JP2564882B2 - Resin composition - Google Patents

Description

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, pharmaceuticals and the like because of its excellent oil resistance, elastic modulus, heat resistance, moisture resistance and the like. However, polypropylene is inferior in transparency as compared with amorphous polymers such as polystyrene and polyvinyl chloride. In addition, there is a drawback that the impact strength is low at a temperature below room temperature.

As a method for improving the transparency of polypropylene, JP-A-58-80329 discloses a method of adding an aluminum salt or sodium salt of an aromatic carboxylic acid, and JP-A-55-12.
In Japanese Patent Laid-Open No. 460 and Japanese Patent Laid-Open No. 58-129036, a method of adding an aromatic carboxylic acid, a metal salt of an aromatic phosphoric acid, a sorbitol derivative or the like is proposed.

Among these methods, the aromatic carboxylic acid, aromatic carboxylic acid salt, and aromatic metal phosphate metal salt have improved transparency and elastic modulus, but their degree is small. The sorbitol derivative has a great effect of improving the transparency, but it significantly reduces the value of the product during the molding process and because the odor of the molded product is large.

As a method for solving such a problem, JP-A-60-139710 discloses a method in which (a) polymerization of vinylcycloalkane having 6 or more carbon atoms and (b) propylene alone or copolymerization with ethylene in multiple stages. Proposed.

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

On the other hand, as a means for improving the impact strength, a method of copolymerizing propylene with another α-olefin, especially ethylene, a method of adding a rubber-like substance and the like are known. The random copolymerization method and the block copolymerization method are generally used as the copolymerization method. In the random copolymerization method, the copolymerization α
-If the olefin content is low, the impact strength improving effect is low, and if the olefin content is high, the elastic modulus is significantly lowered. Further, the block copolymerization method and the method of adding a rubber-like substance have a great effect of improving the impact strength, but the transparency is remarkably lowered.

<Problems to be Solved by the Invention> Impact strength while maintaining transparency, elastic modulus, low odor and heat resistance improved in JP-A-60-139710 and JP-A-60-139731. It is an object of the present invention to provide an improved resin composition of

<Means for Solving the Problem> That is, the present invention provides a polymer of 6 or more carbon atoms and 3-position branched α-olefin or a polymer of vinylcycloalkane from 1 to 100000.
Component (A) composed of crystalline propylene polymer or copolymer containing wtppm of 95 to 40 wt% and component (B) of polymer having a difference in refractive index with respect to component (A) in the range of -0.010 to 0.015 5 to 60 wt%, and the crystalline propylene polymer or copolymer of component (A) is a propylene unit.
75 to 100 mol% and 0 to 25 mol% of ethylene and at least one monomer unit selected from linear or branched α-olefins having 4 to 10 carbon atoms, and the component (A) is The content of xylene-soluble components at 20 ° C is 15 wt% or less, and component (B) is an ethylene polymer or copolymer (provided that component (B) has a refractive index of component (A) or more). And a combination of the following components (A) are excluded).

The method for producing a crystalline propylene polymer or copolymer containing the component (A) 3-position branched α-olefin having 6 or more carbon atoms or a polymer of vinylcycloalkane is (1) Ziegler. A step of polymerizing a 3-position branched α-olefin having 6 or more carbon atoms or vinylcycloalkane in the presence of a Natta catalyst, or copolymerizing with another α-olefin; and propylene alone or with another α-olefin. A method in which the step of polymerizing is performed at least once, (2) a method in which the polymer obtained in (1) above is mixed with propylene alone or a copolymer with another α-olefin, (3) carbon number 6 or more 3-position branched α-olefin or vinyl cycloalkane polymer, or copolymer with other α-olefin, and propylene homopolymer or copolymer of propylene and other α-olefin. The method of mixing, etc. are mentioned.

Among these methods, the methods (1) and (2) are transparent,
The effect of improving the elastic modulus and heat resistance is large and preferable, and the method (1) is most preferable because the effect of improving is largest.

As a method for copolymerizing a 3-position branched α-olefin having 6 or more carbon atoms or a vinylcycloalkane with another α-olefin, either random copolymerization or block copolymerization may be used, but block copolymerization is 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.

As the method for producing the crystalline propylene polymer or copolymer as the component (A), propylene is polymerized alone by a catalyst system which gives isotactic polypropylene, or propylene and ethylene and a straight chain having 4 to 10 carbon atoms are used. It can be obtained by copolymerizing at least one type of monomer selected from chain or branched α-olefins. As the 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.

When the content of the low crystalline component is large, the component (A) bleeds the low crystalline component on the surface of the molded product, thus impairing the commercial value. As a result of the study conducted by the present inventors, it was found that the above problem can be solved by setting the content of the xylene-soluble component at 20 ° C. to a certain value or less.

That is, component (A) preferably has a xylene-soluble component content at 20 ° C. of 40 wt% or less, more preferably 30 wt% or less, most preferably 15 wt% or less.

In order to bring the content of the xylene-soluble component at 20 ° C. of the component (A) into this range, the catalyst system which gives highly isotactic polypropylene described below is used, and Crystalline propylene polymer or copolymer part, ethylene copolymerized with propylene, and
The content of at least one monomer 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, most preferably 10 mol% or less. Can be achieved by

Specific examples of the 3-position branched α-olefin having 6 or more carbon atoms or the vinylcycloalkane used in the present invention are as follows.
3.3-dimethylbutene-1,3-methylpentene-1,
3-methylhexene-1,3,5,5-trimethylhexene-1, vinylcyclopentene, vinylcyclohexane,
Vinyl norbornane, etc. 8 of these
The above olefins are more preferable.

When the content of 3-position branched α-olefin having 6 or more carbon atoms or vinyl cycloalkane polymer is less than 1 wtppm, the effect of improving transparency and elastic modulus is small, and 100000 wtpp
If it is more than m, the transparency will decrease. Therefore 1 to 1
A content of 00000 wtppm is preferred, 100 to 70,000 wtppm is more preferred, and 500 to 50,000 wtppm is most preferred.

Production of a crystalline propylene polymer or copolymer containing a 3-position branched α-olefin having 6 or more carbon atoms or a polymer of vinylcycloalkane is achieved by using a catalyst system which gives isotactic polypropylene. You can do it. A Ziegler-Natta type catalyst system can be most preferably used as a catalyst system for providing isotactic polypropylene.

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

The synthesis method of the solid catalyst component is roughly classified into two.
One of them is a solid catalyst component obtained by reducing a tetravalent titanium compound with hydrogen, metal aluminum, an organometallic compound, or the like, or one obtained by further pulverizing and activating them, or a tetravalent titanium compound is an organometallic compound. The method is to obtain a catalyst by subjecting it to various activation treatments after obtaining a catalyst precursor by reduction with, and the other is to carry a tetravalent titanium compound on a carrier such as activated magnesium chloride. Is a method of obtaining a catalyst.

Among the former methods, methods of reducing a tetravalent titanium compound with an organometallic compound and then performing activation treatment include a method of using an organoaluminum compound as a reducing reagent and a method of using an organomagnesium compound. Specifically, (1) a reduced solid produced by reducing TiCl ₄ with an organoaluminum compound is treated with a complexing agent, and then
How to react with TiCl ₄ . (Japanese Patent Publication No. 53-3356) (2) A method in which a titanium compound represented by the general formula Ti (OR) nX ₄ -n is reduced with an organoaluminum compound and then treated with an ether compound and TiCl ₄ (Japanese Patent Laid-Open No. Sho 63-3356). 60-228504), (3) After a titanium compound represented by the general formula Ti (0R) nX ₄ -n is reduced with an organomagnesium compound in the presence of an organosilicon compound, treatment with an ester compound and ether A method of treating with a mixture of a compound and TiCl ₄ (JP-A-61-287904), (4) A method of immobilizing the catalyst component obtained in (3) on a porous material (JP-A-62-256802). Gazette), etc.

Specific examples of the latter method include: (1) a method in which anhydrous magnesium chloride is co-ground with an ester compound and a silicon compound and then treated with TiCl ₄ (JP-A-57-63310), (2) alcohol A method of treating a carrier obtained by precipitating anhydrous magnesium chloride solubilized by a precipitant with an ester compound and then treating with TiCl ₄ (Japanese Patent Laid-Open No. 58-83006), and the like.

As the polymerization method for producing the component (A), any method of polymerization in an inert solvent, in a liquefied monomer, or in a gas phase can be used. The polymerization may be continuous polymerization, batchwise polymerization, or a combination thereof. Further, each step of the polymerization is a method of carrying out the polymerization while leaving all or a part of the solvent and the monomer in the previous step, or a method of carrying out the polymerization after removing the solvent and the monomer in the previous step, or Any combination of methods can be used.

The difference in the refractive index of the component (B) from that of the component (A) is -0.01.
When it is in the range of 0 to 0.015, preferably in the range of -0.005 to 0.012, and most preferably in the range of -0.000 to 0.010, it is possible to obtain a final composition having extremely improved transparency.

Specific examples of the component (B) are at least one resin composition selected from various ethylene polymers, copolymers, and various rubbery polymers such as polyisobutylene. Of these, various ethylene polymers or copolymers are preferable because they have good heat resistance stability.

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

More specifically, the linear ethylene polymer or copolymer is an ethylene polymer polymerized with a Ziegler-Natta catalyst or a chromium-based catalyst, or
It is a copolymer with other α-olefin and is linear high-density polyethylene, linear medium-density polyethylene, linear low-density polyethylene, ethylene / α-olefin rubber, or the like.

As a branched ethylene polymer or a copolymer with a polar monomer copolymerizable with ethylene, generally 500 kg / cm
^A branched low-density polyethylene, ethylene / vinyl acetate, which is obtained by polymerizing ethylene with a radical catalyst under high pressure of ² or more or by copolymerizing ethylene and a polar monomer copolymerizable with ethylene. Examples thereof include copolymers and ethylene / methyl methacrylate copolymers.

When two or more kinds of polymers are used as the component (B), the refractive index of the mixture is in the above range as compared with the refractive index of the component (A), and the improved transparency of the present invention is achieved. can do.

In this case, the effect of the present invention can be obtained even if the composition of the component (B) is not necessarily 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. It is a value close to.

Component (B) has a flexural modulus of 3000 kg among these
/ cm ² or less, preferably 2000 kg / cm ² or less, since the impact strength of the composition is greatly improved.

The resin composition of the present invention can be used in the usual molding method used for polypropylene. That is, specific examples of the molding method include an injection molding method, a film molding method, a sheet molding method, and a blow molding method.

When the melt index of the final resin composition is extremely low, the surface of the resin composition is roughened during extrusion and the transparency is lowered, and the mold is not sufficiently filled during injection molding, which is not preferable. Further, when the melt index is extremely high, the mechanical strength is lowered, which is not preferable. Therefore, the melt index is 0.1-200g / 10
Min is preferable, and 0.2-100 g / 10 min is more preferable.

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

Hereinafter, the present invention will be specifically described with reference to Examples.
The present invention is not limited by these descriptions.

The physical property values shown in the following examples and comparative examples are measured by the following methods.

(1) [η] It was measured in 135 ° C. tetralin 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) It was measured by an LSI tester manufactured by Toyo Seiki (receives scattered transmitted light of 0.2 ° to 1.2 °).

(5) Haze Measured according to ASTM D1003.

(6) Flexural modulus Measured according to JIS K7203.

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

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

(9) Refractive index A 0.1 mm sheet was processed by the method of (4) and measured with a sodium D line using an Abbe refractometer 2T type (manufactured by Atago Co., Ltd.).

(10) Amount of xylene-soluble components at 20 ℃ Sample 0.5g
The sample was dissolved by adding 100 ml of xylene to the mixture and keeping it in the boiling state for 30 minutes. Then, the mixture was kept under stirring in a constant temperature bath kept at 20 ° C. for 1 hour and then solid-liquid separation was carried out, and the liquid phase was evaporated to dryness to obtain the ratio of the dissolved polymer.

(11) Density Measured by JIS K7122 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 replacing the reactor having an internal volume of 3 m ³ equipped with a stirrer with nitrogen, n-hexane 788, titanium tetrachloride 73, and tetra-n-butoxytitanium 223 were charged into the reactor and stirred in the reactor. The temperature was kept at 20 ° C. A solution consisting of n-hexane 373 and diethylaluminum chloride 172 was gradually added dropwise over 4.5 hours while maintaining the temperature in the reactor at 20 ° C.

After the dropping was completed, the temperature was maintained at 20 ° C for 30 minutes, then heated to 50 ° C, and stirred for 1 hour.

Then, the mixture is allowed to stand at room temperature to separate solid-liquid, and n-hexane 1 m ³
The solid product was obtained by washing 3 times with.

1 m ³ of n-hexane was added to the obtained solid product to make a slurry, diethyl aluminum chloride 8.3 was added, the temperature was adjusted to 42 ° C., and 33 kg of ethylene gas was supplied for about 1 hour to obtain a prepolymerized solid. Then, after solid-liquid separation, n
-Add 1 m ³ of hexane to make a slurry and increase the temperature in the reactor to 3
It was kept at 0 ° C.

Diisoamyl ether 267 was added to this slurry and treated at 30 ° C. for 1 hour. Then the temperature in the reactor 75 ℃
The temperature was raised to 2, and 362 titanium tetrachloride was added, followed by treatment for 2 hours.
After solid-liquid separation, washing with 1 m ³ of n-hexane was repeated 4 times, and then flow-dried with hydrogen gas to obtain 250 kg of titanium trichloride solid catalyst.

(Synthesis of Vinyl Chloroalkane Copolymer) Into a glass flask No. 5, 3.5 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. . Then, propylene was supplied to start polymerization so that the partial pressure became 200 mmHg. Polymerization of propylene was carried out until the amount of polymerization reached 400 g. Then, the temperature was raised to 60 ° C., and 700 g of vinylcyclohexane was dividedly supplied at intervals of 30 minutes, and then the temperature was kept at 60 ° C. for 2 hours to continue the polymerization. The obtained polymer containing titanium trichloride solid catalyst was washed with 1.5 parts of n-hexane and then dried at 40 ° C. under reduced pressure for 6 hours to obtain a polymer containing 1580 g of active catalyst component.

As a result of calculating the material balance, 0.8 g of the propylene polymer and 1 g of the vinylcyclohexane polymer per 1 g of the solid catalyst component,
1.36g has been polymerized.

(Synthesis of Crystalline Polypropylene Copolymer) 5.7m adjusted to 0.5kg / cm ² G at 35 ° C with propylene
³ equipped with a stirrer made of stainless steel reactor, n of dehydrated and purified
-Heptane 2.7 m ³ , diethylaluminum chloride 22.5
Mol, ε-caprolactone 0.24 mol, and 2050 g of a polymer containing the above-mentioned active catalyst component were sequentially added. Then, the temperature was adjusted to 50 ° C., 23 kg of butene-1 was supplied, propylene was supplied at a rate of 500 kg / hr, butene-1 was supplied at a rate of 50 kg / hr, and the pressure in the reactor was increased to 4 kg / cm ² G. .

After increasing the pressure, propylene and butene-1 were supplied so that the pressure in the reactor was maintained at 4 kg / cm ² G. During this period, the supply of propylene and butene-1 kept the ratio of propylene / butene-1 at 1 / 0.045 (weight ratio).

During the polymerization, the hydrogen concentration in the gas phase of the reactor was set to about 0.75 vo
kept at l%. When the propylene supply amount reached 902 kg, the monomer supply was stopped. Pressure in the reactor is 2 kg /
When it reached cm ² , the polymer-containing slurry was transferred to a nitrogen-substituted cleaning tank having an internal volume of 20 m ³ , and n-heptane 2.4 m ³
Then, n-butanol 85 was added to terminate the polymerization. 60
After stirring for 1 hour at ℃, add 1.2m ³ of water and add PH to the aqueous phase.
KOH was added so that was 11. The mixture was 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 by a decanter.
The recovered polymerized polymer cake was dried with hot nitrogen at 70 to 80 ° C. for about 30 hours to obtain 850 kg of a white polymer. The polymer [η] was 3.20 dl / g, the butene-1 content was 6.0, and the polymer content of polyvinylcyclohexane was 1038 wtpp.
The amount of xylene-soluble components at m and 20 ℃ was 1.9wt%.

(Preparation of Resin Composition) With respect to the crystalline polypropylene copolymer synthesized by the above method as the component (A), the density of the component (B) is 0.
900g / cc, melt index 65g / 10min linear ethylene. Butene-1 copolymer, or ethylene with a density of 0.898 g / cc and a melt index of 0.7 g / 10 min. The butene-1 rubbery polymer was blended in the composition shown in Table 1, melt-kneaded with a 65 mmφ extruder, extruded into a strand, and then pelletized.

For the purpose of preventing thermal deterioration of the resin during melt kneading, resin 10
0.05 part calcium stearate, tris (2,4-ditertiarybutylphenyl) phosphite against 0 part
0.23 parts and 0.18 parts of tetra [methylene-3- (3,5-ditertiarybutyl-4-hydroxyphenyl) propionate] methane were added.

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

As a result of measuring the refractive index of each resin component, the crystalline polypropylene copolymer was 1.501, and the linear low ethylene / butene-
One polymer is 1.502, ethylene. The butene-1 rubbery polymer was 1.483.

Comparative Example 3-4 As to the crystalline polypropylene polymer in which [η] is 3.30 dl / g and the xylene-soluble portion at 20 ° C. is 3.9 wt% as the component (A), the density of the component (B) is 0.919. Branched low-density polyethylene having a g / cc and a melt index of 0.9 g / 10 min was blended in the composition shown in Table 3, melt-kneaded by an extruder and pelletized.

For the purpose of preventing thermal deterioration of the resin during melt kneading, resin 10
0.05 part calcium stearate, tris (2,4-ditertiarybutylphenyl) phosphite against 0 part
0.23 parts and 0.08 parts of tetra [methylene-3- (3,5-ditertiarybutyl-4-hydroxyphenyl) propionate] methane were 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.

The crystalline polypropylene polymer and the result of measuring the refractive index of the branched low-density polyethylene are 1.503 and 1.5, respectively.
It was 15.

Comparative Example 1 is a composition of the component (A) consisting of the crystalline propylene copolymer containing the vinyl cycloalkane of the present invention, but compared with the case of the ordinary crystalline propylene polymer shown in Comparative Example 3. It can be seen that the transparency is extremely excellent.

In the step of further polymerizing crystalline propylene, butene-1
However, the flexural modulus and the Vicat softening temperature of the propylene homopolymer of Comparative Example 3 were excellent, even though they were copolymerized. However, the Izod impact strength is not improved at all.

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

Further, in Example 1, the flexural modulus and the Vicat softening temperature are slightly lower than those of Comparative Example 1, but the excellent levels originally possessed by polypropylene are maintained.

Comparative Example 2 is a system in which the component (B) having a large difference in refractive index is added to the component (A), but the transparency is obviously inferior to the examples. Comparative Example 4 is a system in which the component (B) is added to ordinary crystalline polypropylene, but the transparency and impact strength are poor.

<Effect of the Invention> Component (A) consisting of a crystalline propylene polymer or copolymer containing a 3-position branched α-olefin having 6 or more carbon atoms or a polymer of vinylcycloalkane, and refraction to component (A) A composition comprising a polymer component (B) having a difference in ratio in the range of -0.010 to 0.015 and having a composition defined in the present invention has excellent transparency, elastic modulus, heat resistance,
A resin composition having improved impact strength while maintaining low odor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuki Wakamatsu 5-1 Anezaki Kaigan, Ichihara, Chiba Prefecture Sumitomo Chemical Co., Ltd. (72) Inventor Tomohisa Fukao 5-1 Anesaki Kaigan, Ichihara, Chiba Sumitomo Chemical Co., Ltd. Within the corporation (56) Reference JP-A-60-139710 (JP, A) JP-A-53-108146 (JP, A) JP-A-60-139731 (JP, A)

Claims (3)

(57) [Claims] 1. A polymer of 3 or more branched α-olefins having 6 or more carbon atoms or vinyl cycloalkane is 1 to 100000 wtppm.
Component (A) consisting of crystalline propylene polymer or copolymer contained 95 to 40 wt%, and component (B) of the polymer having a difference in refractive index with respect to component (A) in the range of -0.010 to 0.015 60 wt% and the crystalline propylene polymer or copolymer of the component (A) has a propylene unit of 75 to 10
0 mol% and at least 1 selected from ethylene and a linear or branched α-olefin having 4 to 10 carbon atoms.
The component (A) has a content of xylene-soluble components of 15 wt.
% Or less, and the component (B) is an ethylene polymer or a copolymer (provided that the component (B) is a combination of those having a refractive index of component (A) or more and component (A) or less). Resin composition). 2. The resin composition according to claim 1, wherein the component (B) has a flexural modulus of 3000 kg / cm ² or less. 3. The component (B) is at least one selected from a linear ethylene copolymer, a branched ethylene polymer and a copolymer with a polar monomer copolymerizable with ethylene. Resin composition.