JPH0114247B2 - - Google Patents

Description

[Detailed description of the invention]

[] Background of the Invention The present invention provides a soft or hard material suitable for forming various molded products such as films, sheets, bottles, injection molded products, and flat yarns with an excellent balance of heat resistance, impact resistance, and heat-adhesion properties. This invention relates to a propylene copolymer and a method for producing the same. More specifically, the present invention relates to a copolymer with increased heterogeneity in its primary structure in order to exhibit the above-mentioned properties to a high degree, and a method for producing the same. The use of propylene homopolymer as a general-purpose resin has been expanded by taking advantage of its characteristics such as stiffness, moderately high heat resistance, and relatively excellent optical properties, but it has its own disadvantages and advantages. There are many properties that are not fully satisfactory, and in order to improve these properties, many studies have been made on copolymerization with various comonomers, especially α-olefins. Among α-olefins, there are by far the most studies on copolymerization with ethylene, and these are mainly
The purpose is to improve the impact strength, transparency, heat fusion properties, etc. of propylene homopolymers. Among these improvement effects, it can be said that a considerable degree of success was achieved in improving impact resistance strength, but other than that, the results were not necessarily satisfactory. A small number of studies have been conducted on copolymerization with linear α-olefins such as 1-butene, 1-hexane, and 1-octene, or branched chain α-olefins such as 4-methyl-1-pentene. When introduced randomly into the polypropylene chain, it has a greater effect than ethylene on disrupting the crystal structure of polypropylene, and is therefore considered to be more effective than ethylene in softening polypropylene and improving its thermal adhesive properties. . However, on the other hand, this comes at the expense of the relatively high heat resistance properties of polypropylene. As is clear from the above overview, the drawbacks and unsatisfactory features of propylene homopolymer are:
Various improvements have been made by copolymerizing with various α-olefins, but the heat resistance has generally worsened. Therefore, if it is possible to improve heat resistance as well as properties other than heat resistance, it will be possible to use polypropylene in many application fields that were previously thought to be impossible, and its industrial significance will increase. is very large. [] Summary of the Invention The present inventors have devised a method that significantly increases the heat resistance of propylene homopolymers and simultaneously improves the heat fusion properties and impact resistance, which are usually at high risk of deterioration. As a result of our research, we found that by copolymerizing propylene with specific α-olefins and adopting a special copolymerization mode that increases the heterogeneity of the primary structure of the copolymer, The present inventors have discovered that it is possible to simultaneously improve the above-mentioned properties of polypropylene, which had been thought to be difficult to achieve, and have completed the present invention. Therefore, the propylene copolymer according to the present invention comprises propylene (A), a monomer (B) selected from branched α-olefins having 5 to 12 carbon atoms, styrene or styrene derivatives, and optionally a monomer other than propylene having 2 carbon atoms. -12 linear α-olefins (C), and is characterized by having the following conditions (a) to (d). (a) The content of monomer (B) is 2 to 90% by weight. (b) The content of monomer C is 0 to 8% by weight. (c) Intrinsic viscosity at 135℃ in decalin is 0.5~
Must be 15dl/g. (d) A portion where at least one peak position of the melting curve obtained by differential scanning calorimetry (DSC) exists at 145°C or higher, and which melts at 140°C or lower calculated based on the melting curve obtained by DSC. The heat of fusion of the part and the heat of fusion of the part that melts at 150℃ or higher are each 5% or more of the total heat of fusion (However, the melting curve by DSC is 10% or more.
The sample was crystallized at a cooling rate of 10 °C/min.
(obtained by measuring at a heating rate of °C/min). In addition, the method for producing the propylene polymer according to the present invention comprises producing propylene (A) and a branched α-olefin having 5 to 12 carbon atoms or styrene or a styrene derivative using a catalyst comprising at least a titanium component and an organoaluminum compound. Copolymerization with the selected monomer (B) is carried out in the presence or absence of a linear α-olefin (C) having 2 to 12 carbon atoms other than propylene, and the concentration ratio of the monomer (B) and propylene in the reaction system (R )
During a series of copolymerization steps, Rmax and Rmin (however,
Rmax and Rmin are the maximum and minimum values of R during the process, and the process is characterized in that it is carried out under conditions that vary between Rmax/Rmin>1.5). Effects and analysis thereof According to the present invention, the above effects are achieved. Although there are many unknown points as to why the copolymer of the present invention has high heat resistance and excellent heat fusion properties and impact resistance at the same time, fractional extraction,
As a result of analysis of melting/crystallization characteristics by DSC and structural analysis by NMR and IR spectra, we believe that the main cause is not only due to the specificity of the comonomer but also the heterogeneity of the primary structure. be done. That is, according to the method of the present invention, monomer B and propylene are changed in a series of copolymerization steps by a factor in which their concentration ratio (R) in the reaction system is greater than 1.5. Therefore, the composition of the copolymer produced changes from time to time in response to the constantly changing feed composition. This means that the width of the variation in the primary structure (chain length distribution of monomer B) of each copolymer molecule obtained through a series of copolymerization steps is the same as the width of variation in the primary structure (chain length distribution of monomer B) obtained through a series of copolymerization steps. It is much broader than that of polymers, that is, its primary structure is highly heterogeneous;
means. Generally, even a copolymer obtained under a constant feed composition has a statistical chain length distribution determined by the copolymerization reactivity ratio of propylene and monomer B. In this case, both monomer units are mutually distributed in such a way that their chain lengths are significantly shortened, and the crystallinity of the copolymer as a whole is also significantly reduced. Therefore,
As a homopolymer, if monomer B, which gives a higher melting temperature than propylene homopolymer, is copolymerized with propylene, it cannot be expected to have the effect of increasing the melting temperature of the copolymer. On the other hand, in the above-mentioned copolymers with highly heterogeneous primary structures, copolymers (a) containing long propylene chains and short monomer B chains and monomer B
A copolymer containing a long chain of B and a short chain of propylene (B) is the two extremes, and a copolymer with an intermediate primary structure (C) exists between them, so the former two are propylene and monomer B, respectively. It is expected to have physical properties (especially thermal properties shown by the melting curve by DSC) that are close to those of each homopolymer of By changing its structure and content ratio, it is possible not only to simultaneously impart properties ranging from soft to hard, but also to have impact resistance that homopolymers cannot have. Next, when monomer C is used as a third monomer in a smaller proportion than propylene in the copolymer of propylene and monomer B as described above, the heat resistance of the above binary copolymer is It has been found that it is possible to improve heat fusion properties and provide softer properties without substantially impairing properties. This seems to be because under such copolymerization conditions, monomer C hardly breaks the long chains of monomer B, but efficiently breaks only the long chains of propylene. [] Detailed Description of the Invention 1 Production of Copolymer 1) Catalyst The catalyst used in the method of the present invention consists of at least a titanium component and an organoaluminium compound component, and belongs to the so-called Ziegler type composite catalyst. (1) Titanium component The titanium components of the catalyst include α, β, and γ.
Typical examples include various titanium trichlorides of the δ type and titanium trichloride and titanium tetrachloride supported on various carriers mainly composed of magnesium chloride. Among them, a titanium trichloride composition (used) is obtained by extracting and removing aluminum chloride using a complexing agent from a eutectic composite of titanium trichloride and aluminum chloride, which is obtained by reducing titanium tetrachloride using an organic aluminum. (activated with dialkylaluminum halide when used) and titanium trichloride or titanium tetrachloride supported on a carrier containing magnesium chloride (activated with trialkylaluminum when used) are advantageous because of their high activity. In particular, the use of a complexed/extracted titanium trichloride composition is most advantageous because the resulting copolymer has a good particle morphology and the efficiency of introducing monomer B into the copolymer is high. In addition to these compounds, all compounds known to have olefin polymerization ability, such as various halides of tetra- to divalent titanium, alkyl halides, alkoxides, and alkoxy halides, fall within the scope of the present invention. (2) Organoaluminum compound component The organoaluminum compound used in combination with the titanium component has the general formula Al _n X _3-n.
(However, R is hydrogen or a hydrocarbon residue having about 1 to 12 carbon atoms, X is a halogen atom or an alkoxy group having about 1 to 12 carbon atoms, 1≦m
≦3) is typical.
Specifically, triethylaluminum, tri-i-butylaluminum, tri-n-
These include octylaluminum, diethylaluminum hydride, diethylaluminium chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminium iodide, and the like. (3) Other components By adding various electron-donating compounds to the titanium component and organic aluminum compound component, activity, stereoregularity,
It is also possible to improve the particle properties of the copolymer. Various such improvement methods are already known. 2) Monomer B Selected from branched α-olefins having 5 to 12 carbon atoms or styrene or styrene derivatives. These are monomers that are generally known to impart higher temperature melting properties to isotactic polypropylene when incorporated into stereoregular polymers. The branched α-olefin is selected from those having a structure represented by the following general formula. CH ₂ = CH-(CH ₂ ) _n CR ₁ R ₂ R In the formula, m is _an integer from 0 to 7, R ₁ is a methyl group or ethyl group, and R ₂ is an alkyl group having 1 to 5 carbon atoms. , R ₁ and R ₂ are combined to form a cycloalkyl group, and R ₃ is hydrogen, a methyl group, or an ethyl group. Examples of monomers represented by the above general formula include 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 3-methyl-1-hexene, 4-methyl-1- Pentene, 4,4'-dimethyl-1-pentene, 4-
Methyl-1-hexene, 5-methyl-1-hexene, 5,5'-dimethyl-1-hexene,
3,5-dimethyl-1-hexene, 3,5,
Examples include 5'-trimethyl-1-hexene and vinylcyclohexane. Some styrene derivatives have the following general formula. In the formula, p is 1, 2 or 3, and X is an alkyl group having 1 to 5 carbon atoms. Examples of such compounds include o-methylstyrene, m
-methylstyrene, p-methylstyrene, p
-Ethylstyrene, etc. Among these monomers B, preferred are 3
-methyl-1-butene, 4-methyl-1-pentene, 4-methyl-1-hexene, 5-methyl-1-hexene and styrene.
Particularly preferred are 3-methyl-1-butene and 4-methyl-1-pentene. 3) Monomer C Straight chain α- having 2 to 12 carbon atoms other than propylene
Selected from olefin. Preferably it has 2 to 6 carbon atoms, particularly preferably 2 or 4 carbon atoms, thus ethylene or 1-butene. As already mentioned, monomer C can be used without impairing the heat resistance of the binary copolymer of propylene and monomer B.
It is used only when it is necessary to further enhance heat fusion properties and impart softer properties, and is not an essential monomer. 4) Monomer composition of the reaction system The most important thing to increase the heterogeneity of the primary structure of the product system (copolymer) is to change the composition of each monomer in the reaction system during the series of copolymerization steps. It is. In the case of batch copolymerization, the series of copolymerization steps referred to here means from the start to the end of the copolymerization batch; in the case of continuous copolymerization, one or more reactors are connected in series. Even if the reactor is a reactor, it means the period from when the reactants enter the first reactor until they exit the last reactor. Of particular importance is the ratio (R) of monomer B concentration to propylene concentration in the reaction system, where the value of R varies between Rmax and Rmin and the ratio Rmax/Rmin is greater than 1.5, most preferably Making it larger than 2 is an essential requirement for increasing the heterogeneity of the primary structure. The method of changing R is as follows: When changing R continuously in a series of copolymerization steps, when changing stepwise, when changing from Rmax to Rmin, when changing from Rmin to Rmax,
Various variations can be made, such as when changing to have Rmax or Rmin in between. Preferably, Rmax is changed continuously or stepwise from Rmin. In the case of batch copolymerization, for example, monomer B is initially supplied in a short period of time, and thereafter the supply is stopped for a long period of time.
It is also possible to adopt a supply method in which the concentration of propylene is made to be the lowest at the end of copolymerization, while the concentration of propylene is increased continuously as the copolymerization progresses, or the concentration is kept constant throughout. . In the case of continuous copolymerization, for example, two or more reactors are used in series, monomer B is supplied only to the first reactor, propylene is supplied to each reactor, and a constant monomer is supplied in each reactor. A method that maintains the composition can also be adopted. In order to further increase the heterogeneity of the primary structure, in a series of copolymerization steps, R≦
2Rmin and R≧0.5Rmax, the average copolymerization time was
% or more, preferably 7% or more, particularly preferably 10% or more. The average copolymerization time here refers to the time from the start to the end of copolymerization in batch mode copolymerization, and the average residence time of the copolymer in all reactors in which copolymerization is progressing in continuous mode copolymerization. , respectively. If monomer C is used, its feed pattern needs to be different from that of monomer B. In other words, the ratio between the concentration of monomer C and the concentration of propylene in the reaction system should be kept as constant as possible throughout the series of copolymerization steps, or even if it is unavoidable, the maximum and minimum ratios should be within 2 times. things are desirable. 5) Polymerization method Except for the above considerations, the method for producing a copolymer according to the present invention is essentially the same as the polymerization method using a Ziegler-type composite catalyst. Since there are countless references regarding this type of polymerization method, the details thereof will be omitted for the sake of brevity. Note that it is possible to add a propylene homopolymerization step prior to the copolymerization step carried out by the method described above, and this greatly improves the particle properties of the resulting copolymer. This allows for greater freedom in setting the balance between stiffness and heat resistance of the copolymer. If the former purpose were to be achieved, the amount of propylene homopolymer produced could be 0.01 times the amount of copolymer produced in the subsequent process, but the purpose could be achieved if the latter purpose was also met. needs to be generated up to twice as much. If it exceeds this range, the heat resistance and heat fusion properties will be insufficient. The preferred range is 0.02 to 1.5 times,
A more preferable range is 0.05 to 1 times. 2 Copolymer 1) Composition and Molecular Weight In order for the copolymer to exhibit the desired properties, the monomer B unit should be contained in an amount of 2 to 90% by weight, preferably 5 to 80% by weight, and more preferably 7 to 70% by weight. , must be included. Heat resistance is not expected below the lower limit. If the upper limit is exceeded, thermal adhesion and impact resistance will be insufficient. The monomer C unit may not be included at all, but for the purpose of efficiently improving heat fusion properties and impact resistance, it may be included in an amount of 8% by weight or less, preferably 6% by weight or less, more preferably 5% by weight or less. can be done. If the content exceeds this range, not only will the heat resistance deteriorate, but also the particle properties of the resulting copolymer will rapidly deteriorate, making stable operation of the copolymer production process difficult. Note that the contents of monomers B and C are based on the weight of monomers A+B+C, respectively. It goes without saying that the term "monomer" here means the monomer unit in the copolymer. The molecular weight of the copolymer is 135℃ in decalin.
It is necessary that the intrinsic viscosity of the material falls within a range corresponding to 0.5 to 15 dl/g, preferably 0.7 to 6.0 dl/g. If it is less than this, the mechanical properties of the copolymer will not reach a practical level, or molding itself will become impossible. If the molecular weight exceeds this range, the viscoelastic properties in the molten state deteriorate and molding becomes impossible. 2) Thermal Properties The heterogeneity of the primary structure, which requires a copolymer to have heat resistance, thermal adhesion and impact resistance, can be regulated by the melting curve based on the DSC of the copolymer. That is, at least one melting peak position is 145°C or higher,
Preferably exists at 150°C or higher, and 140°C
Heat of fusion of the part that melts below ℃ and 150
The heat of fusion of each part that melts at temperatures above 0.degree. C. is 5% or more of the total heat of fusion. More preferably, one or more melting peak positions exist at 150°C or higher, and the heat of fusion of the portion that melts at 140°C or lower and the heat of fusion of the portion that melts at 150°C or higher are respectively the total heat of fusion. 10% or more of 3) Others It goes without saying that the copolymer of the present invention may contain various auxiliary materials that olefin copolymers normally contain. It goes without saying that it can also be used as a blend with other compatible or miscible resin materials. 3 Examples Example 1 2.3 liters of n-heptane was introduced into an 8 liter stainless steel polymerization vessel equipped with a stirring blade, and after the atmosphere was sufficiently purged with nitrogen, 1.5 g of diethylaluminium chloride (DEAC) and titanium trichloride (Marubeni Added 0.3g of TAU catalyst manufactured by Solvay Chemical Co., Ltd.The temperature was set to 70℃.
250 g of 4-methyl-1-pentene was added all at once in a propylene atmosphere at one atmosphere (absolute pressure). At the same time, propylene was fed at a rate of 75 g/hour over a period of 6 hours, and propylene and 4-
Random copolymerization with methyl-1-pentene was carried out. Propylene and 4- at the start of copolymerization
The concentration of methyl-1-pentene is 0.012, respectively.
(g/g-heptane) and 0.16 (g/g-heptane). On the other hand, the concentration at the end of copolymerization is 0.057 (g/g-heptane) and
It was 0.096 (g/g-heptane). Therefore, Rmax=13.3 (at the start of copolymerization), Rmin=1.68,
Rmax/Rmin=7.92. After the polymerization was completed, the catalyst was decomposed with excess methanol and washed repeatedly with n-heptane.
After separation, the obtained polymer was dried under reduced pressure at 90°C for one day and night. Table 1 shows the measurement results of the physical properties of the obtained copolymer. However, 4-methyl-1- in the copolymer
The content of pentene units was determined from the absorbance at a wave number of 920 cm ^-1 in an infrared absorption spectrum. The melting characteristics of the copolymer based on DSC were measured under the following conditions. Using Parkin-Elmer model DSC-2,
5 mg of the copolymer sample was melted by heating at 250°C for 3 minutes under a nitrogen stream, and then heated to 60°C at a cooling rate of 10°C/min.
The sample is cooled to crystallization, then melted at a heating rate of 10°C/min and measured. The heat of fusion of the copolymer is
From the melting curve (thermogram) based on DSC,
It was determined using indium as a standard substance. Example 2 Same as Example 1 except that 10.5 g of DEAC, 2.1 g of titanium trichloride, and 550 g of 4-methyl-1-pentene were used, and propylene was supplied at a pressure of 1.0 atm (absolute pressure) throughout the copolymerization period. Copolymerization was carried out under the following conditions. Propylene and 4 at the start of copolymerization
- The concentration of methyl-1-pentene in heptane is 0.012 (g/g-heptane) and
It was 0.35 (g/g-heptane). On the other hand, the concentration at the end of copolymerization was 0.012 (g/g
-heptane) and 0.16 (g/g-heptane). Therefore, Rmax=29.2 (at the start of copolymerization), Rmin=13.3 (at the end of copolymerization), Rmax/
Rmin=2.19. The results are shown in Table 1. Example 3 Feed amount of 4-methyl-1-pentene was 190
Copolymerization of propylene and 4-methyl-1-pentene was carried out under the same conditions as in Example 1 except that g was used. The concentrations of propylene and 4-methyl-1-pentene at the start of copolymerization were each 0.012 (g/g
-heptane) and 0.12 (g/g-heptane)
and the concentration at the end of copolymerization is
0.049 (g/g-heptane) and 0.106. Therefore, Rmax=10.0 (at the start of copolymerization),
Rmin=2.16 (at the end of copolymerization), Rmax/Rmin=
It was 4.62. The results are shown in Table 1. Example 4 Copolymerization was carried out under the same conditions as in Example 2, except that the feed amount of DEAC 11.5 g, titanium trichloride 2.3 g, and 4-methyl-1-pentene was changed to 800 g. Propylene and 4-methyl-1 at the start of copolymerization
- the concentration of pentene is 0.012 (g/g-heptane) and 0.52 (g/g-heptane), respectively;
The concentration at the end of copolymerization is also 0.012 (g/g
-heptane) and 0.20 (g/g-heptane). Therefore, Rmax=43.3 (at the start of copolymerization), Rmin=16.7, and Rmax/Rmin=2.59. The results are shown in Table 1. Comparative Example 1 N-heptane was continuously supplied from the top of the polymerization vessel at a rate of 0.67 liters/hour, and the polymerization was continued from the bottom of the polymerization vessel so that the polymer slurry in the polymerization vessel was always 4.0 liters. The combined slurry was extracted. Diethylaluminium chloride and titanium trichloride were supplied so that the concentrations in the polymerization vessel were constantly maintained at 0.65 g/liter and 0.13 g/liter. Propylene and 4-methyl-1-pentene were fed at rates of 190 g/hr and 250 g/hr, respectively. Copolymerization was carried out under the same conditions as in Example 1 except for the above, and after the reaction reached a steady state, the physical properties of the obtained polymer were measured. The results are shown in Table 1. In this example, Rmax/Rmin
It is obvious that =1. Comparative Examples 2 to 3 Copolymerization was carried out under the same conditions as in Comparative Example 1, except that the feed rate of 4-methyl-1-pentene was 1000 and 1500 g/hour. It is obvious that Rmax/Rmin=1 in all of the comparative examples. Table 1 shows the melting properties of the obtained copolymer. Example 5 Random copolymerization of propylene and 4-methyl-1-pentene was carried out under the same conditions as in Example 1 except that the copolymerization temperature was 50°C. The concentrations of propylene and 4-methyl-1-pentene in heptane at the start of copolymerization are 0.023 (g/g-heptane) and 0.16 (g/g-heptane), respectively.
g-heptane). On the other hand, the concentrations at the end of the copolymerization were simultaneously 0.078 (g/g-heptane) and 0.107 (g/g-heptane). Therefore, Rmax=6.96 (at the start of copolymerization), Rmin=1.37
(at the end of copolymerization), Rmax/Rmin=5.08. Example 6 Example 1 except that hydrogen was added at once at 25 c.c./hour (0°C, 1 atm) during the copolymerization period.
Random copolymerization of propylene and 4-methyl-1-pentene was carried out under the same conditions as described above. The concentrations of propylene and 4-methyl-1-pentene in heptane at the start of copolymerization are 0.012 (g/g-heptane) and 0.16 (g/g-heptane), respectively.
g-heptane). On the other hand, the concentration at the end of copolymerization was also 0.044 (g/g-heptane). Therefore, Rmax=13.3 (at the start of copolymerization), Rmin=2.14 (at the end of copolymerization), Rmax/
Rmin=6.21. Example 7 The conditions were the same as in Example 2, except that 11.5 g of DEAC, 2.3 g of titanium trichloride, and 600 g of 4-methylpentene were used, and ethylene was supplied simultaneously with propylene at a rate of 2.5 g/hour for 6 hours. Ternary random copolymerization of propylene, ethylene, and 4-methyl-1-pentene was carried out. Propylene and 4 at the start of copolymerization
- The concentration of methyl-1-pentene in heptane is 0.012 (g/g-heptane) and
It was 0.38 (g/g-heptane). On the other hand, the concentration at the end of copolymerization was 0.012 (g/g
-heptane) and 0.12 (g/g-heptane). Therefore, Rmax=31.7 (at the start of copolymerization), Rmin=10.0 (at the end of copolymerization), Rmax/
Rmin=3.17. The results are shown in Table 1. Example 8 Propylene, ethylene, 4-methyl-
Ternary random copolymerization of 1-pentene was carried out. Propylene and 4 at the start of copolymerization
- The concentration of methyl-1-pentene in heptane is 0.011 (g/g-heptane) and
It was 0.38 (g/g-heptane). On the other hand, the concentration at the end of copolymerization was 0.011 (g/
g-heptane) and 0.10 (g/g-heptane)
It was hot. Therefore, Rmax=9.09 (at the start of copolymerization), Rmin=2.20 (at the end of copolymerization), Rmax/
Rmin=6.05. The results are shown in Table 1. Example 9 4 liters of n-heptane was introduced into the same polymerization vessel as used in Example 1, and after purging with nitrogen,
5.3 g of DEAC and 0.9 g of titanium trichloride (the same as used in Example 1) were added. The temperature was set at 70° C., and 750 g of 3-methyl-1-butene was charged in one batch in a propylene atmosphere at one atmosphere (absolute pressure).
Immediately thereafter, propylene was added at a rate of 190 g/hour.
Propylene and 3-methyl-
Random copolymerization with 1-butene was carried out. The concentrations of propylene and 3-methyl-1-butene in heptane at the start of copolymerization are
0.012 (g/g-heptane) and 0.46 (g/g-
heptane). The concentrations at the end of the copolymerization were similarly 0.038 (g/g-heptane) and
It was 0.29 (g/g-heptane). Therefore,
Rmax=38.3 (at the start of copolymerization), Rmin=7.63 (at the end of copolymerization), and Rmax/Rmin=5.02. The results are shown in Table 1. However, the melting characteristics by DSC were measured in the same manner as in Example 1 except that the copolymer was heated to 290°C. Example 10 Using 3 g of DEAC, 0.6 g of titanium trichloride, and 450 g of styrene instead of 250 g of 4-methyl-1-pentene.
Random copolymerization of propylene and styrene was carried out in the same manner as in Example 1 except that . The concentrations of propylene and styrene in heptane at the start of copolymerization were 0.012 (g/g-heptane) and 0.29 (g/g-heptane), respectively.
On the other hand, the concentration at the end of copolymerization is
0.060 (g/g-heptane) and 0.21 (g/g-heptane)
heptane). Therefore, Rmax=24.2
(at the start of copolymerization), Rmin=3.50 (at the end of copolymerization),
Rmax/Rmin=6.9. The results are shown in Table 1.

【table】

【table】

Claims (1)

[Scope of Claims] 1. Propylene (A), a monomer (B) selected from branched α-olefins having 5 to 12 carbon atoms or styrene or styrene derivatives, and if necessary, a straight chain α having 2 to 12 carbon atoms other than propylene. - A propylene copolymer consisting of olefin (C) and characterized by having the following conditions (a) to (d). (a) The content of monomer B is 2 to 90% by weight. (b) The content of monomer C is 0 to 8% by weight. (c) Intrinsic viscosity at 135℃ in decalin is 0.5~
Must be 15dl/g. (d) A portion where at least one peak position of the melting curve obtained by differential scanning calorimetry (DSC) exists at 145°C or higher, and which melts at 140°C or lower calculated based on the melting curve obtained by DSC. The heat of fusion of the part and the heat of fusion of the part that melts at 150℃ or higher are each 5% or more of the total heat of fusion (However, the melting curve by DSC is 10% or more.
The sample was crystallized at a cooling rate of 10 °C/min.
(obtained by measuring at a heating rate of °C/min). 2 Propylene (A) and carbon number 5 using a catalyst consisting of at least a titanium component and an organoaluminum compound
Copolymerization with a monomer (B) selected from ~12 branched α-olefins or styrene or styrene derivatives is carried out with a linear α-olefin having 2 to 12 carbon atoms other than propylene.
With or without olefin (C), the concentration ratio (R) of monomer (B) and propylene in the reaction system changes between Rmax and Rmin (however, Rmax
and Rmin are the maximum and minimum values of R during the process, and Rmax/Rmin>1.5)
Propylene consisting of monomers (A), (B) and optionally monomer (C) and having the following conditions (a) to (d), characterized by comprising a step carried out under conditions varying between Method for producing copolymers. (a) The content of monomer (B) is 2 to 90% by weight. (b) The content of monomer C is 0 to 8% by weight. (c) Intrinsic viscosity at 135℃ in decalin is 0.5~
Must be 15dl/g. (d) A portion where at least one peak position of the melting curve obtained by differential scanning calorimetry (DSC) exists at 145°C or higher, and which melts at 140°C or lower calculated based on the melting curve obtained by DSC. The heat of fusion of the part and the heat of fusion of the part that melts at 150℃ or higher are each 5% or more of the total heat of fusion (However, the melting curve by DSC is 10% or more.
Samples crystallized at a cooling rate of 10 °C/min
(obtained by measuring at a heating rate of °C/min).