JP2015071701A - Polyolefin resin composition and compact thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyolefin resin composition and a compact thereof having good whole light transmittance, haze degree, and diffusion degree which were not achieved in a conventional art, especially, a light diffusivity injection sheet and a light diffusivity extrusion sheet.SOLUTION: There are provided the polyolefin resin composition and the compact thereof. The polyolefin resin composition comprises a polypropylene resin (A) which is a propylene-ethylene random copolymer which is polymerized using a metallocene catalyst and has specific physical properties and resin (B) having specific physical properties in a specific amount range. Especially, the light diffusivity injection sheet and the light diffusivity extrusion sheet are provided.

Description

  The present invention relates to a polyolefin resin composition having good total light transmittance, brightness, and diffusivity, and a molded article formed by molding the polyolefin resin composition, in particular, a light diffusing injection sheet and a light diffusing extruded sheet.

  In illumination in a room and in an interior illumination type illumination panel, in order to illuminate light over a wide range while effectively utilizing the light quantity of a light source, it is required to transmit light and diffuse efficiently. For this reason, resinous sheets and covers used for illumination covers and the like are also required to have light transmittance and diffusibility.

In recent years, there has been an increasing demand for light transmission / diffusion sheets used for lighting covers and the like using propylene resins instead of acrylic resins and polycarbonate resins for reasons such as economy, recyclability, and weight reduction.
In order to meet such demands, a light-weight polypropylene-based resin composition and a light diffusion plate have been proposed by adding a light diffusing agent (Patent Document 1). However, although this method can provide a light diffusing plate having a balance between light transmittance and mechanical properties, the light diffusibility is not sufficiently considered and is still insufficient.
In addition, light diffusion films having a layer structure in which a propylene-based resin composition is combined with a polyolefin composition and an elastomer have been proposed (Patent Documents 2 and 3). Here, the diffusibility is controlled by using the nanostructure control type elastomer as the diffusion layer, but the effect is still insufficient.

JP 2008-083660 A JP 2010-152230 A JP 2010-152229 A

  The problem to be solved by the present invention is a polyolefin-based material having good total light transmittance, brightness, and diffusivity, which has been difficult to achieve with the conventional technology in view of the current state of the prior art. It is providing the resin composition and the molded object formed by shape | molding it, especially a light diffusable injection sheet and a light diffusable extrusion sheet.

  As a result of intensive research to solve the above problems, the present inventors have obtained a moldability by combining a propylene-based resin polymerized with a metallocene catalyst and an incompatible resin having specific optical characteristics. The inventors have found that a propylene-based resin composition that is good, excellent in total light transmittance, and excellent in diffusibility can be obtained, and has reached the present invention. That is, it is incompatible with the propylene-based resin component having the specific total light transmittance and the degree of polymerization polymerized by the metallocene catalyst and the propylene-based resin component having the specific total light transmittance and the degree of brightness disclosed in the present invention. It has been found that a light diffusing sheet having high light transmittance and high diffusibility can be obtained by combining resins, and the present invention has been completed.

That is, according to the first invention of the present invention, the propylene-based resin (A) satisfying the following requirements (A-1) to (A-4) (hereinafter sometimes abbreviated as component (A)) 100: Part by weight and resin (B) satisfying the following requirements (B-1) to (B-2) with respect to 100 parts by weight of the propylene-based resin (A) (hereinafter sometimes abbreviated as component (B)) A polyolefin resin composition comprising 0.4 to 3.5 parts by weight, wherein the polyolefin resin composition satisfies the following requirements (C-1) to (C-2): Is done.
Requirement (A-1)
The propylene-based resin (A) is a propylene-ethylene random copolymer having an ethylene content of 0.1 to 7% by weight, polymerized using a metallocene catalyst.
Requirement (A-2)
The melt flow rate (230 ° C., 2.16 kg load) of the propylene-based resin (A) is 1 to 100 g / 10 minutes.
Requirement (A-3)
The total light transmittance of the propylene-based resin (A) is 80 to 90% at a test piece thickness of 2 mm.
Requirement (A-4)
The degree of propylene resin (A) is 30 to 95% at a test piece thickness of 2 mm.
Requirement (B-1)
The total light transmittance of the resin (B) is 85% or more at a test piece thickness of 2 mm.
Requirement (B-2)
The degree of the resin (B) is 2% or less at a test piece thickness of 2 mm.
Requirement (C-1)
The propylene-based resin composition (A) and the resin (B) are incompatible.
Requirement (C-2)
The difference in refractive index between the propylene-based resin composition (A) and the resin (B) is 0.04 or more.

  Moreover, according to 2nd invention, the molded object formed by shape | molding the polyolefin-type resin composition in 1st invention is provided.

  Moreover, according to 3rd invention, the molded object in 2nd invention which is a at least 1 sort (s) chosen from the group which a molded object consists of a light diffusable injection sheet and a light diffusable extrusion sheet is provided.

  The polyolefin-based resin composition of the present invention is lightweight, recyclable, and has an excellent balance of permeability and diffusivity, so that when used as a light diffusing sheet for a cover for protecting lighting, etc., the direct light source is dazzled. It is a polypropylene-based resin composition useful for light diffusing sheet material because it has a bright effect even though it is not felt. Therefore, when the resin composition is used as a light diffusive sheet, it is possible to obtain a light diffusive sheet that is excellent in both permeability and diffusibility.

  In addition, since polyolefin resins are generally known to have a low environmental impact, the polyolefin resin composition and light diffusive sheet of the present invention are compared with conventional light diffusive sheets made of acrylic resin and polycarbonate resin compositions. Therefore, it can be said that there is less concern about environmental impact.

The present invention relates to a polyolefin resin composition containing a specific amount of a specific resin (B) in a specific propylene resin (A) and a molded product thereof.
Hereinafter, each component used in the present invention, the obtained polyolefin resin composition, and a molded product thereof will be described in detail.

1. Propylene resin (A)
The propylene-based resin (A) used in the present invention satisfies the following requirements (A-1) to (A-4).
Requirement (A-1): The propylene-based resin (A) is a propylene-ethylene random copolymer having an ethylene content of 0.1 to 7% by weight, polymerized using a metallocene catalyst.
Requirement (A-2): The melt flow rate (230 ° C., 2.16 kg load) of the propylene-based resin (A) is 1 to 100 g / 10 minutes.
Requirement (A-3): The total light transmittance of the propylene-based resin (A) is 80 to 90% at a test piece thickness of 2 mm.
Requirement (A-4): The degree of propylene resin (A) is 30 to 95% at a test piece thickness of 2 mm.

1.1. Propylene resin (A)
The propylene-based resin (A) polymerized with a metallocene catalyst used in the present invention will be described in detail below.

(1) Each requirement (A-1) About ethylene content etc. The propylene-type resin (A) used for this invention is superposed | polymerized using the metallocene catalyst. That is, since it is polymerized by a metallocene catalyst, the molecular weight distribution and the composition distribution are narrow, and the light transmittance is high.
In the present invention, a propylene-ethylene random copolymer polymerized using a metallocene catalyst is most effective in obtaining the effects of the present invention, and is used in the present invention. Moreover, 2 or more types can also be used together for propylene-type resin (A).

  The ethylene content of the propylene-based resin (A) used in the present invention is 0.1 to 7% by weight, preferably 0.5 to 4% by weight, more preferably 0.7 to 3.5% by weight, still more preferably. Is 0.8-3, 4% by weight. By setting the ethylene content in such a range, good light transmittance and rigidity that can be practically used can be obtained. That is, if the ethylene content of the propylene-based resin (A) is less than 0.1% by weight, the light transmittance may be lowered, and if it is 7% by weight or more, the rigidity of the molded product is significantly lowered, which is suitable for practical use. There may not be. The ethylene content can be adjusted by the polymerization conditions (ethylene gas addition amount, etc.) described later. Moreover, the measuring method of ethylene content is mentioned later.

(A-2) Melt flow rate (MFR) The melt flow rate (MFR: 230 ° C., 2.16 kg load) of the propylene-based resin (A) used in the present invention is 1 to 100 g / 10 min, preferably Is 3 to 80 g / 10 min, more preferably 4 to 50 g / 10 min. By setting the melt flow rate of the propylene-based resin (A) used in the present invention within the range specified in the present invention, good moldability is possible in the polyolefin-based resin composition of the present invention. That is, if the MFR is less than 1 g / 10 minutes, moldability may be deteriorated in the resin composition of the present invention and the molded body thereof. On the other hand, if it exceeds 100 g / 10 minutes, burrs and deformation may occur. MFR can be controlled by adjusting polymerization conditions (polymerization temperature, hydrogenation amount, etc.) described later, or using a molecular weight depressant.
In the present specification, MFR is a value measured at a test temperature = 230 ° C. and a load = 2.16 kg in accordance with A method and condition M of JIS K7210: 1999.

(A-3) Total light transmittance The total light transmittance at a test piece thickness of 2 mm of the propylene-based resin (A) used in the present invention is 80 to 90%, preferably 82 to 89%, more preferably. Is 83 to 88%. By making the total light transmittance of the propylene-based resin (A) used in the present invention within the prescribed range of the present invention, both good light transmittance and high diffusibility can be achieved in the polyolefin-based resin composition of the present invention. Can do. That is, if the total light transmittance is less than 80%, the light transmittance in the polyolefin resin composition of the present invention is lowered, so that a sufficient effect cannot be obtained, and if it exceeds 90%, the diffusibility may be lowered. is there.
The total light transmittance can be controlled by changing the amount of ethylene added and adjusting the ethylene content under the polymerization conditions described later.
In this specification, the total light transmittance is a value measured in accordance with JIS K7105 using a sheet piece having a thickness of 2 mm.

(A-4) Concentration Degree of propylene resin (A) used in the present invention at a test piece thickness of 2 mm is 30 to 95%, preferably 50 to 90%, more preferably 60 to 89. %. By setting the purity of the propylene-based resin (A) used in the present invention within the range specified in the present invention, it is possible to achieve both good light transmittance and high diffusibility in the polyolefin-based resin composition of the present invention. . That is, if the degree of purity is less than 30%, the diffusibility in the resin composition of the present invention is lowered, so that a sufficient effect cannot be obtained, and if it exceeds 95%, the light transmittance may be lowered.
The degree of viscosity can be controlled by changing the amount of ethylene added and adjusting the ethylene content under the polymerization conditions described later.
In addition, in this specification, a degree is the value measured based on JISK7105 using the test piece thickness 2mm sheet piece.

(2) About ethylene content Ethylene content is calculated | required by analyzing the ¹³ C-NMR spectrum which measured the propylene-type resin (A) by the proton complete decoupling method. As a representative example, the method used in the present invention will be described below.
Model: GSX-400 (carbon nuclear resonance frequency 400 MHz) manufactured by JEOL Ltd.
Solvent: ODCB / heavy benzene = 4/1 (volume ratio)
Concentration: 100 mg / mL
Temperature: 130 ° C
Pulse angle: 90 °
Pulse interval: 15 seconds Integration count: 5,000 times or more The attribution of the spectrum may be performed with reference to the following documents, for example.
Macromolecules; 17, 1950 (1984).
The spectral attributions measured under the above conditions are shown in Table 1. In the table, symbols such as Sαα follow the notation in the following literature, P represents methyl carbon, S represents methylene carbon, and T represents methine carbon.
Carman, Macromolecules; 10,536 (1977)

Hereinafter, when “P” is a propylene unit in a copolymer chain and “E” is an ethylene unit, six types of triads of PPP, PPE, EPE, PEP, PEE, and EEE may exist in the chain. As described in Macromolecules, 15 1150 (1982), the concentration of these triads and the peak intensity of the spectrum are linked by the following relational expressions <1> to <6>.
[PPP] = k × I (T _ββ ) <1>
[PPE] = k × I (T _βδ ) <2>
[EPE] = k × I (T _δδ ) <3>
[PEP] = k × I (S _ββ ) <4>
[PEE] = k × I (S _βδ ) <5>
[EEE] = k × [I (S _δδ ) / 2 + I (S _γδ ) / 4} <6>
Here, [] indicates the fraction of triads, for example, [PPP] is the fraction of PPP triads in all triads.
Therefore, [PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 <7>.
Further, k is a constant, I indicates the spectral intensity, and for example, I (T _ββ ) means the intensity of the peak at 28.7 ppm attributed to T _ββ .

By using the relational expressions <1> to <7> above, the fraction of each triad is obtained, and the ethylene content is obtained from the following expression.
Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100 In addition, the propylene random copolymer according to the present invention contains a small amount of propylene heterogeneous bonds (2,1-bond and / or Or 1,3-bonds), thereby producing the following minor peaks:

In order to obtain an accurate ethylene content, it is necessary to include these peaks derived from heterogeneous bonds in the calculation, but it is difficult to completely separate and identify the peaks derived from heterogeneous bonds. Since the amount is small, the ethylene content in the present invention uses the relational expressions <1> to <7>, as in the analysis of the copolymer produced with a Ziegler-Natta catalyst that does not substantially contain a heterogeneous bond. To ask.
Conversion from mol% to wt% of ethylene content is performed using the following formula.
Ethylene content (% by weight) = (28 × X / 100) / {28 × X / 100 + 42 × (1−X / 100)} × 100
Where X is the ethylene content in mol%.

(3) Production method Production of the propylene-based resin (A) used in the present invention essentially requires the use of a metallocene catalyst.

(I) Metallocene catalyst The metallocene catalyst is not particularly limited as long as the propylene-based resin (A) used in the present invention can be produced. In order to satisfy the requirements of the present invention, for example, It is preferable to use a metallocene catalyst comprising components (a) and (b) as shown in FIG.
Component (a): at least one metallocene transition metal compound selected from transition metal compounds represented by the following general formula (1).
Component (b): at least one solid component selected from the following (b-1) to (b-4).
(B-1): A particulate carrier on which an organic aluminum oxy compound is supported.
(B-2): A particulate carrier carrying an ionic compound or Lewis acid capable of reacting with component (a) to convert component (a) into a cation.
(B-3): Solid acid fine particles.
(B-4): Ion exchange layered silicate.
Component (c): an organoaluminum compound.

As the component (a), at least one metallocene transition metal compound selected from transition metal compounds represented by the following general formula (1) can be used.
_{Q (C 5 H 4-a} R1 a) (C 5 H 4-b R2 b) MeXY (1)

Here, Q represents a divalent binding group that bridges two conjugated five-membered ring ligands, and has, for example, a divalent hydrocarbon group, a silylene group, an oligosilylene group, or a hydrocarbon group as a substituent. Examples thereof include a silylene group, an oligosilylene group, and a germylene group having a hydrocarbon group as a substituent. Among these, preferred is a silylene group having a divalent hydrocarbon group and a hydrocarbon group as a substituent.
X and Y each represents a hydrogen atom, a halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a silicon-containing hydrocarbon group. , Chlorine, methyl, isobutyl, phenyl, dimethylamide, diethylamide group and the like. X and Y may be each independently, that is, may be the same or different.

R1 and R2 represent hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. . Specific examples of the hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a phenyl group, a naphthyl group, a butenyl group, and a butadienyl group. In addition, as halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing hydrocarbon group, boron-containing hydrocarbon group, or phosphorus-containing hydrocarbon group, methoxy group, ethoxy group, phenoxy group Typical examples include trimethylsilyl group, diethylamino group, diphenylamino group, pyrazolyl group, indolyl group, dimethylphosphino group, diphenylphosphino group, diphenylboron group, dimethoxyboron group and the like. In these, it is preferable that it is a C1-C20 hydrocarbon group, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, and a butyl group. By the way, adjacent R1 and R2 may combine to form a ring, on which a hydrocarbon group, halogenated hydrocarbon group, silicon-containing hydrocarbon group, nitrogen-containing hydrocarbon group, oxygen-containing hydrocarbon A substituent comprising a group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group.
Me is a metal atom selected from titanium, zirconium and hafnium, preferably zirconium and hafnium.
Note that a and b are the number of substituents.

  Among the components (a) described above, those preferable for the production of the propylene-based resin component (a) used in the present invention are those substituted with a silylene group, a germylene group or an alkylene group having a hydrocarbon substituent. It is a transition metal compound composed of a ligand having a cyclopentadienyl group, a substituted indenyl group, a substituted fluorenyl group, or a substituted azulenyl group, and is particularly preferably crosslinked with a silylene group having a hydrocarbon substituent or a germylene group It is a transition metal compound comprising a ligand having a 2,4-position substituted indenyl group and a 2,4-position substituted azulenyl group.

  Non-limiting specific examples include dimethylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, diphenylsilylene bis (2-methyl-4-phenylindenyl) zirconium dichloride, dimethylsilylene bis (2-methyl). Benzoindenyl) zirconium dichloride, dimethylsilylenebis {2-isopropyl-4- (3,5-diisopropylphenyl) indenyl} zirconium dichloride, dimethylsilylenebis (2-propyl-4-phenanthrylindenyl) zirconium dichloride, dimethyl Silylene bis (2-methyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylene bis {2-methyl-4- (4-chlorophenyl) azurenyl} zirconium dichloride, dimethylsilylene bi (2-Ethyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis (2-isopropyl-4-phenylazurenyl) zirconium dichloride, dimethylsilylenebis {2-ethyl-4- (2-fluorobiphenyl) azurenyl} zirconium Examples thereof include dichloride and dimethylsilylenebis {2-ethyl-4- (4-t-butyl-3-chlorophenyl) azurenyl} zirconium dichloride. A compound in which the silylene group of these specific examples is replaced with a germylene group and zirconium is replaced with hafnium is also exemplified as a suitable compound. In addition, since the catalyst component is not an important element of the present invention, it avoids complicated listing and is limited to a representative example, but it is obvious that the effective range of the present invention is not limited thereby. It is.

As the component (b), at least one solid component selected from the aforementioned components (b-1) to (b-4) is used. Each of these components is a well-known thing, and can be used selecting it suitably from well-known techniques. Specific examples and manufacturing methods thereof are described in detail in JP-A No. 2002-284808, JP-A No. 2002-53609, JP-A No. 2002-69116, JP-A No. 2003-105015, and the like.
Of the component (b), particularly preferred is the ion-exchange layered silicate of component (b-4), and more preferred are chemical treatments such as acid treatment, alkali treatment, salt treatment, and organic matter treatment. Is an ion-exchange layered silicate.

Examples of the organoaluminum compound used as the component (c) as necessary include the following general formula (2)
AlRaP3-a (2)
(Wherein R is a hydrocarbon group having 1 to 20 carbon atoms, P is hydrogen, halogen or alkoxy group, a is a number of 0 <a ≦ 3), trimethylaluminum, triethylaluminum, Trialkylaluminum such as tripropylaluminum and triisobutylaluminum or halogen- or alkoxy-containing alkylaluminum such as diethylaluminum monochloride and diethylaluminum monomethoxide. In addition, aluminoxanes such as methylaluminoxane can also be used. Of these, trialkylaluminum is particularly preferred.

  As a method for forming the catalyst, the component (a), the component (b) and, if necessary, the component (c) are brought into contact with each other to form a catalyst. In addition, the contact method will not be specifically limited if it is a method which can form a catalyst, A well-known method can be used.

Moreover, the usage-amount of component (a), (b), and (c) is arbitrary. For example, the amount of component (a) used relative to component (b) is preferably in the range of 0.1 to 1,000 μmol, particularly preferably 0.5 to 500 μmol, relative to 1 g of component (b). The amount of component (c) used relative to component (b) is preferably such that the amount of transition metal is 0.001 to 100 μmol, particularly preferably 0.005 to 50 μmol, relative to 1 g of component (b).
Furthermore, it is preferable that the catalyst used in the present invention is subjected to a prepolymerization treatment in which a small amount of polymer is brought into contact with an olefin in advance.

(Ii) Polymerization process As a polymerization form of the propylene-based resin composition (A), any polymerization method such as a slurry method, a bulk method, and a gas phase method can be used. Moreover, it is also possible to carry out by combining these polymerization formats. 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.
Any process is not particularly problematic, but in the present invention, when producing a propylene-based resin composition (A) having a relatively low Tm, that is, a relatively low crystallinity, the product to the reactor is used. It is preferable to use a vapor phase method in order to avoid problems such as adhesion. 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.

(Iii) Other polymerization conditions The polymerization temperature can be used without any particular problem as long as it is within a commonly used temperature range. Specifically, a range of 0 ° C. to 200 ° C., more preferably 40 ° C. to 100 ° C. can be used.
The polymerization pressure varies depending on the process to be selected, but the optimum pressure can be used without any problem as long as it is in a pressure range usually used. Specifically, the relative pressure with respect to atmospheric pressure can be greater than 0 MPa and up to 200 MPa, more preferably in the range of 0.1 MPa to 50 MPa. At this time, an inert gas such as nitrogen may coexist.
Moreover, when using hydrogen as a molecular weight regulator, it can be used in 1.0 * 10 ^{< -6} > or more and 1.0 * 10 ^<-2 > or less by molar ratio with respect to propylene. Preferably, it is 1.0 × 10 ⁻⁵ or more and 0.9 × 10 ⁻² or less.

  As the propylene-based resin (A) polymerized using a metallocene catalyst, those having desired physical properties can be selected from various commercially available products. For example, Winpoly series manufactured by Nippon Polypro Co., Ltd. is suitable. Can be used.

2. Resin (B)
The resin (B) used in the present invention satisfies the following requirements (B-1) and (B-2).
Requirement (B-1): The total light transmittance of the resin (B) is 85% or more at a test piece thickness of 2 mm.
Requirement (B-2): The degree of resin (B) is 2% or less at a test piece thickness of 2 mm.

2.1. Resin (B)
The resin (B) used in the present invention is characterized in that it has a high total light transmittance and a very low degree of light transmittance, and is combined with the propylene-based resin composition (A) polymerized with a metallocene catalyst to transmit light. A resin composition excellent in rate and diffusibility and a molded body thereof are realized.
In the present invention, the resin used as the resin (B) includes a transparent resin called organic glass, and examples thereof include a vinyl chloride resin, a polystyrene resin, and a polycarbonate resin. In particular, an aromatic polycarbonate made from polystyrene and bisphenol A and carbonic acid is preferable from the viewpoint of mechanical properties.
Specific examples of the resin (B) include HF-77 made by PS Japan as polystyrene, and Novalex 7022A made by Mitsubishi Chemical Engineering Plastics as polycarbonate.

(1) Each requirement (B-1) About total light transmittance The total light transmittance in 2 mm of test piece thickness of resin (B) used for this invention is 85% or more, Preferably it is 87% or more, and more. Preferably it is 89% or more. Although there is no restriction | limiting in particular about an upper limit, Usually, it is 95% or less. By setting the total light transmittance of the resin (B) used in the present invention within the range specified in the present invention, it is possible to achieve both good light transmittance and high diffusibility in the resin composition of the present invention. That is, if the total light transmittance is less than 85%, the light transmittance in the polyolefin resin composition of the present invention may be lowered. In this specification, the total light transmittance is a value measured in accordance with JIS K7105 using a sheet piece having a thickness of 2 mm.

(B-2) Degree of Degree The degree of decrement of the resin (B) used in the present invention at a test piece thickness of 2 mm is 2% or less, preferably 1.5% or less, more preferably 1% or less. . Although there is no restriction | limiting in particular about a minimum, Usually, it is 0.1% or more. By setting the density of the resin (B) used in the present invention within the range specified in the present invention, it is possible to achieve both good light transmittance and high diffusibility in the polyolefin resin composition of the present invention. That is, when the brightness exceeds 2%, the light transmittance may decrease. In addition, in this specification, the angle is a value measured according to JIS K7105 using a sheet piece having a thickness of 2 mm.

(2) Content The content of the resin (B) in the present invention is 0.4 to 3.5 parts by weight, preferably 0.5 to 3.3 parts by weight with respect to 100 parts by weight of the propylene-based resin (A). More preferably, it is 0.6-3 parts by weight, and still more preferably 0.8-2 parts by weight. Since the content of the resin (B) is within the specified range of the present invention, the polyolefin resin composition of the present invention and the molded article comprising the resin composition have excellent total light transmittance and diffusibility. It is possible to satisfy all of the features. That is, when the content of the resin (B) exceeds 3.5 parts by weight, the total light transmittance tends to decrease, and when it is less than 0.4 parts by weight, the diffusibility may decrease.

3. Other Requirements In addition to the requirements (A-1) to (A-4) and the requirements (B-1) and (B-2), the propylene-based resin (A) and the resin (B) used in the present invention are requirements. It is necessary to satisfy (C-1) and (C-2).
Requirement (C-1): Propylene resin (A) and resin (B) are incompatible.
Requirement (C-2): The difference in refractive index between the propylene-based resin (A) and the resin (B) is 0.04 or more.

(1) Each requirement (C-1): About compatibility The propylene-type resin (A) and resin (B) used for this invention need to be incompatible. If they are compatible, the diffusibility may be greatly reduced. The fact that the polyolefin resin composition of the present invention is incompatible means that the phase separation structure has a sea-island structure consisting of a sea phase of the propylene resin (A) and an island phase of the resin (B). Means.
This form can be observed as follows, for example. The polyolefin resin composition of the present invention is cooled to −120 ° C. and cut using an ultramicrotome (for example, UC6 manufactured by Leica) and a cryosystem equipped with a diamond knife, and the cut mirror surface is ion-etched. Since the etching rate differs depending on the polymer type, irregularities corresponding to the fine structure are formed, and the phase structure can be observed. The sample thus treated can be observed in a dispersed phase structure with a scanning electron microscope (for example, S800 manufactured by Hitachi, Ltd.).

(C-2) Refractive index The difference in refractive index between the propylene-based resin (A) and the resin (B) used in the present invention is 0.04 or more, preferably 0.06 or more, more preferably 0.08. As mentioned above, More preferably, it is 0.09 or more. The upper limit is usually 0.3, preferably 0.2. In the present application, the “difference in refractive index” refers to the absolute value of the difference in refractive index between the propylene-based resin (A) and the resin (B). By setting the difference in refractive index between the propylene resin (A) and the resin (B) in such a range, it is possible to achieve good diffusibility and total light transmittance in the polyolefin resin composition of the present invention. It becomes. That is, if the difference in refractive index is less than 0.04, the diffusibility may be greatly reduced, and if it exceeds 0.3, light scattering due to refraction will occur strongly, and the total light transmittance may be deteriorated.

  In addition, many reports are known about the refractive indexes of various resins. For example, in “plastic materials in molding (1999, published by Sigma Publishing Co., Ltd.)”, the refractive index of the crystal part of polypropylene is 1.52. Since the amorphous part is 1.48, the refractive index of polypropylene is 1.50, polystyrene is 1.59, polymethacrylate is 1.49, the crystal part of polycarbonate is 1.65, and the amorphous part is 1.59. For some reason, the refractive index of polycarbonate is reported to be 1.62.

4). Optional additive component The polyolefin resin composition of the present invention contains various optional additive components such as a modified polyolefin, a molecular weight depressant, a lubricant, and an antioxidant as long as they do not significantly impair the effects of the present invention. can do.
Two or more optional additional components may be used in combination, and may be added directly to the polyolefin resin composition of the present invention, or may be added in advance to each component of the propylene resin (A) and the resin (B). Two or more of these components may be used in combination. In the present invention, the content of the optional additive component is not particularly limited, but is usually about 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the polyolefin resin composition, and is appropriately selected according to the purpose. The

(1) Molecular weight depressant The molecular weight depressant is effective for further imparting and further improving moldability (fluidity) and the like.
As the molecular weight depressant, for example, various organic peroxides and so-called decomposition (oxidation) accelerators can be used, and organic peroxides are preferable.
Examples of the organic peroxide include benzoyl peroxide, t-butyl perbenzoate, t-butyl peracetate, t-butyl peroxyisopropyl carbonate, 2,5-di-methyl-2,5-di- (benzoylperoxide). Oxy) hexane, 2,5-di-methyl-2,5-di- (benzoylperoxy) hexyne-3, t-butyl-di-peradipate, t-butylperoxy-3,5,5-trimethylhexa Noate, methyl-ethylketone peroxide, cyclohexanone peroxide, di-t-butyl peroxide, dicumyl peroxide, 2,5-di-methyl-2,5-di- (t-butylperoxy) hexane 2,5-di-methyl-2,5-di- (t-butylperoxy) hexyne-3,1,3-bis- (t-butyl Luperoxyisopropyl) benzene, t-butylcumyl peroxide, 1,1-bis- (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis- (t-butylperoxy) Cyclohexane, 2,2-bis-t-butylperoxybutane, p-menthane hydroperoxide, di-isopropylbenzene hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, p-cymene hydroperoxide, 1 , 1,3,3-tetra-methylbutyl hydroperoxide and 2,5-di-methyl-2,5-di- (hydroperoxy) hexane selected from the group consisting of one or more Can be mentioned.

(2) Lubricant A lubricant is effective for imparting and improving the releasability during molding of the polyolefin resin composition of the present invention and the molded body thereof.
Examples of the lubricant include fatty acid amides such as oleic acid amide, stearic acid amide, erucic acid amide, and behenic acid amide, butyl stearate, and silicone oil.

(3) Antioxidant Antioxidant is effective in preventing the quality deterioration of the polyolefin resin composition of the present invention and its molded product.
Examples of the antioxidant include a phenol-based, phosphorus-based and sulfur-based antioxidant.

(4) Others The polyolefin resin composition of the present invention is a thermoplastic resin heat such as a polyolefin resin other than the propylene resin (A), a polyamide resin, or a polyester resin, as long as the effects of the present invention are not significantly impaired. A plastic elastomer (rubber component) or the like can be contained.
As these optional components, various products are commercially available from many companies, and desired products can be obtained and used according to the purpose.

5. Production method of polyolefin resin composition The polyolefin resin composition of the present invention is a propylene resin (A) and a resin (B), optionally added components as necessary, with the above content, in a conventionally known method. It can manufacture by passing through the kneading | mixing process of mix | blending and melt-kneading.
Mixing is usually performed using a mixing device such as a tumbler, V blender, or ribbon blender, and melt kneading is usually performed by a single screw extruder, twin screw extruder, Banbury mixer, roll mixer, Brabender plastograph, kneader, stirring. Using a kneading machine such as a granulator (semi) melt kneading and granulating. When manufacturing by (semi) melt kneading and granulating, the blend of the above components may be kneaded at the same time, and each component may be divided and kneaded to improve performance. A method in which part or all of the component propylene-based resin (A) and part of the resin (B) are kneaded and then the remaining components are kneaded and granulated can be employed.

6). Manufacturing method and characteristics of molded article The polyolefin resin composition of the present invention is excellent in total light transmittance, brightness and light diffusibility when formed into a sheet. The molded sheet is preferably formed by injection molding or extrusion molding to be a light diffusing injection sheet or a light diffusing extruded sheet (hereinafter sometimes collectively referred to as “sheet”). When the sheet has a thickness of 2 mm, the total light transmittance is preferably 56% or more, more preferably 57% or more, still more preferably 58% or more, and 60% or more. It is particularly preferred. In addition, when the thickness of the sheet of the present invention is 2 mm, the hardness is preferably 98% or more, and more preferably 99% or more. When the total light transmittance and the brightness are “total light transmittance is 60% or more and the brightness is 99% or more”, the balance between light transmittance and diffusibility is excellent.
The total light transmittance and the degree of brightness are values measured using a molded sheet piece in accordance with JIS K7105.
As described above, the polyolefin resin composition of the present invention, the light diffusing injection sheet and the light diffusing extruded sheet using the same, are lightweight, recyclable with polyolefin, and have an excellent balance of light transmission and diffusibility. It is useful as a light diffusing sheet material.
Therefore, it can be preferably applied to LED lighting covers, backlight type liquid crystal panels, rear projector screens, and the like.

Examples The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
The evaluation methods, analysis methods and materials used in the examples are as follows.

1. Evaluation method (1) Preparation of test piece A test piece was prepared in the following manner.
-Molding machine: Toshiba Machine EC20 type injection molding machine.
-Mold: One test piece for bending elastic modulus evaluation (80 × 40 × 2t (mm)) is taken.
Molding conditions: molding temperature 200 ° C., mold temperature 40 ° C., injection pressure 50 MPa, injection time 8 seconds, cooling time 12 seconds.

(2) Total light transmittance, brightness:
Using the test piece prepared in (1) above, measurement was performed in accordance with JIS K7105.

(3) Diffusivity measurement:
A variable angle photometer GC5000L (manufactured by Nippon Denshoku Industries Co., Ltd.) is used to automatically change the light receiving section at 1 ° intervals with respect to the transmitted light of the sample (thickness: 2.0 mm) using the test piece prepared in (1) above The transmission intensity at each angle was measured in a range of ± 85 ° while making the angle, and the diffusivity was calculated by the following formula. In addition, the greater the diffusivity, the better the diffusibility, and the better if it is 0.29 or more, the better if it is 0.30 or more.
(Diffusion degree) = [T (40) / T (5)]
* However, T: Transmitted light intensity () value is angle (radian)
(4) Compatible / Incompatible The specimen obtained in (1) above was cooled to −120 ° C. and cut using an ultramicrotome (UC6 manufactured by Leica) equipped with a diamond knife and a cryosystem. The cut surface was subjected to ion etching treatment and observed with a scanning electron microscope (S800 manufactured by Hitachi, Ltd.). On the observation surface, the particles in which the dispersed particles of the resin (B) were observed were judged to be “incompatible”.
(5) Refractive index From "plastic material in molding (1999, published by Sigma Publishing Co.)", the refractive index of polypropylene is 1.52, and the amorphous part is 1.48. 1.50, polystyrene is 1.59, polymethacrylate is 1.49, polycarbonate crystal part is 1.65, and amorphous part is 1.59. Therefore, the refractive index of polycarbonate was 1.62.
(6) Melt flow rate (MFR)
Each sample was measured according to JIS K7210: 1999, Method A and Condition M, at a test temperature of 230 ° C. and a load of 2.16 kg.
(7) Ethylene content The ethylene content was determined by analyzing a ¹³ C-NMR spectrum measured by a proton complete decoupling method. The details of the measurement method are as described above.

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2. Raw materials: The following commercially available resins were used.
(1) Propylene resin (A)
PP-1: Wintech WMG03 (manufactured by Nippon Polypro Co., Ltd., propylene-ethylene random copolymer)
PP-2: Wintech WMG03UX (manufactured by Nippon Polypro Co., Ltd., propylene-ethylene random copolymer)
PP-3: Wintech WFX6 (manufactured by Nippon Polypro Co., Ltd., propylene-ethylene random copolymer)
PP-4: Novatec MA1B (manufactured by Nippon Polypro, propylene homopolymer)
PP-5: Novatec BC03B (Nippon Polypro Co., Ltd., propylene homopolymer)
PP-6: Novatec MG03B (manufactured by Nippon Polypro Co., Ltd., propylene-ethylene random copolymer)

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(2) Resin (B)
B-1: Polystyrene (PS): PS Japan, HF-77
B-2: Polymethacrylate (PMMA): Mitsubishi Rayon Co., Ltd., Acrypet MD
B-3: Polycarbonate (PC): manufactured by Mitsubishi Chemical Engineering Plastics, Novalex 7022A
B-4: Ethylene butene rubber: manufactured by Mitsui Chemicals, Toughmer A4050S

3. [Examples 1-5 and Comparative Examples 1-9]
(1) Production of resin composition The components (A) and (B) were blended together with the following additives in the proportions shown in Table 5, and kneaded and granulated under the following conditions to produce resin pellets.
Under the present circumstances, 0.1 weight part of IRGANOX1010 made from BASF, and 0.05 weight part IRGAFOS168 made from BASF were mix | blended per 100 weight part of the whole composition which consists of said component (A) and (B).
Kneading apparatus: “KZW-15-MG” type twin screw extruder manufactured by Technobel.
Kneading conditions: temperature = 200 ° C., screw rotation speed = 400 rpm, discharge amount = 3 kg / Hr.

(2) Molding of resin composition Using the obtained resin pellets, injection molding was performed under the above conditions to obtain various test pieces of the resin composition.

(3) Evaluation Performance evaluation was performed using the various test pieces. The results are shown in Table 5. The “difference in refractive index” indicates the absolute value of the difference in refractive index between the propylene resin (A) and the resin (B).

4). Evaluation From Examples 1 to 5 satisfying the invention requirements of the resin composition of the present invention and the molded product thereof from the results shown in Table 5, the total light transmittance, the brightness, and the diffusivity are good. In Example 2, the total light transmittance is high, but the diffusivity is also high and the balance is excellent. On the other hand, in Example 3, the total light transmittance is slightly lower than that in Example 2, but the diffusivity is higher than that in Example 2 and the balance is excellent.
On the other hand, in the comparative examples that do not satisfy the specific matters of the invention, the resin compositions having the compositions shown in Comparative Examples 1 to 9 and the molded products thereof are poor in balance, and those of Examples 1 to 5 are used. On the other hand, it is inferior.
For example, in Comparative Examples 1 and 3, the total light transmittance is high, but the diffused light at 40 degrees is not observed, and thus the diffuseness is 0. This is because the resin (B) having a different refractive index is not contained or is contained in a small amount, so that the light is not sufficiently diffused. In Comparative Example 2, the diffusivity is high, but the total light transmittance is greatly inferior. This is presumably because the light transmittance was lowered because the amount of resin (B) blended was large and diffusion occurred strongly. In Comparative Example 4, the total light transmittance is high, but the diffusivity is very poor. This is because there was no difference in refractive index between the propylene-based resin (A) and the resin (B) and no diffusion occurred. In Comparative Example 5, the diffusivity is inferior. This is because the propylene-based resin (A) has a low degree of dispersion and inferior diffusion, and thus results in inferior diffusion even when combined with the resin (B). In Comparative Examples 6 and 7, the total light transmittance is inferior. This is because the propylene-based resin (A) has a low ethylene content and is polymerized using a Ziegler catalyst and has a low total light transmittance. In Comparative Example 8, the result is inferior in diffusivity. This is because the resin (B) has almost no contribution to diffusion since the total light transmittance is low and the brightness is high. In Comparative Example 9, the total light transmittance and the diffusivity are slightly inferior to those of Examples 1 to 5. Since the propylene-based resin composition (A) is polymerized with a Ziegler catalyst, the regularity and molecular weight distribution are broader than that of the metallocene catalyst, and hence the total light transmittance and the degree of brightness are inferior. It is done.

Claims (3)

The following requirements (B-1) to (B-) with respect to 100 parts by weight of propylene resin (A) satisfying the following requirements (A-1) to (A-4) and 100 parts by weight of propylene resin (A). 2) A polyolefin-based resin composition containing 0.4 to 3.5 parts by weight of a resin (B) that satisfies the following (2), wherein the following requirements (C-1) to (C-2) are satisfied A polyolefin resin composition.
Requirement (A-1)
The propylene-based resin (A) is a propylene-ethylene random copolymer having an ethylene content of 0.1 to 7% by weight, polymerized using a metallocene catalyst.
Requirement (A-2)
The melt flow rate (230 ° C., 2.16 kg load) of the propylene-based resin (A) is 1 to 100 g / 10 minutes.
Requirement (A-3)
The total light transmittance of the propylene-based resin (A) is 80 to 90% at a test piece thickness of 2 mm.
Requirement (A-4)
The degree of propylene resin (A) is 30 to 95% at a test piece thickness of 2 mm.
Requirement (B-1)
The total light transmittance of the resin (B) is 85% or more at a test piece thickness of 2 mm.
Requirement (B-2)
The degree of the resin (B) is 2% or less at a test piece thickness of 2 mm.
Requirement (C-1)
Propylene resin (A) and resin (B) are incompatible.
Requirement (C-2)
The difference in refractive index between the propylene-based resin (A) and the resin (B) is 0.04 or more.   The molded object formed by shape | molding the polyolefin resin composition of Claim 1.   The molded article according to claim 2, wherein the molded article is at least one selected from the group consisting of a light diffusing injection sheet and a light diffusing extruded sheet.