JPH03153349A - Polypropylene laminated sheet - Google Patents

Abstract

PURPOSE:To attempt to form a surface layer with excellent pearl feeling, high surface hardness and excellent scratch resistance by preparing the surface layer by compounding a crystalline polypropylene homopolymer with a high degree of crystallinity with a nucleating agent and a pearl pigment and with a specified thickness. CONSTITUTION:The laminated sheet consists of a combination of two layers selected from a layer (A) prepd. by incorporating a nucleating agent and a pearl pigment in a crystalline polypropylene homopolymer with a degree of crystallinity of 0.945 or higher, a layer (B) prepd. by incorporating each a white pigment in a crystalline polypropylene homopolymer with a Q value of 8 or larger or one or more crystalline propylene-alpha-olefin block copolymers, a foamed layer (C) consisting of a compsn. incorporated with a white pigment, a layer (D) wherein a white pigment and an inorg. filler are incorporated and a foamed layer (E) consisting of a compsn. wherein a white pigment and an inorg. filler are incorporated. These layers are laminated in a combination of A/B, A/B/A, A/C, A/C/A, A/D, A/D/A, A/E or A/E/A and the thickness of one layer of the layer A in each laminated body is 30-500mum.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a laminated sheet of crystalline polypropylene having a surface with excellent scratch resistance and burl texture, and excellent thermoformability.

[Conventional technology]

Conventionally, sheets using polypropylene resins have been widely used in various industrial fields because of their excellent heat resistance, chemical resistance, and mechanical strength. In addition, sheets made of polypropylene resin with a burr feel have also been developed and are in use.

However, the conventionally known polypropylene resin sheets with a pearly feel do not have an adequate pearly feel because they are made by simply adding a burr pigment to a general polypropylene resin and then form a sheet as a single layer. Although the pearlescent feel was good, there were problems such as insufficient scratch resistance and thermoformability.

A common method for imparting a pearlescent feel to a polypropylene resin sheet is to add a pearlescent pigment to the resin to form a sheet.

In this method, a crystalline propylene-α-olefin random copolymer (α
-Olefins include ethylene, butene-1, pentene-1, hexene-1, pentene-1, octene-1,
When decene-1 and a mixture of two or more of these are used, the scratch resistance and heat resistance are insufficient, and when a general polypropylene homopolymer is used, the burl feel is insufficient. Further, when a crystalline propylene-α-olefin block copolymer containing propylene as a main component is used, the pearly feel is also insufficient. That is, even if these are made into a single-layer sheet made of the same material, the pearly feel will be lacking in depth and the thermoformability will be insufficient.

[Problem to be solved by the invention]

The object of the present invention is to provide a polypropylene resin sheet imparted with a pearly feel, which has an excellent pearly feel and scratch resistance, and also has excellent thermoformability.

[Means to solve the problem]

The present inventors conducted extensive research to solve the problems of the prior art, and as a result, they discovered that the problems could be solved by creating a laminated sheet having the following configuration, and completed the present invention.

That is, the present invention provides a layer (A) in which a nucleating agent and a Burr pigment are added to a homopolymer of crystalline polypropylene having a crystallinity of 0.945 or more, a homopolymer of crystalline polypropylene having a Q value of 8 or more, or Crystalline propylene-α-olefin block copolymer Layer (B) in which one or more whitening pigments are added
, a foamed layer (C) consisting of a composition in which a white pigment is added to one or more types of crystalline polypropylene homopolymer or crystalline propylene-α-olefin block copolymer having a Q value of 8 or more, a Q value of 8 or more layer (D) in which a white pigment and an inorganic filler are added to one or more types of crystalline polypropylene homopolymer or crystalline propylene-α-olefin block copolymer; Homopolymer or crystalline propylene-a-olefin block copolymer IFJ
The foamed layer (E) is composed of a composition to which a white pigment and an inorganic filler are added.
A/B/A1A/C, A/C/A, A/DSA/D/A
SA/E or A/E/A1. This is a polypropylene laminate sheet in which the thickness of each A layer of each laminate including the MFA layer is 30 to 500 μm.

The homopolymer crystallinity of the crystalline polypropylene used in layer A is a characteristic value that indicates crystallinity (stereoregularity). is in the range of 0.85 to 0.92. The degree of crystallinity can be measured by an analytical method such as infrared analysis or nuclear magnetic resonance.

For example, in measurements by infrared spectroscopy, a test piece with an appropriate thickness (for example, 40 μm) is prepared, and the ratio of absorbance at wave numbers 1 997 cm and 977 am-' (A99
7/A 977) is the crystallinity. Crystallinity is 0.9
When a pearl pigment is added to a polypropylene homopolymer with a particle diameter of 45 or higher, preferably 0.950 or higher, a burr feeling superior to that obtained using a polypropylene homopolymer with a low degree of crystallinity is obtained, and a nucleating agent is further added to this. However, we found that this effect also depends on the thickness of the sheet, and that this effect almost disappears when the thickness of the sheet exceeds 0.51 mm. By forming two surface layers, it became possible to obtain a sheet with an excellent burl feel.

Furthermore, as the degree of crystallinity increases, the surface hardness of the sheet increases, and the scratch resistance of the obtained sheet also improves.

The thickness of the A layer is 30 to 500 μm, but if it exceeds 500 μm, there will be no significant difference in the burr feel from that using a normal polypropylene resin for the above-mentioned reasons. 3
If it is less than 0 μm, the layer thickness becomes too thin and the underlying layer becomes visible, which impairs the pearly feel, which is not preferable.

A method for achieving crystallinity of 0.945 or higher is to react a reaction product of a special catalyst such as an organoaluminum compound (diethyl aluminum monochloride, etc.) with an electron donor (diisoamyl ether, etc.) with titanium tetrachloride. The obtained solid product is further reacted with an electron donor (diisoamyl ether, etc.) and an electron acceptor (titanium tetrachloride, etc.), and the obtained solid product (I) is reacted with an organoaluminum compound (diethyl aluminum chloride, etc.) and aromatic carboxylic acid esters (such as methyl paratoluate)
In combination with ■, the molar ratio of (n)/(1) is 0.1 to 1.
It can be produced by polymerizing propylene using a catalyst reduced to zero.

The amount of the nucleating agent additive is preferably 0.03 to 0.3% by weight, regardless of the thickness and the amount of pearl pigment added. If the amount added is less than 0.03% by weight, the pearly feeling improvement effect will be small;
Moreover, even if it exceeds 0.3!11%, the above-mentioned improvement effect will be saturated and no further improvement effect will be achieved.

Further, the amount of pearl pigment added is about 1 to 5% by weight.

The polypropylene resin used in the B, C, D, and E layers other than the A layer is a homopolymer of crystalline polypropylene with a Q value of 8 or more, or a polypropylene-based resin containing propylene as the main component and a mixture of propylene and α-olefins (e.g., ethylene, butene-1, Pentene-1, Hexene-1, Pentene-1, Octene-1
1, decene-1, and mixtures of two or more thereof). The Q value is a characteristic value that indicates the molecular weight distribution of the polypropylene resin, and is calculated by the weight average molecular weight (Mw) and number average molecular weight (Mw) of the polypropylene resin.
Mn) ratio (Mw/Mn), and the larger this value is, the broader the molecular weight distribution is, and the Q value of a typical polypropylene resin is 3 to 7.

Methods for increasing the Q value to 8 or more include multistage polymerization;
Methods using special catalysts are known. For example, in the multistage polymerization method, several polymerization vessels are connected in series, and propylene or propylene and α-olefin are continuously produced while adjusting the concentration of the catalyst and hydrogen as a polymerization degree regulator supplied to each polymerization vessel. It can be produced by polymerizing.

By setting the Q value to 8 or more, it is possible to obtain a laminated sheet with good thermoformability such as vacuum moldability, pressure moldability, and compression moldability.

Adding pearl pigment to layer A reduces the thermoformability of layer A, but to compensate for this, Q is added to layers other than layer A.
By using a polypropylene resin with a value of 8 or more, it is possible to obtain a multilayer sheet with no practical problems. B,C,
There is no particular restriction on the degree of crystallinity of the above-mentioned polypropylene resin used for the D and E layers.

Since the B, C, D, and E layers contain a white pigment, they can be used as a back layer or an intermediate layer of the A layer to give the A layer a deeper pearly feel.

The amount of the white pigment added is preferably 0.5 to 3% by weight, and the thinner the layer, the more preferably the amount added is increased.

Layer B and layer D are unfoamed layers, but if you want to improve heat resistance and rigidity, use layer D, which is made by adding an inorganic filler to polypropylene resin, to achieve high heat resistance and rigidity. It is possible to manufacture laminated sheets. The amount of the inorganic filler added is preferably 5 to 50% by weight. If the amount added is less than 5% by weight, the effect of improving the stiffness of the resulting laminate sheet is small, and if it exceeds 50% by weight, the thermoformability such as vacuum formability of the resulting laminate sheet is reduced.

Layer 0 and layer E are foamed layers. Foaming ratio is 1.1~
1.5 times is common. By using a foam layer, not only is the weight reduced and the heat insulation improved, but also an uneven pattern is imparted to the A layer, providing the same effect as embossing.

If it is desired to impart heat resistance or rigidity to the laminated sheet, the purpose can be achieved by using an E layer containing an inorganic filler.

The sheet can be foamed by adding a pyrolytic foaming agent such as azodicarbonamide and extruding it, or by injecting a substance that is gaseous at room temperature, such as air, Freon, or carbon dioxide, into a part of the cylinder of an extruder and melting it. Methods such as extrusion with resin are known, and the present invention can also produce foamed sheets using these methods. When a pyrolyzable foaming agent is used, the amount of the foaming agent added is generally 0.15 to 0.5% by weight.

When producing a sheet with a high expansion ratio, it is necessary to increase the amount added.

Examples of polypropylene and each additive used in the present invention are shown below.

In addition to the above-mentioned properties, polypropylene also has a melt flow rate (MFR). MFR is measured according to JIS K-6758 and is a characteristic value indicating flow characteristics. In the present invention, M
Although there is no FH regulation, the appropriate MFR of the crystalline polypropylene homopolymer for the A layer is 1 to 5 g/10 minutes, and the MFR of the polypropylene resin for the BSC%D1E layer is the same as the multilayer sheet of the present invention. 0.2 to 1.0 g/10 minutes when used for vacuum forming, 0.2 to 5.0 g/10 minutes when used for pressure molding, 0.5 to 20 g/10 minutes when used for compression molding. A 10 minute polypropylene resin is suitable.

Pearl pigments: Commonly used mica tubes coated with titanium dioxide or iron oxide, bismuth oxychloride crystal tubes, etc., but are not limited to these. The amount added varies depending on the pigment used and the thickness of the sheet, but is generally 1 to 5% by weight.

Nucleating agent: Aluminum P-t-butylbenzoate, sodium salt of methylene bis(2,4-di-t-butylphenol) acid phosphate, sodium bis(4-t-butylphenyl) phosphate, 1.3,2. 4-di(P-
Examples include sorbitol compounds such as methylbenzylidene) sorbitol, bis(P-ethylbenzylidene) sorbitol, and 2,2'-methylenebis(4,6-di-t-butylphenyl) sodium phosphate, but are limited to these. It is not something that will be done.

In addition to the white pigment titanium dioxide, calcium carbonate and calcium oxide, which have high whiteness, can also be used, but are not limited to these.

Inorganic fillers: talc, calcium carbonate, clay,
Examples include barium sulfate, calcium sulfate, silica, mica, glass fiber, etc., but are not limited thereto.

The laminated sheet of the present invention contains an antioxidant,
Coloring agents other than white, weathering agents, antistatic agents, dispersants, synthetic resins other than polypropylene resins, synthetic rubbers, etc. can be appropriately added and used.

Coextrusion methods, extrusion lamination methods, thermal lamination methods, dry lamination methods, and the like are known as methods for producing multilayer sheets, and any one of these methods can also be used in the present invention.

Coextrusion method and extrusion lamination method are suitable from the viewpoint of productivity.

〔Example〕

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the same extent by these Examples.

The resin used, composition, thickness, etc. are as follows.

In addition, each of the following compositions contains 0.1% by weight of butylated hydroxytoluene and tetrakis[methylene-
3-(3', 5'-di-t-butyl-4'
-Hydroxyphenyl)propionate comethane at 0.
05% by weight, 0.05% by weight of calcium stearate
, 0.10% by weight of zinc stearate was added.

A layer: MFR-2g/10min crystalline polypropylene homopolymer, crystallinity -0,950,0,9550,9
70 3FJ.

Added 4 types of nucleating agents with thicknesses of 50μ, 100μ, 250μ, and 450μ - 1,3゜2.4-di (p
-Methylbenzylidene) sorbitol (trade name Gelol MD), phosphoric acid 2゜2' manufactured by Adeka Argus Chemical ■
-Methylenebis(4,6-di-t-butylphenyl)sodium (trade name mark NA-11), added amount 0.1
5% by weight Pearl pigment: t! Pearl white manufactured by L Marl Corporation, additive amount 2% by weight B layer: MFR-0.5g/
10 minutes, block copolymer of homopolypropylene with a crystallinity of 0.920 and ethylene/propylene with a crystallinity of 0.900 Q value - 9,5,15,0 Thickness - 450μ, white pigment - manufactured by Sakai Chemical Industry ■ Added 1% by weight of rutile titanium dioxide.

0 layer: MFR-0,5+r/10 min crystalline ethylene-propylene block copolymer (ethylene containing f
f18fffffi%, Q value -9.5, thickness, white pigment is the same foaming agent as B layer - 0.35% by weight of azodicarbonamide was added to make the expansion ratio 1.25 D layer: MFR - 0.5g /10 minutes of crystalline ethylene.
Propylene block copolymer, Q value -9.5, thickness, white pigment is the same as layer B, inorganic filler - Talc manufactured by Hayashi Kasei ■ (Micron White 5000S, particle size 2.8μ) used. Added ff1lo, 25% by weight B layer: Foaming agent (azodicarbonamide) added to the D layer composition
was added in an amount of 0.35% by weight to give an expansion ratio of 1.25.

Manufacture of laminated sheets Equipped with two extruders with cylinder diameters of 90 mm and 65 mm, and a multi-manifold type with a T-die width of 1,000 mm, we can produce sheets of 2 types, 2 layers, and 2 types, 3 layers. Using co-extrusion equipment that can produce, layer A material is put into a 651mm Φ extruder, and B is put into a 90mm Φ extruder.

Materials C, D, and E were supplied, the resin temperature was adjusted to 210°C, the thickness of each layer was adjusted to the thickness of the example and comparative example, and a sheet was extruded, which was guided to a cooling roll and cooled. A laminated sheet was obtained.

Evaluation method Pearl feeling: Clarity, depth, etc. were visually judged and ranked as follows.

◎ Good 0 Good although the sharpness is slightly decreased Δ Slightly poor due to a large decrease in sharpness etc.

5B→4B→3B-B-F4H→ Hardness in order of 2H → 3H → 4H → 5H becomes higher and has better scratch resistance. Growth Preferred when using shaped products The pencil hardness is H or higher.

Thermoformability: Containers with a size of 150 x 200 x 35 were molded using a vacuum forming method, and the molded products were ranked as follows based on their fillet properties, drawdown properties during molding, etc.

◎ Good 0 Practically usable Δ Poor drawdown properties and practical problems × Poor formability (Examples 1 to 11. Comparative Examples 1 to 7) Sheets with layer configurations of A/B and A/B/A was created with the contents shown in Table 1, and its performance was investigated.

From Table 1, the examples that meet the present invention are excellent in pearl properties, pencil hardness, and thermoformability, but the comparative examples that do not meet the invention are excellent in pearl properties, pencil hardness, and thermoformability. It turns out that there are practical problems.

(Examples 12 to 19) The test results are shown in Table 2. Examples 12 to 14 and 18 and 19, which used the foamed 0 layer and E layer, had good pearl properties while the AJW surface was A molded product with a high value-added state was obtained, as if it had been embossed. In Examples 15 to 19, in which layers D and E to which talc was added were used, molded products having stiffness about 1.3 to 2 times higher than products to which no talc was added were obtained.

〔Effect of the invention〕

In the present invention, layer A, which is the surface layer, is made by blending a nucleating agent and a sisseir pigment into a homopolymer of crystalline poly-propylene resin with a high degree of crystallinity. ~5
Assuming 00 μm, j,,',', >"<'"
The surface layer has excellent texture, high surface hardness, and excellent scratch resistance. The B, C, D, and E layers, which are the back layer or intermediate layer, use crystalline polypropylene homopolymer or crystalline propylene-α-olefin block copolymer with a Q value of 8 or more, so thermoformability is improved. You can make it better.

B, C, D, and E layers contain white pigments, so A
As a backing for the layer, the crowbar feel of the A layer has more depth.

Layer B and layer D are unfoamed layers, but by using layer D to which an inorganic filler is added, a laminated sheet with higher heat resistance and rigidity can be obtained.

Since the laminated sheet with 0 layer and E layer has a foam layer, it is not only lighter and has improved heat insulation properties, but also has the same effect as embossed material, and has an inorganic filler added. By providing layers, it is possible to obtain a sheet with further improved heat resistance and rigidity.

That is, the laminated sheet of the present invention has an excellent pearlescent feel and scratch resistance, and also has excellent thermoformability.

Claims (1)

[Claims] A layer in which a nucleating agent and a pearl pigment are added to a homopolymer of crystalline polypropylene having a crystallinity of 0.945 or more (
A), a layer in which a white pigment is added to one or more types of crystalline polypropylene homopolymer or crystalline propylene-α-olefin block copolymer having a Q value of 8 or more (B)
, a foamed layer (C) consisting of a composition in which a white pigment is added to one or more types of crystalline polypropylene homopolymer or crystalline propylene-α-olefin block copolymer having a Q value of 8 or more, a Q value of 8 or more A layer (D) in which a white pigment and an inorganic filler are added to one or more types of crystalline polypropylene homopolymer or crystalline propylene-α-olefin block copolymer, a crystalline polypropylene homopolymer having a Q value of 8 or more From the following two combinations selected from the group consisting of a foamed layer (E) consisting of a composition in which a white pigment and an inorganic filler are added to one or more polymers or crystalline propylene-α-olefin block copolymers. and these layers are A/B, A/B/A, A/C, A/C/A, A/D, A
A polypropylene laminate sheet which is laminated in /D/A, A/E, or A/E/A, and the thickness of each A layer of each laminate is 30 to 500 μm.