JP2018135419A - Polypropylene-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polypropylene-based resin composition that maintains high flowability, in which rigidity of a molded body prepared by injection molding and extrusion molding is particularly improved and a molded body of the same, and an automotive member using the same.SOLUTION: A polypropylene-based resin composition contains 5-50 wt.% of a polypropylene-based resin (X) having a branch structure and 95-50 wt.% of a polypropylene-based resin (Y) satisfying conditions (Y-i) to (Y-ii) (where, total of polypropylene-based resin (X) and polypropylene-based resin (Y) is 100 wt.%).SELECTED DRAWING: None

Description

The present invention relates to a polypropylene-based resin composition and a molded body thereof, and more specifically, a polypropylene-based resin composition having excellent moldability and excellent balance between rigidity and impact resistance, and particularly improved rigidity, and molding thereof. About the body.

Polypropylene resin compositions have excellent moldability and mechanical strength as various molded products in the field of industrial parts, such as automobile parts such as bumpers, side moldings, and instrument panels, and parts of household electrical appliances such as televisions. It has been put into practical use by taking advantage of its adaptability to environmental issues and economic characteristics. In particular, molded articles in the automotive field are becoming larger, more complicated in design, thinner and unpainted, and accordingly, polypropylene resin compositions and molded articles have a high balance of physical properties (for example, It is desired to develop a balance between high rigidity and impact strength.

Particularly in the automobile field, many efforts have been made recently to reduce the weight by using a resin as the outer plate material and to improve the fuel efficiency by improving the fuel efficiency. Up to now, polyamide resin with excellent rigidity and impact resistance has been used as the outer panel material in many cases. However, the use of polyamide resin is not necessarily economical and has a low degree of freedom in molding and design. Therefore, it has been desired to apply a polyolefin-based resin having a significant advantage in these respects, and in particular, a polypropylene-based resin from the viewpoint of rigidity. However, the conventional polypropylene resin does not always have a satisfactory level of rigidity, and further improvement in rigidity has been desired.

Since polypropylene is a semi-crystalline polymer, the one that contributes most to improving the rigidity of the resin is
Crystallinity. Since crystallinity is strongly controlled by the stereoregularity of polypropylene,
Many technological development efforts have so far been made to improve the stereoregularity of polypropylene. The history is outlined in detail in Chapter 2 of "New Edition Polypropylene Handbook: From Basics to Application Development, edited by Nero Pasquini, Nikkan Kogyo Shimbun, 2012". On the other hand, the rigidity and elastic modulus of a molded body produced through injection molding or extrusion molding are not necessarily controlled only by crystallinity. Chapter 3 of the “New Edition Polypropylene Handbook” shows that skin core morphology is formed by injection molding. This usually consists of an oriented crystal layer (shear orientation layer) near the surface of the compact and a spherulite layer near the center. In the same book, R.A. Report of Phillips et al.
Polym. Eng. Sci. 34, p. 1731 (1994)), it is shown that mechanical properties such as flexural modulus (FM) depend not only on crystallinity but also on crystal orientation.

For the morphology of the alignment layer and the core layer in the injection-molded piece and the physical properties of each layer, see “Polypropylene, structure, blends and com”.
positions, Volume 1, Structure and Morpholog
y, J. et al. Karger-Kocsis ed. , Chapman & Hall, 19
95 ”is well summarized, and it is shown that the thickness of the alignment layer is increased by increasing the molecular weight of polypropylene, the alignment layer has a Shishi-kebab morphology, and a high elastic modulus. Later, Somani et al. (Macromolecules 33, 9385 (2
000)) and Seki et al. (Macromolecules 35, 2583 (2002)).
), The presence of a high molecular weight component is important for the formation of the alignment layer.
Therefore, high-molecular weight is advantageous for forming many oriented structures with high elastic modulus in molded products that are formed with shear flow, such as injection molded products and extrusion molding. In particular, as described above, it is difficult to meet the recent demands for reducing the thickness and weight of the molded product.

As one of the measures for achieving both of these, there is a method in which a low molecular weight component and a high molecular weight component are simultaneously present, that is, a molecular weight distribution is widened.
A propylene homopolymer having an MFR of 0.001 to 5 g / 10 min, b) a propylene / ethylene copolymer having an ethylene content of 5 to 80 w / w%, c) an MFR of 1 to 104 g
/ 10 of propylene homopolymer having c / 10 min, propylene homopolymer c)
A blend of different propylene polymers, characterized in that the ratio of R to propylene homopolymer a) to MFR is in the range of 10: 1 to 10 ⁷ : 1, has good flowability, and It is described that it has good mechanical properties, in particular high rigidity.

In Patent Document 2, the intrinsic viscosity ([η] A1P) measured in tetralin at 135 ° C.
) Is 0.5 dl / g or more and less than 2.0 dl / g, and the molecular weight distribution (Mw / Mn) is 3.
Intrinsic viscosity measured in tetralin at 20 to 80% by weight and 135 ° C. for a propylene polymer having a structural unit content of less than 0 and derived from propylene of 90% by weight or more ([η
] A2P) is 2.0 dl / g or more and 7.0 dl / g or less, and the molecular weight distribution (Mw / Mn)
) Is 3.0 or more, and the content of the structural unit derived from propylene is 90 to 50% by weight of the propylene polymer of 5 to 55% by weight, and the content of the structural unit derived from ethylene is 20 to 20%.
It is described that a resin composition consisting of 10 to 50% by weight of a copolymer of ethylene and propylene or an α-olefin having 4 to 20 carbon atoms, which is 80% by weight, has an excellent balance between toughness and fluidity.

However, also in the propylene-based resin composition in which these various improved methods have been made,
It cannot be said that the balance of rigidity and fluidity has been sufficiently improved and improved, and it should be said that further improvement of these physical properties is still awaited.

Japanese Patent Laid-Open No. 7-149974 JP 2013-79375 A

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a polypropylene resin composition in which the rigidity of a molded product produced by injection molding or extrusion molding is particularly improved while maintaining high fluidity and the molded product thereof An object of the present invention is to provide an automobile member using the same.

As a result of intensive studies to solve the above problems, the present inventors have found that a polypropylene system comprising a combination of a polypropylene resin having a branched structure and a polypropylene resin having a specific high fluidity, that is, a high MFR. The present inventors have found that the resin composition has high fluidity, good mechanical properties, and particularly high rigidity, and has completed the present invention.

That is, the present invention
[1] 5 to 50% by weight of a polypropylene resin (X) having a branched structure and the following condition (Y-
A polypropylene resin composition containing 95 to 50% by weight of a polypropylene resin (Y) satisfying i) to (Y-ii) (however, the total of the polypropylene resin (X) and the polypropylene resin (Y)) Is 100% by weight).
Condition (Yi)
Polypropylene resin (Y) is propylene homopolymer (YA), propylene-α-
It is at least one polypropylene resin selected from the group consisting of an olefin random copolymer (Y-B) and a propylene-α-olefin block copolymer (Y-C).
Condition (Y-ii)
Melt flow rate of polypropylene resin (Y) (MFR, 230 ° C., 2.16 kg)
Load) is in the range of 50 to 500 g / 10 min.
[2] Polypropylene resin (Y) is a propylene-α-olefin block copolymer (Y
-C) The polypropylene resin composition according to [1].
[3] Propylene-α-olefin block copolymer (YC) is subjected to the following conditions (YC-
The polypropylene resin composition according to [2], which satisfies i).
Condition (YC-i)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and the melt flow rate of the propylene (co) polymer (MFR, 230 ° C., 2.16 kg load) is 80 to 500
g / 10 minutes.
[4] Propylene-α-olefin block copolymer (YC) is subjected to the following conditions (YC-
The polypropylene resin composition according to [2] or [3], which satisfies ii).
Condition (YC-ii)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and propylene-α
-The content of the α-olefin in the olefin random copolymer is 30 to 80% by weight (provided that the content of the α-olefin is 100% by weight of the monomer of the entire propylene-α-olefin random copolymer. % Is the proportion of α-olefin).
[5] Propylene-α-olefin block copolymer (YC) is subjected to the following conditions (YC-
The polypropylene resin composition according to any one of [2] to [4], which satisfies iii).
Condition (YC-iii)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and propylene-α
-Ratio of propylene-α-olefin random copolymer to olefin block copolymer (Y-C) is 5 to 50 wt% (provided that the total propylene-α-olefin block copolymer is 100 wt%) ).
[6] The polypropylene resin composition according to any one of [1] to [5], wherein the polypropylene resin (X) having a branched structure satisfies the following condition (Xi).
Condition (X-i)
The branching index g ^′ when the absolute molecular weight Mabs of the polypropylene resin (X) is 1 million is 0.
. 30 or more and less than 1.00.
[7] A polypropylene resin (X) having a branched structure is subjected to the following conditions (X-ii) to (X
-The polypropylene resin composition according to [6] that satisfies -vi).
Condition (X-ii)
Melt flow rate of polypropylene resin (X) (MFR, 230 ° C., 2.16 kg)
Load) is in the range of 0.1 to 30 g / 10 min.
Condition (X-iii)
The 25 degreeC paraxylene soluble component amount (CXS) of polypropylene resin (X) is less than 5.0 weight% with respect to polypropylene resin (X) whole quantity.
Condition (X-iv)
The mm fraction of propylene unit 3 chain | strand by ¹³ C-NMR of polypropylene resin (X) is 95% or more.
Condition (X-v)
10. Molecular weight distribution Mw / Mn by polypropylene resin (X) GPC is 3.0 or more.
0 or less, and Mz / Mw is 2.5 or more and 10.0 or less.
Condition (X-vi)
The melt tension (MT) (unit: g) of the polypropylene resin (X) is log (MT) ≧ −
Satisfy either 0.9 × log (MFR) +0.7 or MT ≧ 15.
[8] Further containing 1 to 50 parts by weight of an ethylene-α-olefin elastomer (Z) with respect to 100 parts by weight of the total of the polypropylene resin (X) and the polypropylene resin (Y) [
The polypropylene resin composition according to any one of [1] to [7].
[9] 1 to 50 parts by weight of filler (M) satisfying the following condition (Mi) is further contained with respect to 100 parts by weight of the total of the polypropylene resin (X) and the polypropylene resin (Y)
The polypropylene resin composition according to any one of [1] to [8].
Condition (Mi)
The filler (M) is at least 1 selected from the group consisting of inorganic fillers and organic fillers.
It is a seed filler.
[10] Using the polypropylene resin composition according to any one of [1] to [9] as a material,
A molded body that satisfies the following condition (1).
Condition (1)
The molded body is either an injection molded body or an extruded molded body.
[11] An automotive member using the molded article according to [10].
Is to provide.

The polypropylene resin composition of the present invention has high fluidity, good mechanical properties, and particularly high rigidity.

Conceptual diagram of CFC-FT-IR The outline of the experiment of the X-ray small angle scattering shows the crystal orientation structure of the injection-molded piece of the example. The Qratio plot about the test piece obtained by Example 1, the comparative example 1, and the reference example 1 is shown.

In the following, embodiments of the present invention will be described in detail.
It is an example of an embodiment of the present invention, and the present invention is not limited to the following description unless it exceeds the gist.

The polypropylene resin composition of the present invention comprises a polypropylene resin (X
) Propylene-ethylene obtained by sequential polymerization of homopolypropylene, random polypropylene, polypropylene and propylene-ethylene random copolymer having a melt flow rate measured at 230 ° C. of 5 to 50% by weight and 50 g / 10 min or more. Contains 95 to 50% by weight of at least one polypropylene resin (Y) selected from the group consisting of block copolymers (however, the total of polypropylene resin (X) and polypropylene resin (Y) is 100% by weight) And).
The propylene-ethylene block copolymer here is a polypropylene and a propylene-ethylene copolymer produced by a sequential polymerization method in which a crystalline polypropylene is produced in the first step and a propylene-ethylene copolymer is produced in the second step. A resin composition comprising a reactor blend of

Among these, the preferable range of the content of the polypropylene resin (X) having a branched structure is 5
~ 50% by weight. When the content of the polypropylene resin (X) is within this range, the effect of improving the rigidity is remarkable, and the fluidity does not decrease. As a more preferable range, the content of the polypropylene resin (X) having a branched structure is 7 to 40% by weight, more preferably 10 to 3%.
0% by weight. Accordingly, the preferable range of the content of the polypropylene resin (Y) is 9
It is 3 to 60% by weight, more preferably 90 to 70% by weight.

1. Polypropylene resin (X)
The polypropylene resin (X) used in the present invention is a polypropylene having a branched structure.
The definition of having a branched structure will be described later. Polypropylene resin (X)
May be homopolypropylene or random polypropylene containing ethylene and other α-olefins in the range of several weight percent, but from the viewpoint of improving the rigidity of the polyolefin resin composition, the homopolypropylene having a branched structure It is desirable that Examples of the α-olefin include ethylene, 1-butene, 1-hexene, 1-octene, and the like, which are usually linear or branched α-olefins having up to about 10 carbon atoms. 1-butene is preferably used. In the case of random polypropylene, the upper limit of the content of α-olefin (comonomer amount) as a comonomer is generally about 5% by weight when the total amount of monomers of the polymer is 100% by weight.

The presence of a branched structure can be confirmed by various analytical methods. One method is to use the intrinsic viscosity of a polymer in a solution. Details are described below.
The branching index g ′ is determined by the ratio of the intrinsic viscosity [η] lin of the linear polymer having the same molecular weight as the intrinsic viscosity [η] br of the polymer having a long chain branched structure, that is, [η] br / [η] lin. Given a long chain branching structure, it takes a value less than one.
The definition is, for example, “Developments in Polymer Characte”.
Rization-4 "(JV Dawkins ed. Applied Scie
nce Publishers, 1983), which is an indicator known to those skilled in the art.
For example, g ′ can be obtained as a function of the absolute molecular weight Mabs by using a GPC equipped with a light scatterometer and a viscometer as described below.

In one preferred embodiment of the present invention, a polypropylene resin (X) having a branched structure
Satisfies the following condition (X-i).
Condition (X-i)
The branching index g ^′ when the absolute molecular weight Mabs of the polypropylene resin (X) is 1 million is 0.
. 30 or more and less than 1.00.

1-1) Condition (Xi): Branch index g ^′
The polypropylene-based resin (X) having a long-chain branched structure according to the present invention needs to maintain high fluidity of the entire polypropylene-based resin composition at the same time as branching exists, and as a result, g ′
There are preferable upper and lower limits, and the absolute molecular weight Mabs determined by light scattering is 10
When it is 100,000, g ′ is preferably 0.30 or more and less than 1.00, more preferably 0.
. 55 to 0.98, more preferably 0.75 to 0.96, most preferably 0
. It is 78 or more and 0.95 or less.
When g ′ is in this range, the amount of branching is sufficient, the effect of improving the rigidity is obtained, and the fluidity is good.

A specific method for calculating g ′ is as follows.
Waters Alliance GPCV2000 is used as a GPC apparatus equipped with a differential refractometer (RI) and a viscosity detector (Viscometer). In addition, as a light scattering detector, a multi-angle laser light scattering detector (MALLS) Wyatt Technol
ogy's DAWN-E is used. Detectors are MALLS, RI, Viscometer
Connect in this order. The mobile phase solvent is 1,2,4-trichlorobenzene (added with an antioxidant Irganox 1076 manufactured by BASF Japan Ltd. at a concentration of 0.5 mg / mL).
The flow rate is 1 mL / min, and two columns of Tosoh Corporation GMHHR-H (S) HT are connected and used. The temperature of the column, sample injection section, and each detector is 140 ° C. Sample concentration is 1
The injection volume (sample loop volume) is 0.2175 mL.
Absolute molecular weight (Mabs), root mean square radius (Rg) and V obtained from MALLS
In determining the intrinsic viscosity ([η]) obtained from iscometer,
Calculation is performed using the attached data processing software ASTRA (version 4.73.04) with reference to the following document.

References:
1. "Developments in Polymer Characterizat
ion-4 "(JV Dawkins ed. Applied Science)
Publishers, 1983. Chapter 1. )
2. Polymer, 45, 6495-6505 (2004).
3. Macromolecules, 33, 2424-2436 (2000).
4). Macromolecules, 33, 6945-6925 (2000).

The branching index (g ′) is the intrinsic viscosity ([η] br) obtained by measuring the sample with the above Viscometer and the intrinsic viscosity ([η] lin) obtained separately by measuring the linear polymer.
As a ratio ([η] br / [η] lin).
Here, as a linear polymer for obtaining [η] lin, a commercially available homopolypropylene (Novatech PP (registered trademark) grade name: FY6 manufactured by Nippon Polypro Co., Ltd.) is used. The logarithm of [η] lin of a linear polymer is linearly related to the logarithm of molecular weight.
Since it is known as the uwink-Sakurada equation, [η] lin can be appropriately extrapolated to the low molecular weight side or the high molecular weight side to obtain a numerical value.

In addition, additional properties required for the polypropylene resin (X) of the present invention will be described below.

In one preferred embodiment of the present invention, a polypropylene resin (X) having a branched structure
Satisfies the following conditions (X-ii) to (X-vi) in addition to the condition (X-i).
Condition (X-ii)
Melt flow rate of polypropylene resin (X) (MFR, 230 ° C., 2.16 kg)
Load) is in the range of 0.1 to 30 g / 10 min.
Condition (X-iii)
The 25 degreeC paraxylene soluble component amount (CXS) of polypropylene resin (X) is less than 5.0 weight% with respect to polypropylene resin (X) whole quantity.
Condition (X-iv)
The mm fraction of propylene unit 3 chain | strand by ¹³ C-NMR of polypropylene resin (X) is 95% or more.
Condition (X-v)
10. Molecular weight distribution Mw / Mn by polypropylene resin (X) GPC is 3.0 or more.
0 or less, and Mz / Mw is 2.5 or more and 10.0 or less.
Condition (X-vi)
The melt tension (MT) (unit: g) of the polypropylene resin (X) is log (MT) ≧ −
Satisfy either 0.9 × log (MFR) +0.7 or MT ≧ 15.

1-2) Condition (X-ii): Melt flow rate (MFR)
The melt flow rate (MFR) of the polypropylene resin (X) is 0.1 to 30.0 g.
/ 10 minutes, preferably 0.3-20.0 g / 10 minutes,
Most preferably, it is 0.5-10.0 g / 10min. When the melt flow rate is in this range, the fluidity is high and the effect of improving the rigidity is high.

MFR is JIS K7210: 1999 “Plastic-thermoplastic plastic melt mass flow rate (MFR) and melt volume flow rate (MVR).
Measured in accordance with Method A, Condition M (230 ° C., 2.16 kg load) of “No. Test Method”, the unit is g / 10 minutes.

1-3) Condition (X-iii): 25 ° C. paraxylene soluble component amount (CXS)
The polypropylene resin (X) preferably has few low crystalline components that cause stickiness and a decrease in rigidity when it becomes a product. This low crystalline component is the amount of xylene soluble component (25 ° C
CXS) and is preferably less than 5.0% by weight, more preferably 3.0% by weight or less, particularly preferably 1.0% by weight, based on the total amount of component (X)
Or less, most preferably 0.5% by weight or less. The lower limit is not particularly limited, but is usually 0.01% by weight or more, preferably 0.03% by weight or more. Details of the CXS measurement method are as follows.
2 g of sample was added to 300 ml of p-xylene (containing 0.5 mg / ml BHT)
After dissolving at 0 ° C. to make a solution, it is left at 25 ° C. for 12 hours. Thereafter, the precipitated polymer is separated by filtration, p-xylene is evaporated from the filtrate, and further dried under reduced pressure at 100 ° C. for 12 hours to recover room temperature xylene-soluble components. Ratio of weight of recovered component to charged sample weight [wt%]
Is defined as CXS.

1-4) Condition (X-iv): mm fraction of propylene units 3 chain by ¹³ C-NMR It is preferable that the polypropylene resin (X) has high stereoregularity. Stereoregularity of the ^height, can be evaluated by 13 ^C-NMR, mm fraction of the propylene unit triad sequences obtained by 13 C-NMR is preferably has a 95.0% or more stereoregular.
The mm fraction is the proportion of three propylene units in which the direction of methyl branching in each propylene unit is the same in any three propylene units consisting of head-to-tail bonds in the polymer chain, and the upper limit is 100% It is. This mm fraction is a value indicating that the steric structure of the methyl group in the polypropylene molecular chain is controlled isotactically, and the higher the value, the higher the degree of control. When the mm fraction is equal to or greater than this value, mechanical properties such as a high elastic modulus of the product are good.
Therefore, the mm fraction is preferably 95.0% or more, more preferably 96.0% or more, and further preferably 97.0% or more.

In addition, the detail of the measuring method of mm fraction of the propylene unit 3 chain | strand by ¹³ C-NMR is as follows.
A sample of 375 mg is completely dissolved in 2.5 ml of deuterated 1,1,2,2, -tetrachloroethane in an NMR sample tube (10φ), and then measured at 125 ° C. by a proton complete decoupling method. The chemical shift sets the central peak of the three peaks of deuterated 1,1,2,2-tetrachloroethane to 74.2 ppm. The chemical shift of other carbon peaks is based on this.
Flip angle: 90 degrees
Pulse interval: 10 seconds
Resonance frequency: 100MHz or more
Integration count: 10,000 times or more
Observation range: -20ppm to 179ppm
Number of data points: 32768
The analysis of the mm fraction is performed using a ¹³ C-NMR spectrum measured under the above conditions.
The spectrum is assigned with reference to Macromolecules, (1975) 8 pp. 687 and Polymer, 30 pages 1350 (1989).
Note that a more specific method for determining the mm fraction is described in detail in paragraphs [0053] to [0065] of Japanese Patent Laid-Open No. 2009-275207, and the present invention is performed according to this method. .

1-5) Condition (Xv): Molecular weight distribution Mw / Mn by GPC
The polypropylene resin (X) needs to have a relatively wide molecular weight distribution, and is obtained by gel permeation chromatography (GPC). Mw / Mn (where Mw is a weight average molecular weight, Mn is a number average) The molecular weight is preferably from 3.0 to 10.0. Molecular weight distribution Mw / M of polypropylene resin (X) having a long-chain branched structure
n is more preferably in the range of 3.5 to 8.0, and still more preferably in the range of 4.1 to 6.0.

Furthermore, as a parameter that more significantly represents the breadth of the molecular weight distribution, Mz / Mw (where,
Mz is a Z average molecular weight) and is preferably 2.5 or more and 10.0 or less. Mz / M
A more preferable range of w is 2.8 to 8.0, and more preferably 3.0 to 6.0.
As the molecular weight distribution is wider, the moldability is improved, but those having Mw / Mn and Mz / Mw in this range are particularly excellent in moldability.
The definitions of Mn, Mw, and Mz are described in “Basics of Polymer Chemistry” (Edited by Polymer Society, Tokyo Kagaku Dojin, 1978) and can be calculated from molecular weight distribution curves by GPC.
The specific measurement method of GPC is as follows.
Apparatus: GPC manufactured by Waters (ALC / GPC 150C)
Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm)
Column: AD806M / S (3 pieces) manufactured by Showa Denko KK
-Mobile phase solvent: orthodichlorobenzene (ODCB)
・ Measurement temperature: 140 ℃
・ Flow rate: 1.0 ml / min
・ Injection volume: 0.2ml
Sample preparation: Sample is 1 mg / m using ODCB (containing 0.5 mg / mL BHT)
A solution of L is prepared and dissolved at 140 ° C. in about 1 hour.
Conversion from the retention capacity obtained by GPC measurement to the molecular weight is performed using a calibration curve prepared in advance by standard polystyrene (PS). The standard polystyrenes used are all the following brands manufactured by Tosoh Corporation.
F380, F288, F128, F80, F40, F20, F10, F4, F1, A50
00, A2500, A1000
A calibration curve is created by injecting 0.2 mL of a solution dissolved in ODCB (containing 0.5 mg / mL BHT) so that each is 0.5 mg / mL. The calibration curve uses a cubic equation obtained by approximation by the least square method.
In addition, the following numerical value is used for the viscosity formula [η] = K × M ^α used for conversion to molecular weight.
PS: K = 1.38 × 10 ⁻⁴ , α = 0.7
PP: K = 1.03 × 10 ⁻⁴ , α = 0.78

1-6) Condition (X-vi): Melt tension (MT) (unit: g)
The polypropylene resin (X) preferably satisfies the following condition (1).
・ Condition (1)
log (MT) ≧ −0.9 × log (MFR) +0.7
Or
MT ≧ 15
Satisfy at least one of
Here, MT is a capillary using Capillograph 1B manufactured by Toyo Seiki Seisakusho Co., Ltd.
Diameter 2.0 mm, length 40 mm, cylinder diameter: 9.55 mm, cylinder extrusion speed: 2
The melt tension when measured under the conditions of 0 mm / min, take-off speed: 4.0 m / min, and temperature: 230 ° C. is expressed in grams. However, when MT of component (X) is extremely high,
At a take-up speed of 4.0 m / min, the resin may break. In such a case, the take-up speed is lowered, and the tension at the highest speed at which take-up is possible is MT. Also,
The measurement conditions and units of MFR are as described above.
This rule is an index for the polypropylene-based resin (X) having a long-chain branched structure to have a sufficient melt tension for foam molding. Generally, since MT has a correlation with MFR, It is described by a relational expression with MFR.

As described above, a method for defining MT with a relational expression with MFR is a normal method for those skilled in the art. A relational expression is proposed.
log (MS)> − 0.61 × log (MFR) +0.82 (230 ° C.)
(Here, MS is synonymous with MT.)

Japanese Unexamined Patent Application Publication No. 2003-64193 proposes the following relational expression as a definition of polypropylene having a high melt tension.
11.32 × MFR−0.7854 ≦ MT (230 ° C.)

Furthermore, Japanese Patent Laid-Open No. 2003-94504 proposes the following relational expression as a definition of polypropylene having a high melt tension.
MT ≧ 7.52 × MFR−0.576
(MT is a value measured at 190 ° C. and MFR at 230 ° C.)

If the polypropylene resin (X) having a long-chain branched structure satisfies the above condition (1), it can be said that the resin has a sufficiently high melt tension, and the effect of improving the rigidity is remarkable. In addition, the following condition (1)
It is more preferable to satisfy ', and it is further preferable to satisfy the condition (1) ".
・ Condition (1) '
log (MT) ≧ −0.9 × log (MFR) +0.9
Or
MT ≧ 15
Satisfy at least one of
・ Condition (1) ”
log (MT) ≧ −0.9 × log (MFR) +1.1
Or
MT ≧ 15
Satisfy at least one of
There is no need to provide the upper limit value of MT. However, when MT exceeds 40 g, the take-up speed is remarkably slowed by the above-described measurement method, making measurement difficult. In such a case, since it is considered that the spreadability of the resin is also deteriorated, it is preferably 40 g or less, more preferably 35 g or less, and most preferably 30 g or less.

As a preferred method for producing a polypropylene resin (X) having all these characteristics,
The method described in [0042]-[0099] of Unexamined-Japanese-Patent No. 2013-199643 is mentioned.

2. Polypropylene resin (Y)
The polypropylene resin (Y) used in the present invention has the following conditions (Y-i) to (Y-ii).
) Is satisfied.
Condition (Yi)
Polypropylene resin (Y) is propylene homopolymer (YA), propylene-α-
It is at least one polypropylene resin selected from the group consisting of an olefin random copolymer (Y-B) and a propylene-α-olefin block copolymer (Y-C).
Condition (Y-ii)
Melt flow rate of polypropylene resin (Y) (MFR, 230 ° C., 2.16 kg)
Load) is in the range of 50 to 500 g / 10 min.

2-1) Condition (Yi):
The polypropylene resin (Y) used in the present invention is a propylene homopolymer (YA).
And at least one polypropylene resin selected from the group consisting of a propylene-α-olefin random copolymer (Y-B) and a propylene-α-olefin block copolymer (Y-C).

Here, the propylene homopolymer (homopolypropylene) (YA) is a polymer using only propylene as a monomer, and in the present invention, it is necessary to keep the rigidity of the entire polypropylene resin composition high. Therefore, the stereoregularity mm is preferably 95.0% or more, more preferably 96.0% or more, and further preferably 97.0% or more. In addition, how to obtain mm is as already described.

The polypropylene resin (Y) may be random polypropylene. Random polypropylene is a propylene-α-olefin random copolymer (YB) containing propylene and ethylene or other α-olefin in a range of several weight%. Α
Examples of the olefin include ethylene, 1-butene, 1-hexene, 1-octene and the like, which are usually linear or branched α-olefins having up to about 10 carbon atoms. Preferably used. In the case of a propylene-α-olefin random copolymer, the content of α-olefin (comonomer amount) as a comonomer is generally about 5% by weight when the total amount of monomers of the polymer is 100% by weight. is there. In order to keep the rigidity of the polypropylene resin composition of the present invention high, the upper limit of the comonomer amount is preferably 4% by weight, more preferably 3% by weight.

Propylene-α-olefin block copolymer (Y-C) is propylene (co)
A sequential polymer of a polymer and a propylene-α-olefin random copolymer is preferable.
The propylene-α-olefin block copolymer obtained by sequentially polymerizing a propylene (co) polymer and a propylene-α-olefin random copolymer is a propylene (co) produced by a conventionally known sequential polymerization. It is a polypropylene resin comprising a polymer and a propylene-α-olefin copolymer, and is also referred to as a propylene block copolymer. Here, the propylene (co) polymer is a homopolypropylene or a random polypropylene obtained by copolymerizing a small amount of α-olefin of usually several% within a range not impairing the gist of the present invention. On the other hand, propylene-α-olefin random copolymer is α-
It means a soft copolymer containing olefin usually in an amount of 10% by weight or more (the monomer of the entire propylene-α-olefin random copolymer is 100% by weight).
The term propylene-based block copolymer used here is a common name for a polypropylene-based resin composition obtained by performing multi-step polymerization by a sequential polymerization method, which is conventionally used by those skilled in the art. This is different from a so-called (real) block copolymer or graft copolymer in which components polymerized in stages are bonded by chemical bonds. Since the components produced in each step of multi-stage polymerization are not chemically bonded, in general, the difference in crystallinity, molecular weight, solubility in solvent, etc. is used for each component, so that fractionation of crystallinity is achieved. It is possible to separate each component produced in each step by a method such as molecular weight fractionation or solubility fractionation.
Further, in this conventionally known block copolymer obtained by the sequential polymerization method, a long chain branched structure by a chemical bond such as the polypropylene resin (X) does not exist with an analyzable accuracy.

2-2) Condition (Y-ii): Melt flow rate (MFR)
A preferable range of MFR of the polypropylene resin (Y) is 50 g / 10 min or more,
More preferably, it is 60 g / 10 minutes or more. When the MFR of the polypropylene resin (Y) is within this range, the fluidity of the entire polypropylene resin composition is preferably high. The upper limit is 500 g / 10 min or less, preferably 400 g / 10 min or less, more preferably 300 g / 10 min or less, from the viewpoint of impact resistance of the entire polypropylene resin composition.
The MFR is JIS K7210: 1999 “Plastic-thermoplastic plastic melt mass flow rate (MFR) and melt volume flow rate (MVR)”.
Measured in accordance with Method A, Condition M (230 ° C., 2.16 kg load) of “No. Test Method”, the unit is g / 10 minutes.

Production method of polypropylene resin (Y)
As the catalyst for producing the polypropylene resin (Y), any catalyst can be used, but usually a catalyst using a Ziegler-Natta catalyst is used. In the case of using a Ziegler-Natta catalyst, a specific method for producing the catalyst is not particularly limited, but as an example, a catalyst disclosed in Japanese Patent Application Laid-Open No. 2007-254671 can be exemplified.
In producing a propylene-α-olefin block copolymer, it is necessary to produce two polymer components, a propylene (co) polymer and a propylene-α-olefin copolymer.
A propylene-α-olefin copolymer having a relatively high molecular weight and a low MFR is converted to propylene (
From the viewpoint of neatly dispersing in the co) polymer and expressing the original performance of the propylene-based block copolymer, it is necessary to produce both the components by sequential polymerization.

Specifically, it is desirable to polymerize the propylene-α-olefin copolymer in the second step after polymerizing the propylene (co) polymer in the first step. Although it is possible to reverse the order of production, since the propylene-ethylene copolymer is a polymer having low crystallinity, when it is produced in the first step, it adheres inside the polymerization tank or closes the transfer pipe. This is not preferable because it is likely to cause manufacturing trouble.

When performing sequential polymerization, either a batch method or a continuous method can be used, but it is generally desirable to use a continuous method from the viewpoint of productivity.
In the case of the batch method, it is possible to polymerize propylene (co) polymer and propylene-α-olefin copolymer individually using a single polymerization reactor by changing the polymerization conditions with time. . As long as the effects of the present invention are not impaired, a plurality of polymerization reactors may be connected in parallel.
In the case of a continuous process, it is necessary to use a production facility in which two or more polymerization reactors are connected in series because it is necessary to individually polymerize a propylene (co) polymer and a propylene-α-olefin copolymer. A polymerization reactor corresponding to the first step for producing a propylene (co) polymer and propylene
The polymerization reactor corresponding to the second step for producing the α-olefin copolymer must be in a series relationship, but a plurality of polymerization reactors are connected in series and / or in each of the first step and the second step. Or you may connect and use in parallel.

Any polymerization process can be used for the polypropylene resin (Y).
The reaction phase may be a method using a liquid medium or a method using a gas medium. Specific examples include a slurry method, a bulk method, and a gas phase method. Although it is possible to use supercritical conditions as intermediate conditions between the bulk method and the gas phase method, they are substantially equivalent to the gas phase method, and are therefore included in the gas phase method without particular distinction. In the case of a multi-tank continuous polymerization process, a gas phase polymerization reactor may be attached after a bulk polymerization reactor. In the case of a batch method, the first step may be performed by a bulk method and the second step may be performed by a vapor phase method. As described above, the reaction phase is not particularly limited, but the slurry method has a problem that production costs are generally increased because of the use of an organic solvent such as hexane and heptane because there are many attached facilities. Therefore, it is more desirable to use a bulk method or a gas phase method.
Various processes have been proposed for the bulk method and the gas phase method. Although there is a difference in the stirring (mixing) method and the heat removal method, the present invention does not limit the particular process type in this respect.

As the polypropylene resin (Y), it is preferable to use a propylene-α-olefin block copolymer (YC) from the viewpoint of improving the balance of mechanical properties of rigidity and impact resistance.
Moreover, in one preferable aspect of the present invention, the propylene-α-olefin block copolymer (YC) satisfies the following condition (YC-i).
Condition (YC-i)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and the melt flow rate of the propylene (co) polymer (MFR, 230 ° C., 2.16 kg load) is 80 to 500
g / 10 minutes.

2-3) Conditions (YC-i)
The propylene-α-olefin block copolymer (YC) is more preferably a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer.
Furthermore, in this case, when the MFR of the propylene (co) polymer produced in the first step of the propylene-α-olefin block copolymer is 80 g / 10 min or more, the fluidity of the entire composition can be increased, preferable. More preferably, it is 100 g / 10 minutes or more, More preferably, it is 120 g / 10 minutes or more. When MFR exceeds 500 g / 10 minutes, impact resistance may deteriorate, which is not preferable.
In this case, the MFR of the propylene (co) polymer produced in the first step of the propylene-α-olefin block copolymer is analyzed by extracting a part of the sample when the first stage polymerization of the sequential polymerization is completed. Other methods include cross-fractionation method and FT described later.
-The weight average molecular weight of the 140 ° C elution component obtained by the combined method of IR method and the first
It is also possible to prepare an experimental correlation with the MFR of the process propylene (co) polymer and calculate it from the weight average molecular weight of the 140 ° C. elution component using it as a calibration curve.

Moreover, in one preferable aspect of the present invention, the propylene-α-olefin block copolymer (YC) satisfies the following condition (YC-ii).
Condition (YC-ii)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and propylene-α
-The content of the α-olefin in the olefin random copolymer is 30 to 80% by weight (provided that the content of the α-olefin is 100% by weight of the monomer of the entire propylene-α-olefin random copolymer. % Is the proportion of α-olefin).

2-4) Condition (YC-ii)
The propylene-α-olefin block copolymer (YC) is more preferably a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer.
Furthermore, in this case, from the viewpoint of the balance of mechanical properties of rigidity and impact resistance, propylene-
The α-olefin content in the propylene-α-olefin random copolymer of the α-olefin block copolymer (Y-C) is preferably 30 to 80% by weight. However, the α-olefin content here is a value when the monomer fraction of the entire propylene-α-olefin random copolymer is 100% by weight. A more preferable range is 33 to 75% by weight, and a further preferable range is 35 to 70% by weight. When the α-olefin content is within this range, impact resistance, particularly low temperature impact resistance is improved, which is preferable.

Moreover, in one preferable aspect of the present invention, the propylene-α-olefin block copolymer (YC) satisfies the following condition (YC-iii).
Condition (YC-iii)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and propylene-α
-Ratio of propylene-α-olefin random copolymer to olefin block copolymer (Y-C) is 5 to 50 wt% (provided that the total propylene-α-olefin block copolymer is 100 wt%) ).

2-5) Conditions (YC-iii)
The propylene-α-olefin block copolymer (YC) is more preferably a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer.
Furthermore, in this case, for the same reason as in the above condition (YC-ii), the weight fraction of the propylene-α-olefin random copolymer of the propylene-α-olefin block copolymer (YC) is 5 to 5. It is preferably 50% by weight. However, here, the entire propylene-α-olefin block copolymer is 100% by weight. A more preferable range is 7 to 45% by weight, and a further preferable range is 10 to 35% by weight.

Analysis of propylene-α-olefin block copolymer, ethylene content of propylene-α-olefin random copolymer, propylene-α-olefin block copolymer, weight fraction of propylene-α-olefin random copolymer The method is described below. Here, a propylene-α-olefin random copolymer in which the α-olefin is ethylene will be described. In this description, the propylene (co) polymer produced in the first step is the component (
Y-1), the propylene-ethylene copolymer produced in the second step is referred to as component (Y-2).

In the present invention, various indices of the propylene-ethylene block copolymer can be determined by a combination of the cross fractionation method and the FT-IR method described below.
(1) Analytical device to be used (i) Cross fractionator CFC T-100 (abbreviated as CFC) manufactured by Dia Instruments
(Ii) Fourier transform infrared absorption spectrum analysis
FT-IR, Perkin Elmer 1760X
Remove the fixed wavelength infrared spectrophotometer attached to the CFC detector,
Instead, an FT-IR is connected and this FT-IR is used as a detector. The transfer line from the outlet of the solution eluted from the CFC to the FT-IR is 1 m long, and the temperature is maintained at 140 ° C. throughout the measurement. The flow cell attached to the FT-IR has an optical path length of 1
mm and an optical path width of 5 mmφ are used, and the temperature is maintained at 140 ° C. throughout the measurement.
(Iii) Gel permeation chromatography (GPC)
The GPC column at the latter stage of the CFC is used by connecting three AD806MS manufactured by Showa Denko in series.
(2) CFC measurement conditions
(I) Solvent: orthodichlorobenzene (ODCB)
(Ii) Sample concentration: 4 mg / mL
(Iii) Injection volume: 0.4 mL
(Iv) Crystallization: The temperature is lowered from 140 ° C. to 40 ° C. over about 40 minutes.
(V) Sorting method:
The fractionation temperature at the time of temperature-raising elution fractionation is 40, 100, and 140 ° C., and fractionation is performed in three fractions in total. In addition, a component eluting at 40 ° C. or lower (fraction 1), a component eluting at 40 to 100 ° C. (fraction 2), a component eluting at 100 to 140 ° C. (fraction 3)
Are defined as W40, W100, and W140, respectively. W40 + W
100 + W140 = 100. In addition, each fractionated fraction is used as it is in FT-I.
Automatically transported to R analyzer.
(Vi) Solvent flow rate during elution: 1 mL / min
(3) FT-IR measurement conditions
After elution of the sample solution starts from GPC at the latter stage of CFC, FT-IR measurement is performed under the following conditions, and GPC-IR data is collected for each of the above-described fractions 1 to 3.
A conceptual diagram of CFC-FT-IR is shown in FIG.
(I) Detector: MCT
(Ii) Resolution: 8 cm ⁻¹
(Iii) Measurement interval: 0.2 minutes (12 seconds)
(Iv) Number of integrations per measurement: 15 times

(4) Post-processing and analysis of measurement results
The elution amount and molecular weight distribution of the components eluted at each temperature are obtained 2945 by FT-IR.
The absorbance at cm ⁻¹ is determined using the chromatogram. The elution amount is normalized so that the total elution amount of each elution component is 100%. Conversion from the retention volume to the molecular weight is performed using a calibration curve prepared in advance with standard polystyrene. The specific method is the same as described above.
The ethylene content distribution (distribution of ethylene content along the molecular weight axis) of each eluted component is GP
Ethylene-propylene rubber (EPR) whose ethylene content is known by polyethylene, polypropylene, ¹³ C-NMR measurement, etc., using the ratio of the absorbance at 2956 cm ⁻¹ and the absorbance at 2927 cm ⁻¹ obtained by C-IR. ) And a mixture thereof, and converted into ethylene content (% by weight) using a calibration curve prepared in advance.

(5) Propylene-ethylene copolymer content
The propylene-ethylene copolymer (Y-2) (hereinafter referred to as EP) content of the propylene-based block copolymer (Y) in the present invention is defined by the following formula (I) and is as follows. Desired.

EP content (% by weight) = W40 × A40 / B40 + W100 × A100 / B100 + W1
40 x A140 / B140 (I)

W40, W100, and W140 are the elution ratio (unit weight%) in each of the above-mentioned fractions.
A40, A100, and A140 are average ethylene contents (unit weight%) of actual measurement in each fraction corresponding to W40, W100, and W140, and B40, B
100, B140 is the ethylene content of EP contained in each fraction (unit weight%)
It is.
A method for obtaining A40, A100, A140, B40, B100, and B140 will be described later.
The meaning of the formula (I) is as follows. The first term on the right side of the formula (I) is the fraction 1 (4
This is a term for calculating the amount of EP contained in the portion soluble in 0 ° C. When fraction 1 contains only EP and does not contain PP, W40 contributes to the EP content derived from fraction 1 in the whole as it is, but fraction 1 contains a small amount in addition to EP-derived components. PP
Since components derived from the components (extremely low molecular weight components and atactic polypropylene) are also included, it is necessary to correct the portion. Therefore, by multiplying W40 by A40 / B40, the amount derived from the EP component in fraction 1 is calculated. For example, when the average ethylene content (A40) of fraction 1 is 30% by weight and the ethylene content (B40) of EP contained in fraction 1 is 40% by weight, 30/40 = 3/4 of fraction 1 (Ie 75% by weight) comes from EP and the remaining 1/4 comes from PP. Thus, the operation of multiplying A40 / B40 in the first term on the right side means that the contribution of EP is calculated from the weight% (W40) of fraction 1. The same applies to the second term on the right side, and for each fraction, the EP content is calculated by adding and calculating the EP contribution.
(I) As described above, the average ethylene contents corresponding to the fractions 1 to 3 obtained by CFC measurement are A40, A100, and A140, respectively (the unit is% by weight). A method for obtaining the average ethylene content will be described later.
(Ii) The ethylene content corresponding to the peak position in the differential molecular weight distribution curve of fraction 1 is defined as B40 (unit is% by weight). For fractions 2 and 3, it is considered that the rubber part is completely eluted at 40 ° C. and cannot be defined with the same definition, so in the present invention, it is defined as B100 = B140 = 100. B40, B100, B14
0 is the ethylene content of EP contained in each fraction, but it is practically impossible to obtain this value analytically. The reason is that there is no means for completely separating and separating PP and EP mixed in the fraction. As a result of examination using various model samples, it was found that B40 can explain the effect of improving the material properties well by using the ethylene content corresponding to the peak position of the differential molecular weight distribution curve of fraction 1. It was. In addition, B100 and B140 have two reasons for having crystallinity derived from ethylene chain and that the amount of EP contained in these fractions is relatively smaller than the amount of EP contained in fraction 1. Therefore, both approaches to 100 are closer to the actual situation, and almost no errors occur in the calculation. Therefore, analysis is performed with B100 = B140 = 100.

(Iii) The EP content is determined according to the following formula.

EP content (% by weight) = W40 × A40 / B40 + W100 × A100 / 100 + W14
0xA140 / 100 (II)

That is, W40 × A40 / B40, which is the first term on the right side of the formula (II), indicates the EP content (% by weight) having no crystallinity, and W100 × A100 / which is the sum of the second term and the third term. 100+
W140 × A140 / 100 indicates the EP content (% by weight) having crystallinity.
Here, average ethylene content A40, A100, A140 of each fraction 1-3 obtained by B40 and CFC measurement is calculated | required as follows.
Fraction 1 fractionated by the difference in crystal distribution is converted into a molecular weight distribution curve by a curve obtained by measuring the molecular weight distribution with a GPC column constituting a part of the CFC analyzer, and FT-IR connected to the back of the GPC column. A corresponding distribution curve of the ethylene content is determined. The ethylene content corresponding to the peak position of the differential molecular weight distribution curve is B40.
Moreover, the sum total of the products of the weight ratio for each data point and the ethylene content for each data point, which are captured as data points during measurement, is the average ethylene content A40.
The significance of setting the three types of fractionation temperatures is as follows.
In the CFC analysis of the present invention, 40 ° C. means a polymer having no crystallinity (for example, E
It has a significance that it is a temperature condition necessary and sufficient for fractionating most of P, or only a propylene polymer component (PP) having an extremely low molecular weight and an atactic component).
Further, 100 ° C. means a component that is insoluble at 40 ° C. but becomes soluble at 100 ° C. (for example, E
In P, the temperature is necessary and sufficient to elute only the component having crystallinity due to the chain of ethylene and / or propylene and PP having low crystallinity. Furthermore, 140 ° C
Eluting only those components that are insoluble at 100 ° C. but soluble at 140 ° C. (eg, components with particularly high crystallinity in PP and components with extremely high molecular weight and ethylene crystallinity in EP), and The temperature is necessary and sufficient to recover the entire amount of the propylene-based block copolymer used for the analysis. Note that the EP component contained in W140 is extremely small and can be substantially ignored.

Ethylene content (% by weight) in EP = (W40 × A40 + W100 × A100 + W140
× A140) / [EP] (III)

However, [EP] is the EP content (% by weight) determined previously.
Of the EP, the ethylene content (E) (% by weight) of the portion having no crystallinity is approximated by the value of B40 since the elution of the rubber portion is almost completed at 40 ° C. or less.
However, in the analysis method based on the combination of the above-described cross fractionation method and FT-IR, (
In the case where the ethylene content of Y-2) is less than 15 wt%, the crystallinity from (Y-1) is not greatly different, and the separation by temperature cannot be performed sufficiently, accurate analysis becomes difficult. In such a case, the component (Y-1) is withdrawn during the successive polymerization, and its molecular weight (when comonomer is copolymerized, the comonomer content is also measured),
By calculating the material balance, determine the quantity ratio of the (Y-1) and (Y-2) components,
Furthermore, it is preferable to determine the comonomer content of the component (Y-2) by measuring the comonomer content of the entire component (Y) at the end of sequential polymerization and using the following simple addition rule of weight. . When ethylene is used as a comonomer, the ethylene content of (Y-2) is determined by the following formula.

(Y-2) component ethylene content = [(Y) total ethylene content-{(Y-1) component ethylene content x (Y-1) component weight fraction / 100}] / {(Y-2 ) Component weight fraction / 10
0}

Regarding other methods for obtaining the amount ratio of the component (Y-1) and the component (Y-2), when producing products having different average molecular weights of the component (Y-1) and the component (Y-2) (Y) After the completion of sequential polymerization, GPC measurement of the whole is performed, the obtained multimodal molecular weight distribution curve is peak-separated using commercially available data analysis software, and the weight ratio is calculated. It is also possible.

Even when the α-olefin of the propylene-α-olefin block copolymer is other than ethylene, the cross fractionation method and the FT
Since the analysis method by -IR combination cannot be applied, in this case as well, the component (Y-1) is withdrawn during the sequential polymerization and its molecular weight (when comonomer is copolymerized, the comonomer content is also known). FT-IR method or NMR method)
Furthermore, by calculating the material balance, the amount ratio of the components (Y-1) and (Y-2) is determined, and by measuring the comonomer content of the entire component (Y) at the end of sequential polymerization,
It is preferable to determine the comonomer content of the component (Y-2) by using a simple addition rule.

Additional components In order to further improve the mechanical properties such as rigidity and impact resistance of the polypropylene resin composition, the polypropylene resin composition of the present invention is appropriately composed of an ethylene-α-olefin elastomer and an inorganic or organic filler. Can be added.

That is, in another preferred embodiment of the present invention, 1 to 50 parts by weight of ethylene-α-olefin elastomer (Z) is added to 100 parts by weight of the total of polypropylene resin (X) and polypropylene resin (Y). Furthermore, it is a polypropylene resin composition to be contained.

As a range which adds ethylene-alpha-olefin elastomer (Z), (X) and (
From the viewpoint of the balance between rigidity and impact resistance, 1 to 50 parts by weight of the ethylene-α-olefin elastomer is preferable based on 100 parts by weight of the entire polypropylene resin composition comprising Y). As a preferred range, the ethylene-α-olefin elastomer is 3-45 parts by weight, more preferably 5-40 parts by weight.

Here, the ethylene-α-olefin elastomer is, for example, an ethylene / propylene copolymer elastomer (EPR), an ethylene / butene copolymer elastomer (EBR),
Ethylene / α-olefin copolymer elastomers such as ethylene / hexene copolymer elastomer (EHR) and ethylene / octene copolymer elastomer (EOR);
Mention may be made of ethylene / α-olefin / diene terpolymer elastomers such as propylene / ethylidene norbornene copolymer, ethylene / propylene / butadiene copolymer, and ethylene / propylene / isoprene copolymer.
Here, the preferable density range of the ethylene-α-olefin elastomer is 0.85.
˜0.91 g / cm ^3, more preferably 0.86 to 0.90 g / cm ³ , and the MFR range is 0.00.
It is 05 to 100 g / 10 minutes, more preferably 1.0 to 30 g / 10 minutes. Where MF
R is a value measured according to JIS K7210: 1999, Method A, Condition M (230 ° C., 2.16 kg load).

Moreover, one preferable another aspect of this invention is the filler (M) 1 which satisfies the following conditions (Mi) with respect to a total of 100 weight part of polypropylene resin (X) and polypropylene resin (Y). The polypropylene resin composition according to any one of claims 1 to 8, further comprising -50 parts by weight.
Condition (Mi)
The filler (M) is at least 1 selected from the group consisting of inorganic fillers and organic fillers.
It is a seed filler.

As a range to which the filler (M) is added, 100 parts by weight of the entire polypropylene resin composition composed of (X) and (Y), and 1 to 50 parts by weight of filler (M) are added. It is preferable from the viewpoint of balance of impact resistance. A preferred range is filler (M
) Is 3 to 45 parts by weight, more preferably 5 to 40 parts by weight.

2-6) Conditions (Mi)
The filler (M) is at least 1 selected from the group consisting of inorganic fillers and organic fillers.
It is a seed filler.
Inorganic fillers include silica, diatomaceous earth, barium ferrite, beryllium oxide,
Oxides such as pumice and pumice balun, hydroxides such as aluminum hydroxide, magnesium hydroxide and basic magnesium carbonate, carbonates such as calcium carbonate, magnesium carbonate, dolomite and dawsonite, calcium sulfate, barium sulfate, ammonium sulfate, sulfurous acid Sulfate or sulfite such as calcium, talc, clay, mica, glass fiber, glass balloon, glass bead, silicate such as calcium silicate, wollastonite, montmorillonite, bentonite, molybdenum sulfide, boron fiber, zinc borate , Barium metaborate, calcium borate, sodium borate, basic magnesium sulfate fiber, potassium titanate fiber, aluminum borate fiber, calcium silicate fiber, calcium carbonate fiber and the like.
On the other hand, as the organic filler, for example, shell fiber such as fir shell, wood powder, cotton, jute,
Examples thereof include paper strips, cellophane pieces, aromatic polyamide fibers, cellulose fibers, nylon fibers, polyester fibers, various organic fibers, and thermosetting resin powders.
Among these, various organic fibers (including resin pellets and master resin pellets) such as glass fiber, talc and polyester fiber are preferable from the viewpoint of a large improvement effect such as strength, dimensional stability and economic efficiency.
Among these, particularly preferable fillers include inorganic fillers, and talc is particularly preferably used from the viewpoint of improving rigidity.

Additives and the like Additional additional components can be added to the polypropylene resin composition of the present invention. Specifically, colorants such as pigments, light stabilizers such as hindered amines, UV absorbers such as benzotriazoles, nucleating agents such as sorbitols, antioxidants such as phenols and phosphoruss, nonionics Antistatic agents such as inorganic compounds, antibacterial and antifungal agents such as thiazoles, flame retardants such as halogen compounds, plasticizers, dispersants such as organic metal salts, lubricants such as fatty acid amides, Examples thereof include metal deactivators such as nitrogen compounds, nonionic surfactants, polyolefin resins such as polypropylene resins other than those described above, and thermoplastic resins such as polyamide resins and polyester resins.
These optional additional components may be used in combination of two or more thereof, may be added to the composition, may be added to each component constituting the composition, or two types in each component. It can also be used in combination.

Although not intending to be bound by theory, the inventors consider that the polypropylene resin composition of the present invention induces crystal orientation and improves rigidity due to flow during molding. Yes. As described above, the phenomenon that the rigidity is improved by the crystal orientation has been reported.
The polypropylene resin composition of the present invention is characterized in that the crystal orientation in flow is expressed mainly by a polypropylene resin having a branched structure. As described in the background art section, the crystal orientation by flow is closely related to the molecular weight, that is, the relaxation time of the polymer component in the resin. However, a polymer having a branched structure has a dramatically different relaxation time than a polymer having no molecular weight, and has a long relaxation time. For example, “Rheology for chemists” written by Shigeharu Onoki Chemistry Doujin, 1982, Chapter 8 ”and is known to those skilled in the art. That is, in the present invention, a long relaxation time due to the branched polypropylene is used, and the crystal orientation is formed in the composition by the flow during molding by the effect more than a normal linear molecule, and as a result, the rigidity is improved. I think the mechanism of making it important is important.
Therefore, as a preferable molding method of the polypropylene resin composition of the present invention, a molding method that has a certain flow history during molding, such as extrusion molding represented by injection molding or film / sheet molding, is preferably used. Among them, in particular, the injection molding is generally a molding method in which a polypropylene resin heated up to around 200 ° C. is poured into a mold for a short time of several seconds to several tens of seconds, and then cooled and solidified. It can be said that this is a particularly preferable molding method from the viewpoint.

Another aspect of the present invention is a molded article that satisfies the following condition (1) using the polypropylene resin composition of the present invention as a material.
Condition (1)
The molded body is either an injection molded body or an extruded molded body.

The molded product obtained by molding the polypropylene resin composition of the present invention is a sheet, film, or life industry materials such as food containers formed by secondary processing of these, automobile members, housings for home appliances, etc. It can be suitably used in all fields where polypropylene resins have been used in the past, such as industrial materials, but it is particularly suitable as a member for automobiles because of its excellent balance of rigidity and impact resistance. I can do it.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
In Examples and Comparative Examples, various physical properties of polypropylene resins and polypropylene resin compositions were measured and evaluated according to the following evaluation methods.

(1) Melt flow rate (MFR):
Measured in accordance with JIS K7210: 1999, Method A, Condition M (230 ° C., 2.16 kg load). The unit is g / 10 minutes.
(2) Melt tension (MT):
It measured on the following conditions using the Toyo Seiki Seisakusho Capillograph.
・ Capillary: Diameter 2.0mm, length 40mm
・ Cylinder diameter: 9.55mm
・ Cylinder extrusion speed: 20mm / min
・ Pickup speed: 4.0m / min
・ Temperature: 230 ℃
When the MT is extremely high, the resin may break at a take-up speed of 4.0 m / min. In such a case, the take-up speed is lowered and the tension at the highest speed at which the take-up can be taken is MT. And The unit is gram.
(3) Molecular weight distributions Mw / Mn and Mz / Mn:
It was determined by GPC measurement according to the method described above.
(4) mm fraction:
As described above, GSX-400 and FT-NMR manufactured by JEOL Ltd. were used.
It measured by the method as described in paragraph [0053]-[0065] of 9-275207 gazette.
The unit is%.
(5) Branch index g ′
As described above, it was determined by GPC equipped with a differential refractometer (RI), a viscosity detector (Viscometer), and a light scattering detector (MALLS) as detectors.
(6) Proportion of (Y-1) and (Y-2) in propylene-ethylene block copolymer, (Y
-2) Ethylene content:
The cross-fractionation method described in the specification and the FT-IR method were combined.
(7) 25 ° C. paraxylene soluble component amount (CXS)
It was determined by the method described in the specification.

The mechanical physical property test specimen is a molding machine (EC20 type injection molding machine manufactured by TOSHIBA MACHINERY CO., LTD.), Using a plate test specimen mold for physical property evaluation (10 × 80 × 4t (mm), 2 pieces). Molding conditions (molding temperature 200 ° C,
Mold temperature 40 ° C, injection pressure 50 MPa, injection time 8 seconds, cooling time 10 seconds, mold opening distance 250
mm).
(8) Flexural modulus, flexural strength:
The flexural modulus was measured according to JIS K7171. The test temperature was 23 ° C.
As the test piece, the physical property evaluation test piece was used.
(9) Impact resistance:
Charpy impact strength (notched) was measured according to JIS K7111. The test temperature was 23 ° C. and −30 ° C. As the test piece, the physical property evaluation test piece was used.
(10) Deflection temperature under load (HDT):
Using a test piece conforming to JIS K7152-1, measurement was performed at a load of 0.46 MPa according to JIS K7191-1.
(11) Rockwell hardness Rockwell hardness was measured according to JIS K-7202-1982.
(12) Gloss After using each sample as a test piece under the following conditions, the gloss was measured using the following gloss meter. The unit is (%).
Test piece = flat plate shape (60 × 80 × 2 t (mm)).
-Molding machine = EC20 type injection molding machine manufactured by Toshiba Machine.
Molding conditions = molding temperature 220 ° C., mold temperature 40 ° C., injection pressure 50 MPa, injection time 5 seconds,
Cooling time 20 seconds.
Gloss meter: VG-2000 model manufactured by Nippon Denshoku Industries Co., Ltd. Measured under an incident angle of 60 ° (n number = 5).

Polypropylene resin (X) such as resin used
As the polypropylene resin (X), one produced according to the method described in Examples of JP2013-199643A was used. Let these be (X1) and (X2). As a result of analysis,
The values shown in Table 1 were obtained.
As (X3), linear homopolypropylene polymerized using a known Ziegler-Natta catalyst (Novatech polypropylene manufactured by Nippon Polypro Co., Ltd.) was used. The analytical values are listed in Table 1.

Polypropylene resin (Y)
As the polypropylene resin (Y), linear homopolypropylene (Y1) polymerized using a known Ziegler-Natta catalyst and propylene-ethylene block copolymer (Y2) were used (Novatech Polypropylene, manufactured by Nippon Polypro Co., Ltd.). ). As a result of analysis, the values shown in Table 2 were obtained.

Ethylene-α-olefin elastomer (Z)
A4050S manufactured by Mitsui Chemicals, Inc. was used as the ethylene-α-olefin elastomer. The density is 0.86 and the MFR is 6 g / 10 min at 230 ° C.

Filler (M)
As the inorganic filler, MW5000SMA manufactured by Nippon Talc was used.

[Reference Examples 1 to 6]
According to the weight fraction shown in Table 3, each material was dry blended and then granulated with a twin-screw kneader (Technobel, KZW-15-MG type) to produce resin composition pellets. The kneading conditions were a temperature of 200 ° C., a screw rotation speed of 400 rpm, and a discharge amount of 3 kg / hr. Using the pellets, injection molding was performed by the method described above to produce physical property test pieces, and the physical property evaluation results are shown in Table 3.

[Examples 1 to 13]
According to the weight fraction shown in Table 4, each material was dry blended and then granulated with a twin-screw kneader (manufactured by Technobel, KZW-15-MG type) to produce resin composition pellets. The kneading conditions were a temperature of 200 ° C., a screw rotation speed of 400 rpm, and a discharge amount of 3 kg / hr. Using the pellets, injection molding was performed by the method described above to produce physical property test pieces, and the physical property evaluation results are shown in Table 4. Moreover, the reference example used as a reference | standard was shown in the table | surface based on the reference examples 1-6 of Table 3 which does not contain polypropylene resin (X), and the elastic modulus increase rate, the bending strength increase rate, and the HDT increase rate were calculated.

弾性率上昇率＝１００×（実施例の曲げ弾性率／参考例の曲げ弾性率）−１００
強度上昇率＝１００×（実施例の曲げ強度／参考例の曲げ強度）−１００
ＨＤＴ上昇率＝１００×（実施例の曲げ強度／参考例のＨＤＴ）−１００

Elastic modulus increase rate = 100 × (flexural modulus of the example / flexural modulus of the reference example) −100
Strength increase rate = 100 × (bending strength of example / bending strength of reference example) −100
HDT increase rate = 100 × (bending strength of example / HDT of reference example) −100

[Comparative Examples 1 to 12]
According to the weight fraction shown in Table 5, each material was dry blended and then granulated with a twin-screw kneader to produce resin composition pellets. Using the pellets, injection molding was performed by the method described above to produce physical property test pieces, and the physical property evaluation results are shown in Table 4. Polypropylene resin (X)
Based on Reference Examples 1 to 6 in Table 3 that do not include the above, reference reference examples are shown in the table, and the elastic modulus increase rate, bending strength increase rate, and HDT increase rate were calculated.

弾性率上昇率＝１００×（比較例の曲げ弾性率／参考例の曲げ弾性率）−１００
強度上昇率＝１００×（比較例の曲げ強度／参考例の曲げ強度）−１００
ＨＤＴ上昇率＝１００×（比較例の曲げ強度／参考例のＨＤＴ）−１００

Elastic modulus increase rate = 100 × (bending elastic modulus of comparative example / bending elastic modulus of reference example) −100
Strength increase rate = 100 × (bending strength of comparative example / bending strength of reference example) −100
HDT increase rate = 100 × (bending strength of comparative example / HDT of reference example) −100

As mentioned above, when an Example and a comparative example are compared and considered, in Example 1 and Comparative Example 1, when a polypropylene resin having a branch is used as the polypropylene resin (X), polypropylene is used when there is no branch. Compared to the case, the bending elastic modulus, bending strength, and HDT increase rate are high, and there is a clear advantage in Rockwell hardness, etc. it is obvious. Similarly, in Example 2 and Comparative Example 2, the blending amount of the polypropylene resin (X) is increased, but the superiority of the branched polypropylene resin can be confirmed. In the comparison between Examples 3 and 4 and Comparative Examples 3 and 4, respectively, even when an elastomer is added, when a polypropylene-based resin having a branch is used as the polypropylene-based resin (X), when there is no branch, polypropylene is used. Compared to the above, the flexural modulus, flexural strength, and HDT increase rate are high. In the comparison between Examples 5 and 6 and Comparative Examples 5 and 6, respectively, even when talc as a filler is added, when a polypropylene resin having a branch is used as the polypropylene resin (X), polypropylene is used when there is no branch. Compared to the case of using, the flexural modulus, bending strength, and HDT increase rate are high. About Examples 7-12 and Comparative Examples 7-12, polypropylene (Y) is changed, and the polypropylene resin (as seen in the comparison between Examples 1-6 and Comparative Examples 1-6, respectively) When a polypropylene-based resin having a branch is used as X), the bending elastic modulus, the bending strength, and the increase rate of HDT are higher than when polypropylene is used when there is no branch. In Example 13, a polypropylene resin (X) having a high MFR is used. However, the polypropylene resin (X) also has a branch, and the bending elastic modulus, the bending strength, and the increase rate of HDT are high. .

The crystal orientation structure of the injection-molded piece was examined by X-ray small angle scattering. The experiment was conducted at the beam line BL03XU of the high-intensity synchrotron radiation facility SPring-8. The assignment number is 2016A72
18 and 2016B7268.
In the 10 × 80 × 4 (mm) test piece created in the above molding section, since the resin flows in the longitudinal direction, this is the MD direction, the 10 mm length direction orthogonal to the TD direction, and the thickness (4 mm) direction Is the ND direction. MD-N using the Zege microtome from approximately the center in the longitudinal direction
D section was cut out. The thickness of this section is about 300 μm.
X-rays with a wavelength of 0.1 nm and a beam size of 29 × 29 μm were converted into the above section MD-ND.
The incident light was perpendicular to the surface, and a small-angle scattered image was recorded with a two-dimensional detector at a camera length of about 1.7 m.
X-rays were scanned from the end surface of the sample (that is, the surface of the injection-molded piece) to the opposite end surface.
The scanning interval was 25 μm. The outline of this experiment is shown in FIG.

Small angle scattering is a scattering vector and collects data up to at least 1 nm ⁻¹ . From the obtained raw data, the background intensity was subtracted in consideration of the transmittance and used for the subsequent analysis. In this experimental system, the minimum value of the measured scattering vector is 0.06 nm because of the beam stopper.
^-1 . In the X-ray small angle scattering region of the polypropylene resin, a peak derived from the long period of the crystal lamella is observed, but when the crystal has anisotropy, the anisotropy also occurs in the scattering derived from the long period. Therefore, on the two-dimensional detector, ± 45 degrees centered in the direction parallel to the sample MD, and N
One-dimensional data of the scattering intensity and the scattering vector is calculated by taking each sector average of ± 45 degrees centering on the D direction. From the one-dimensional data created in this way, the scattering vector 0
. The scattering invariant (Q; (intensity) × (integral value of the scattering vector squared) in the above range) is obtained in the range of ¹ to 1.0 nm ^{−1, and} the ratio of Q in the MD direction to Q in the ND direction (Qratio) Asked. That is, when the crystal orientation develops in the injection flow direction MD, Qratio increases.
FIG. 3 is a plot of the test pieces obtained in Example 1, Comparative Example 1, and Reference Example 1, which are plotted. The horizontal axis in FIG. 3 is displayed by normalizing the center in the sample ND direction as 0, the sample thickness as D, and the distance from the ND center as x, and 1 is the sample surface.

As shown in FIG. 3, the Qratio of Example 1 that satisfies the provisions of the present invention clearly has larger crystal anisotropy than that of Reference Example 1, and the difference is particularly remarkable near the sample surface. Moreover, in Example 1, it is clear that the region where the crystal anisotropy reaches is much wider than that of the comparative example, and exists widely up to the vicinity of the central portion of the sample thickness. Comparative Example 1 uses a low MFR, that is, a high molecular weight linear (branch index is 1) polypropylene,
Although it is recognized that the anisotropy is large with respect to the reference example 1, the effect is extremely small as compared with the example 1, and the effect of improving the rigidity is limited.
The high rigidity improvement effect of the composition of the present invention is confirmed by this experiment that the reason is due to the crystal orientation. In particular, the comparison between Example 1 and Comparative Example 1 shows that the crystal orientation It is clear that the effect of the property is particularly prominent in the case of a polymer chain having a branch compared to the case of a linear molecular chain.

Claims (11)

5 to 50% by weight of a polypropylene-based resin (X) having a branched structure and the following condition (Yi)
Polypropylene resin composition containing 95 to 50% by weight of polypropylene resin (Y) satisfying (Y-ii) (provided that the total of polypropylene resin (X) and polypropylene resin (Y) is 100) %).
Condition (Yi)
Polypropylene resin (Y) is propylene homopolymer (YA), propylene-α-
It is at least one polypropylene resin selected from the group consisting of an olefin random copolymer (Y-B) and a propylene-α-olefin block copolymer (Y-C).
Condition (Y-ii)
Melt flow rate of polypropylene resin (Y) (MFR, 230 ° C., 2.16 kg)
Load) is in the range of 50 to 500 g / 10 min. Polypropylene resin (Y) is a propylene-α-olefin block copolymer (Y-C
The polypropylene resin composition according to claim 1. Propylene-α-olefin block copolymer (Y-C) has the following conditions (YC-i)
The polypropylene resin composition according to claim 2 satisfying
Condition (YC-i)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and the melt flow rate of the propylene (co) polymer (MFR, 230 ° C., 2.16 kg load) is 80 to 500
g / 10 minutes. Propylene-α-olefin block copolymer (Y-C) has the following conditions (YC-ii)
The polypropylene resin composition according to claim 2 or 3, wherein
Condition (YC-ii)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and propylene-α
-The content of the α-olefin in the olefin random copolymer is 30 to 80% by weight (provided that the content of the α-olefin is 100% by weight of the monomer of the entire propylene-α-olefin random copolymer. % Is the proportion of α-olefin). Propylene-α-olefin block copolymer (Y-C) has the following conditions (YC-ii)
The polypropylene resin composition according to any one of claims 2 to 4, which satisfies i).
Condition (YC-iii)
The propylene-α-olefin block copolymer (Y-C) is a sequential polymer of a propylene (co) polymer and a propylene-α-olefin random copolymer, and propylene-α
-Ratio of propylene-α-olefin random copolymer to olefin block copolymer (Y-C) is 5 to 50 wt% (provided that the total propylene-α-olefin block copolymer is 100 wt%) ). The polypropylene resin composition according to any one of claims 1 to 5, wherein the polypropylene resin (X) having a branched structure satisfies the following condition (X-i).
Condition (X-i)
The branching index g ^′ when the absolute molecular weight Mabs of the polypropylene resin (X) is 1 million is 0.
. 30 or more and less than 1.00. The polypropylene resin (X) having a branched structure is subjected to the following conditions (X-ii) to (Xv)
The polypropylene resin composition according to claim 6, which satisfies i).
Condition (X-ii)
Melt flow rate of polypropylene resin (X) (MFR, 230 ° C., 2.16 kg)
Load) is in the range of 0.1 to 30 g / 10 min.
Condition (X-iii)
The 25 degreeC paraxylene soluble component amount (CXS) of polypropylene resin (X) is less than 5.0 weight% with respect to polypropylene resin (X) whole quantity.
Condition (X-iv)
The mm fraction of propylene unit 3 chain | strand by ¹³ C-NMR of polypropylene resin (X) is 95% or more.
Condition (X-v)
10. Molecular weight distribution Mw / Mn by polypropylene resin (X) GPC is 3.0 or more.
0 or less, and Mz / Mw is 2.5 or more and 10.0 or less.
Condition (X-vi)
The melt tension (MT) (unit: g) of the polypropylene resin (X) is log (MT) ≧ −
Satisfy either 0.9 × log (MFR) +0.7 or MT ≧ 15. 8. The composition according to claim 1, further comprising 1 to 50 parts by weight of an ethylene-α-olefin elastomer (Z) with respect to 100 parts by weight of the total of the polypropylene resin (X) and the polypropylene resin (Y). The polypropylene resin composition described in 1. The filler further containing 1 to 50 parts by weight of a filler (M) satisfying the following condition (Mi) with respect to a total of 100 parts by weight of the polypropylene resin (X) and the polypropylene resin (Y). The polypropylene resin composition according to any one of the above.
Condition (Mi)
The filler (M) is at least 1 selected from the group consisting of inorganic fillers and organic fillers.
It is a seed filler. The molded object which uses the polypropylene resin composition of any one of Claims 1-9 as a material, and satisfies the following conditions (1).
Condition (1)
The molded body is either an injection molded body or an extruded molded body.   The member for motor vehicles using the molded object of Claim 10.

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