JPH01247444A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition improved in impact strength without detriment to its transparency, modulus, low odor and heat resistance, by mixing a crystalline propylene (co)polymer with a specified polymer. CONSTITUTION:A step of (co)polymerizing a 6C or higher alpha-olefin branched in the position 3 or a vinylcycloalkane (a) with, optionally, another alpha-olefin (b) in the presence of a Ziegler-Natta catalyst and a step of copolymerizing propylene (c) with, optionally, another alpha-olefin (d) are repeated at least once to obtain a crystalline (co)polymer (A) preferably comprising 75-100mol% propylene units and 0-25mol% at least one kind of monomer units selected from among ethylene units and 4-10C linear or branched alpha-olefin units and having a xylene-soluble (20 deg.C) content <=40wt.% and containing 1-100000ppm wt. of a polymer of component (a). 95-40wt.% component A is mixed with a polymer, preferably an ethylene (co)polymer (B) having a refractive index different from that of component A by -0.010-0.015 and a bending modulus <=3000kg/cm<2>.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a resin composition having excellent transparency, elastic modulus, heat resistance, low odor, and impact strength.

<Prior Art> Polypropylene has been widely used as a packaging material for foods, medicines, etc. because it has excellent oil resistance, elastic modulus, heat resistance, moisture resistance, etc. However, polypropylene has inferior transparency compared to non-grade polymers such as polystyrene and polyvinyl chloride. Additionally, it has the disadvantage of low impact strength at temperatures below room temperature.

Methods for improving the transparency of polypropylene include the method of adding an aluminum salt or sodium salt of an aromatic carboxylic acid, as described in Jikai M58-80329, and the method described in JP-A-55-12460, Shii JP-A-58- Japanese Patent No. 129036 proposes a method of adding an aromatic carboxylic acid, an aromatic metal phosphate, a sorbitol derivative, etc.

Among these methods, aromatic carboxylic acids, aromatic carboxylates, and aromatic metal phosphates improve transparency and elastic modulus, but the degree of improvement is small. Although sorbitol derivatives have a great effect on improving transparency, they significantly reduce the value of the product due to their large odor during molding and molded products.

As a method to solve this problem, Japanese Patent Laid-Open No. 1397-1987
No. 10 proposes a method in which (a) polymerization of a vinylcycloalkane having 6 or more carbon atoms and (1) polymerization of propylene alone or copolymerized with ethylene are carried out in multiple stages.

Further, JP-A-60-139731 proposes a crystalline polypropylene composition containing a branched α-olefin or vinylcycloalkane having 6 or more carbon atoms. These methods are excellent because transparency and elastic modulus are significantly improved and there is little odor.

On the other hand, known methods for improving impact strength include copolymerizing propylene with other α-olefins, particularly ethylene, and adding rubber-like substances. Common copolymerization methods include random copolymerization and block copolymerization, but in random copolymerization, the copolymerized α-
When the content of olefin is small, the effect of improving impact strength is small, and when the content is large, the elastic modulus is significantly reduced. In addition, the block copolymerization method and the method of adding a rubbery substance have a large impact strength improvement effect, but the transparency is significantly reduced.

<Problem to be solved by the invention> JP-A-60-139710 and JP-A-60-139710
The object of the present invention is to provide a resin composition that has improved impact strength while maintaining the improved transparency, elastic modulus, low odor, and heat resistance that were disclosed in Publication No. 39731.

<Means for Solving the Problem> That is, the present invention uses a polymer of 3-branched α-olefin or vinylcycloalkane having 6 or more carbon atoms in 1 to 1 o
95 to 40 wt% of a crystalline propylene polymer or copolymer containing oooo wtppm;
The difference in refractive index with respect to component (5) is -0,010 to 0.0
Component (B) of the polymer in the range of 15 to 5 Q w
t%.

The method for producing a crystalline propylene polymer or copolymer containing a polymer of a 3-branched α-olefin having 6 or more carbon atoms or a vinylcycloalkane as component (5) is as follows: (1) Ziegler, Natsuta Catalyst 6 carbons in the presence
The above step of polymerizing the 3-branched α-olefin or vinylcycloalkane or copolymerizing it with other α-olefins and the step of copolymerizing propylene alone or with other α-olefins are carried out at least once. (2) A method of mixing the polymer obtained in (1) above with a propylene alone or a copolymer with another α-olefin, (3) A 3-branched α-olefin having 6 or more carbon atoms. Alternatively, a method of mixing a vinylcycloalkane polymer or a copolymer with another α-olefin with a propylene homopolymer or a copolymer of propylene with another α-olefin, etc. It will be done.

Among these methods, methods (1) and (2) are preferable because they have a large improvement effect on transparency, elastic modulus, and heat resistance, and method (1) is most preferable because it has the largest improvement effect.

As a method for copolymerizing a 3-branched α-olefin having 6 or more carbon atoms or a vinylcycloalkane with other α-olefins, either random copolymerization or block copolymerization may be used, but block copolymerization is most effective. Therefore, it is particularly preferable. The α-olefin to be copolymerized is preferably a linear or branched α-olefin having 2 to 20 carbon atoms.

Component 4, the crystalline propylene polymer or copolymer, can be produced by polymerizing propylene alone using a catalyst system that provides isotactic polypropylene, or by polymerizing propylene, ethylene, and a linear polymer having 4 to 10 carbon atoms. Alternatively, it can be obtained by copolymerizing at least one type of heptamer selected from branched α-olefins. As a copolymerization method, either a random copolymerization method or a block copolymerization method can be used, but the random copolymerization method is preferable because it has a greater effect of improving transparency.

If the component holes contain a large amount of low-crystalline components, the low-crystalline components bleed onto the surface of the molded product, impairing its commercial value. The inventors have found that the above problem can be solved by reducing the content of xylene-soluble components at 20° C. to a certain value or less.

That is, the component hole preferably has a content of xylene soluble components at 20° C. of 40 wt% or less, more preferably 30 wt% or less, and most preferably 15 wt% or less.

In order to keep the xylene-soluble component content of component (5) at 20°C within this range, it is necessary to use a catalyst system that provides highly isotactic polypropylene as described below, and to use component (2). ), the crystalline propylene polymer or copolymer portion of ethylene copolymerized with propylene;
The content of at least one type of hexamer selected from linear or branched α-olefins having 4 to 10 carbon atoms is preferably 25 mol% or less, more preferably 15 mol% or less, and most preferably 10 mol%. This can be achieved by keeping it below %.

Specific examples of the 3-branched α-olefin or vinylcycloalkane having 6 or more carbon atoms used in the present invention are 3
．． 3-dimethylbutene-1,3-methylpentene-1,
Examples include 3-methylhexene-1,3,5,5-trimethylhexene-1, vinylcyclopentene, vinylcyclohexane, vinylnorbornane, and the like. Among these, olefins having 8 or more carbon atoms are more preferred.

If the content of the 3-branched α-olefin having 6 or more carbon atoms or the vinylcycloalkane polymer is less than 1 wtppm, the effect of improving transparency and elastic modulus is small;
When the amount is more than ooowc ppm, the transparency decreases. Therefore, the content is preferably from 1 to 1,100,000 Wtpp, more preferably from 100 to 70,000 Wtppm, and most preferably from 500 to 50,000 Wtppm.

The production of crystalline propylene polymers or copolymers containing a 3-branched α-olefin having 6 or more carbon atoms or a vinylcycloalkane polymer is achieved by using a catalyst system that provides isotactic polypropylene. You can. As a catalyst system for producing isotactic polypropylene, a Ziegler-Natsuta type catalyst system can be most preferably used.

Among the Ziegler-Natsuta type catalyst systems, those consisting of a solid catalyst component containing at least titanium and chlorine, and an organoaluminium compound, or further an electron-donating compound are preferred, and more preferably, the catalyst system is immersed in liquefied propylene for 4 hours. When polymerized, the xylene soluble portion at 20° C. in the polymer is 5% by weight or less, most preferably 4% by weight or less. The solid catalyst component that can be suitably used in the present invention will be explained in more detail below.

Methods for synthesizing solid catalyst components are broadly classified into two types. One of them is a solid catalyst component obtained by reducing a tetravalent titanium compound with hydrogen, metal aluminum, an organometallic compound, etc., or a solid catalyst component obtained by further crushing and activation of these, or a solid catalyst component obtained by reducing a tetravalent titanium compound with an organometallic compound. After obtaining a catalyst precursor by reduction with This is a method of obtaining a catalyst by supporting the catalyst.

Among the former methods, methods in which a tetravalent titanium compound is reduced with an organometallic compound and then subjected to activation treatment include a method using an organoaluminum compound as a reducing reagent and a method using an organomagnesium compound. Specifically, (1) a method in which a reduced solid produced by reducing TiC1+ with an organoaluminum compound is treated with a complexing agent and then reacted with T1Cl+. (Japanese Patent Publication No. 53-3356) (2) A method in which a titanium compound represented by the general formula Ti (OR)n -228504), (3) General formula Ti (Q
R) After reducing the titanium compound represented by nX<-n with an organomagnesium compound in the coexistence of an organosilicon compound, treatment with an ester compound and treatment with an ether compound and T
Method of treatment with a mixture with iCl4 (Unexamined Japanese Patent Publication No. 61-2
87904), (4) a method of immobilizing the catalyst component obtained in (3) on a porous substance (Japanese Patent Application Laid-Open No. 62-256802), and the like.

Further, specific examples of the latter method include: (1) A method in which anhydrous magnesium chloride is co-pulverized with an ester compound and a silicon compound, and then treated with TiCl4.
(JP-A-57-63310), (2) A method in which a carrier obtained by precipitating anhydrous magnesium chloride solubilized with alcohol with a precipitant is treated with an ester compound and then treated with TiCl4 (JP-A-57-63310). Showa 58-8
3006), and the like.

The polymerization method for producing component (5) may be any one of polymerization in an inert solvent, in a liquefied monomer, or in a gas phase. Further, the polymerization may be carried out by continuous polymerization, batch polymerization, or a combination thereof. In addition, each step of the polymerization may be carried out by carrying out the polymerization with all or part of the solvent and monomer remaining in the previous step, or by carrying out the polymerization after completely removing the solvent and monomer from the previous step, or Any combination of these methods may be used.

Component (B) has a refractive index difference of -α01 with respect to component (A).
In the range of 0 to 0.015, preferably -0,005 to 0.
012, most preferably -o,ooo to 0.01
In the range of 0, a final composition with significantly improved transparency can be obtained.

A specific example of component (B) is at least one resin composition selected from various ethylene polymers and copolymers, and various rubbery polymers such as polyisobutylene. Among these, various ethylene polymers or copolymers are preferred because they have good heat resistance stability.

Further examples of various ethylene polymers or copolymers include linear ethylene polymers or copolymers, branched ethylene polymers, and copolymers with polar monomers copolymerizable with ethylene.

More specifically, linear ethylene polymers or copolymers include ethylene polymers polymerized using Ziegler-Natsuta catalysts or chromium-based catalysts, or copolymers with other α-olefins that are linear. These include linear high-density polyethylene, linear medium-density polyethylene, linear low-density polyethylene, ethylene/α-olefin rubber, and the like.

Branched ethylene polymers or copolymers with polar monomers copolymerizable with ethylene are generally 500 to 9
Ethylene is polymerized using a radical catalyst under high pressure of /cI or higher, and is obtained by copolymerizing ethylene with a polar monomer that can be copolymerized, such as branched low-density polyethylene or ethylene/acetic acid. vinyl copolymer,
Examples include ethylene/methyl methacrylate copolymer.

When two or more types of polymers are used as component +j3), the improved transparency of the present invention can be achieved if the refractive index of the mixture is within the above range compared to the refractive index of component (A). be able to.

In this case, the effect of the present invention can be obtained even if the composition of component (B) is not uniform in molecular size, and the refractive index of the composition in this case is the weighted average value of the refractive index of each component. The value is close to .

Components (B, l are those whose flexural modulus is 300
0 to 9/cd or less, preferably 2000 kg/c
It is preferable that the impact strength of the composition is greatly improved when it is less than 1.

The resin composition of the present invention can be used in the usual molding process used for polypropylene. Specifically, specific examples of molding methods include injection molding, film molding, sheet molding, blow molding, and the like.

If the melt index of the final resin composition is extremely low, it is not preferable because the surface becomes rough during extrusion processing, resulting in decreased transparency, and the mold (A) becomes insufficiently filled during injection molding. Furthermore, if the melt index is extremely high, the mechanical strength will decrease, which is undesirable. Therefore, the melt index is 0.1-2
009/10 minutes is preferable, 0.2~100f/10
minutes is more preferred.

Further, known inorganic or organic fillers and resins can be added to the resin composition of the present invention. In addition, the resin composition can be molded into a single layer, or it can be used as part of a multilayered molded product for the purpose of improving gas barrier properties and the like.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited by these descriptions.

The physical property values shown in the following Examples and Comparative Examples were measured by the following method.

It was measured in Tetralin at 135°C using an Ubbelohde viscometer.

(2) Melt index Measured according to JIS K6758.

(3) Press molding Measured according to JIS K6758.

(4) Diffuse transmitted light intensity (LSI) Measured using an LSI tester manufactured by Toyo Seiki (receives scattered transmitted light at 0.2 rou 1.2°).

(5) Haze Measured according to ASTM D1003.

(6) Flexural modulus Measured according to JIS K7203.

(7) Izotsu impact strength Measured according to JIS K7110.

(8) Vicat softening temperature Measured according to JIS K7206-B method.

(9) Refractive index A 0.1H sheet was processed by the method described in (4), and measured using a sodium D line using an Atsbe refractometer model 2T (manufactured by Atago ■).

(10) Amount of xylene soluble components at 20℃ Add 100□l of xylene to 0.51 sample and bring to a boil for 30 minutes.
The sample was dissolved by holding for a minute. The solution was then kept under stirring in a constant temperature bath kept at 20°C for 1 hour to separate the solution, and the liquid phase was evaporated to dryness to determine the proportion of the dissolved polymer.

(11) Density Measurement was performed using JIS K7112 A method.

Examples Example 1, Comparative Example 1-2 (Synthesis of titanium trichloride solid catalyst) A titanium trichloride solid catalyst was synthesized according to the method disclosed in JP-A-60-228504. After purging a reactor with an internal volume of 3 doors equipped with a stirrer with nitrogen, 788 mL of n-hexane was added.
1, 73 g of titanium tetrachloride, and 2231 g of tetra-n-butoxytitanium were charged into a reactor and the temperature inside the reactor was maintained at 20° C. with stirring. A solution consisting of 3731 parts of n-hexane and 172 parts of diethylaluminium chloride was gradually added dropwise over 4.5 hours while maintaining the temperature inside the reactor at 20°C.

After dropping, the temperature was kept at 20°C for 30 minutes, and then the temperature was raised to 50°C.
Stir for hours.

Next, the mixture was allowed to stand at room temperature to separate solid and liquid, and washed three times with one layer of n-hexane to obtain a solid product.

? ! ) Raret: n-hexane 1.777 to solid product
' was added to form a slurry, then 8.31 g of diethyl aluminum chloride was added, the temperature was adjusted to 42°C, and 3 g of ethylene gas was added.
3 kq was supplied for about 1 hour to obtain a prepolymerized solid. After solid-liquid separation, n-hexane 1772' was added to form a slurry, and the temperature inside the reactor was maintained at 30°C.

Diisoamyl ether 2671 was added to this slurry and treated at 30°C for 1 hour. Then the temperature inside the reactor is 75
The temperature was raised to ℃, 362 liters of titanium tetrachloride was added, and the mixture was treated for 2 hours. After solid-liquid separation, washing was repeated four times with n-hexane 177/2, and then flow-dried using hydrogen gas at 250
A titanium trichloride solid catalyst No. 9 was obtained.

(Synthesis of vinylcycloalkane copolymer) In a 51 glass flask, 3.51 g of dehydrated and purified n-hexane,
165 mmol of diethylaluminum chloride and 500 g of the above titanium trichloride solid catalyst were added, and the temperature was raised to 40°C. Next, propylene was supplied so that the partial pressure was 200 nHg to initiate polymerization. Polymerization of propylene was carried out until the amount of polymerization reached 400 grams. Then increase the temperature to 6
After raising the temperature to 0° C. and feeding 700 g of vinylcyclohexane in three portions at 30 minute intervals, the temperature was maintained at 60° C. for 2 hours to continue polymerization. The obtained polymer containing the titanium trichloride solid catalyst was washed with 1.5 l of n-hexane and then dried at 40°C under reduced pressure for 6 hours to obtain a polymer containing an active catalyst component of 1580F. .

As a result of calculating the material balance, it was found that 1.361 o and sy of propylene polymers and 1.361 vinylcyclohexane polymers were polymerized per door of the solid catalyst component.

(Synthesis of crystalline polypropylene copolymer) Dehydrated and purified n-hebutane 2.777%/ , diethylaluminum chloride 2
2.5 moles of ε-caprolactone, 0.24 moles of ε-caprolactone, and polymer 20501 containing the active catalyst component described above were sequentially charged. The temperature was then adjusted to 50°C and the butene-1 was converted to 2
After supplying 3 k (j, propylene is 500 kg/hr
, butene 1 was supplied to Flea 50 at a rate of 9/hr, and the pressure inside the reactor was increased to 4 kg/7G.

After increasing the pressure, propylene and butene-1 were supplied to maintain the pressure inside the reactor at 4 kg/cAG. During this period, the propylene and butene-1 feeds maintained the propylene/butene-1 ratio at 1/0.045 (by weight).

During the polymerization, the hydrogen concentration in the gas phase of the reactor was maintained at approximately 0.75%.
VO was kept at 1%. Propylene supply amount is 992k (7
When this was reached, the monomer supply was stopped. When the pressure inside the reactor reached 2 kg/c-, the slurry containing the polymer was transferred to a cleaning tank with an internal volume of 20 doors and replaced with nitrogen.
Polymerization was stopped by adding 2.4 liters of n-hebutane and 851 liters of n-butanol. After stirring at 60°C for 1 hour, add 1.2 parts of water and adjust the temperature so that the pH of the aqueous phase becomes 11.
Added OH. Stirred at 50-55°C for 30 minutes.

Subsequently, stirring was stopped, the aqueous phase was separated and removed, and the remaining heptane slurry was subjected to solid-liquid separation using a decanter. The recovered polymer cake was dried with hot nitrogen at 70 to 80° C. for about 30 hours to obtain 850 kti of white polymer. The ω of the polymer is 3.20 old/f, and the butene-1 content is 6.
．． The content of the polyvinylcyclohexane polymer was 1038 wtppm, and the amount of components soluble in xylene at 20°C was 1.9 wt%.

(Preparation of resin composition) For the crystalline polypropylene copolymer synthesized by the above method as the component formula, as component (B) density 0.90
0! i'/ω, linear ethylene with melt index 65f/10 min, butene-1 copolymer, or density 0.
898 f/cc, melt index 0.7971
A 0 minute ethylene, butene-1 rubbery polymer was blended with the composition shown in Table 1, melt-kneaded in a 65MND extruder, extruded into a strand, and then pelletized.

In order to prevent thermal deterioration of the resin during melt cross-contact,
Calcium stearate 0.05 part, tris(2,4-ditertibutylphenyl) phosphite 0.23 part, tetra[methylene-3-(3,5-ditertiarybutyl-4,-hydroxyphenyl) ) Propionate] 0.18 part of methane was added.

The obtained pellets were molded into a sheet using a hot press molding machine and their physical properties were measured. The results are shown in Table 2.

As a result of measuring the refractive index of each resin component in Table 1, the crystalline polypropylene copolymer was 1,501, the linear low ethylene 7-butene-1 polymer was 1,502, and the ethylene-butene-1 rubbery polymer was: It was 1.483.

Comparative Example 3-4 As component (5) [t is 3.30 dl/da, 20゛C
For a crystalline polypropylene polymer whose xylene soluble portion is 3.9 wt%, the density as component (B) is 0.919! V/company, melt index 0.95'/
10-minute branched low-density polyethylene was blended with the composition shown in Table 3, melt-kneaded using an extruder, and pelletized.
two.

In order to prevent thermal deterioration of the resin during melt-kneading, resin 10
Calcium stearate 0.05 part, tris(2,4-ditertibutylphenyl)phosphite 0.23 part, tetra[methylene-3-(3,5-ditertiarybutyl-4-hydroxyphenyl)] 20.08 parts of propionate cometa was added.

The obtained pellets were press-molded under the same conditions as in the above example. The results of measuring the physical properties of the obtained molded product are
Shown in Table 2.

Table 3 The refractive index of the crystalline polypropylene polymer and the branched low density polyethylene was measured and the results were 1.503.
It was 1.515.

Comparative Example 1 is a composition with a single component formula consisting of a crystalline propylene copolymer containing the vinylcycloalkane of the present invention. It can be seen that the transparency is extremely excellent.

Furthermore, although butene-1 was copolymerized in the process of polymerizing crystalline propylene, the flexural modulus and Vicat softening temperature were superior to those of the propylene homopolymer of Comparative Example 3, with no color retention. be. However, the Izot impact strength has not been improved in any way.

It can be seen from Table 2 that the impact strength of Example 1 is improved without impairing the transparency of Comparative Example 1.

Furthermore, although Example 1 has a slightly lower flexural modulus and Vicat softening temperature than Comparative Example 1, it maintains the excellent level inherent to polypropylene.

Comparative Example 2 is a component (B) with a large difference in refractive index from the component (A).
However, the transparency is clearly inferior to that of the example. In Comparative Example 4, component (B) was added to ordinary crystalline polypropylene.
), but its transparency and impact strength are inferior.

Effect of the invention> Component (5) consisting of a crystalline propylene polymer or copolymer containing a 3-branched α-olefin having 6 or more carbon atoms or a vinylcycloalkane polymer, and component (A)
A composition comprising a polymer component (B) having a refractive index difference in the range of -0,010 to 0.015 and having a composition defined by the present invention has excellent transparency, elastic modulus, and heat resistance. This is a resin composition that has improved impact strength while maintaining good properties and low odor.

Claims (5)

[Claims] (1) 1 to 100,000 wtp of a 3-branched α-olefin having 6 or more carbon atoms or a vinylcycloalkane polymer
95 to 40 wt% of component (A) consisting of a crystalline propylene polymer or copolymer containing pm and a polymer component whose refractive index difference with respect to component (A) is in the range of -0.010 to 0.015. (B) A resin composition characterized by comprising 5 to 60 wt%. (2) Component (B) has a bending modulus of 3000 kg/cm^
2. The resin composition according to claim 1, which has a molecular weight of 2 or less. (3) The resin composition according to claim 1, wherein component (B) is an ethylene polymer or a copolymer. (4) The crystalline propylene polymer or copolymer of component (A) contains 75 to 100 mol% of propylene units, ethylene, and linear or branched α-
Consisting of 0 to 25 mol% of at least one type of monomer unit selected from olefins, and component (A) at 20°C
The resin composition according to claim 1, wherein the content of xylene-soluble components in the resin composition is 40 wt% or less. (5) Component (B) is at least one resin composition selected from a linear ethylene copolymer, a branched ethylene polymer, or a copolymer with a polar monomer copolymerizable with ethylene. 1. The resin composition according to 1.