JPH0730218B2 - Low crystalline propylene random copolymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a low-polymerizable polypropylene composite laminate having an improved heat-sealing property by being laminated on the surface of a crystalline polypropylene substrate. The present invention relates to a crystalline propylene-based random copolymer composition.

[Prior Art] Crystalline polypropylene films are excellent in mechanical properties such as tensile strength, rigidity, surface hardness and impact strength, optical properties such as gloss and transparency, and nontoxic and odorless food hygiene. Therefore, it is widely used in the field of packaging, especially food packaging. However, the polypropylene film has a drawback that a single layer has a high heat-sealable temperature and an appropriate temperature range is narrow.

Therefore, in order to improve the heat-sealing property of the polypropylene film, some methods have already been proposed for laminating a resin having a low melting point on one or both sides of the crystalline polypropylene film.

For example, in JP-A-55-65552, a propylene random copolymer comprising an ethylene / propylene random copolymer containing propylene as a main component and a propylene / α-olefin random copolymer containing propylene as a main component. A method of laminating the composition to a crystalline polypropylene film is disclosed. Further, JP-A-55-91665 discloses a propylene random copolymer composed of an ethylene / propylene random copolymer containing propylene as a main component and a 1-butene / ethylene random copolymer containing 1-butene as a main component. A method of laminating the coalesced composition to a crystalline polypropylene film is disclosed. Furthermore, JP-A-54-10
No. 6585 discloses an ethylene-propylene random copolymer containing propylene as a main component, a 1-butene / ethylenically unsaturated monomer copolymer containing 1-butene as a main component, and a propylene comprising a low molecular weight thermoplastic resin. A method of laminating a random copolymer composition to a crystalline polypropylene film is disclosed. Further, U.S. patents filed in the U.S.A. by claiming priority to the above-mentioned JP-A-55-91665 (JP-A-53-165137) and JP-A-54-106585 (JP-A-53-13932). No. 4,230,767, a propylene random copolymer which may include a composition comprising an ethylene-propylene random copolymer containing propylene as a main component and a 1-butene / propylene copolymer containing 1-butene as a main component. Disclosed is a propylene random copolymer composition which may include an embodiment of laminating the coalesced composition to a crystalline polypropylene film. However, no specific example of the above aspect is shown, and as specified in JP-A-54-106585, only an example in which a low molecular weight thermoplastic resin is further used in combination is shown in this aspect. There is.

The laminates obtained by these methods all have improved heat-sealing properties of propylene film, but the heat-sealable temperature is still considerably high, and the applicable temperature range is narrow, and it is hard to say that it is still sufficient. Further, it was difficult to say that the heat seal strength was sufficient. In addition, since there are non-negligible amounts of components eluting in hydrocarbon solvents such as xylene and hexane, their use in the food packaging field was also limited.

Further, in order to develop the antistatic performance of these polypropylene composite laminates, a method of subjecting them to a low temperature heat treatment for several days is usually adopted, but in that case, the heat seal temperature rises considerably. There was a flaw. In this way, in the field of packaging applications using polypropylene film, the heat seal application temperature is lowered, the heat seal application temperature range is widened, the heat seal strength is excellent, and the heat sealable temperature rise due to heat treatment is small, and the hydrocarbon There is a strong demand for a polypropylene composite film having very few components that elute in a solvent.

[Problems to be Solved by the Invention] The present inventors provide a polypropylene composite laminate excellent in low-temperature heat sealability and heat seal strength by laminating it on at least one surface of a crystalline polypropylene base material layer. A study was conducted for the purpose of developing a low-crystalline propylene-based random copolymer composition that can be formed. As a result, ethylene and 4 to 4 carbon atoms
Crystalline propylene random copolymer [I] obtained by copolymerizing 20 α-olefins and low crystalline propylene random copolymer obtained by copolymerizing propylene and α-olefin having 4 to 20 carbon atoms A polypropylene composite laminate obtained by laminating a low crystalline propylene random copolymer composition comprising a copolymer [II] on at least one side of a crystalline propylene base layer can be heat-sealed at a relatively low temperature. It was also discovered that the temperature range applicable to heat-sealing is wide, the heat-sealing strength is excellent, the degree of rise in heat-sealable temperature due to heat treatment is small, and the components eluted into the hydrocarbon solvent are small.

Therefore, an object of the present invention is to form a polypropylene composite laminate having excellent low-temperature heat sealability and heat seal strength by laminating on at least one surface of a crystalline polypropylene base material layer, which is a low crystalline propylene type. It is to provide a random copolymer composition.

The above as well as many other objects and advantages of the present invention will become more apparent in the following description.

[Means for Solving Problems] and [Action] According to the present invention, [I] a repeating unit derived from propylene, a repeating unit derived from ethylene and a carbon number of 4 to 20
A propylene-based random copolymer comprising repeating units derived from α-olefin as described in (A) below, wherein the repeating unit (a) derived from propylene is 86
To 97 mol%, the repeating unit (b) derived from ethylene is 0.5 to 6 mol%, and the repeating unit (c) derived from the α-olefin is in the range of 2 to 13 mol%, and the molar ratio c / ( b + c) is in the range of 0.3 to 0.9, (B) intrinsic viscosity [η] measured in decalin at 135 ° C.
Is in the range of 0.5 to 6 dl / g, (C) Melting point [Tm] measured by a differential scanning calorimeter
Is in the range of 115 to 145 ° C., (D) the degree of crystallinity measured by X-ray diffraction is in the range of 30 to 60%, and the propylene-based random copolymer satisfying
Wt% and [II] 50 repeating units (d) derived from propylene
5 to 40% by weight of a low crystalline propylene random copolymer having a repeating unit (e) derived from α-olefin having 4 to 20 carbon atoms in the range of 20 to 50% by mole, A low crystalline propylene random copolymer composition formed from (i) a repeating unit (f) derived from propylene of 75 to 96 mol%, and a repeating unit derived from ethylene (g) )
Is 0.3 to 5 mol% and the repeating unit (h) derived from α-olefin having 4 to 20 carbon atoms is in the range of 4 to 20 mol%, and (ii) the limit measured in decalin at 135 ° C. Viscosity [η]
Is in the range of 0.5 to 6 dl / g, (iii) the degree of crystallinity measured by X-ray diffraction is in the range of 25 to 60%, and (iv) to p-xylene at 25 ° C. A low crystalline propylene-based random copolymer composition characterized by having a soluble content of 30% by weight or less, and (v) an amount of extraction into n-hexane at 50 ° C. of 10% by weight or less. The object of the present invention is achieved.

Crystalline propylene random copolymer [I] constituting the low crystalline propylene random copolymer composition of the present invention
Is a copolymer containing propylene as a main component, which is a copolymer comprising a propylene component (a), an ethylene component (b) and an α-olefin component (c) having 4 to 20 carbon atoms.

The composition (A) of the propylene-based random copolymer has a repeating unit (a) derived from propylene of 86 to 97 mol%, preferably 88 to 96 mol%, more preferably 89 to 95 mol%, derived from ethylene. Repeating unit (b)
Is 0.5 to 6 mol%, preferably 1 to 5 mol%,
More preferably 1.5 to 4 mol% and 2 to 13 mol%, preferably 3 to 11 mol%, more preferably 4 to 9 mol of the repeating unit (c) derived from α-olefin having 4 to 20 carbon atoms. It is in the range of%.

The content of the repeating unit (a) derived from propylene in the crystalline propylene random copolymer [I] is 86 mol%.
Repeating units (b) smaller and derived from ethylene
When the sum of the content of the repeating units (c) derived from α-olefin exceeds 14 mol%, the polypropylene composite laminate in which the low crystalline propylene random copolymer composition is laminated may block. In addition, the scratch resistance is reduced, and the heat-sealable temperature rises significantly due to the heat treatment. In addition, the content of the repeating unit (a) derived from propylene is greater than 97 mol% and the content of the repeating unit (b) derived from ethylene and the content of the repeating unit (c) derived from the α-olefin. If the sum is less than 3 mol%, the heat-sealing temperature of the polypropylene composite laminated product will be high and the heat-sealing strength will be low.

Regarding the repeating unit (b) derived from ethylene and the repeating unit (c) derived from the α-olefin, the molar ratio c / (b + c) is 0.3 to 0.9, preferably 0.1.
It is in the range of 4 to 0.8, more preferably 0.5 to 0.8. When the molar ratio c / (b + c) is larger than 0.9, the rigidity of the film is lowered, and when the molar ratio c / (b + c) is smaller than 0.3, the blocking resistance tends to be deteriorated.

The intrinsic viscosity [η] (B) of the crystalline propylene random copolymer measured in decalin at 135 ° C. is 0.5 to 6 dl.
/ g, preferably in the range of 1 to 5 dl / g. When the intrinsic viscosity of the crystalline propylene random copolymer is more than 6 dl / g, it is possible to reduce the thickness of the heat seal layer of the polypropylene composite laminate in which the low crystalline propylene random copolymer composition is laminated. Becomes difficult, 0.5dl / g
When it becomes smaller, the heat-sealing strength of the composite laminate decreases, and the heat-sealable temperature increases by heat treatment.

The melting point [Tm] (C) of the crystalline propylene random copolymer measured by a differential scanning calorimeter is 115 ° C to 1
45 ° C, preferably 120 ° C to 140 ° C, more preferably 12
It is in the range of 0 ° C to 135 ° C. When the melting point of the crystalline propylene random copolymer is higher than 145 ° C., the heat sealing temperature of the polypropylene composite laminate in which the low crystalline propylene random copolymer composition is laminated is increased,
In addition, the heat seal strength also decreases, and 115
If the temperature is lower than 0 ° C, the polypropylene composite laminate will be blocked and the scratch resistance will be lowered, and the heat-sealable temperature will be increased by the heat treatment. Here, the DSC melting point was measured for a press sheet having a thickness of 0.1 mm after a lapse of 20 hours of molding from 0 to 200 ° C. at a temperature rising rate of 10 ° C./min, and the maximum endothermic peak was defined as Tm.

The crystallinity (D) of the crystalline propylene-based random copolymer measured by X-ray diffractometry is in the range of 30 to 60%, preferably 35 to 55%. When the crystallinity of the crystalline propylene random copolymer is more than 60%,
The heat-sealing temperature of the polypropylene composite laminate in which the low crystalline propylene random copolymer composition is laminated becomes high, and the heat-sealing strength also becomes low,
When it is less than 35%, the polypropylene composite laminate comes to be blocked, the scratch resistance is lowered, and further, the heat seal temperature is increased by the heat treatment.

The crystallinity was determined by X-ray diffraction measurement of a 1.5 mm thick pressed sheet by pressing at 180 ° C. for 10 minutes and then at 25 ° C. for 10 minutes.

The crystalline propylene-based random copolymer [I] satisfies the binding factors represented by the characteristic values of (A) to (D) described above, and more preferable copolymers satisfy the following characteristic values. .

The soluble amount [w ₁ % by weight] (E) of n-decane at 25 ° C. of the crystalline propylene random copolymer [I] is
In relation to the melting point Tm of the copolymer, the general formula 0.03 (165-Tm) ≤ W ₁ ≤ 0.20 (165-Tm) preferably the general formula 0.03 (165-Tm) ≤ W ₁ ≤ 0.15 (165-Tm) (Here, Tm is a numerical value of the melting point of the copolymer,
It shows the value excluding the dimension). When the amount of the n-decane-soluble component is more than the above range, the blocking resistance of the polypropylene composite laminate molded body in which the low crystalline propylene random copolymer composition is laminated is deteriorated.

Here, the crystalline propylene-based random copolymer of 25 ℃
The amount of soluble matter in the n-decane solvent in is measured and determined by the following method. In a flask equipped with a stirrer with stirring blades, 5 g of the copolymer sample, 0.3 g of 2,6-ditert-dimertyl-4-methylphenol and 500 ml of n-decane were added and dissolved in an oil bath at 140 ° C. Let After the solution is dissolved, it is naturally cooled at room temperature for about 3 hours and then cooled on a water bath at 25 ° C for 12 hours.
An n-decane solution containing the precipitated copolymer and dissolved polymer was overseparated with a G-4 glass filter, and the solution was adjusted to 10 mm.
It is dried with Hg at 150 ° C. to a constant weight, and the polymer dissolved in n-decane is collected. Measure its weight, 25 ℃
The soluble content of the copolymer in n-decane solvent was calculated and determined as a percentage with respect to the weight of the sample copolymer.

The low crystalline propylene random copolymer constituting the low crystalline propylene random copolymer composition of the present invention [I
[I] is formed of a repeating unit (d) derived from propylene and a repeating unit (e) derived from α-olefin having 4 to 20 carbon atoms. The composition of the low crystalline propylene random copolymer [II] has a repeating unit (d) derived from propylene in the range of 50 to 80 mol%, and a repeating unit (e) derived from the α-olefin is It is in the range of 20 to 50 mol%.

As the α-olefin having 4 to 20 carbon atoms constituting the low crystalline propylene random copolymer, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-
Pentene, 1-octene, 1-decene, 1-dodecene and the like can be exemplified, and a mixed component of two or more kinds thereof may be used. The low crystallinity α-olefin random copolymer [II] has an intrinsic viscosity [η] measured in decalin at 135 ° C. of usually 1 to 6, preferably 1.5 to 4, and more preferably 1.7 to 3.5 dl / g. Melting point [Tm] in the range measured by the differential scanning heat flow
Is usually 110 ° C to 145 ° C, preferably 115 ° C to 130 ° C
, And the crystallinity measured by X-ray diffraction method is
It is in the range of 20 to 60%, preferably 30 to 50%.

The low crystalline propylene random copolymer composition of the present invention is a composition formed from the crystalline propylene random copolymer [I] and the low crystalline propylene random copolymer [II].

The content of the low crystalline propylene random copolymer [II] in the low crystalline propylene random copolymer composition is 5 to 40% by weight, preferably 8 to 30% by weight, more preferably 12 to 25% by weight. %, And the content of the crystalline propylene random copolymer [I] is 60 to 95% by weight, 70 to 92% by weight, and more preferably 75 to 88% by weight.

The composition (i) of the entire low crystalline propylene random copolymer composition of the present invention has a repeating unit (f) derived from propylene of 96 to 75 mol%, preferably 94 to 80 mol%, and more preferably Is in the range of 92 to 84 mol%, the repeating unit (g) derived from ethylene is in the range of 0.3 to 5 mol%, preferably 0.7 to 4.5 mol%, more preferably 1 to 4 mol%, The repeating unit (h) derived from α-olefin having a number of 4 to 20 is in the range of 4 to 20 mol%, preferably 5 to 15 mol%, more preferably 7 to 12 mol%.

In the low crystalline propylene random copolymer composition of the present invention, the intrinsic viscosity [η] (ii) measured in decalin at 135 ° C. is 0.5 to 6 dl / g, preferably 1 to 5 d.
l / g, preferably 1.5 to 4 dl / g, particularly preferably 1.7
Or in the range of 3.5 dl / g. This characteristic value is a scale showing the molecular weight of the low crystalline propylene random copolymer composition of the present invention, and by combining with other characteristic values, it is useful for providing a random copolymer having the above-mentioned excellent properties. ing.

The crystallinity (iii) of the low crystalline propylene random copolymer composition of the present invention measured by X-ray diffractometry is 25 to 60%, preferably 30 to 55%, more preferably 35.
Or in the range of 50%. This characteristic value is a measure showing that it has excellent tensile properties, and by combining with other characteristic values, it serves to provide the random copolymer having the above-mentioned excellent properties. Crystallinity is 1.5 mm after 20 hours of molding
The pressed sheet of was obtained by X-ray diffraction measurement.

In the low crystalline propylene random copolymer composition of the present invention, the amount of soluble component (iv) in the p-xylene solvent at 25 ° C is 30% by weight or less, preferably 25% or less. The amount (v) of the extractable component in the n-hexane solvent at 50 ° C. is 10% by weight or less, preferably 8% by weight or less,
It is more preferably 6% by weight or less.

In the present invention, the soluble content of the copolymer composition in a p-xylene solvent at 25 ° C is measured and determined by the following method. That is, 2 equipped with a stirring blade and a reflux condenser
The copolymer sample (5 g) and hexane (1) are added to the flask (1) and the mixture is kept under reflux of p-xylene for at least 2 hours to dissolve the sample in p-xylene. Then, after cooling the contents to 50 ° C under air cooling, the container is put in a cold water bath and rapidly cooled to 25-30 ° C. Put the container in a constant temperature bath kept at 25 ° C. 2
Keep time P- containing the precipitated copolymer and dissolved polymer
The xylene suspension was over-separated with a G-4 glass filter, the solution was dried under reduced pressure of about 10 mmHg at 150 ° C. until a constant temperature was reached, and the polymer dissolved in p-xylene at 25 ° C. was collected. The weight of the copolymer is measured, and the amount of the undersoluble component of the copolymer in the p-xylene solvent at 25 ° C is calculated and determined as a percentage with respect to the weight of the sample copolymer.

In the low crystalline propylene random copolymer composition of the present invention, the extraction amount of the copolymer composition in an n-hexane solvent at 50 ° C is measured and determined by the following method. That is, the copolymer sample and 1 n-hexane were added to 2 flasks equipped with a stirring blade and a reflux condenser, and the contents were heated to 50 ° C. and kept at the same temperature for 2 hours. The suspension was then over-separated with a G-4 glass filter while warm, and the liquid was dried under reduced pressure of about 10 mmHg at 150 ° C until a constant temperature was reached, and the polymer was extracted with n-hexane at 50 ° C. To collect. The weight is measured, and the extracted amount of the copolymer in the n-hexane solvent at 50 ° C. is calculated and determined as a percentage with respect to the weight of the sample copolymer.

As a method for producing the low crystalline propylene random copolymer composition of the present invention, the crystalline propylene random copolymer [I] and the low crystalline random copolymer [II] are tumbler, V type. A uniform blending method using a blender or a Hensiel mixer. After the mixing, a method of further kneading with an extruder, Banbury mixer, kneader, roll or the like can be exemplified.

Further, as a more preferable method for producing the low crystalline propylene random copolymer of the present invention, a polymerizer for producing the crystalline propylene random copolymer [I] and the low crystalline random copolymer An example is a method of directly producing a low-crystalline propylene random copolymer composition by a block copolymerization method using a series multistage polymerization apparatus in which a polymerization vessel for producing [II] is connected in series.

The following method can be illustrated as a specific example of such a manufacturing method.

(1) Suspension polymerization step in a propylene solvent [a] A suspension polymerization step [b] in a manufacturing process including three steps of a flash step [b] for vaporizing liquid propylene and a gas phase polymerization step [b] Alternatively, after synthesizing the crystalline propylene random copolymer [I] in the suspension polymerization step [a] and the flash step [II],
A method for producing a low-crystalline propylene-based copolymer composition by synthesizing a low-crystalline propylene-based random copolymer [II] in the gas phase polymerization step [C].

(2) In a production process including at least two gas phase polymerization steps, a crystalline propylene random copolymer [I] and a low crystalline propylene random copolymer [II] are synthesized in the gas phase polymerization step, respectively. The method for producing a low-crystalline propylene-based copolymer composition.

Examples of the method for directly producing the low crystalline propylene random copolymer composition of the present invention by the block copolymerization method using the series multistage polymerization apparatus include (A) magnesium, titanium, halogen and an electron donor. Contains as an essential ingredient and has an average particle size of about 5 to about
A highly active and highly stereoregular titanium catalyst component having a geometric standard deviation of less than 2.1 at a particle size of 200 μ, (B) a catalyst component of an organometallic compound of a metal of Group 1 to 3 of the periodic table, and (C) A catalyst formed from an electron donor catalyst component, which is obtained by prepolymerizing α-olefin having 2 to 10 carbon atoms in the range of 1 to 2000 g per gram of the titanium catalyst component (A). -The crystalline propylene system by copolymerizing propylene, ethylene and α-olefin having 4 to 20 carbon atoms in the presence of an olefin prepolymerization catalyst according to the method described in (1) or (2) above. A random copolymer [I] is produced, and propylene and α-olefin having 4 to 20 carbon atoms are copolymerized in the presence of the crystalline propylene random copolymer [I]. To produce a low crystalline propylene random copolymer [II] by, it is possible to form a low-crystalline propylene random copolymer composition of the present invention as a result.

More specifically, the following method can be mentioned as a method for producing the low-crystalline propylene random copolymer composition of the present invention by the above-mentioned block copolymerization method. That is, (A) contains magnesium, titanium, halogen and an electron donor as essential components and has an average particle size of about 5 to about
A highly active and highly stereoregular titanium catalyst component having a geometric standard deviation of less than 2.1 at a particle size of 200 μ, (B) a catalyst component of an organometallic compound of a metal of Group 1 to 3 of the periodic table, and (C) A catalyst formed from an electron donor catalyst component, which is obtained by prepolymerizing α-olefin having 2 to 10 carbon atoms in the range of 1 to 2000 g per gram of the titanium catalyst component (A). -In the presence of an olefin prepolymerization catalyst, propylene, ethylene and 4 to 4 carbon atoms
A step of copolymerizing 20 α-olefins in a suspension polymerization step [a] using liquid propylene as a solvent, and then vaporizing by liquid flushing the liquid unreacted raw material in the polymerization reaction mixture obtained in the suspension polymerization step. The repeating unit (a) derived from propylene becomes
86 to 97 mol%, 0.5 to 6 mol% of the repeating unit (b) derived from ethylene and 2 to 13 mol% of the repeating unit (c) derived from α-olefin having 4 to 20 carbon atoms. Yes, the molar ratio c / (b + c)
A flash step (b) for producing a propylene random copolymer [I] in the range of 0.3 to 0.9, and in the presence of the propylene random copolymer [I],
And under the condition that the reaction system forms a gas phase, propylene and α-olefin having 4 to 20 carbon atoms are copolymerized, and the repeating unit (d) derived from propylene is 50 to 80 mol% and 4 to 4 carbon atoms
20 repeating units (e) derived from 20 α-olefins
To a low crystallinity of the present invention by a gas phase polymerization step [C] for producing a low crystalline propylene random copolymer [II] in the range of 50 to 50 mol%. A propylene-based random copolymer composition can be produced. Details of the catalyst components, copolymerization conditions, other manufacturing conditions, etc. are described in the patent application specification of the title of the invention "Production method of propylene-based block copolymer" filed by the applicant on the same date as this application. Therefore, the propylene-based random copolymer can be produced according to this method. At the time of manufacturing, the characteristic values (A) to (E), the characteristic values (i) to (v), and the other characteristic value measuring and determining methods are described in detail above, and these characteristic (A) to (E) Characteristic value (i)
The catalyst and the polymerization conditions can be easily experimentally selected and determined in advance so as to satisfy (v) and other characteristic values.

The low crystalline propylene random copolymer composition of the present invention may consist of only two components, the crystalline propylene random copolymer [I] and the low crystalline propylene random copolymer [II]. However, it may be a composition containing a polymer other than the above two components. In the low crystalline propylene random copolymer composition, in addition to the polymer component, a heat resistance stabilizer, a weather resistance stabilizer, a nucleating agent, a lubricant, a slip agent, an antistatic agent, an antiblocking agent, an antifogging agent, It is safe to mix pigments and dyes. The blending ratio is appropriate as long as it does not impair the low temperature heat seal and heat seal strength of the polypropylene composite laminate.

The low crystallinity propylene random copolymer composition of the present invention is laminated on one surface or both surfaces of a crystalline polypropylene substrate to form a polypropylene composite laminate. The crystalline polypropylene to be the base layer is, in addition to the crystalline propylene homopolymer, a crystalline propylene / α-olefin random copolymer mainly containing a propylene component, for example, an ethylene content of 0.1 to 8 mol. % Propylene / ethylene random copolymer, ethylene content 0.1 to 5 mol% and 1-butene content 0.1 to 8 mol% propylene / ethylene / 1-butene random copolymer, 1-butene content 0.
Examples thereof include 1 to 10 mol% propylene / 1-butene random copolymer. Intrinsic viscosity [η] of the crystalline polypropylene measured in decalin at 135 ° C
Is usually in the range of 1.5 to 4 dl / g, preferably 1.7 to 3.5 dl / g, and the crystallinity measured by the X-ray diffraction method is usually in the range of 50 to 70%, preferably 55 to 70%. is there. The base material layer made of the crystalline polypropylene may be unstretched or uniaxially or biaxially stretched.

As a method for producing a polypropylene composite laminate by laminating the low crystalline propylene random copolymer composition of the present invention on one side or both sides of the substrate layer made of the crystalline polypropylene, for example, the following method may be exemplified. it can.

(1) A base material made of crystalline polypropylene and the low crystalline propylene random copolymer composition are coextruded to be laminated, and if necessary, vertical axis stretching and / or horizontal axis stretching are separately performed. Or the method of applying at the same time.

(2) The low crystalline propylene random copolymer composition is extruded in a molten state and laminated on the surface of a non-stretched, uniaxially stretched or biaxially stretched crystalline polypropylene substrate, and the substrate is in a non-stretched state. If it is, a method of further performing uniaxial stretching or biaxial stretching as necessary. When the base material is in a uniaxially stretched state, it is similarly extruded and laminated, and then, if necessary, further stretched in the same direction as the base material or in the cross direction.

(3) A method of laminating a film of the low crystalline propylene random copolymer composition on the surface of a substrate made of crystalline polypropylene with an adhesive.

The shape of the polypropylene composite laminate formed by laminating the low crystalline propylene random copolymer composition of the present invention on one side or both sides of a substrate made of crystalline propylene may be any shape, Examples thereof include a film, a laminated sheet, a laminated packaging bag, a laminated container, and other molded articles having heat sealability.

The substrate layer made of crystalline polypropylene that constitutes the propylene composite laminate may be in a non-stretched state, a uniaxially stretched state, or a biaxially stretched state, as is clear from the examples of the laminating method described above. The layer made of the low crystalline propylene random copolymer may be in a non-stretched state, a uniaxially stretched state, or a biaxially stretched state. Further, the base material layer made of crystalline polypropylene of the polypropylene composite laminate and the layer made of the low crystalline propylene random copolymer may be constituted by any combination of the above-mentioned states.

The thickness of the base material layer made of crystalline polypropylene that constitutes the polypropylene composite laminate is arbitrary and is not particularly limited, but the thickness of the heat seal layer made of the low crystalline propylene random copolymer composition is not particularly limited. It is generally in the range of 0.1 to 50μ, preferably 0.5 to 30μ. When the polypropylene composite laminate is a composite laminate film or a composite laminate sheet, the thickness of the base material layer made of crystalline polypropylene is in the range of 5 to 200 μ, preferably 10 to 70 μ, and the low crystalline propylene is used. The thickness of the heat seal layer composed of the random copolymer composition is usually
It is in the range of 0.1 to 50μ, preferably 0.5 to 30μ.

[Measurement of blocking resistance and complete heat-sealing temperature of film] A method for obtaining the blocking resistance and perfect heat-sealing temperature of the film of the obtained copolymer is described below.

Film making Aluminum sheet with a thickness of 0.1 mm on the press plate, Polyester
Lu-made sheet (made by Toray Industries, Inc., trade name Lumirror) and medium
A polyimide tree with a thickness of 50μ, which is a 15 cm × 15 cm square cut from the center.
Fat (made by DuPont, product name Kapton) sheets in this order
Lay out and place 0.8 g of sample in this center (cut out part)
Ku. Then Lumirror , Aluminum plate, press plate
Are further stacked in this order (see FIG. 1).

Put the sample sandwiched between the above press plates in a 200 ° C hot press and preheat for about 5 minutes, then pressurize (20 kg / cm ² G) depressurization operation to remove air bubbles in the sample. Repeat 3 times. Then, finally, the pressure is increased to 150 kg / cm ² G, and pressure heating is performed for 5 minutes. After depressurizing, remove the press plate from the press machine and transfer it to another press machine where the crimping part was kept at 30 ° C.
After pressure cooling at cm ² for 4 minutes, the pressure is released and the sample is taken out. Among the obtained films, a film having a uniform thickness of 50 to 70 μm is used as the following instep film.

Anti-blocking test Two pieces of film cut into 6 x 10 cm are stacked and
After sandwiching it with two sheets of paper of uniform thickness,
Scissor further with a lath plate and place in a constant temperature bath at 60 ° C under a load of 7 kg.
Leave for 2 days (aging). Remove the film from the constant temperature bath
After taking out and cooling to room temperature, a piece of this double-layered film
Peel off one end and place Teflon here Inserted a stick
After that, clip the end of the peeled film with a clip and
Fix it to the upper chuck of the test machine. Down the Teflon stick at the same time
It is fixed to the part chuck via the fixing bracket. (See Figure 2
See). Pull up the chuck at a speed of 10 cm / min
Teflon fixed by Two films through a stick
Measure the stress of peeling using a tensile tester
It Film width (6 cm) using the obtained stress value
It is a measure of blocking resistance by dividing by
Determine the blocking value (g / cm) of Rum.

Measurement of heat seal strength The film prepared by the above-mentioned method is placed in a thermostatic chamber at 50 ° C.
Leave for a day (Acing). When aging, put paper on both sides of the film so that the films do not touch each other.

Cut the film with the above-mentioned aging into pieces of 15 mm width, stack the two pieces, and then heat-seal the two pieces with a teflon film having a thickness of 0.1 mm.

Heat sealing is performed by keeping the lower temperature of the heat plate of the heat sealer constant at 70 ° C and changing only the temperature of the upper part of the heat plate in steps of 5 ° C. The pressure during heat sealing is 2 kg / cm ² , the heat sealing time is 1 second, and the seal width is 5 mm (so the sealing area is 15 mm × 5 mm).

The heat-sealing strength is obtained by performing a peeling test on the peel strength of the film which has been heat-sealed at each of the above heat-sealing temperatures at a pulling speed of 30 cm / min (Fig. 3
reference).

The peel strength at each heat-sealing temperature in increments of 5 ° C. is obtained by the method described above, and a plot of heat-sealing temperature vs. peel strength is connected by a curve. Based on this curve, the heat seal temperature at which the peel strength is 800 g / 15 cm is completely taken as the heat seal temperature (see FIG. 4).

Example 1 [Preparation of titanium catalyst component (A)] Anhydrous magnesium chloride 714 g Decane 3.7 and 2-ethylhexyl alcohol 3.5 were heated and reacted at 130 ° C. for 2 hours to form a uniform solution, and phthalic anhydride was added to this solution. Then, the mixture is further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride into the solution uniformly. The homogeneous solution thus obtained is cooled to room temperature, and then the whole amount is dropped into titanium tetrachloride 20 kept at -20 ° C over 1 hour.
After the completion of charging, the temperature of this mixed solution is raised to 110 ° C. over 4 hours, and when it reaches 110 ° C., 0.4 of diisobutyl phthalate is added, and the mixture is maintained at the same temperature for 2 hours with stirring. After the completion of the reaction for 2 hours, the solid portion was collected by heating, the solid portion was resuspended in 28 TiCl ₄ , and then the reaction was carried out again at 110 ° C. for 2 hours. After completion of the reaction, the solid portion is again collected by heating and washed with decane and hexane at 110 ° C. sufficiently until no free titanium compound is detected in the washing liquid. The titanium catalyst component synthesized by the above manufacturing method was dried with a dryer. The composition of the titanium catalyst component thus obtained was 2.3% by weight titanium and 5% chlorine.
It was 8.0% by weight, magnesium 18.0% by weight and diisobutyl phthalate 14.0% by weight.

The titanium catalyst component was a granular catalyst having an average particle size of 18μ and a geometric standard deviation (δg) of particle size distribution of 1.2.

[Preliminary Polymerization] Hexane 1, triethylaluminum 5 mmol, diphenyldimethoxysilane 1 mmol and the titanium catalyst component 0.5 mmol in terms of titanium atom were added to a glass reactor equipped with a stirrer in a nitrogen atmosphere, and then propylene 11.
The mixture was fed for 5 hours at a rate of 1 Nl / Hr. During this period, the temperature was kept at 20 ° C. Five hours after starting the propylene feed, the propylene feed was stopped, nitrogen was fed instead, and the inside of the reactor was replaced with nitrogen. After the stirring was stopped and the mixture was allowed to stand, the supernatant was removed, and 1 purified hexane was newly added. This washing operation was repeated three times, then reslurried in hexane again, and transferred to a storage catalyst bottle. The amount of prepolymerization was 98 g-pp / g-catalyst.

[Polymerization] 7.5 kg of propylene, 2.3 kg of 1-butene, 38 Nl of ethylene and 25 Nl of hydrogen were added to an autoclave having an inner volume of 50 and having propylene substitution. Then, the temperature was raised to 50 ° C., 25 mmol of triethylaluminum, 25 mmol of diphenyldimethoxysilane and 0.15 mmol of the titanium catalyst component which had been subjected to the above-mentioned prepolymerization were added in terms of titanium atom, and the mixture was heated at 60 ° C. for 15 minutes.
It was carried out for a minute ([a] suspension polymerization step). Then, while maintaining the temperature at 50 ° C, the internal pressure of the autoclave was 0.1 kg / cm ² G.
It was depressurized until it became, and the olefins in the autoclave were removed ([b] flash step). After that, 5Nl of hydrogen was added, and further, feed was carried out until the internal pressure of the mixed gas autoclave having a propylene / 1-butene molar ratio of 30/70 was 5.5 kg / cm ² G to initiate gas phase polymerization. During the polymerization, the temperature is 50 ℃
And the pressure was 5.5 kg / cmG, and the propylene / 1-butene mixed gas was replenished ([C] gas phase polymerization step). After 90 minutes of polymerization, 5 ml of methanol was added to stop the polymerization, and after depressurization, the produced polymer was recovered and left overnight at 60 ° C.
And dried under reduced pressure of 300 mmHg. The yield of the obtained white powdery polymer was 3.2 kg, and the apparent bulk specific gravity was 0.34 g.
/ ml, ethylene content 2.3 mol%, 1-butene content 9.7
Mol%, MFR is 5.6 dg / min, n-decane-soluble part amount is 19.3 wt%, p-xylene-soluble part amount at 25 ° C is 24.3 wt%, 50
The amount of n-hexane extracted at ℃ was 4.8% by weight. Also,
The blocking property of the film produced by the above-mentioned method was 16 g / cm, and the perfect heat sealing temperature was 113 ° C.

On the other hand, according to the analysis of each step, the ethylene content of the copolymer after the [b] flash step is 28 mol% 1-butene content is 5.
8 mol%, so the molar ratio of 1-butene / (1-butene + ethylene) was 0.67. In addition, the polymerization rate in the vapor phase polymerization step [C] was 23% by weight. Therefore, [C]
The 1-butene content of the copolymer produced in the gas phase polymerization process is
It was 24 mol%.

Example 2 Polymerization was performed according to the method of Example 1 except that the conditions at the time of polymerization were changed to those shown in Table 1. The results are shown in Table 1.

Examples 3 to 5 The diphenyldimethoxysilane used as the electron donor in Example 1 was replaced with the compounds shown in Table 1, and polymerization was carried out according to the conditions shown in Table 2. The results are shown in Table 1.

Example 6 [Preparation of Titanium Catalyst Component (A)] A high-speed stirrer (made by Tokushu Kika Kogyo Co., Ltd.) with an internal volume of 2 was sufficiently used for N ₂
After replacement, 700 ml of refined kerosene, 10 g of commercially available MgCl ₂ , 24.2 g of ethanol and ₃ g of trade name Emazol 320 (Kao Atlas, sorbitan distearate) were added, the system was heated under stirring, and the rpm was increased to 800 rpm at 120 ° C. It was stirred for 30 minutes. Under high-speed stirring, using a Teflon tube with an internal diameter of 5 mm, refined kerosene 1 that has been cooled to -10 ° C is put in. 2
The liquid was transferred to a glass flask (with a stirrer). The resulting immobilization was collected by filtration and thoroughly washed with hexane to obtain a carrier.

After suspending 7.5 g of the carrier in 150 ml of titanium tetrachloride at room temperature, 4.5 ml of di-n-octyl phthalate was added, and the suspension was kept at 120 ° C. for 2 hours.
After stirring and mixing for an hour, collect the solid part by filtration
The mixture was suspended in 1 part of titanium tetrachloride and again stirred and mixed at 130 ° C. for 2 hours. A solid reaction product was collected from the reaction product in excess and washed with a sufficient amount of purified hexane to obtain a solid catalyst component [A]. The particle size of the catalyst was 64 μm and the geometric standard deviation was 1.4.

[Preliminary Polymerization] It was carried out in the same manner as in Example 1. Prepolymerization amount is 89g ^- pp
/ g ^- catalyst.

[Polymerization] Polymerization was carried out under the conditions shown in Table 1. The results are shown in Table 1.

Comparative Example 1 (Preparation of titanium catalyst component (A)) Anhydrous magnesium chloride 714 g Decane 3.7 and 2-ethylhexyl alcohol 3.5 were heated and reacted at 130 ° C. for 2 hours to form a uniform solution, and phthalic anhydride was added to this solution. Then, the mixture is further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride into the solution uniformly. The homogeneous solution thus obtained is cooled to room temperature, and then the whole amount is dropped into titanium tetrachloride 20 kept at -20 ° C over 1 hour.
After the completion of charging, the temperature of this mixed solution is raised to 110 ° C. over 4 hours, and when it reaches 110 ° C., 0.4 of diisobutyl phthalate is added, and the mixture is maintained at the same temperature for 2 hours with stirring. After the completion of the reaction for 2 hours, a solid part was collected by hot filtration, and the solid part was resuspended in 28 TiCl ₄ , and then the reaction was carried out again at 110 ° C. for 2 hours. After completion of the reaction, the solid portion is again collected by hot filtration, and thoroughly washed with decane and hexane at 110 ° C. until no free titanium compound is detected in the washing liquid. The titanium catalyst component synthesized by the above manufacturing method was dried with a dryer. The composition of the titanium catalyst component thus obtained was 2.3% by weight of titanium, 58.0% by weight of chlorine, 18.0% by weight of magnesium and 14.0% by weight of diisobutylphthalate.

The titanium catalyst component was a granular catalyst having an average particle size of 18μ and a geometric standard deviation (δg) of particle size distribution of 1.2.

[Preliminary Polymerization] Hexane 1, triethylaluminum 5 mmol, diphenyldimethoxysilane 1 mmol and the titanium catalyst component 0.5 mmol in terms of titanium atom were added to a glass reactor equipped with a stirrer in a nitrogen atmosphere, and then propylene 11.
The mixture was fed for 5 hours at a rate of 1 Nl / Hr. During this period, the temperature was kept at 20 ° C. Five hours after starting the propylene feed, the propylene feed was stopped, nitrogen was fed instead, and the inside of the reactor was replaced with nitrogen. After stirring was stopped and the mixture was allowed to stand, the supernatant was removed, and 1 purified hexane was newly added. This washing operation was repeated three times, then reslurried in hexane again, and transferred to a storage catalyst bottle. The amount of prepolymerization was 98 g-pp / g-catalyst.

[Polymerization] 7.5 kg of propylene, 2.3 kg of 1-butene, 38 Nl of ethylene and 25 Nl of hydrogen were added to an autoclave having an inner volume of 50 and having propylene substitution. Then, the temperature was raised to 50 ° C., 25 mmol of triethylaluminum, 25 mmol of diphenyldimethoxysilane and 0.15 mmol of the titanium catalyst component which had been subjected to the above-mentioned prepolymerization were added in terms of titanium atom, and the mixture was heated at 60 ° C. for 15 minutes.
Polymerization was carried out for 1 minute ([a] suspension polymerization step), and then
The internal pressure of the autoclave is 0.1k while maintaining the temperature at 50 ℃.
The pressure was reduced to g / cm ² G, and the olefins in the autoclave were removed ([b] Flashlash process). Then hydrogen 5N
was added, and the propylene / 1-butene molar ratio was 10/90.
The mixed gas was fed until the internal pressure of the autoclave reached 5.5 kg / cm ² G, and gas phase polymerization was started. During the polymerization, the temperature was kept at 45 ° C, and the pressure was 5.5 kg / cm ² G.
The propylene / 1-butene mixed gas was replenished ([C] gas phase polymerization step), 5 ml of methanol was added after the polymerization for 120 minutes to stop the polymerization, and after depressurization, the produced polymer was recovered and allowed to stand overnight Drying was performed at 60 ° C. under a reduced pressure of 300 mmHg. The amount of p-xylene solubles at 25 ° C was 22.4% by weight, and the amount of n-hexane extracted at 50 ° C was 9.4% by weight. The blocking property of the film produced by the method of the present application was 23 g / cm, and the complete heat-sealing temperature was 112 ° C.

On the other hand, according to the analysis of each step, the ethylene content of the copolymer after the [b] flush process was 2.9 mol% and the 1-butene content was
5.6 mol%, therefore 1-butene / (1-butene +
The ethylene) molar ratio was 0.66. Further, the content of 1-butene in the copolymer produced in the [ha] vapor phase polymerization step was 68 mol%.

The copolymer composition ratio ([I] / [II]) is 97/2 by weight.
Was 1.

The results are shown in Table 2.

Comparative Example 2 (Preparation of Titanium Catalyst Component (A)) Anhydrous magnesium chloride 714 g Decane 3.7 and 2-ethylhexyl alcohol 3.5 were heated and reacted at 130 ° C. for 2 hours to form a uniform solution, and phthalic anhydride was added to this solution. Then, the mixture is further stirred and mixed at 130 ° C. for 1 hour to dissolve phthalic anhydride into the solution uniformly. The homogeneous solution thus obtained is cooled to room temperature, and then the whole amount is dropped into titanium tetrachloride 20 kept at -20 ° C over 1 hour.
After the completion of charging, the temperature of this mixed solution is raised to 110 ° C. over 4 hours, and when it reaches 110 ° C., 0.4 of diisobutyl phthalate is added, and from this, the mixture is maintained at the same temperature for 2 hours with stirring. After the completion of the reaction for 2 hours, a solid part was collected by hot filtration, and the solid part was resuspended in 28 TiCl ₄ , and then the reaction was carried out again at 110 ° C. for 2 hours. After completion of the reaction, the solid portion is again collected by hot filtration, and thoroughly washed with decane and hexane at 110 ° C. until no free titanium compound is detected in the washing liquid. The titanium catalyst component synthesized by the above manufacturing method was dried with a dryer. The composition of the titanium catalyst component thus obtained was 2.3% by weight of titanium, 58.0% by weight of chlorine, 18.0% by weight of magnesium and 14.0% by weight of diisobutylphthalate.

The titanium catalyst component was a granular catalyst having an average particle size of 18μ and a geometric standard deviation (δg) of particle size distribution of 1.2.

[Preliminary Polymerization] Hexane 1, triethylaluminum 5 mmol, diphenyldimethoxysilane 1 mmol, and the above titanium catalyst component 0.5 mmol in terms of titanium atom were added to a glass reactor equipped with a stirrer in a nitrogen atmosphere, and then propylene 11.
The mixture was fed for 5 hours at a rate of 1 Nl / Hr. During this period, the temperature was kept at 20 ° C. Five hours after starting the propylene feed, the propylene feed was stopped, nitrogen was fed instead, and the inside of the reactor was replaced with nitrogen. After stirring was stopped and the mixture was allowed to stand, the supernatant was removed, and 1 purified hexane was newly added. This washing operation was repeated three times, then reslurried in hexane again, and transferred to a storage catalyst bottle. The amount of prepolymerization was 98 g-pp / g-catalyst.

[Polymerization] 7.5 kg of propylene, 2.3 kg of 1-butene, 38 Nl of ethylene and 25 Nl of hydrogen were added to an autoclave having an inner volume of 50 and having propylene substitution. Then, the temperature was raised to 50 ° C., 25 mmol of triethylaluminum, 25 mmol of diphenyldimethoxysilane and 0.15 mmol of the titanium catalyst component which had been subjected to the above-mentioned prepolymerization were added in terms of titanium atom, and the mixture was added at 15 ° C. at 15 ° C.
Polymerization was carried out for 1 minute ([a] suspension polymerization step), and then
The internal pressure of the autoclave is 0.1k while maintaining the temperature at 50 ℃.
The pressure was reduced to g / cm ² G, and the olefins in the autoclave were removed ([b] Flashlash process). Then hydrogen 6N
l was added, and a mixed gas having an ethylene / 1-butene molar ratio of 4/96 was fed until the internal pressure of the autoclave reached 5.5 kg / cm ² G to initiate gas phase polymerization. During the polymerization, the temperature
The mixture was kept at 45 ° C., and the propylene / 1-butene mixed gas was replenished so that the pressure was 5.5 kg / cm ² G ([C] gas phase polymerization step). After 100 minutes of polymerization, 5 ml of methanol was added. Polymerization was stopped by adding it, and after depressurization, the produced polymer was recovered and left overnight.
Drying was performed at 60 ° C. under a reduced pressure of 300 mmHg. P at 25 ° C
-The amount of xylene solubles was 20.3% by weight, and the amount of n-hexane extracted at 50 ° C was 11.0% by weight. The blocking property of the film produced by the method of the present application was 26 g / cm, and the perfect heat sealing temperature was 114 ° C.

On the other hand, according to the analysis of each step, the ethylene content of the copolymer after the [b] flush process was 2.9 mol% and the 1-butene content was
5.6 mol%, therefore 1-butene / (1-butene +
The ethylene) molar ratio was 0.66. Further, the content of 1-butene in the copolymer produced in the [ha] vapor phase polymerization step is 62.6.
Mol%.

The copolymer composition ratio ([I] / [II]) is 75/2 by weight.
Was 5.

The results are shown in Table 3.

EFFECTS OF THE INVENTION A polypropylene composite laminate formed by laminating a tank made of the low crystalline propylene random copolymer composition of the present invention on one side or both sides of a substrate made of crystalline polypropylene has a low temperature. It has excellent heat-sealing property and sheet-sealing strength, and has an improved heat-sealable temperature range.
Excellent blocking resistance. Therefore, the polypropylene composite laminate is suitable for daily commodities such as food packaging, clothing packaging, and miscellaneous goods packaging by utilizing such characteristics.

[Brief description of drawings]

FIG. 1 shows a schematic cross-sectional view of the film preparation method used in the test, FIG. 2 shows a schematic view of the method for measuring the blocking value of the film, and FIG. 3 shows a schematic view of the method for measuring the heat-sealing strength. FIG. 4 shows the relationship between heat seal temperature and peel strength.

Claims (1)

[Claims] 1. A propylene random copolymer comprising [I] a repeating unit derived from propylene, a repeating unit derived from ethylene and a repeating unit derived from α-olefin having 4 to 20 carbon atoms, The following items (A) The repeating unit (a) derived from propylene is 86.
To 97 mol%, the repeating unit (b) derived from ethylene is 0.5 to 6 mol%, and the repeating unit (c) derived from the α-olefin is in the range of 2 to 13 mol%, and the molar ratio c / ( b + c) is in the range of 0.3 to 0.9, (B) intrinsic viscosity [η] measured in decalin at 135 ° C.
Is in the range of 0.5 to 6 dl / g, (C) Melting point [Tm] measured by a differential scanning calorimeter
Is in the range of 115 to 145 ° C., (D) the crystallinity measured by X-ray diffraction is in the range of 30 to 60%, and the propylene-based random copolymer satisfying
%, And [II] Propylene-derived repeating unit (d) is 50
To 80% by mole and 5 to 40% by weight of a low crystalline propylene random copolymer having a repeating unit (e) derived from α-olefin having 4 to 20 carbon atoms in the range of 20 to 50% by mole, A low crystalline propylene-based random copolymer composition formed from: (i) a repeating unit (f) derived from propylene;
To 96 mol%, 0.3 to 5 mol% of repeating units derived from ethylene (g) and 4 to 20 mol% of repeating units (h) derived from α-olefin having 4 to 20 carbon atoms. (Ii) Intrinsic viscosity [η] measured in decalin at 135 ° C
Is in the range of 0.5 to 6 dl / g, (iii) the crystallinity measured by X-ray diffraction is in the range of 25 to 60%, and (iv) soluble in p-xylene at 25 ° C. A low crystalline propylene random copolymer composition, characterized in that the amount thereof is 30% by weight or less, and (v) the amount extracted into n-hexane at 50 ° C. is 10% by weight or less.