JPH0517936B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a crystalline propylene polymer composition with improved crystallization rate, melt tension and stiffness. [Prior art] Crystalline propylene polymers have superior transparency, rigidity, surface gloss, and heat resistance compared to other polyolefins, but their slow crystallization rate and low melt tension make them difficult to use in blow molding and injection molding. Poor moldability in flasion film molding, etc. As a method to improve such drawbacks, for example, aluminum powder,
Methods of improving the crystallization rate by blending talc, etc., and methods of improving melt tension by blending high-pressure low density polyethylene are known, but the former results in a decrease in impact strength and This method impairs the original transparency and surface gloss of the polymer, and the latter also causes a decrease in transparency and rigidity, so it cannot be said to be a satisfactory method. On the other hand, when an organic peroxide is added to a crystalline propylene polymer and heat treated, not only a crosslinking reaction occurs, but also a
Since polymer chain scission occurs and the improvement in physical properties due to crosslinking is offset, by using a crosslinking agent in combination,
It is well known that crosslinking reactions between polymer molecules occur preferentially (for example, Handbook of Additives for Plastics and Rubber, published by Kagaku Kogyosha, 896-
897 pages). However, since the purpose of conventional crosslinking reactions was to form strong three-dimensional bonds and improve heat resistance, there was no concept of secondary processing after crosslinking, and organic peroxides and crosslinking agents were used. A large amount was used to achieve a high degree of crosslinking. However, such highly crosslinked products have poor fluidity when melted, and secondary processing such as blow molding or inflation molding is often impossible. There was a risk that this would result in loss of product value. In addition, an attempt was made to improve the physical properties of an uncrosslinked crystalline propylene polymer by blending a crystalline propylene polymer crosslinked by electron beam irradiation, Kusntstoffe, 73, 15-16 (1983).
However, the crystalline propylene polymer obtained with this formulation does not have a sufficient effect on improving the crystallization rate, and even when used for secondary processing such as blow molding and inflation molding, the melt tension and It was also difficult to say that the effect of improving rigidity was sufficient. [Problems to be Solved by the Invention] The present inventors have investigated formulations for improving the crystallization rate, melt tension, and rigidity of crystalline propylene-based polymers, and improving moldability. The inventors have discovered that a composition consisting of a crosslinked product of a polypropylene polymer and a crystalline propylene polymer can achieve the above object, and have arrived at the present invention. [Summary of the Invention] To summarize the present invention, the present invention provides (a) a crystalline propylene polymer having a propylene component as a main component, and (b) a crystalline propylene polymer having a DSC crystallization temperature of T ^O _C. A cross-linked product of a crystalline propylene-based polymer obtained by cross-linking a system polymer with a cross-linking agent in the presence of a radical initiator, whose DSC crystallization temperature T ^C _C satisfies T ^C _C − T ^O _C ≧10, And the amount of boiling paraxylene insoluble matter is
A crosslinked product of a crystalline propylene polymer in a range of 50% by weight or less is added to the crystalline propylene polymer (a).
The gist of the invention is a crystalline propylene polymer composition containing in the range of 0.2 to 100 parts by weight per 100 parts by weight of. [Means and effects for solving the problems] The crystalline propylene polymer (a) constituting the crystalline propylene polymer composition of the present invention consists only of a propylene component, or consists of propylene and α other than propylene. - It is a crystalline propylene polymer consisting of a copolymer with olefin and having a propylene component as its main component. α-olefin components other than propylene include ethylene, 1-butene, 1
-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc.
A mixed component of two or more of these α-olefins may be used. When the crystalline propylene polymer is a copolymer of propylene and the α-olefin, the content of α-olefin is usually in the range of 0.1 to 15 mol%, preferably 0.1 to 10 mol%. The crystallinity of the crystalline propylene polymer measured by X-ray diffraction is usually 30 to 30.
70%, preferably in the range of 40 to 70%, and the crystallization temperature measured by differential scanning calorimeter [DSC crystallization temperature] is usually in the range of 70 to 115°C. In addition, the crystalline propylene polymer
Intrinsic viscosity [η] measured in Delicalin at 135℃
usually ranges from 0.5 to 4.5 dl/g, preferably from 0.8 to 4.0 dl/g. Crosslinked product (b) of crystalline propylene polymer to be blended into the crystalline propylene polymer composition of the present invention
is preferably a crosslinked product of a crystalline propylene polymer having a DSC crystallization temperature of T ^O _C °C, which is crosslinked with a crosslinking agent in the presence of a radical initiator under melt shearing. And that
It is necessary that the crosslinked product is a crystalline propylene polymer whose DSC crystallization temperature T ^CL _C °C satisfies T ^CL _C −T ^O _C ≧10, more preferably 30≧T ^CL _C −T ^O _C ≧14 Particularly preferred is a crosslinked product of a crystalline propylene polymer that satisfies 30≧T ^CL _C −T ^O _C ≧16. Crosslinked product of the crystalline propylene polymer
If the difference between the DSC crystallization temperature T ^CL _C ℃ and the crystallization temperature T ^O _C ℃ of the crystalline propylene polymer before crosslinking is less than 10℃, the crystallization rate, stiffness, and melt tension of the composition will decrease. become. Further, the content of the crosslinked crystalline propylene polymer insoluble in boiling paraxylene is 50% by weight or less, preferably 30% by weight or less, particularly preferably 5% by weight.
The range is as follows. The boiling paraxylene insoluble content of the crosslinked product of the crystalline propylene polymer is 50% by weight.
If it exceeds, the moldability of the composition will become poor,
In addition, the product will start to have hard eyes.
Moreover, the crystallization rate and stiffness of the composition will not improve sufficiently. The crystallinity of the crosslinked crystalline propylene polymer measured by X-ray diffraction is usually in the range of 30 to 70%, preferably 40 to 70%. In addition, the crosslinked crystalline propylene polymer has a melt flow rate MFR ^O of 0.1 to 2000 g/10 min (230
℃) of a crosslinked crystalline propylene polymer whose melt flow rate MFR ^CL g/min
(230°C) usually satisfies 0.1≦MFR ^CL /MFR ^O ≦50, preferably 0.5≦MFR ^CL /MFR ^O ≦20. Further, the crosslinked product of the crystalline polypropylene polymer is a crosslinked product of the crystalline propylene polymer whose melting temperature (DSC melting point) is T ^O _n °C.
The DSC melting point T ^CL _n °C is usually in a range that satisfies -5≦T ^CL _n -T ^O _n ≦5, preferably -3≦T ^CL _n -T ^O _n ≦3. The crosslinked product of the crystalline propylene polymer may be obtained by a crosslinking reaction in a solution state as well as a crosslinking reaction under melt shear, as long as its crystallization temperature is within the above range. good. As the crystalline propylene polymer constituting the crosslinked product of the crystalline propylene polymer, the above-mentioned crystalline propylene polymer can be similarly exemplified, but the crystalline propylene polymer (a) and the crystalline propylene polymer constituting the crosslinked product (b) of the crystalline propylene polymer may be the same or different. Specifically, the crosslinking agent component constituting the crosslinked product of the crystalline propylene polymer includes ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, and diethylene glycol di(meth)acrylate. ) acrylate, polyethylene glycol di(meth)acrylate, trimerolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, tris[2-(meth)acryloyloxyethyl]cyanurate, tris[2-(meth)acryloyloxyethyl ]Isocyanurate, Polyfunctional (meth)acrylate compounds such as 1,3,5-tri(meth)acryloylhexahydro-s-triazine, triallyl cyanurate,
Polyallyl compounds such as triallyl isocyanurate, maleimide compounds such as phenylmaleimide, quinone dioxime compounds such as P,P'-dibenzoylquinone dioxime, polyvinylbenzene compounds such as divinylbenzene and diisopropenylbenzene. For example, The crosslinked product of the crystalline propylene polymer can be obtained by reacting the crystalline propylene polymer and the crosslinking agent component in the presence of a radical initiator under heated melt shear conditions or in a solution state. It can be obtained by As the reactor, one that can apply shearing force to the raw material mixture under heating and melting conditions is used, and specific examples include a kneader, a Banbury mixer, a single screw extruder, a twin screw extruder, etc. . It is also preferable to mix the raw material mixture in advance using a Henschel mixer, V-blender, etc. before supplying it to these melt-shear reactors. The temperature during the reaction under melt shear conditions is usually in the range of 180 to 300°C, preferably 200 to 270°C, and the reaction time is usually in the range of 2 to 15 minutes, giving the molten mixture The shearing force is usually 0.05 to 0.3KW, preferably 0.1KW as the power required per 1Kg of the molten mixture.
It ranges from 0.25KW to 0.25KW. Further, the temperature when reacting in a solution state is usually in the range of 100 to 200°C, preferably 150 to 200°C, and the reaction time is in the range of 10 minutes to 10 hours. Specifically, as a solvent for solution reaction, n-decane, n
Examples include aliphatic hydrocarbons such as -undecane and n-dodecane. Organic peroxides are usually used as radical initiators for the reaction, and those with a decomposition temperature in the range of 150 to 270°C at which their half-life is 1 minute are particularly preferred. Peresters, such as benzoyl peroxide,
dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,
5-dimethyl-2,5-di(peroxybenzoate)hexyne-3,1,4-bis(tert-butylperoxyisopropyl)benzene, lauroyl peroxide, tert-butyl peracetate,
2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl-
2,5-di(tert-butylperoxy)hexane, tert-butyl perbenzoate, tert-butyl perphenyl acetate, tert-butyl perisobutyrate, tert-butyl per-sec-octoate, tert-butyl perpivalate, Cumyl perpivalate and tert-butyl perdiethyl acetate are mentioned. In the composition of the present invention, the blending ratio of the crosslinked product (b) of the crystalline propylene polymer is from 0.2 to 100 parts by weight of the crystalline propylene polymer (a).
It needs to be in the range of 100 parts by weight, more preferably in the range of 0.2 to 50 parts by weight.
When the proportion of the crosslinked product (b) of the crystalline propylene polymer exceeds 100 parts by weight, the extrusion formation of the crystalline propylene polymer composition becomes poor, and when it falls below 0.2 parts by weight, The crystallization rate, rigidity, and melt tension of the crystalline propylene polymer composition decrease. In addition to the crystalline propylene polymer (a) and the crosslinked product (b) of the crystalline propylene polymer, the crystalline propylene polymer composition of the present invention optionally contains an antioxidant, Various additives such as heat stabilizers, ultraviolet absorbers, lubricants, nucleating agents, antistatic agents, flame retardants, pigments, dyes, and inorganic or organic fillers can be blended. These blending ratios are within an appropriate range. The crystalline propylene polymer composition of the present invention can be prepared by blending by a conventionally known method. For example, a mixture consisting of the crystalline propylene polymer (a), the crosslinked product (b) of the crystalline propylene polymer, and optional additives is mixed in a Henschel mixer, a V blender, etc. Examples include a method of kneading with a kneader, a Banbury mixer, a single screw extruder, and a twin screw extruder. [Example] Next, the present invention will be specifically explained using Examples. Examples 1 to 4 100 parts by weight of a crystalline propylene polymer (abbreviated as PP-1) having the physical properties shown in Table 1 was added with an antioxidant, a rust preventive, and 2,5-dimethyl- as an organic peroxide. 2,5-di(tert-butylperoxy)
Hexane [Product name Perhexa 25B, NOF Corporation
Add 0.03 parts by weight of Triaryl Cyanurate [trade name: TAC, manufactured by Musashino Shoji Co., Ltd.] as a crosslinking agent, mix with a Henschel mixer, and then use a 30 mmφ single screw extruder at a resin temperature of 220°C. The reaction was carried out under the following conditions to obtain a crosslinked crystalline propylene polymer (KLPP-1). The physical properties are shown in Table 2. Next, PP-1 and XLPP-1 were mixed in a Henschel mixer in the proportions shown in Table 3, and then kneaded and granulated using a 30 mmφ single screw extruder. The following physical properties were measured for the composition. The results are shown in Table 3. Crystallization temperature (°C): Used as an index to express the crystallization rate; the higher the crystallization temperature, the faster the crystallization rate. Crystallization temperature is determined by PerkinElmer DSC
- Using a mold machine, about 5 mg of the sample was held at 200°C for 10 minutes, and the temperature was lowered at a rate of 10°C/min to measure the exothermic curve, and the peak temperature was taken as the crystallization temperature. Spherulite size (μ): 2mm thick hot plate, 0.1mm thick Al plate,
Using a 0.1 mm thick Lumirror sheet and a 1 mm thick spacer, the cross section of the pressed sheet was hot pressed at 200°C and cooled at about 1°C/min, and the cross section was observed with a polarizing microscope. The spherulite radius of the pressed sheet was determined from a polarized light micrograph. Melt tension (g): Measured using a melt tension tester manufactured by Toyo Seiki Seisakusho at an extrusion speed of 10 mm/min, a winding speed of 200 rpm, and a temperature of 190°C. Furthermore, the composition was applied to an IS-50 injection molding machine (Toshiba
(manufactured by KK), a test piece with a shape of 12 cm x 13 cm x 0.2 cm was made, and the initial flexural modulus (FM)
(ASTM D790) was measured. Example 5 A crosslinked crystalline propylene polymer (XLPP-2) was obtained in the same manner as in Example 1 except that 1 part by weight of triallyl cyanurate was used as a crosslinking agent. The physical properties are shown in Table 2. Next, PP-1 and XLPP-2 were mixed in a Henschel mixer in the proportions shown in Table 3, and then kneaded and granulated using a 30 mmφ single screw extruder. The measured physical properties are shown in Table 3. Example 6 To 100 parts by weight of a crystalline propylene polymer (PP-2) having the physical properties shown in Table 1, an antioxidant, a rust inhibitor, 0.03 parts by weight of Perhexa 25B, and triallylisocyanurate [trade name TAIC, Nippon Kasei
Co., Ltd.], and after mixing with a Henschel mixer, use a 30 mmφ single screw extruder to adjust the resin temperature to
The reaction was carried out at 220°C to obtain a crosslinked crystalline propylene polymer (XLPP-3). Physical properties are the second
Shown in the table. Next, PP-2 and XLPP-3 were mixed in a Henschel mixer in the proportions shown in Table 3, and then kneaded and granulated using a 30 mmφ single screw extruder. The measured physical properties are shown in Table 3. Example 7 A crosslinked product of crystalline propylene polymer ( XLPP-4) was obtained. The physical properties are shown in Table 2. Next, PP-1 and XLPP-4 were mixed in a Henschel mixer in the proportions shown in Table 3, and then kneaded and granulated using a 30 mmφ single screw extruder. The measured physical properties are shown in Table 3. Example 8 A crosslinked product of crystalline propylene polymer (XLPP- 5) was obtained. The physical properties are shown in Table 2. Next, PP-1 and XLPP-5 were mixed in a Henschel mixer in the proportions shown in Table 3, and then kneaded and granulated using a 30 mmφ single screw extruder. The measured physical properties are
Shown in the table. Example 9 A crosslinked product of a crystalline propylene polymer ( XLPP-6) was obtained.
The physical properties are shown in Table 2. Next, PP-2 and XLPP-6 were mixed in the proportions shown in Table 3 using a Henschel mixer, and then kneaded and granulated using a 30 mmφ single screw extruder. The measured physical properties are shown in Table 3. Comparative Example 1 PP-1 and XLPP-1 were mixed in the proportions shown in Table 3 using a Henschel mixer, and then kneaded and granulated using a 30 mmφ single screw extruder. The measured physical properties are shown in Table 3. Comparative Examples 2 and 3 A crosslinked crystalline propylene polymer (XLPP-7) was obtained in the same manner as in Example 1, except that dicumyl peroxide was used as 0.005 parts by weight and triallyl cyanurate was used as 0.2 parts by weight. . The physical properties are shown in Table 2. Next, PP-1 and XLPP-7 were mixed in the proportions shown in Table 3 using a Henschel mixer, and then kneaded and granulated using a 30 mmφ single screw extruder. The measured physical properties are shown in Table 3. Comparative Examples 4 to 8 2 parts by weight of antioxidant, rust preventive agent and TAC were added to 100 parts by weight of PP-1, and after mixing with a Henschel mixer, the resin temperature was adjusted using a 30 mmφ single screw extruder.
The pellets were kneaded and granulated at 180°C, and the pellets obtained were molded into a 1 mm thick press sheet at 180°C. By irradiating this press sheet with cobalt-60 gamma rays (irradiation dose: 5, 10, 15, 20, 25 Mrad), electron beam crosslinked products of crystalline propylene polymers (EXLPP-1 to 5) were obtained. Ta. Next, after mixing PP-1 and EXLPP-1 to 5 in the proportions shown in Table 3 using a Henschel mixer,
The mixture was kneaded and granulated using a single screw extruder. The measured physical properties are shown in Table 3. Comparative Examples 9 to 13 Crosslinked products of crystalline propylene polymers ( EXLPP-6 to 10) were obtained. The physical properties are shown in Table 2. Next, after mixing PP-2 and EXLPP-6 to 10 in the proportions shown in Table 3 using a Henschel mixer,
The mixture was kneaded and granulated using a single screw extruder. The measured physical properties are shown in Table 3. Comparative Example 14 Example 6 except that 1.5 parts by weight of DCP was used as the organic peroxide and 9.2 parts by weight of liquid 1,2-polybutadiene (NISSO-PBB-1000, manufactured by Nippon Soda Co., Ltd.) was used as the crosslinking agent. A crosslinked crystalline propylene polymer (XLPP-8) was obtained in the same manner as above. The physical properties are shown in Table 2. Next, PP-2 and XLPP-8 were mixed in a Henschel mixer in the proportions shown in Table 3, and then kneaded and granulated using a 30 mmφ single screw extruder. The measured physical properties are shown in Table 3.

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[Table] *1 The molten sample broke into pieces and could not be measured.

Claims (1)

[Scope of Claims] 1. (a) A crystalline propylene polymer containing a propylene component as a main component, and (b) a crystalline propylene polymer having a DSC crystallization temperature of T ^O _C °C, which is a radical initiator. A cross-linked product of a crystalline propylene polymer cross-linked with a cross-linking agent in the presence of a DSC crystallization temperature T ^CL _C °C that satisfies T ^CL _C −T ^O _C ≧10 and a boiling para-xylene insoluble content Crystalline propylene containing a crosslinked product of a crystalline propylene polymer in an amount of 50% by weight or less in an amount of 0.2 to 100 parts by weight based on 100 parts by weight of the crystalline propylene polymer (a). based polymer composition.