阅读说明：本技术 汽车车顶用构件和用于生产汽车车顶用构件的方法 (Component for a vehicle roof and method for producing a component for a vehicle roof ) 是由 三宅裕一 渡边敏雄 德原渡 泉美奈子 千叶俊辅 于 2020-03-24 设计创作，主要内容包括：本发明涉及通过对层合体进行挤压成型而提供的汽车车顶用构件,其中所述层合体包括三个层：按所提及的顺序层合的层A-a、层B和层A-b,当假设层A-a、层B和层A-b的厚度之和对应于100％时,层A-a和层A-b的厚度之和占6％至8％,层A-a的厚度占0.5％至7.5％,层A-b的厚度占0.5％至7.5％,以及层B的厚度占92％至94％,所述挤压成型以使得层A-a、层B和层A-b的厚度之和占70％至93％的方式来进行。(The present invention relates to a member for an automobile roof provided by extrusion-molding a laminate, wherein the laminate comprises three layers: layer a-a, layer B and layer a-B laminated in the mentioned order, the sum of the thicknesses of layer a-a and layer a-B accounting for 6% to 8%, the thickness of layer a-a accounting for 0.5% to 7.5%, the thickness of layer a-B accounting for 0.5% to 7.5%, and the thickness of layer B accounting for 92% to 94%, when it is assumed that the sum of the thicknesses of layer a-a, layer B and layer a-B corresponds to 100%, the extrusion molding being performed in such a manner that the sum of the thicknesses of layer a-a, layer B and layer a-B accounts for 70% to 93%.)

1. A member for an automobile roof provided by extrusion-molding a laminate, wherein

The laminate includes three layers: the following layer A-a, the following layer B and the following layer A-B laminated in the mentioned order,

when it is assumed that the sum of the thickness of the layer a-a, the thickness of the layer B and the thickness of the layer a-B corresponds to 100%,

the sum of the thickness of the layer A-a and the thickness of the layer A-b is 6% or more and 8% or less, and the thickness of the layer A-a is 0.5% or more and 7.5% or less, and the thickness of the layer A-b is 0.5% or more and 7.5% or less, and

the thickness of the layer B is 92% or more and 94% or less,

the extrusion molding is performed in such a manner that the sum of the thickness of the layer A-a, the thickness of the layer B, and the thickness of the layer A-B accounts for 70% or more and 93% or less:

layer A-a and layer A-b:

a layer comprising the following propylene polymer component (A1), the following ethylene-methyl methacrylate copolymer component (A2), and the following ethylene- (1-butene) copolymer component (A3), wherein

When the total content of the propylene polymer component (A1), the ethylene-methyl methacrylate copolymer component (A2) and the ethylene- (1-butene) copolymer component (A3) is assumed to be 100% by weight,

the content of the propylene polymer component (a1) is 42.5% by weight or more and 47.5% by weight or less, the content of the ethylene-methyl methacrylate copolymer component (a2) is 32.5% by weight or more and 37.5% by weight or less, and the content of the ethylene- (1-butene) copolymer component (A3) is 15% by weight or more and 25% by weight or less;

propylene polymer component (a 1):

as a component of a propylene homopolymer having an isotactic structure, wherein

The component has an isotactic pentad fraction of 0.90 or more and 0.99 or less as measured using 13C-NMR, and

a melt mass flow rate of 0.1g/10 minutes or more and 5.0g/10 minutes or less measured under the conditions of a temperature of 230 ℃ and a load of 2.16 kgf;

ethylene-methyl methacrylate copolymer component (a 2):

an ethylene-methyl methacrylate copolymer component having a melt mass flow rate of 1.5g/10 minutes or more and 5.0g/10 minutes or less measured at a temperature of 190 ℃ and a load of 2.16 kgf;

ethylene- (1-butene) copolymer component (a 3):

an ethylene- (1-butene) copolymer component having a melt mass flow rate of 0.1g/10 minutes or more and 1.0g/10 minutes or less measured at a temperature of 190 ℃ and a load of 2.16 kgf;

layer B:

a layer comprising the following propylene polymer component (B1) and the following talc (B2), wherein

When the total content of the propylene polymer component (B1) and the talc (B2) is assumed to be 100% by weight,

the propylene polymer component (B1) is contained in an amount of 65% by weight or more and 75% by weight or less, and the talc (B2) is contained in an amount of 25% by weight or more and 35% by weight or less;

propylene polymer component (B1):

as a component of a propylene homopolymer having an isotactic structure, wherein

The component has an isotactic pentad fraction of 0.90 or more and 0.99 or less as measured using 13C-NMR, and

a melt mass flow rate of 0.1g/10 minutes or more and 5.0g/10 minutes or less measured under the conditions of a temperature of 230 ℃ and a load of 2.16 kgf;

talc (B2):

talc that satisfies the following requirement (1-a), the following requirement (1-b), and the following requirement (1-c);

requirement (1-a):

talc having a median diameter D50(L) of 10 μm or more and 25 μm or less as measured by a laser diffraction method according to JIS R1629;

requirement (1-b):

talc having a median diameter D50(S) of 2 μm or more and 8 μm or less as measured by centrifugal sedimentation according to JIS R1619; and

requirement (1-c):

talc having an aspect ratio constant of 2 or more and 15 or less, determined by the following expression (1):

the aspect ratio constant { D50(L) -D50(S) }/D50(S) expression (1).

2. A method for producing a member for an automobile roof, comprising a step of extrusion-molding a laminated body, wherein

The laminate includes three layers: the following layer A-a, the following layer B and the following layer A-B laminated in the mentioned order,

when it is assumed that the sum of the thickness of the layer a-a, the thickness of the layer B and the thickness of the layer a-B corresponds to 100%,

the sum of the thickness of the layer A-a and the thickness of the layer A-b is 6% or more and 8% or less, the thickness of the layer A-a is 0.5% or more and 7.5% or less, the thickness of the layer A-b is 0.5% or more and 7.5% or less, and

the thickness of the layer B is 92% or more and 94% or less,

the extrusion molding is performed in such a manner that the sum of the thickness of the layer A-a, the thickness of the layer B, and the thickness of the layer A-B accounts for 70% or more and 93% or less:

layer A-a and layer A-b:

a layer comprising the following propylene polymer component (A1), the following ethylene-methyl methacrylate copolymer component (A2), and the following ethylene- (1-butene) copolymer component (A3), wherein

When the total content of the propylene polymer component (A1), the ethylene-methyl methacrylate copolymer component (A2) and the ethylene- (1-butene) copolymer component (A3) is assumed to be 100% by weight,

the content of the propylene polymer component (a1) is 42.5% by weight or more and 47.5% by weight or less, the content of the ethylene-methyl methacrylate copolymer component (a2) is 32.5% by weight or more and 37.5% by weight or less, and the content of the ethylene- (1-butene) copolymer component (A3) is 15% by weight or more and 25% by weight or less;

propylene polymer component (a 1):

as a component of a propylene homopolymer having an isotactic structure, wherein

The component has an isotactic pentad fraction of 0.90 or more and 0.99 or less as measured using 13C-NMR, and

a melt mass flow rate of 0.1g/10 minutes or more and 5.0g/10 minutes or less measured under the conditions of a temperature of 230 ℃ and a load of 2.16 kgf;

ethylene-methyl methacrylate copolymer component (a 2):

an ethylene-methyl methacrylate copolymer component having a melt mass flow rate of 1.5g/10 minutes or more and 5.0g/10 minutes or less measured at a temperature of 190 ℃ and a load of 2.16 kgf;

ethylene- (1-butene) copolymer component (a 3):

an ethylene- (1-butene) copolymer component having a melt mass flow rate of 0.1g/10 minutes or more and 1.0g/10 minutes or less measured at a temperature of 190 ℃ and a load of 2.16 kgf;

layer B:

a layer comprising the following propylene polymer component (B1) and the following talc (B2), wherein

When the total content of the propylene polymer component (B1) and the talc (B2) is assumed to be 100% by weight,

the propylene polymer component (B1) is contained in an amount of 65% by weight or more and 75% by weight or less, and the talc (B2) is contained in an amount of 25% by weight or more and 35% by weight or less;

propylene polymer component (B1):

as a component of a propylene homopolymer having an isotactic structure, wherein

The component has an isotactic pentad fraction of 0.90 or more and 0.99 or less as measured using 13C-NMR, and

a melt mass flow rate of 0.1g/10 minutes or more and 5.0g/10 minutes or less measured under the conditions of a temperature of 230 ℃ and a load of 2.16 kgf;

talc (B2):

talc that satisfies the following requirement (1-a), the following requirement (1-b), and the following requirement (1-c);

requirement (1-a):

talc having a median diameter D50(L) of 10 μm or more and 25 μm or less as measured by a laser diffraction method according to JIS R1629;

requirement (1-b):

talc having a median diameter D50(S) of 2 μm or more and 8 μm or less as measured by centrifugal sedimentation according to JIS R1619; and

requirement (1-c):

talc having an aspect ratio constant of 2 or more and 15 or less, determined by the following expression (1):

the aspect ratio constant { D50(L) -D50(S) }/D50(S) expression (1).

Technical Field

The invention relates to a component for a vehicle roof and a method for producing a component for a vehicle roof.

Background

Because laminated flat panels comprising propylene polymers are very inexpensive and lightweight, they have been used in a variety of industrial parts such as automobile interior and exterior parts and household appliance parts.

As one of methods for producing a laminated flat plate containing a propylene polymer, an extrusion molding (compression molding) method is known. The extrusion molding method is a method that can improve the impact resistance of the laminated flat plate.

For example, patent document 1 describes a formed article obtained by extrusion-forming a laminate for extrusion forming.

Reference list

Patent document

Patent document 1: japanese patent No. 6191762

Disclosure of Invention

Exterior materials for automobiles such as members for automobile roofs are required to have excellent coatability. Accordingly, an object of the present invention is to provide an automotive roof member excellent in coatability and a method for producing the automotive roof member.

The present invention relates to a member for an automobile roof provided by extrusion-molding a laminate, wherein the laminate comprises three layers: the following layer a-a, the following layer B, and the following layer a-B laminated in the mentioned order, when it is assumed that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B corresponds to 100%, the sum of the thickness of the layer a-a and the thickness of the layer a-B accounts for 6% or more and 8% or less, the thickness of the layer a-a accounts for 0.5% or more and 7.5% or less, the thickness of the layer a-B accounts for 0.5% or more and 7.5% or less, and the thickness of the layer B accounts for 92% or more and 94% or less, the extrusion molding being performed in such a manner that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B accounts for 70% or more and 93% or less:

layer A-a and layer A-b: a layer comprising the following propylene polymer component (a1), the following ethylene-methyl methacrylate copolymer component (a2), and the following ethylene- (1-butene) copolymer component (A3), wherein, when assuming that the total content of the propylene polymer component (a1), the ethylene-methyl methacrylate copolymer component (a2), and the ethylene- (1-butene) copolymer component (A3) is 100% by weight, the content of the propylene polymer component (a1) is 42.5% by weight or more and 47.5% by weight or less, the content of the ethylene-methyl methacrylate copolymer component (a2) is 32.5% by weight or more and 37.5% by weight or less, and the content of the ethylene- (1-butene) copolymer component (A3) is 15% by weight or more and 25% by weight or less;

propylene polymer component (a 1): a component which is a propylene homopolymer having an isotactic structure, wherein the component has an isotactic pentad fraction of 0.90 or more and 0.99 or less as measured using 13C-NMR, and a melt mass flow rate of 0.1g/10 minutes or more and 5.0g/10 minutes or less as measured under the conditions of a temperature of 230 ℃ and a load of 2.16 kgf;

ethylene-methyl methacrylate copolymer component (a 2): an ethylene-methyl methacrylate copolymer component having a melt mass flow rate of 1.5g/10 minutes or more and 5.0g/10 minutes or less measured at a temperature of 190 ℃ and a load of 2.16 kgf;

ethylene- (1-butene) copolymer component (a 3): an ethylene- (1-butene) copolymer component having a melt mass flow rate of 0.1g/10 minutes or more and 1.0g/10 minutes or less measured at a temperature of 190 ℃ and a load of 2.16 kgf;

layer B: a layer comprising the following propylene polymer component (B1) and the following talc (B2), wherein, when assuming that the total content of the propylene polymer component (B1) and talc (B2) is 100% by weight, the content of the propylene polymer component (B1) is 65% by weight or more and 75% by weight or less, and the content of talc (B2) is 25% by weight or more and 35% by weight or less;

propylene polymer component (B1): a component which is a propylene homopolymer having an isotactic structure, wherein the component has an isotactic pentad fraction of 0.90 or more and 0.99 or less as measured using 13C-NMR, and a melt mass flow rate of 0.1g/10 minutes or more and 5.0g/10 minutes or less as measured under the conditions of a temperature of 230 ℃ and a load of 2.16 kgf;

talc (B2): talc that satisfies the following requirement (1-a), the following requirement (1-b), and the following requirement (1-c);

requirement (1-a): talc having a median diameter D50(L) of 10 μm or more and 25 μm or less as measured by a laser diffraction method according to JIS R1629;

requirement (1-b): talc having a median diameter D50(S) of 2 μm or more and 8 μm or less as measured by centrifugal sedimentation according to JIS R1619; and

requirement (1-c): talc having an aspect ratio (aspect ratio) constant of 2 or more and 15 or less, determined by the following expression (1):

the aspect ratio constant { D50(L) -D50(S) }/D50(S) expression (1).

Such a member for an automobile roof has excellent coatability.

The invention also relates to a method for producing a member for an automobile roof, comprising the step of extrusion-molding a laminate, wherein the laminate comprises three layers: the above-mentioned layer a-a, the above-mentioned layer B, and the above-mentioned layer a-B laminated in the mentioned order, when it is assumed that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B corresponds to 100%, the sum of the thickness of the layer a-a and the thickness of the layer a-B accounts for 6% or more and 8% or less, the thickness of the layer a-a accounts for 0.5% or more and 7.5% or less, the thickness of the layer a-B accounts for 0.5% or more and 7.5% or less, and the thickness of the layer B accounts for 92% or more and 94% or less, the extrusion molding being performed in such a manner that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B accounts for 70% or more and 93% or less.

According to such a method, a member for an automobile roof having excellent coatability can be produced.

According to the present invention, there are provided an automotive roof member having excellent coatability and a method for producing the automotive roof member.

Drawings

Fig. 1A and 1B show schematic cross-sectional views for explaining an exemplary member for an automobile roof and an exemplary method for producing the member for an automobile roof of the present embodiment.

Detailed Description

Hereinafter, some embodiments of the present invention will be described in detail. However, the present invention is not intended to be limited to the following embodiments.

Fig. 1A and 1B show schematic cross-sectional views for explaining an exemplary member for an automobile roof and an exemplary method for producing the member for an automobile roof of the present embodiment.

The member 200 for an automobile roof shown in fig. 1B can be produced by press-molding the laminate 100 shown in fig. 1A by hot-pressing the laminate 100 in the thickness direction of the laminate 100. That is, the member 200 for an automobile roof is provided by extrusion-molding the laminated body 100.

The laminate 100 includes three layers: layer A-a (10a), layer B (20) and layer A-B (10B) laminated in the order mentioned. When assuming the thickness t of the layer A-a (10a)₁₁Thickness t of layer B (20)₁₂And thickness t of layer A-b (10b)₁₃The sum (thickness t)₁₀₀) Thickness t corresponding to 100%₁₁And a thickness t₁₃The sum of the thicknesses t is 6% or more and 8% or less₁₁0.5% or more and 7.5% or less, thickness t₁₃0.5% or more and 7.5% or less, and a thickness t₁₂92% or more and 94% or moreIs small. In the member 200 for automobile roof, the thickness t of the layer A-a (10a)₂₁Thickness t of layer B (20)₂₂And thickness t of layer A-b (10b)₂₃The sum (thickness t)₂₀₀) Thickness t in the laminate 100₁₀₀70% or more and 93% or less.

Hereinafter, the member for an automobile roof and the method for producing the member for an automobile roof of the present embodiment will be described in further detail.

The member for an automobile roof of the present embodiment is provided by extrusion-molding a laminate, wherein the laminate includes three layers: the layers a-a, B and a-B laminated in the mentioned order, when assuming that the sum of the thickness of the layers a-a, B and a-B is 100%, the sum of the thickness of the layers a-a and a-B is 6% or more and 8% or less, the thickness of the layers a-a is 0.5% or more and 7.5% or less, the thickness of the layers a-B is 0.5% or more and 7.5% or less, and the thickness of the layers B is 92% or more and 94% or less (hereinafter also referred to as "laminate for extrusion") which is performed in such a manner that the sum of the thickness of the layers a-a, B and a-B is 70% or more and 93% or less.

[ layer A-a and layer A-b ]

The layer a-a and the layer a-b are layers containing a propylene polymer component (a1) (hereinafter also referred to as "component a 1"), an ethylene-methyl methacrylate copolymer component (a2) (hereinafter also referred to as "component a 2") and an ethylene- (1-butene) copolymer component (A3) (hereinafter also referred to as "component A3"), in which, assuming that the total content of the component a1, the component a2 and the component A3 is 100% by weight, the content of the component a1 is 42.5% by weight or more and 47.5% by weight or less, the content of the component a2 is 32.5% by weight or more and 37.5% by weight or less, and the content of the component A3 is 15% by weight or more and 25% by weight or less.

Component a1 is a component which is a propylene homopolymer having an isotactic structure, wherein the component has an isotactic pentad fraction (hereinafter also referred to as [ mmmm ]) of 0.90 or more and 0.99 or less measured using 13C-NMR and a melt mass flow rate of 0.1g/10 minutes or more and 5.0g/10 minutes or less measured under the conditions of a temperature of 230 ℃ and a load of 2.16 kgf. One component a1 may be used alone, or two or more components a1 may be used in combination.

The melt mass flow herein refers to a value determined according to JIS K6758.

A propylene homopolymer is a polymer composed of constituent units derived from propylene.

Here, the isotactic pentad fraction means a proportion of isotactic sequences in terms of pentad units in a molecular chain measured using 13C-NMR, that is, a fraction of propylene-derived constituent units present at the center of a sequence of five propylene-derived constituent units which are sequentially meso-bonded (meso-bonded). Specifically, the value was calculated as the fraction of [ mmmm ] peak in the methyl carbon region occupied in all absorption peaks observed in the 13C-NMR spectrum. Here, the [ mmmm ] peak is a peak derived from propylene present at the center of a chain of five constituent units which are successively meso-bonded.

The [ mmmm ] can be determined by the method described in the report of A.Zambelli et al (Macromolecules, 1973, 6 th).

The [ mmmm ] of component A1 is preferably 0.95 or more, more preferably 0.96 or more, and even more preferably 0.97 or more.

The melt mass flow rate of component A1 measured at a temperature of 230 ℃ and a load of 2.16kgf is preferably 0.1g/10 min or more and 2g/10 min or less, more preferably 0.2g/10 min or more and 1.5g/10 min or less, and even more preferably 0.3g/10 min or more and 1.0g/10 min or less. The smaller the above-mentioned value of the melt mass flow rate of component a1, the more excellent the elastic bending strength of the automotive roof structural member tends to be.

The melting point of component a1 as determined by differential scanning calorimetry (hereinafter, denoted as DSC) is preferably 150 ℃ or more, more preferably 155 ℃ or more, and even more preferably 160 ℃ or more. The amount of heat of fusion of component A1 as determined by DSC is preferably 60J/g or more, more preferably 80J/g or more, and even more preferably 90J/g or more.

The melting point of component a1 is the melting temperature of the crystalline phase contained in component a 1. Specifically, the melting point is the peak top temperature of the endothermic peak on the highest temperature side on the DSC curve obtained when the temperature of component a1 is raised.

The amount of heat of fusion of component a1 is the amount of heat required to convert the crystalline phase contained in component a1 into a molten state. Specifically, the amount of heat of fusion was determined as the total peak area of all endothermic peaks on the DSC curve obtained when the temperature of component a1 was raised.

The melting point and the amount of heat of fusion of component a1 were measured using DSC under the following conditions. (i) About 10mg of component A1 was heat-treated at 220 ℃ for five minutes under nitrogen atmosphere and then cooled to 50 ℃ at a cooling rate of 5 ℃/min. (ii) Subsequently, component A1 was held at 50 ℃ for one minute and heated from 50 ℃ to 180 ℃ at a ramp rate of 5 ℃/minute.

Component a1 can be produced by known polymerization methods using the following catalyst system: a catalyst system formed by bringing a known solid titanium catalyst component, an organometallic compound catalyst component and, in addition, an electron donor (as needed) into contact with each other; a catalyst system formed by contacting a compound of a transition metal of group 4 of the periodic table having a cyclopentadienyl ring and alkylaluminoxane with each other; a catalyst system formed by contacting a compound of a transition metal of group 4 of the periodic table having a cyclopentadienyl ring, a compound which forms an ionic complex by reacting with a transition metal compound, and an organoaluminum compound with each other; and so on.

Component A2 is an ethylene-methyl methacrylate copolymer component having a melt mass flow rate of 1.5g/10 minutes or more and 5.0g/10 minutes or less measured at a temperature of 190 ℃ and a load of 2.16 kgf. The ethylene-methyl methacrylate copolymer component is a copolymer containing 15% by weight or more and 20% by weight or less of constituent units derived from methyl methacrylate (also referred to as "methyl methacrylate units") and containing 80% by weight or more and 85% by weight or less of constituent units derived from ethylene (also referred to as "ethylene units"). One component a2 may be used alone, or two or more components a2 may be used in combination.

The content of methyl methacrylate units in the ethylene-methyl methacrylate copolymer component can be determined by producing a pressed sheet having a thickness of 0.3mm and measuring the pressed sheet by infrared absorption spectrometry using an infrared spectrometer. 3448cm assigned to methyl methacrylate^-1The peak at (b) was used as a characteristic absorption of the infrared absorption spectrum, and the absorbance was corrected with the thickness according to the following expression to determine the content of methyl methacrylate units:

MMA＝4.1×log(I_o/I)/t-5.3

wherein MMA denotes the content (% by weight) of methyl methacrylate units, I denotes a value in 3448cm^-1Intensity of transmitted light at a frequency of (1)_oExpressed at 3448cm^-1And t represents the thickness (cm) of the sample sheet to be measured.

The content of ethylene units in the ethylene-methyl methacrylate copolymer component is calculated by, for example, subtracting the content of methyl methacrylate units from 100% by weight.

From the viewpoint of coatability, the melt mass flow rate of component A2 measured under the conditions of a temperature of 190 ℃ and a load of 2.16kgf is preferably 1.8g/10 min or more and 3g/10 min or less, more preferably 1.9g/10 min or more and 2.2g/10 min or less, and even more preferably 1.95g/10 min or more and 2.1g/10 min or less.

Component a2 can be produced by polymerizing ethylene and methyl methacrylate using a polymerization catalyst. Examples of the polymerization catalyst include: catalysts described in Japanese unexamined patent publication Nos. S61-176617, S61-179210 and H6-16726, and metallocene catalysts containing rare earth metals described in Japanese unexamined patent publication No. H3-263412.

In component a2, the content of methyl methacrylate units may be 16% by weight or more, may be 17% by weight or more, or may be 18% by weight or more.

In component a2, the content of ethylene units may be 84% by weight or less, may be 83% by weight or less, or may be 82% by weight or less.

As component a2, commercially available products can be used. Examples of commercially available component a2 include Acryft WH102 (manufactured by Sumitomo Chemical co., ltd., trade name).

Component A3 is an ethylene- (1-butene) copolymer component having a melt mass flow rate of 0.1g/10 minutes or more and 1.0g/10 minutes or less measured at a temperature of 190 ℃ and a load of 2.16 kgf. Here, the ethylene- (1-butene) copolymer component is a copolymer containing 10% by weight or more and 40% by weight or less of constituent units derived from 1-butene (also referred to as "1-butene units") and containing 60% by weight or more and 90% by weight or less of constituent units derived from ethylene. One component A3 may be used alone, or two or more components A3 may be used in combination.

The content of ethylene units in the ethylene- (1-butene) copolymer component can be determined from 13C-NMR spectra measured under the following conditions according to the report of Kakugo et al (Macromolecules,1982,15, 1150-1152).

The sample was prepared by uniformly dissolving about 200mg of an ethylene- (1-butene) copolymer in 3ml of o-dichlorobenzene in a test tube having a diameter of 10 mm. The 13C-NMR spectrum of the sample was measured under conditions of a measurement temperature of 135 deg.C, a pulse repetition time of 10 seconds, a pulse width of 45 deg. and a cumulative number of 2500.

The content of 1-butene units in the ethylene- (1-butene) copolymer component is calculated by, for example, subtracting the content of ethylene units from 100% by weight.

From the viewpoint of coatability, the melt mass flow rate of component A3 measured at a temperature of 190 ℃ and a load of 2.16kgf may be 0.1g/10 minutes or more, may be 0.2g/10 minutes or more, or may be 0.3g/10 minutes or more.

Component A3 can be produced by polymerizing ethylene and 1-butene using a polymerization catalyst. Examples of the polymerization catalyst include catalyst systems composed of a vanadium compound and an organoaluminum compound, Ziegler-Natta catalyst systems and metallocene catalyst systems. Examples of the polymerization method include a solution polymerization method, a slurry polymerization method, a high-pressure ionic polymerization method, and a gas phase polymerization method.

In component a3, the content of 1-butene units may be 15% by weight or more and 35% by weight or less, may be 15.5% by weight or more and 32.5% by weight or less, or may be 20% by weight or more and 30% by weight or less.

In component a3, the content of ethylene units may be 65% by weight or more and 85% by weight or less, may be 67.5% by weight or more and 82.5% by weight or less, or may be 70% by weight or more and 80% by weight or less.

As component a3, commercially available products can be used. Examples of commercially available component a3 include ENGAGEENR7447 (manufactured by Dow DuPont Elastomers, trade name) and Tafmer a0250 (manufactured by Mitsui Chemicals, inc.

In layers a-a and a-b, component a1 may be present in an amount of 43 wt% or more, 43.5 wt% or more, or 44 wt% or more, and may be 47 wt% or less, 46.5 wt% or less, or 46 wt% or less. In layers a-a and a-b, component a2 may be present in an amount of 33 wt% or more, 33.5 wt% or more, or 34 wt% or more, and may be 37 wt% or less, 36.5 wt% or less, or 36 wt% or less. In the layers a-a and a-b, the content of the component a3 may be 15.5 wt% or more, 15 wt% or more, or 14.5 wt% or more, and may be 24.5 wt% or less, 24 wt% or less, or 23.5 wt% or less. Note that the total content of component a1, component a2, and component A3 is assumed to be 100% by weight.

Component a1, component a2 and component A3 contained in layer a-a are the same as component a1, component a2 and component A3 contained in layer a-b, respectively.

[ layer B ]

Layer B is a layer containing a propylene polymer component (B1) (hereinafter, also referred to as "component B1") and talc (B2) (hereinafter, also referred to as "component B2"), wherein, when it is assumed that the total content of component B1 and component B2 corresponds to 100% by weight, the content of component B1 is 65% by weight or more and 75% by weight or less, and the content of component B2 is 25% by weight or more and 35% by weight or less.

As component B1, a component similar to component A1 contained in layers A-a and A-B can be used.

Component B2 is a talc which satisfies all of the following requirements (1-a), the following requirements (1-B) and the following requirements (1-c).

Requirement (1-a):

talc having a median diameter D50(L) of 10 μm or more and 25 μm or less as measured by a laser diffraction method according to JIS R1629;

requirement (1-b):

talc having a median diameter D50(S) of 2 μm or more and 8 μm or less as measured by centrifugal sedimentation according to JIS R1619; and

requirement (1-c):

talc having an aspect ratio constant of 2 or more and 15 or less, determined by the following expression (1):

the aspect ratio constant { D50(L) -D50(S) }/D50(S) expression (1).

One component B2 may be used alone, or two or more components B2 may be used in combination.

(median diameter D50(L) by laser diffraction method)

The measurement was performed using a laser method particle size distribution analyzer according to JIS R1629, and the median diameter D50(L) can be determined from the particle size value at 50 wt% of the cumulative amount read on the obtained cumulative particle size distribution curve. An example of a laser particle size distribution analyzer is MT-3300EX-II manufactured by Nikkiso Co., Ltd.

The median diameter D50(L) of the component B2 measured by a laser diffraction method according to JIS R1629 may be 22 μm or less, may be 20 μm or less, or may be 18 μm or less, from the viewpoint of impact resistance of members for automobile roofs.

(median diameter D50(S) by centrifugal sedimentation)

The measurement was performed using a centrifugal sedimentation type particle size distribution analyzer according to JIS R1619, and the median diameter D50(S) can be determined from the particle size value at 50 wt% of the cumulative amount read on the obtained cumulative particle size distribution curve. An example of a centrifugal sedimentation type particle size distribution analyzer is SA-CP3 manufactured by SHIMADZU CORPORATION.

The median diameter D50(S) of the component B2 measured by a centrifugal sedimentation method according to JIS R1619 may be 6 μm or less, may be 5 μm or less, or may be 4 μm or less.

(aspect ratio constant)

The aspect ratio constant can be determined from the values of the above-described median diameter D50(L) and median diameter D50(S) by the above-described expression (1). The aspect ratio constant of component B2 may be 2.1 or more and 10 or less, may be 2.2 or more and 9 or less, or may be 2.3 or more and 8 or less.

The content of component B1 contained in layer B is preferably 66% by weight or more and 74% by weight or less, more preferably 67% by weight or more and 73% by weight or less, and even more preferably 68% by weight or more and 72% by weight or less. The content of the component B2 contained in the layer B is preferably 26% by weight or more and 34% by weight or less, more preferably 27% by weight or more and 33% by weight or less, and even more preferably 28% by weight or more and 32% by weight or less. Note that the total content of component B1 and component B2 is assumed to be 100% by weight.

Examples of the method for mixing the components constituting the layer A-a, the layer A-B and the layer B include a method of melt-kneading the components in a kneader such as a single-screw extruder, a twin-screw extruder, a Banbury mixer or hot rolls, and a method of mixing the components during polymerization for producing the component A1, the component A2, the component A3 or the component B1.

Examples of methods for producing layers a-a, a-B and B include press molding, extrusion and injection molding.

[ laminate for extrusion Molding ]

The laminate for extrusion molding according to the present embodiment is a laminate including one layer a-a, one layer a-B, and one layer B. In the laminate for extrusion molding, the layer A-a is provided as one surface of the laminate, and the layer A-b is provided as a surface of the laminate on which the layer A-a is not provided.

The laminate for extrusion molding of the present embodiment is a laminate of: wherein when it is assumed that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B accounts for 100%, the sum of the thickness of the layer a-a and the thickness of the layer a-B accounts for 6% or more and 8% or less, the thickness of the layer a-a accounts for 0.5% or more and 7.5% or less, the thickness of the layer a-B accounts for 0.5% or more and 7.5% or less, and the thickness of the layer B accounts for 92% or more and 94% or less.

From the viewpoint of the amount of deformation by heating, in the above extrusion laminate, the thickness of the layer a-a may correspond to 1% or more and 7% or less, may correspond to 2% or more and 6% or less, or may correspond to 3% or more and 5% or less. From the viewpoint of the amount of deformation by heating, in the above extrusion laminate, the thickness of the layer a-b may correspond to 1% or more and 7% or less, may correspond to 2% or more and 6% or less, or may correspond to 3% or more and 5% or less. In the above laminate for extrusion molding, the thickness of the layer B may correspond to 93.5% or less, may correspond to 93% or less, or may correspond to 92% from the viewpoint of the amount deformed by heating. Note that it is assumed that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B corresponds to 100%.

The laminate for extrusion molding may contain various additives and crystal nucleating agents.

Examples of the additives include antioxidants, ultraviolet absorbers, antistatic agents, slip agents, pressure-sensitive adhesives, antifogging agents, and antiblocking agents.

Examples of the crystal nucleating agent include α -crystal nucleating agents such as sorbitol-based nucleating agents, organic phosphate ester metal salt-based compounds, organic carboxylic acid metal salt-based compounds and rosin-based compounds; and beta crystal nucleating agents such as amide-based compounds and quinacridone-based compounds. From the viewpoint of the effect of addition, the content of the crystal nucleating agent is preferably 0.001 parts by weight or more based on 100 parts by weight of the laminate for extrusion molding, and the content of the crystal nucleating agent is more preferably 1.5 parts by weight or less based on 100 parts by weight of the laminate for extrusion molding, in order to prevent the dispersibility of the crystal nucleating agent from deteriorating.

The laminate for extrusion molding can be produced by extruding the layers a-a, a-B and B by coextrusion.

The member for an automobile roof according to the present embodiment can be produced by subjecting the above-described laminate for extrusion molding to extrusion molding (hot extrusion of the laminate in the thickness direction) in such a manner that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B accounts for 70% or more and 93% or less. That is, the member for an automobile roof may be obtained by extrusion-molding the laminate for extrusion molding in such a manner that: when it is assumed that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B in the laminate before extrusion (laminate for extrusion) corresponds to 100%, the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B after extrusion accounts for 70% or more and 93% or less. The total thickness (%) of the layers a-a, B and a-B in the laminate after extrusion (automotive roof member) is also referred to as the extrusion ratio with respect to the total thickness of the layers a-a, B and a-B in the laminate before extrusion (laminate for extrusion).

In the member for an automobile roof of the present embodiment, the surface perpendicular to the thickness direction of the component B2 is preferably oriented parallel to the direction in which each component contained in the laminate for extrusion molding flows during hot extrusion.

The orientation state of component B2 in the automotive roof member can be evaluated by measuring the wide-angle X-ray scattering of the automotive roof member.

The orientation state of component B2 can be quantified by the degree of orientation of component B2. The degree of orientation of component B2 can be determined by the following expression (2) using the half width of the azimuthal intensity distribution of the crystal plane perpendicular to the thickness direction of component B2 in a two-dimensional wide-angle X-ray scattering image. Note that it is assumed that the scattering angle width used for calculating the azimuthal intensity distribution is within ± 0.5 ° from the diffraction peak position derived from the above-described crystal plane:

degree of orientation (%) { (180-hwd)/180} × 100 expression (2)

Wherein hwd represents the half width (unit: degree) in the azimuthal intensity distribution of the crystal plane perpendicular to the thickness direction of component B2.

In the case where the above-described value of the degree of orientation is high, it can be said that the surface of the component B2 is oriented parallel to the direction in which each component contained in the laminate for extrusion molding flows during hot extrusion.

The degree of orientation of component B2 contained in the automobile roof member is, for example, 80% or more, and preferably 85% or more from the viewpoint of impact resistance.

The atoms in the crystal of component B1 are repeatedly arranged in a three-dimensional periodic manner, and in consideration of the periodicity, it is considered that parallelepipeds having a certain structure are three-dimensionally stacked to form a crystal. Such parallelepipeds are referred to as unit cells. The three sides of the unit cell are each referred to as the a-axis, b-axis, and c-axis. In the unit lattice of the α -crystal polypropylene crystal, the molecular chain direction is referred to as c-axis, and of the other two crystal axes, the shorter axis is referred to as a-axis and the longer axis is referred to as b-axis.

In the member for automobile roofs, the c-axis or a-axis of the α crystal in the crystal structure of component B1 is preferably oriented parallel to the flow direction during hot extrusion. When the c-axis or a-axis of the α crystal of the component B1 is oriented in the direction in which each component contained in the laminate for extrusion molding flows during hot extrusion, the impact strength of the member for automobile roofs can be improved.

The crystal orientation state of component B1 can be evaluated by measuring the wide angle X-ray scattering of automotive roof components.

The crystal orientation state of component B1 can be quantified by the degree of crystal orientation. The half width of the azimuthal intensity distribution of the (040) plane in the two-dimensional wide-angle X-ray scattering image can be used to determine the degree of crystal orientation by the following expression (3). Note that, assuming that the scattering angle width used for calculating the azimuthal intensity distribution is within ± 0.5 ° from the diffraction peak position derived from the above (040) plane:

degree of crystal orientation (%) { (180-hw)₀₄₀) /180 × 100 expression (3)

Wherein hw₀₄₀Represents the half width (unit: degree) in the azimuthal intensity distribution of the (040) plane in the α crystal of component B1.

In the case where the value of the degree of crystal orientation is high, it can be said that the c-axis or the a-axis of the α crystal of the component B1 is oriented parallel to the direction in which each component contained in the laminate for extrusion molding flows during hot extrusion.

The degree of crystal orientation of component B1 contained in the automobile roof member is, for example, 75% or more, and preferably 80% or more.

The member for an automobile roof of the present embodiment can be produced by extrusion-molding the laminate for extrusion molding at the above extrusion ratio. That is, the method for producing the member for an automobile roof of the present embodiment includes the steps of: the laminate for extrusion molding is extruded in such a manner that the sum of the thickness of the layer a-a, the thickness of the layer B, and the thickness of the layer a-B accounts for 70% or more and 93% or less.

The step of extrusion molding is, for example, a step of hot extrusion at a temperature close to the melting point of component B1.

In the hot extrusion of the laminate for extrusion molding, the temperature of the pressurized portion to be brought into contact with the laminate for extrusion molding in the apparatus for hot extrusion is a temperature close to the melting point (Tm) of component B1, preferably a melting point (Tm) -20 ℃ or higher and a melting point (Tm) +10 ℃ or lower, and more preferably a melting point (Tm) -10 ℃ or higher and a melting point (Tm) +5 ℃ or lower.

The time for thermally extruding the laminate for extrusion molding is preferably 15 seconds or more and 60 minutes or less, more preferably 1 minute or more and less than 30 minutes, and even more preferably 10 minutes or more and less than 15 minutes, in order to improve the impact resistance of the member for automobile roofs and prevent thermal degradation of the components contained in the laminate for extrusion molding.

Examples of the apparatus for hot-extruding the laminate for extrusion molding include a press-molding apparatus having a temperature adjusting function, a track-type hot press-molding apparatus, a pressurizable belt-type sealer, and a roll-molding apparatus. As the hot extrusion method, a method of hot extruding the laminate for extrusion molding in the thickness direction by a press molding apparatus having a temperature adjusting function is preferable.

From the viewpoint of increasing the load on the apparatus at the time of extrusion ratio and the viewpoint of obtaining a large-sized member for an automobile roof, a press molding apparatus having a temperature adjusting function is preferable. With the molding apparatus, a large member for a vehicle roof having any portion with a length of more than 40cm when viewed from the top surface can be easily obtained.

As a method for hot-extruding the laminate for extrusion, it is also possible to apply a lubricant on a pressing portion of the hot-extrusion apparatus to be in contact with the laminate for extrusion. Examples of lubricants include silicone oils. The application of the lubricant reduces frictional resistance between the laminate for extrusion molding and the pressing portion to enable smoother hot extrusion of the laminate for extrusion molding, resulting in an improvement in molding cycle and a reduction in load on the apparatus for hot extrusion.

The member for an automobile roof of the present embodiment has excellent coatability. Such a member for an automobile roof has low heat distortion, excellent impact resistance and high elastic bending strength. According to the method for producing an automotive roof member of the present invention, an automotive roof member having excellent coatability can be produced. Further, according to the method for producing a member for an automobile roof of the present invention, the load on the equipment for extrusion molding is reduced.