113695,
JP-A-55-5969, JP-A-55-115417, JP-A-61-69821, JP-A-61-69822
No. 61-69823 and Japanese Unexamined Patent Publication No. 61-69823 have been proposed. However, there is a need for further improvement in the balance between rigidity and impact resistance.

0003

OBJECTS OF THE INVENTION An object of the present invention is to provide a propylene block polymer that provides molded articles with an excellent balance of rigidity and impact resistance.

0004

[Means for solving the problem] [Summary of the invention] <Summary>
As a result of various exploration studies, the present inventors have found that by using a specific propylene-ethylene random copolymer (component (B)) having a wide copolymerization composition distribution, an excellent balance of rigidity and impact resistance can be achieved. The present invention was achieved by discovering that a molded article can be obtained.

[0005] Therefore, the propylene block polymer according to the present invention consists essentially of the following blocks (A) 50 to 9.
5% by weight and block (B) 5 to 50% by weight, and has an MFR of 0.1 to 100 g/10 minutes;
It is characterized by: Block (A) A propylene homopolymer or a random copolymer of propylene and a C2 to C6 α-olefin, with an MFR of 1 to 200.
g/10 min, and the isotactic index (I.I.) of the polymer is 95% or more (however, in the case of a copolymer of propylene and a C2 to C6 α-olefin, α- (Olefin content is 3% by weight or less based on the total amount of this copolymer), block (B) a random copolymer of propylene and ethylene,
The ethylene content in this copolymer is 20-90% by weight, the copolymer composition distribution index [C] determined by NMR measurement is 300 or more, and the MFR is 0.001-90% by weight.
Block that is 5.0 g/10 minutes.

Further, the propylene-ethylene random copolymer according to the present invention is a random copolymer of propylene and ethylene, and the ethylene content in this copolymer is 20 to 90% by weight. It is characterized in that the required copolymer composition distribution index [C] is 300 or more, and the MFR is 0.01 to 5.0 g/10 minutes.

<Effects> The propylene block polymer according to the present invention has an excellent mechanical strength balance, particularly a balance between rigidity and impact resistance, and is very useful as a resin for injection molding or extrusion molding. .

[0008] The reason for the good balance of physical properties has not yet been fully elucidated, but the wide composition distribution of the copolymer increases the affinity between block (A) and block (B), resulting in interfacial adhesion during mixing. This is thought to be due to improved strength.

[Detailed Description of the Invention] [I] Propylene Block Polymer <General Description> The propylene block polymer according to the present invention consists essentially of block (A) and block (B) and has an MFR of 0.1. ~100g/10 minutes. Here, "substantially consisting of block (A) and block (B)" means that at least one block (A) and (B) each exists, and both blocks exist on the unit polymer chain. In addition to true "block copolymers", physical mixtures of both blocks can occur correspondingly to the formation of both blocks by successively carrying out the polymerization steps that produce each block. It should be understood that this does not exclude block polymers or physical mixtures with third blocks or third components other than both blocks. However, a typical or preferred propylene block polymer is one in which one of each of the two blocks exists, and is obtained by first producing block (A) and then producing block (B). It is.

In the propylene block polymer of the present invention, the proportion of block (A) is 50 to 95% by weight, preferably 60 to 92% by weight, based on the total amount of block (A) and block (B). be. If the proportion of block (A) is less than 50% by weight, the rigidity will be insufficient, and if it exceeds 95% by weight, there will be problems in terms of impact resistance. Block (B)
The proportion of is therefore between 5 and 50% by weight, preferably between 8 and 50% by weight.
40% by weight.

MF of the propylene block polymer of the present invention
R is 0.1 to 100 g/10 min, preferably 0.3 to
80g/10 minutes. If the MFR is less than 0.1 g/10 minutes, the moldability will be poor, while if it exceeds 100 g/10 minutes, the impact resistance will be insufficient. In addition, the MFR value is JIS
This is when measured according to K7210.

<Block (A)> Block (A) is a propylene homopolymer or propylene and C2 to C6 α
- A random copolymer with an olefin (especially preferably ethylene (ethylene is also treated as an α-olefin in the present invention)), and has an MFR of 1 to 200 g/10 minutes, preferably 5 to 100 g/10 minutes. , and the isotactic index (I.I.), that is, the proportion of insoluble matter extracted by boiling n-heptane, is 95% or more, preferably 97% or more (provided that propylene and C
When it is a copolymer with 2-C6 α-olefin, α
- The content of olefins is below 3% by weight, preferably from 0 to 2% by weight, based on the total weight of the copolymer).

<Block (B)> Block (B) is a random copolymer of propylene and ethylene, and the ethylene content in this copolymer is 20 to 90% by weight, preferably 30 to 65% by weight. , and the copolymer composition distribution index [C] determined by NMR measurement is 300 or more, preferably 350 or more, and the upper limit is about 1500.

[0014] If the ethylene content is outside the above range, the impact resistance will be insufficient. Copolymer composition distribution index [C] is 30
If it is less than 0, the balance between rigidity and impact resistance will be poor and therefore undesirable.

In the present invention, the copolymer composition distribution index "C
” is determined using 13C-NMR as follows. In the case of a block copolymer in which a crystalline propylene polymer portion and an amorphous ethylene-propylene random copolymer portion are mixed, the approximate average composition f(E /P) is the probability theory of copolymer chains (for example, "Copolymerization I Reaction Analysis" Chapter 1 Analysis Theory (pp. 1-98) edited by the Society of Polymer Science and Technology (1975, Baifukan)), Average chain length of ethylene n
E is calculated as follows, assuming that the copolymerization is random. P41 According to the formula written in the 4th to 5th lines, the average chain length nE of ethylene is nE = 1
/P1 {propylene} where P1 {propylene}
is the probability that propylene units are present in the copolymer. P38 According to equation (115), P1 {ethylene} + P1 {propylene} = 1, so by definition, the composition ratio f is determined by nE = 1 + f. Therefore, f = nE -1. Here nE is the literature (G. Jos
eph Ray, et al. ”Macromol
ecules” Vol. 10, page 773
~778 (1977)), P776 (2)
Or, the ethylene amount E calculated by formula (7) is P777
The number of ethylene chains written in the 8th to 9th lines from the bottom 1/
2 (αγ + αδ), the signal intensity 1/2 (Iα
Determined from the 13C-NMR spectrum by dividing by γ+Iαδ).

Next, using this f, the triad ratio P3{PPE}:P3{EPE}:P3{EE
E}=a:1:b is calculated by Bernoulli trial.

On the other hand, the actually measured triad ratio P3{PPE}:P3{EPE}:P3{EE
E}=x:1:y can be obtained. The breadth of the composition distribution of the polymer is defined as the deviation from a completely random copolymer using the following formula from the above calculation and the actually measured triad ratio. C=(x/a)×(y/b)×100 The breadth of the composition distribution of the block copolymer can be determined from the value of “C”.

[II] Production of propylene block polymer The propylene block polymer according to the present invention is as described above. The method for producing such a block polymer is arbitrary as long as the prescribed polymer of the present invention can be obtained. The following is a typical method for producing the propylene block polymer of the present invention.

<Representative Production Method> The propylene block polymer of the present invention is prepared by performing at least two polymerization steps (hereinafter, the first step polymerization step is referred to as pre-polymerization, and the second step polymerization step is polymerization step 2) in the presence of a specific catalyst. The polymerization process is sometimes called post-polymerization)
It can be manufactured by carrying out.

<Catalyst> Catalyst component The catalyst used in the present invention consists of catalyst component (A) and catalyst component (
B) and falls under the category of Ziegler type catalysts.

[0021] Here, "catalyst component (A) and catalyst component (B
) is understood to mean that it does not exclude the case where the invention includes a third component that does not unduly impair the effects of the present invention, or more preferably a third component that has an advantageous effect on the present invention. I want to be A typical example of such a third component is an electron donor (catalyst component (C) (details will be described later)) as a so-called external donor.
The catalyst formed from A), (B) and (C) forms a preferred embodiment of the invention.

The catalyst of the present invention can be said to further contain a specific compound, ie, an alkoxytitanium compound, in the latter stage of block copolymerization.

Catalyst component (A) The solid titanium catalyst component (A) used in the present invention contains magnesium, titanium, halogen and an electron donor as essential components. Here, "making it an essential component" means not only that the solid titanium catalyst component (A) consists only of these three specific components, but also that it at least maintains the effect of the combination of these three components or This means that additional ingredients may be included so long as they do not unduly detract. Such additional components are, for example, halogenated silicon compounds.

Magnesium is generally introduced into the catalyst component (A) by magnesium halide, titanium by a titanium compound, and halogen by these compounds.

(1) Magnesium Halide The magnesium halide is preferably magnesium dihalide, and magnesium chloride, magnesium bromide and magnesium iodide can be used. More preferably it is magnesium chloride, more preferably substantially anhydrous.

Magnesium halides include magnesium oxide, magnesium hydroxide, hydrotalcite, magnesium carboxylate, alkoxymagnesium, allyloxymagnesium, alkoxymagnesium halide, allyloxymagnesium halide, organomagnesium compounds, etc. It may also be magnesium halide obtained by treatment with a donor, halosilane, alkoxysilane, silanol, Al compound, halogenated titanium compound, titanium tetraalkoxide, or the like.

(2) Titanium Compounds Typical titanium compounds are trivalent and tetravalent titanium halogen compounds. A preferred titanium halogen compound has the general formula Ti(OR1)nX4-n (R1 is C
Among the compounds represented by 1 to C10 hydrocarbon residues, X is halogen, it is a tetravalent halogenated titanium compound where n=0, 1 or 2. Specifically, TiCl4, T
i(OC4H9)Cl3, Ti(OC4H9)2Cl2
For example, Ti is particularly preferable.
These are tetrahalogenated titanium and monoalkoxytrihalogenated titanium compounds such as Cl4 and Ti(OC4H9)Cl3. As the titanium compound, halogen-free titanium compounds, specifically Ti(OC4H9)4, etc. are also preferably used.

(3) Electron donor The electron donor, which is an essential component of the solid catalyst component (A) of the present invention, is at least one of the specific compounds (a) to (c). Among these, compound (c) is particularly preferred.

(a) One of the electron donors is an ester (a) of a polyfunctional compound selected from the group consisting of polyhydric carboxylic acids, polyhydric alcohols, and hydroxy-substituted carboxylic acids. Suitable esters of these polyfunctional compounds are, for example, those represented by the following formula.

[0030]

[Chemical formula 1]

[0031]

[Case 2]

[0032]

[Chemical formula 3]

[0033] or

[0034]

[C4]

Here, R5 is a substituted or unsubstituted hydrocarbon group, R2, R3 and R4 are each hydrogen or a substituted or unsubstituted hydrocarbon group, and R6 and R7 are each hydrogen or a substituted or unsubstituted hydrocarbon group. is a hydrocarbon group, preferably at least one of which is a substituted or unsubstituted hydrocarbon group. R3 and R
4 may be connected to each other. Here, the substituted hydrocarbon groups include those containing different atoms such as N, O, and S;
For example, C-O-C, COOR, COOH, OH, SO3
Some have groups such as H, -C-N-C-, and NH2.

Among these, particularly preferred are R5, R
A diester of dicarboxylic acid in which at least one of 2 is an alkyl group having 2 or more carbon atoms.

Specific examples of preferred polyhydric carboxylic acid esters include (a) diethyl succinate, dibutyl succinate, diethyl methylsuccinate, diisobutyl α-methylglutarate, dibutyl methylmalonate, diethyl malonate, and ethylmalonic acid. Diethyl, diethyl isopropylmalonate, diethyl butylmalonate, diethyl phenylmalonate, diethylmalonate, diethyl allylmalonate, diethyl diisobutylmalonate, diethyl di-n-butylmalonate, dimethyl maleate,
Monooctyl maleate, dioctyl maleate, dibutyl maleate, dibutyl butyl maleate, diethyl butyl maleate, diisopropyl β-methylglutarate, diallyl ethylsuccinate, di-2-ethylhexyl fumarate, diethyl itaconate, dibutyl itaconate, Aliphatic polycarboxylic acid esters such as dioctyl citraconate and dimethyl citraconate, (b) aliphatic polycarboxylic acid esters such as diethyl 1,2-cyclohexanecarboxylate, diisobutyl 1,2-cyclohexanecarboxylate, diethyl tetrahydrophthalate, and ethyl nadic acid. Polycarboxylic acid ester, (c) monoethyl phthalate, dimethyl phthalate, methylethyl phthalate, monoisobutyl phthalate,
Mono-normal butyl phthalate, diethyl phthalate, ethyl isobutyl phthalate, ethyl normal butyl phthalate, di-n-propyl phthalate, diisopropyl phthalate,
Di-n-butyl phthalate, diisobutyl phthalate, di-n-heptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, dineopentyl phthalate, didecyl phthalate, benzylbutyl phthalate, diphenyl phthalate, naphthalene Examples include aromatic polycarboxylic acid esters such as diethyl dicarboxylate, dibutyl naphthalene dicarboxylate, triethyl trimellitate, and dibutyl trimellitate, and different carbon polycarboxylic acid esters such as (d)3,4-furandicarboxylic acid. can.

[0038] Specific examples of preferable polyhydric hydroxy compound esters include 1,2-diacetoxybenzene, 1-methyl-2,3-diacetoxybenzene, 2,3-diacetoxynaphthalene, and ethylene glycol dipylene. Valate, butanediol pivalate, etc. can be mentioned.

Examples of esters of hydroxy-substituted carboxylic acids include benzoylethyl salicylate, acetyl isobutyl salicylate, and acetyl methyl salicylate.

Other examples of polyvalent carboxylic acid esters that can be supported in the titanium catalyst component include diethyl adipate, diisobutyl adipate, diisopropyl sebacate, di-n-butyl sebacate, di-n sebacate.
-octyl, di-2-ethylhexyl sebacate, and other long-chain dicarboxylic acid esters.

[0041] Among these polyfunctional esters, those having the skeleton of the above-mentioned general formula are preferred, and more preferably esters containing phthalic acid, maleic acid, substituted malonic acid, etc. and alcohols having 2 or more carbon atoms. Among the esters, particularly preferred are diesters of phthalic acid and alcohols having 2 or more carbon atoms.

(b) Still another group of electron donor components which are essential components of the solid catalyst component (A) is R8COOR.
9 (R8 and R9 are each a hydrocarbyl group having about 1 to 15 carbon atoms, and at least one of them is a branched (including alicyclic) or ring-containing chain group) monocarboxylic acid ester Examples of R8 and/or R9 include (CH3)2CH-,
C2H5CH(CH3)-, (CH3)2CHCH2-
, (CH3)3C-, C2H5CH(CH3)CH2-
, C6H5-CH2-, CH3-C6H4-CH2-,
C6H5-CO-, cycloC6H11-, CH2=C(
CH3)- and the like can be exemplified. R8 and R
If either one of 9 is a branched group as described above, the other may be the above group or another group, such as a linear or cyclic group.

Examples of such monocarboxylic acid esters include α-methylbutyric acid, β-methylbutyric acid, methacrylic acid,
Examples include various monoesters such as benzoyl acetic acid, and various monocarboxylic acid esters of alcohols such as isopropanol, isobutyl alcohol, and tert-butyl alcohol.

(c) Organosilicon compound As the electron donor, an organosilicon compound represented by the general formula R10R11Si(OR12)2 or R10Si(OR12)3 can be selected. In the formula, R10 is a cyclic aliphatic hydrocarbon group, preferably a bicyclic hydrocarbon group having 3 to 20 carbon atoms, more preferably 5 to 12 carbon atoms. R1
1 is a cyclic or chain aliphatic hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms. R12 is a cyclic or chain aliphatic hydrocarbon group, preferably a chain aliphatic hydrocarbon group having 4 or less carbon atoms. Table 1 below
3 shows a specific example of an electron donor by a structural formula.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

Furthermore, an organosilicon compound represented by the following formula can also be selected. R13R143-pSi(OR15)p (where R1
3 is a branched hydrocarbon residue, R14 and R15 are each a branched or linear hydrocarbon residue, p is a number of 2≦p≦3).

Preferably, R13 is branched from the carbon atom adjacent to the silicon atom. In that case, the branching group is preferably an alkyl group, a cycloalkyl group, or an aryl group (eg, a phenyl group or a methyl-substituted phenyl group). More preferred R13 is one in which the carbon atom adjacent to the silicon atom, ie, the carbon atom at the α-position, is a secondary or tertiary carbon atom. Particularly preferred are those having a structure in which three alkyl groups extend from a carbon atom bonded to a silicon atom. The number of carbon atoms in R13 is usually 3 to 20, preferably 4 to 10. R1
4 is usually a branched or linear aliphatic hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. R15 is an aliphatic hydrocarbon group, preferably having 1 or more carbon atoms.
4 chain aliphatic hydrocarbon group.

Specific examples are shown below using structural formulas. (CH3)
3Si(CH3)(OCH3)2, (CH3)3C-S
i(CH(CH3)2)(OCH3)2,(CH3)3
C-Si(CH3)(OC2H5)2, (C2H5)3
C-Si(CH3)(OCH3)2, (C2H5)(C
H3) CH-Si(CH3)(OCH3)2, ((CH
3) 2CHCH2)2Si(OCH3)2, (C2H5
)(CH3)2C-Si(CH3)(OCH3)2,(
C2H5)(CH3)2C-Si(CH3)(OC2H
5) 2, (CH3)3C-Si(OCH3)3, (CH
3) 3C-Si(OC2H5)3, (C6H5)(CH
3) 2C-Si(OC2H5)3, (C6H11)(C
H3)2C-Si(OC2H5)3, (C6H5)(C
H3)2C-Si(OCH3)3, (C6H11)(C
H3)2C-Si(OCH3)3, (C2H5)3C-
Si(OC2H5)3, (C2H5)(CH3)CH-
Si(OCH3)3, (C2H5)(CH3)2C-S
i(OCH3)3.

[0051] These electron donor components are combined with a solid catalyst component (
When containing in A), it is not necessarily necessary to use these as starting materials, and compounds that can be converted into these during the preparation of the solid catalyst component may be used and converted into these compounds at the preparation stage.

(4) Preparation of solid catalyst component (A) In preparing the solid catalyst component (A), the magnesium halide is preferably pretreated. This preliminary treatment can be carried out by various conventionally known methods, and specifically, the following methods can be exemplified.

(a) Magnesium dihalide,
Alternatively, magnesium dihalide and a halogen compound of titanium, silicon or aluminum or a halogenated hydrocarbon compound are pulverized. Grinding can be carried out using a ball mill or an oscillating mill. (b) Magnesium dihalide is dissolved using a hydrocarbon or halogenated hydrocarbon as a solvent and alcohol, phosphoric acid ester, or titanium alkoxide as a dissolution promoter. Next, the dissolved magnesium dihalide is precipitated by adding a poor solvent, an inorganic halide, an electron donor such as an ester, or a polymeric silicon compound such as methyl hydrogen polysiloxane to this solution. (c) Contact reaction of magnesium mono- or dialcoholate or magnesium carboxylate with a halogenating agent. (d) Bringing magnesium oxide and chlorine or AlCl3 into a catalytic reaction. (e) Contact reaction between MgX2·nH2O (X is halogen) and a halogenating agent or TiCl4. (F) MgX2・nR16OH (X is halogen, R
16 is an alkyl group) and a halogenating agent or TiCl4 are brought into a contact reaction. (g) Grignard reagent, MgR172 compound (R
17 is an alkyl group), or a complex of an MgR172 compound and a trialkylaluminium compound, using a halogenating agent, such as AlX3, AlR18qX3-q (X is a halogen, R18 is an alkyl group, and q is 1≦q≦2).
, SiCl4 or HSiCl3. (H) A Grignard reagent and a silanol or a polysiloxane, H2O or a silanol are brought into contact reaction, and then a halogenating agent or TiCl4 is brought into contact reaction.

For details of such pretreatment of magnesium halide, see Japanese Patent Publication No. 46-611, No. 46
-34092, 51-3514, 56-673
No. 11, No. 53-40632, No. 56-50888, No. 57-48565, No. 52-36786, No. 5
No. 8-449, JP-A-53-45686, JP-A No. 50-1
No. 26590, No. 54-31092, No. 55-135
No. 102, No. 55-135103, No. 56-811, No. 56-11908, No. 57-180612, No. 58-5309, No. 58-5310, No. 58-53
No. 11 publications can be referred to.

Contacting the pretreated magnesium chloride, titanium halide, and electron donor can also be carried out by forming a complex between the titanium halide and the electron donor and then contacting this complex with magnesium chloride. Also, after bringing magnesium chloride and titanium halide into contact,
It may be brought into contact with an electron donor, or it may be brought into contact with magnesium chloride and an electron donor and then brought into contact with titanium halide.

The contact may be carried out by pulverization using a ball mill, a rocking mill, or the like, or by adding magnesium chloride or an electron donor-treated product of magnesium chloride to the liquid phase of titanium halide. Washing with an inert solvent may be performed after contacting these components or at an intermediate stage of contacting each component.

The solid catalyst component (A
) has a titanium halide content of 1 to 20% by weight, a magnesium halide content of 50 to 98% by weight, and a molar ratio of electron donor compound to titanium halide of 0.05 to 2.
．． It is normal that it is about 0.

Catalyst component (B) The organoaluminum compound used as component (B) in the present invention has the general formula AlR19rX3-r (where R1
9 is a hydrocarbon residue having 1 to 12 carbon atoms, X is a halogen or alkoxy group, and r represents 0<r≦3.

[0059] Specifically, such organoaluminum compounds include, for example, triethylaluminum, tri-
n-propyl aluminum, tri-n-butyl aluminum, triisobutyl aluminum, tri-n-hexyl aluminum, triisohexyl aluminum, trioctyl aluminum, diethylaluminum hydride, diisobutyl aluminum hydride, diethylaluminum monochloride, ethyl aluminum sesquichloride, These include diethylaluminum monoethoxide. Of course, two or more of these organoaluminum compounds can also be used in combination.

Organoaluminum compound component (B) and solid catalyst component (A) used in the polymerization of α-olefin
) can be varied over a wide range, but is generally between 1 and 100 per titanium atom contained in the solid catalyst component.
The organoaluminum compound can be used in a ratio of 0, preferably 10 to 500 (molar ratio).

Catalyst component (C) In the production of the block polymer of the present invention, various electron donors can be used as necessary. As the electron donor, ether compounds, amine compounds, organosilicon compounds, etc. are preferably used. A specific example is shown below.

(a) Ether compound An example of the ether compound used in the present invention is the general formula

[0063]

[C5]

It is an ether represented by In the formula, R2
0 to R22 are saturated or unsaturated hydrocarbon residues, generally having 1 to 10 carbon atoms, preferably about 1 to 10 carbon atoms.
4, alkyl group or alkenyl group (including substituted derivatives substituted with halogen or phenyl group), or phenyl group (halogen, alkyl group (especially lower alkyl group)
or a substituted derivative with a phenyl group). However, one or two of R19 to R22 are phenyl groups (including substituted derivatives with halogen or alkyl groups (particularly lower alkyl groups)). R23 is a hydrocarbon group.

Specific examples of such ether compounds include α-cumyl methyl ether, α-cumyl ethyl ether, 1,1-diphenylethyl methyl ether, 1
, 1-diphenylethyl ethyl ether, α-cumyl tert-butyl ether, diα-cumyl ether, 1,1-ditriethyl methyl ether, 1,1-ditriethyl ethyl ether, bis(1,1-ditriethyl) ether,
Examples include 1-tolyl-1-methylethyl methyl ether. In addition to the above, ether compounds such as 1,4-cineole, 1,8-cineole, and m-cineole can also be used.

(b) Amine compound The amine compound used in the present invention is a 2,2,6,6-
These are sterically hindered amines such as tetramethylpiperidine and 2,2,6,6-tetraethylpiperidine.

(c) Organosilicon compound Specific examples of the organosilicon compound used in the present invention include the above-mentioned organosilicon compound (c) used as an electron donor contained in the solid titanium catalyst component. Among these, dialkoxy or trialkoxy silanes are preferably used. A specific example is shown as a structural formula as follows.

[0068]

[C6]

[0069]

[C7]

[0070]

[Chemical formula 8]

[0071]

[Chemical formula 9]

[0072]

[Chemical formula 10]

[0073]

[Chemical formula 11]

(CH3)3C-Si(CH3)(OCH
3) 2, (CH3)3C-Si(CH(CH3)2)(
OCH3)2, (CH3)3C-Si(CH3)(OC
2H5)2, (C2H5)3C-Si(CH3)(OC
H3)2, (C2H5)(CH3)CH-Si(CH3
)(OCH3)2, ((CH3)2CHCH2)2Si
(CH3) (OCH3), (C2H5) (CH3)2C
-Si(CH3)(OCH3)2, (C2H5)(CH
3) 2C-Si(CH3)(OC2H5)2, (CH3
)3C-Si(OCH3)3, (CH3)3C-Si(
OC2H5)3, (C6H5)(CH3)2C-Si(
OC2H5)3, (C6H11)(CH3)2C-Si
(OC2H5)3, (C6H5)(CH3)2C-Si
(OCH3)3, (C6H11)(CH3)2C-Si
(OCH3)3, (C2H5)3C-Si(OC2H5
)3, (C2H5)(CH3)CH-Si(OCH3)
3, (C2H5)(CH3)2C-Si(OCH3)3
, (C2H5)(CH3)2C-Si(OC2H5)3
,

The molar ratio of the electron donor (C) to the organoaluminum compound (B) is usually 0.01 to 1.0, preferably 0.02 to 0.5.

<Block copolymerization> The polymerization process of the present invention carried out in the presence of the catalyst includes the first stage polymerization for producing a crystalline homopolymer or copolymer of propylene (block (A)), and the copolymerization of propylene and ethylene. The process consists of two stages of post-polymerization to produce a random copolymer (block (B)). The latter stage polymerization is usually and preferably carried out in the presence of an alkoxytitanium compound.

Here, "conducted in the presence of an alkoxytitanium compound" means that a substantial part of the post-polymerization is carried out in the presence of an alkoxytitanium compound. This means that the addition operation itself is carried out after the latter half of the first-stage polymerization, especially after its substantial completion, and up to the first half of the second-stage polymerization, especially before its substantial completion.

[0078] The "block polymer" according to the present invention does not necessarily have an ideal form, that is, a block produced in the first stage polymerization (ie, block (A)) and a block produced in the second stage polymerization (ie, block (A)). B)) does not mean only those present on one molecular chain, but physical mixtures of polymers produced in each step according to customary practice, and the ideal block copolymerization of this and the above. As mentioned above, it includes various forms of polymers that can be combined.

First-stage polymerization: Production of block (A) The first-stage polymerization is a polymerization in which propylene alone or a propylene/C2 to C6 α-olefin mixture is added with the catalyst components (A), (B), and (C) if necessary. Propylene homopolymer or α-olefin content of 3% by weight or less,
Preferably 2.0% or less of propylene/C2 to C6 α-olefin copolymer is added in one or more stages to 50 to 95% by weight, preferably 60 to 92% by weight of the total polymerization amount.
This is a step of forming the film in an amount corresponding to .

If the α-olefin content in the propylene/α-olefin copolymer increases further than this in the first stage polymerization,
The bulk density of the final copolymer decreases and the amount of low crystalline polymer by-product increases significantly. Furthermore, even if the polymerization ratio is less than the above range, the same phenomenon occurs as when the α-olefin content in the propylene/α-olefin copolymer is high. On the other hand, if the polymerization ratio exceeds the above range, although the amount of by-product of the low crystalline polymer tends to decrease, it is not preferable because the impact strength, which is the objective of block copolymerization, decreases.

[0081] The polymerization temperature in the first stage polymerization is about 30 to 90°C, preferably about 50 to 80°C. Polymerization pressure is 1~
It is about 30 kg/cm2.

In the first stage polymerization, it is preferable to use a molecular weight regulator so that the final polymer has appropriate fluidity, and a preferred example of such a molecular weight regulator is hydrogen.

Addition of alkoxytitanium compound Preferred alkoxytitanium compounds to be added during the post-polymerization are tetraalkoxytitaniums, ie, tetraalkyl titanates. In the present invention, the alkyl group preferably has about 1 to 10 carbon atoms, particularly about 2 to 6 carbon atoms. Specific examples include tetraethyl titanate, tetra n
Examples include -propyl titanate, tetra i-propyl titanate, tetra n-butyl titanate, tetra t-butyl titanate, tetra n-hexyl titanate, tetraoctyl titanate, etc. Among them, alkyl titanates having 3 or more carbon atoms are preferred, particularly tetra Preferred is n-butyl titanate.

The amount of the alkoxytitanium compound added is usually 1 to 40 mol, preferably 5 to 30 mol, per 1 mol of titanium in the catalyst component (A). The alkoxytitanium compound may be added during the first stage polymerization or during the second stage polymerization. The preferred addition time is at the end of the first stage polymerization or at the beginning of the second stage polymerization.

Post-polymerization: Production of block (B) In the post-polymerization, following the first-stage polymerization, a propylene/ethylene mixture is further introduced to achieve an ethylene content of 20 to 90% by weight.
, preferably 30 to 65% by weight, of a propylene/ethylene copolymer in one or multiple stages. In this step, 5 to 50% by weight of the total polymerization amount, preferably 8 to 50% by weight,
It is desirable to form an amount corresponding to 40% by weight.

If the polymerization ratio in the latter stage polymerization and the composition of the propylene/ethylene mixture are less than the above ranges, impact resistance (especially low-temperature impact resistance) will be poor. Moreover, when the above range is exceeded, operational problems such as a significant increase in the amount of by-product of the low crystalline polymer and a significant increase in the viscosity of the polymerization solvent occur.

In the latter stage polymerization, it is also possible to coexist a small amount of other comonomers. Examples of such comonomers include C3 to C10 α-olefins such as 1-butene, 1-pentene, and 1-hexene.

The polymerization temperature in the second stage polymerization is about 30 to 90°C, preferably about 50 to 80°C. Polymerization pressure is 1~
It is about 30 kg/cm2.

When moving from the first-stage polymerization to the second-stage polymerization, it is preferable to purge the propylene gas or propylene/α-olefin mixed gas and hydrogen gas derived from the first-stage polymerization before moving on to the second-stage polymerization. In the post-polymerization, a molecular weight regulator may or may not be used depending on the purpose, but when it is desired to increase the impact resistance of the final polymer, it is preferable not to use a molecular weight regulator.

Polymerization Method The method for producing the block polymer according to the present invention can be carried out by any of the batch, continuous and semi-batch methods. At this time, there are methods of conducting polymerization in an inert hydrocarbon solvent such as heptane, methods of using the monomer itself as a medium, and methods of conducting polymerization in a gaseous monomer without using a medium. , and a method that combines these methods can also be adopted. The first stage polymerization and the second stage polymerization may be carried out in separate polymerization tanks.

[0091]

EXAMPLES The following examples are intended to explain the present invention more specifically. These are illustrative of some embodiments of the invention and are not intended to limit the invention.

Example 1 (1) Preparation of solid catalyst component 75 ml of purified heptane, 75 ml of titanium tetrabutoxide and 10 g of titanium tetrabutoxide were placed in a 500 ml three-necked glass flask (with thermometer and stirring bar) purged with nitrogen. Add anhydrous magnesium chloride. After that, add 90 flasks.
The temperature was raised to 0.degree. C., and magnesium chloride was completely dissolved over 2 hours. Next, the flask was cooled to 40° C., and 15 ml of methylhydrogenpolysiloxane was added to precipitate a magnesium chloride/titanium tetrabutoxide complex. This was washed with purified heptane to obtain an off-white solid.

65 ml of the heptane slurry containing 20 g of the precipitated solid obtained above was introduced into a 300 ml glass three-necked flask (equipped with a thermometer and stirring bar) that had been purged with nitrogen. Then, 25 ml of a heptane solution containing 8.7 ml of silicon tetrachloride was added over 30 minutes at room temperature, and
The reaction was carried out at ℃ for 30 minutes. The reaction was further carried out at 90° C. for 1 hour, and after the reaction was completed, the reaction mixture was washed with purified heptane. Next, 50 ml of a heptane solution containing 1.6 ml of phthaloyl chloride was added and reacted at 50°C for 2 hours, and then washed with purified heptane, and further 25 ml of titanium tetrachloride was added and the reaction was heated at 90°C.
The mixture was allowed to react for 2 hours. Wash this with purified heptane and
A solid catalyst component was obtained. The titanium content in the solid catalyst component is 3
．． It was 22% by weight.

(2) After sufficiently purging a stirred autoclave with a polymerization internal volume of 200 liters with propylene, 60 liters of dehydrated and deoxygenated n-heptane was introduced, and triethylaluminum (
B) 15.0 g, 3.0 g of said solid composition (A) and 6.4 g of diphenyldimethoxysilane were introduced at 70° C. under a propylene atmosphere. The first-stage polymerization was started by heating the autoclave to 75° C. and then introducing propylene at a rate of 9 kg/hour while maintaining the hydrogen concentration at 2.0%. After 215 minutes, the introduction of propylene was stopped and the polymerization was continued for an additional 90 minutes at 75°C. The gas phase was purged with propylene until the gas concentration reached 0.2 kg/cm2.

Next, tetra n-butyl titanate 6.8
After adding 1.57 kg/hour of propylene and 2.5 kg/hour of ethylene, the temperature of the autoclave was lowered to 60°C.
This was done by feeding for 87 minutes at a feed rate of 35 kg/hour. The slurry thus obtained was filtered and dried to obtain a powdery block polymer. The following physical properties were measured for the obtained propylene polymer. Table 4 shows the results. Note that the weight ratio of the produced polymers in the first-stage polymerization and the second-stage polymerization and the weight ratio of propylene and ethylene in the second-stage polymerization are calculated values on a feed basis.

(3) Measurement of physical properties (a) MFR was measured according to JIS K7210. Note that the second stage MFR was determined using the following formula.

log (MFR of block copolymer) -
(First stage polymerization ratio) x log (first stage MFR) = (second stage polymerization ratio) x log (second stage MFR) (b) The ethylene content was calculated from the IR absorption spectrum. (c) The copolymerization composition distribution index was determined by NMR as described above. (d) I. I. was determined as the percentage of insoluble matter extracted by boiling n-heptane. (e) A heat-resistant stabilizer and a rust-proofing agent were blended into the obtained powdered polymer, each pelletized using an extruder, and a test piece was molded using an injection molding machine. (f) Flexural modulus was measured according to JIS K7203. (g) Izod impact strength is JIS K7110
Measured according to. (H) Falling weight impact strength was measured by molding a 2 x 80 x 120 mm sheet using an injection molding machine and using it as a test piece.

<Examples 2 and 3> When carrying out block polymerization, polymers were produced in the same manner as in Example 1, except that the weight ratio between the first stage polymerization and the second stage polymerization and the weight ratio of propylene and ethylene in the second stage polymerization were changed. It was manufactured and its physical properties were measured using the same method.

<Comparative Example 1> A polymer was produced in the same manner as in Example 1, except that the post-polymerization temperature was changed to 65°C and tetra-n-butyl titanate was not added at the start of the post-polymerization. , physical properties were measured using a similar method.

<Comparative Example 2> After the stirring autoclave was sufficiently purged with propylene, 80 liters of dehydrated and deoxygenated n-heptane was charged. Keep the internal temperature at 60℃ and add 20g of diethylaluminum chloride (DEAC).
and 10 g of titanium trichloride (manufactured by Marubeni Solvay Chemical Co., Ltd.)
added. After raising the temperature inside the vessel to 65° C., the pre-polymerization was carried out by introducing propylene at a rate of 9 kg/hour while maintaining the hydrogen concentration at 4.0%. 215
After a few minutes, the introduction of propylene was stopped and the polymerization was continued for an additional 60 minutes at 65°C. 0.4 kg of propylene in the gas phase
/cm2G was purged. Next, propylene 1
．． Post-polymerization was carried out by feeding for 80 minutes at a feed rate of 0.02 kg/hour and ethylene of 1.54 kg/hour. Physical properties of the obtained polymer were measured in the same manner as in Example 1.

<Comparative Example 3> When performing block copolymerization, the polymerization operation was carried out in the same manner as in Comparative Example 2, except that the weight ratio of the first stage polymerization and the second stage polymerization and the weight ratio of propylene and ethylene in the second stage polymerization were changed. Ta. Physical properties of the obtained polymer were measured in the same manner as in Example 1.

[0102]

[Table 4]

[Effects of the Invention] The propylene block polymer according to the present invention has an excellent mechanical strength balance, particularly a balance between rigidity and impact resistance, and is extremely useful as a resin for injection molding or extrusion molding. This has been mentioned above in the section of "Means for solving the problem."

Claims (2)

[Claims] Claim 1: Blocks (A) 50 to 95 consisting essentially of the following:
% by weight and block (B) 5 to 50% by weight,
A propylene block polymer having an MFR of 0.1 to 100 g/10 minutes. Block (A) A propylene homopolymer or a random copolymer of propylene and a C2 to C6 α-olefin, which has an MFR
is 1 to 200 g/10 min, and the isotactic index (I.I.) of the polymer is 95% or more (however, in the case of a copolymer of propylene and a C2 to C6 α-olefin) , the α-olefin content is 3% by weight or less based on the total amount of the copolymer), block (B) a random copolymer of propylene and ethylene,
The ethylene content in this copolymer is 20-90% by weight, the copolymer composition distribution index [C] determined by NMR measurement is 300 or more, and the MFR is 0.001-90% by weight.
Block that is 5.0 g/10 minutes. Claim 2: A random copolymer of propylene and ethylene, wherein the ethylene content in the copolymer is 20 to 9.
0% by weight, a copolymer composition distribution index [C] determined by NMR measurement of 300 or more, and an MFR of 0.01 to 5.0 g/10 min.
Propylene-ethylene random copolymer.