JPH10329191A - Method for producing olefin-based laminated sheet - Google Patents

Abstract

(57) Abstract: An object of the present invention is to provide an olefin-based laminated sheet which is excellent in grain retention and moldability, and is capable of obtaining a beautiful molded article having excellent thermal stability and having no surface whitening. And a method for producing the same. SOLUTION: A propylene-based resin layer is formed on one surface of each of two cross-linked foamed sheets made of a propylene-based resin and an ethylene-based resin by extrusion lamination to form two laminates, and each cross-linking of the laminates is performed. In the method for producing an olefin-based laminated sheet in which a surface on the foam sheet side is melted and pressed to form a heat-sealing layer on the portion, at least one of the propylene-based resin layers is a homopropylene resin and / or a block propylene resin 100.
Parts by weight, 1 to 50 parts by weight of a low-melting-point propylene-based resin and 1 to 50 parts by weight of an inorganic filler, and is characterized by forming a concavo-convex pattern on the surface of the layer during extrusion lamination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin laminate sheet used for interior materials for automobiles and the like.

[0002]

2. Description of the Related Art Interior materials for automobiles, particularly ceiling materials for automobiles, are required to have properties such as lightness, moldability, heat resistance, and deflection resistance. As a device satisfying the required performance, Japanese Patent Publication No. 9137/1992 discloses a laminated sheet in which a non-foamed propylene polymer sheet is laminated on both sides of a cross-linked foamed sheet composed of an ethylene polymer and a propylene polymer. And Japanese Patent Publication No. 6-24767 discloses a non-foamed skin made of a propylene polymer on one surface of two crosslinked foamed sheets made of a propylene polymer and an ethylene polymer. There is disclosed a method for manufacturing an interior material for an automobile in which layers are laminated, and the crosslinked foamed sheets of the obtained laminate are melted and pressure-bonded to be integrated.

[0003] Since the interior material for automobiles is generally used after forming a grain pattern on the surface thereof, the laminated sheet and the interior material for automobile have a grain pattern on the surface. After being formed, it is used after being formed into a desired shape while maintaining the grain pattern.

[0004] However, both the laminated sheet and the interior material for automobiles have a skin layer made of a propylene-based polymer laminated on the surface thereof, and the surface layer has a textured pattern. In order to maintain the formed grain pattern, it is necessary to mold at a temperature 20 to 30 ° C. lower than the melting point of the propylene polymer forming the surface layer. There has been a problem that the formability of the entire material is low and deep drawing is difficult.

[0005] Therefore, in forming, the surface on which the grain pattern is formed is kept at a low temperature while the surface on which the grain pattern is not formed is kept at a high temperature, and a temperature gradient is applied in the thickness direction of the laminated sheet and the interior material for automobiles. However, in this case, molding distortion occurs in the molded products, and when these molded products are left in a high temperature range of about 85 ° C., which is practically necessary,
There was a problem that a warp or the like was deformed on the molded product.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to an olefin-based laminated sheet which is excellent in grain retention and moldability, and which can provide a beautiful molded article which is excellent in thermal stability and does not cause whitening on the surface. It is to provide a manufacturing method of.

[0007]

According to the method for producing an olefin-based laminated sheet of the present invention, a propylene-based resin layer is formed by extrusion lamination on one surface of each of two crosslinked foamed sheets composed of a propylene-based resin and an ethylene-based resin. Forming a two-laminate product, melting and pressing each surface of the laminate product on the crosslinked foam sheet side, and forming a heat-sealing layer on the portion; At least one of the resin layers is composed of 100 parts by weight of a homopropylene-based resin and / or a block propylene-based resin, 1 to 50 parts by weight of a low-melting-point propylene-based resin, and 1 to 50 parts by weight of an inorganic filler. It is characterized in that an uneven pattern is formed during lamination.

First, the cross-linked foam sheet used in the present invention will be described. Propylene resin (hereinafter referred to as "propylene resin (A)") constituting the crosslinked foamed sheet used in the method for producing the olefin laminate sheet.
Is a copolymer with another monomer containing propylene as a main component, and examples thereof include a propylene-α-olefin copolymer, and a propylene-α-olefin copolymer is a block copolymer or a random copolymer. Any of a polymer and a random block copolymer may be used, and these may be used alone or in combination.

The above-mentioned α-olefin includes, for example, ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene and 1-octene. If the content of the α-olefin in the α-olefin copolymer is large, the surface properties of the crosslinked foamed sheet may be reduced, and if the content is small,
Since the flexibility and elongation of the crosslinked foamed sheet may be reduced and the moldability may be reduced, the content is preferably 1 to 8% by weight,
5% by weight is more preferred.

The propylene resin (A) has a large melt index (hereinafter referred to as “MI”).
The heat resistance of the crosslinked foamed sheet may be reduced, and if the heat resistance is reduced, the moldability of the crosslinked foamed sheet may be reduced and the surface property of the obtained molded product may be reduced. 10 minutes is preferred. In the present invention, MI refers to that measured in accordance with JIS K7210.

Further, the above-mentioned propylene resin (A)
If the amount eluted at 94 ° C or higher by
As the moldability of the foamed sheet decreases, the resulting molding
The surface properties of the product may be reduced,
The heat resistance of the foamed sheet is reduced, and air bubbles are broken during molding.
50 to 95% by weight is preferable,
0 to 90% by weight is more preferred. And the cross fractionation method
The weight average molecular weight of the eluate at 94 ° C or higher by
In this case, the moldability of the crosslinked foamed sheet decreases and
The surface properties of the resulting molded product may also be
In this case, the heat resistance of the crosslinked foamed sheet decreases,
2 × 10 ^Five -10 × 10
^Five Is preferred.

The propylene resin (A) has an MI of 0.2 to 10 g / 10 min, an elution amount at 94 ° C. or higher of 50 to 95% by weight by a cross separation method, and a weight average of the elution amount. Most preferred is a propylene-α-olefin copolymer having a molecular weight of 2 × 10 ⁵ to 10 × 10 ⁵ .

The elution amount by the cross fractionation method and the weight-average molecular weight of the elution portion referred to in the present invention are those measured by the following method. That is, first, after the resin is dissolved in o-dichlorobenzene at 140 ° C. or a temperature at which the resin is completely dissolved, the resin is cooled at a constant temperature, and the surface of the inert carrier prepared in advance has high crystallinity. It is formed as a thin polymer layer in order. Next, the temperature is raised continuously or stepwise, the temperature of the eluted components is sequentially detected, and the composition distribution (crystallinity distribution) is measured. This is referred to as temperature rise elution fractionation. At the same time, the eluted components are analyzed by high-temperature GPC to measure the molecular weight and the molecular weight distribution. This allows
The amount eluted at each temperature and the weight average molecular weight of the eluted portion are calculated. In the present invention, a cross-separation chromatograph (trade name "C manufactured by Mitsubishi Chemical Corporation") having both the above-mentioned temperature-eluting elution fractionation part and the high-temperature GPC part as a system is provided.
FC-T150A type ").

The ethylene-based resin (hereinafter referred to as "ethylene-based resin (A)") constituting the crosslinked foamed sheet used in the above-mentioned method for producing an olefin-based laminated sheet is used in combination with another monomer containing ethylene as a main component. A polymer, for example, ethylene-α-olefin copolymer,
These may be used alone or in combination.

The α-olefin includes, for example, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene,
Octene, etc., and the ethylene content in the ethylene-α-olefin copolymer is low. If the content is small, the heat resistance of the crosslinked foamed sheet may be reduced. Therefore, the content is preferably 60% by weight or more, and more preferably 80% by weight or more. Is more preferred.

The MI of the ethylene resin (A) is as follows:
If it is large, the heat resistance of the crosslinked foamed sheet may decrease, and the surface properties of the obtained molded article may also decrease.
Also, when the size is reduced, the flowability of the resin component may be reduced and the productivity of the crosslinked foamed sheet may be reduced.
10 g / 10 min is preferable, 0.7 to 4 g / 10 min is more preferable, and 0.9 to 3 g / 10 min is particularly preferable.

Further, if the amount of the ethylene resin (A) eluted at 94 ° C. or higher by the cross fractionation method is large, the recovery of the crosslinked foamed sheet from the compressive strain may be reduced. Since the heat resistance of the crosslinked foamed sheet may be reduced and the surface properties of the obtained molded article may be reduced, the content is preferably 5 to 20% by weight, more preferably 6 to 10% by weight. If the weight average molecular weight of the elution at 94 ° C. or higher by the cross fractionation method is large, the recovery of the crosslinked foamed sheet from the compressive strain may be reduced,
Further, when the particle size is small, the heat resistance of the crosslinked foamed sheet is reduced, and the surface property of the obtained molded product is sometimes reduced. Therefore, 1.5 × 10 ⁵ to 10 × 10 ⁵ is preferable, and 2 × 1
0 ^{5 to} 5 × 10 ⁵ is more preferable.

The ethylene resin (A) has an MI of 0.5 to 10 g / 10 min, an elution amount at 94 ° C. or higher of 5 to 20% by weight by a cross separation method, and a weight average of the elution amount. Most preferred is an ethylene-α-olefin copolymer having a molecular weight of 1.5 × 10 ⁵ to 10 × 10 ⁵ .

The crosslinked foamed sheet comprises the propylene-based resin (A) and the ethylene-based resin (A). When the content of the propylene-based resin (A) is large, the flexibility and compression strain of the crosslinked foamed sheet are increased. In some cases, the recovery of the crosslinked foamed sheet may be reduced, and when the amount is small, the heat resistance of the crosslinked foamed sheet is reduced. Therefore, the weight is preferably 50 to 90% by weight, more preferably 55 to 85% by weight. The ethylene resin (A)
Is preferably 50 to 10% by weight, and more preferably 45 to 15% by weight.
% Is more preferred.

The combination of the propylene resin (A) and the ethylene resin (A) may be a propylene resin (A) having an MI of 0.2 to 10 g / 10 min. Elution amount of 50-95% by weight
And the weight average molecular weight of the eluted portion is 2 × 10 ⁵ to 10 × 1.
With 0 ⁵ a is propylene -α- olefin copolymer, as the ethylene-based resin (A), MI is 0.5 to 10
g / 10 min, the amount of elution at 94 ° C. or higher by the cross fractionation method is 5 to 20% by weight, and the weight average molecular weight of the eluted portion is 1.5%.
It is preferable to use an ethylene-α-olefin copolymer having a size of × 10 ⁵ to 10 × 10 ⁵ .

Next, a method for producing the crosslinked foamed sheet will be described. As a method for producing a crosslinked foamed sheet, any known method for producing a foam can be used, and an example thereof will be described below.

That is, first, a crosslinking aid is added to a resin component comprising a propylene resin (A) and an ethylene resin (A).
In addition to the pyrolytic foaming agent, if necessary, an antioxidant, a metal harm inhibitor, a heat stabilizer, a pigment, etc. are added, and these are added to a single screw extruder, a twin screw extruder, a Banbury mixer, a kneader mixer. , Melt-kneaded at a temperature lower than the decomposition temperature of the pyrolytic foaming agent in a kneading device such as a roll, extruded into a sheet shape, irradiated the resulting sheet with ionizing radiation, crosslinked the sheet, A method of producing a crosslinked foamed sheet by heating the foaming agent to a temperature equal to or higher than the decomposition temperature of the foaming agent to foam the sheet.

As the crosslinking aid, generally used polyfunctional monomers and monofunctional monomers are used. For example, divinylbenzene, trimethylolpropane trimethacrylate, 1,9-nonanediol dimethacrylate, 1,1 10-decanediol dimethacrylate, triallylic acid triallyl ester, triallyl isocyanurate, ethylvinylbenzene, neopentyl glycol dimethacrylate, 1,2,4-benzenetricarboxylic acid triallyl ester, 1,6-hexanediol dimethacrylate , Lauryl methacrylate, stearyl methacrylate and the like, which may be used alone or in combination.

If the amount of the crosslinking aid is small, the crosslinking is insufficient and a uniform crosslinked foamed sheet may not be obtained. On the other hand, if the amount is large, the crosslinking density is increased and the moldability of the crosslinked foamed sheet is deteriorated. Since it may decrease, the amount is preferably 0.5 to 10 parts by weight, and more preferably 0.8 to 6 parts by weight based on 100 parts by weight of the total amount of the propylene-based resin (A) and the ethylene-based resin (A).
Parts by weight are more preferred.

The pyrolytic foaming agent is not particularly limited as long as it has been conventionally used in the production of foams. For example, azodicarbonamide, hydradodicarbonamide, barium azodicarboxylate, Nitrosoguanidine, p, p'-oxybisbenzenesulfonyl semicarbazide, benzenesulfonyl hydrazide, N,
N'-dinitrosopentamethylenetetramine, toluenesulfonyl hydrazide, 4,4-oxybis (benzenesulfonyl hydrazide), azobisisobutyronitrile, and the like, among which the decomposition temperature is 180 to 270
C. is preferred.

The amount of the pyrolytic foaming agent to be added is appropriately adjusted according to the desired expansion ratio of the crosslinked foamed sheet. If the amount is large, the foam may be broken. Therefore, with respect to 100 parts by weight of the total amount of the propylene-based resin (A) and the ethylene-based resin (A), 3 to
It is preferably 40 parts by weight, more preferably 4 to 25 parts by weight.

The degree of crosslinking by ionizing radiation is as follows:
The gel fraction is adjusted as a guide, as the gel fraction,
If it is large, the moldability of the crosslinked foamed sheet may be reduced, and if it is small, the flexural strength of the crosslinked foamed sheet may be reduced, so that it is preferably 30 to 70% by weight, more preferably 40 to 65% by weight. %, And the ionizing radiation dose is usually 1 to 20 Mrad. The ionizing radiation is not particularly limited as long as it is conventionally used for crosslinking a foam, and examples thereof include α-rays, β-rays, γ-rays, and electron beams.

In the present invention, the gel fraction refers to a value measured by the following method. First, a predetermined amount of a crosslinked foamed sheet is weighed, immersed in 25 ml of xylene at 120 ° C. for 24 hours, filtered through a 200-mesh stainless steel wire mesh, and the insoluble matter on the wire mesh is vacuum-dried. next,
The weight of the vacuum-dried insoluble matter is weighed, and the gel fraction is calculated by the following formula. [Gel fraction (%)] = (weight of insoluble matter / weight of weighed crosslinked foam sheet) × 100

The antioxidant is not particularly limited as long as it has been conventionally added to a crosslinked foamed sheet. For example, a phenolic antioxidant such as 2,6-di-t-butyl-p-cresol is used. Oxidizing agents, sulfur-based antioxidants such as dilaurylthiopropionate, phosphorus-based antioxidants, amine-based antioxidants and the like can be mentioned.

The metal damage inhibitor is not particularly limited as long as it has been conventionally added to the crosslinked foamed sheet, and examples thereof include methylbenzotriazole.

If the expansion ratio of the above-mentioned crosslinked foamed sheet is large, the mechanical strength of the crosslinked foamed sheet may decrease, and if it is small, the lightness of the crosslinked foamed sheet may decrease. 50 times is preferred, and 15 to 40
Double is more preferred. Incidentally, the expansion ratio in the present invention,
It refers to the volume of the crosslinked foamed sheet divided by its weight.

Next, in the method for producing an olefin laminate sheet of the present invention, first, two crosslinked foamed sheets are prepared, and a propylene resin layer is formed on one surface of each of the crosslinked foamed sheets by extrusion lamination. Obtain one laminate.

The propylene resin constituting the propylene resin layer (hereinafter referred to as “propylene resin (B)”)
Is not particularly limited, and in addition to the homopropylene resin, the same propylene-based resin (A) used in the crosslinked foamed sheet is used, and these may be used alone or in combination. And these propylene-based resins (B)
Among them, homoolefin resin, block propylene resin, when used alone from the viewpoint that the obtained olefin-based laminated sheet is excellent in grain retention and thermal stability,
When used in combination, a combination of a homopropylene resin and a block propylene resin is preferred.

As the homopropylene resin, an isotactic propylene resin having excellent mechanical strength, heat resistance and friction resistance is preferable. Examples of the block propylene resin include a propylene-α-olefin block copolymer containing propylene as a main component.
Examples of the olefin include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and the like, with ethylene being preferred. The melting point of block propylene resin is
If it is high, the moldability of the obtained olefin-based laminated sheet is reduced, and whitening may occur on the surface during molding, and if it is low, the grain retention of the olefin-based laminated sheet may be reduced, 160-170 ° C is preferred. In the present invention, the melting point is defined as a heating rate of 10
Refers to the peak temperature of the differential thermal analysis curve in ° C./min.

If the MI of the propylene-based resin (B) is large, the melt viscosity is reduced, making it difficult to form a sheet.
On the other hand, when it is small, molding distortion tends to remain when the olefin-based laminated sheet is molded, and molding stability is reduced.

In the present invention, at least one of the propylene resin layers extruded and laminated on one side of the crosslinked foamed sheet is composed of 100 parts by weight of a homopropylene resin and / or a block propylene resin, 1 to 50 parts by weight of resin and inorganic filler 1
Consists of 50 parts by weight. As described above, by forming at least one propylene-based resin layer having a specific structure, beautiful molding that is excellent in grain retention and moldability, has excellent thermal stability, and does not cause whitening on the surface. An olefin-based laminated sheet from which a product can be obtained can be obtained. The homo-propylene resin and the block propylene resin are the same as those described for the propylene-based resin (B), and a description thereof will not be repeated.

The low-melting propylene resin is not particularly limited as long as it has a melting point lower than that of the propylene resin (B). For example, a propylene-α-olefin random copolymer, propylene -Ethylene-butene terpolymer and the like;
Examples of the olefin include ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene and the like, with ethylene being preferred.

When the content of the α-olefin is large, the heat resistance of the propylene-based resin layer is reduced, and the grain retention is reduced. Since whitening may occur on the surface,
-10% by weight is preferred.

If the melting point of the low melting point propylene resin is high, whitening may occur on the surface of the olefin laminated sheet when the olefin laminated sheet is molded, and if the melting point is low, the heat resistance of the olefin laminated sheet is reduced. 125 to 150 ° C. is preferable because the molding stability may be reduced.

The MI of the low-melting-point propylene-based resin is set to 0.1 for the same reason as in the case of the propylene-based resin (B).
3-15 g / 10 min is preferred.

If the content of the low-melting-point propylene-based resin in the propylene-based resin layer is large, the heat resistance of the propylene-based resin layer is reduced, and the grain retention of the olefin-based laminated sheet is reduced. When the stress relaxation property of the obtained olefin-based laminated sheet is reduced, and the sheet is deformed at a high temperature during molding, or is highly stretched at the time of secondary processing, the surface of the obtained molded article becomes white. , As the surface properties decrease,
It is limited to 1 to 50 parts by weight based on 100 parts by weight of the homopropylene resin and / or the block propylene resin.

Next, the form of the inorganic filler is powdery,
It is not particularly limited whether it is balun-like or fibrous, and examples of the powdery inorganic filler include, for example, calcium carbonate, talc, kaolin clay, mica, and titanium oxide. For example, Shirasu balun, glass balun, fly ash balun and the like can be mentioned, and as the fibrous inorganic filler, for example, glass fiber, whisker and the like can be mentioned. Among these inorganic fillers, calcium carbonate, talc, and mica are preferable, in that the effect of improving rigidity with respect to the resin is large, and the obtained olefin-based laminated sheet has excellent molding stability.
Talc and mica are more preferred.

When the size of the inorganic filler is increased, the impact strength of the olefin-based laminated sheet at a low temperature is lowered. Therefore, the particle size or the fiber diameter is preferably 20 μm or less.

When the content of the inorganic filler in the propylene-based resin layer is large, the lightness of the obtained olefin-based laminated sheet is reduced, and when the content is small, the rigidity of the olefin-based laminated sheet is reduced. 1 to 100 parts by weight of homopropylene resin and / or block propylene resin
Limited to 50 parts by weight.

The laminate used in the present invention is obtained by forming the propylene resin layer on one side of the crosslinked foamed sheet by extrusion lamination. As a method of laminating a propylene-based resin layer on a crosslinked foamed sheet, in addition to the method of extrusion lamination, for example, hot roll lamination in which a propylene-based resin sheet previously formed into a crosslinked foamed sheet is pressure-bonded with a thermocompression roll. And a method of three-layer simultaneous extrusion lamination in which a propylene-based resin layer is formed on both sides of a crosslinked foamed sheet by extrusion lamination, but the method of hot roll lamination has poor moldability, and warps and wrinkles are generated in the laminated product. In addition, there is a problem that the adhesion between the laminated products is also reduced.
In the method using layer coextrusion lamination, there is a problem that the apparatus becomes complicated and large, and therefore, it is not adopted in the method for producing an olefin-based laminated sheet of the present invention.

Further, an irregular pattern is formed on the propylene-based resin layer containing an inorganic filler during the extrusion lamination. As a method of forming the concavo-convex pattern, in addition to the above method, (1) a method for forming a concavo-convex pattern on a propylene-based resin sheet before bonding to a crosslinked foamed sheet, (2)
A method in which a propylene-based resin sheet formed in advance is bonded to a crosslinked foamed sheet with a pressure-sensitive roll having an uneven pattern, (3) a laminated product is heated to a temperature close to the melting point of the propylene-based resin layer, and a roll having an uneven pattern is used. In the method (1), a notch is formed between the metal roll having an uneven pattern and the backup roll made of hard rubber in the production of the propylene-based resin sheet. Causes molding failure,
In the methods (2) and (3), if the propylene-based resin sheet and the propylene-based resin layer are not heated to near their melting points, the concavo-convex pattern may disappear during the subsequent heat molding. If the layer is heated to near its melting point, there is a problem that the crosslinked foamed sheet may be damaged, so that it is not employed in the method for producing an olefin-based laminated sheet of the present invention.

In the method for producing an olefin-based laminated sheet according to the present invention, the laminate product obtained by the above-mentioned method wherein the propylene-based resin layer is integrally laminated on one side and the homopropylene resin and / or block propylene A laminate comprising 100 parts by weight of a resin, 1 to 50 parts by weight of a low-melting propylene-based resin, and 1 to 50 parts by weight of an inorganic filler, and a propylene-based resin layer having a concavo-convex pattern formed by extrusion lamination and integrated. The surface of the cross-linked foam sheet side of each product is pressed by a pressure roll or the like while being melted by a heating device such as a gas, a flame, or a strong infrared heater, and a heat-sealing layer is formed on this portion to form an olefin-based laminate. Make a sheet.

The heat-sealing layer is a low-foaming layer or a non-foaming layer, and reduces molding distortion remaining during the production of the crosslinked foamed sheet. Heat during fusion has the effect of annealing the molding distortion. In addition, the moldability of the olefin-based laminated sheet is improved.

When the total thickness of the two crosslinked foamed sheet layers and the heat-sealing layer of the olefin laminate sheet is increased, the economic efficiency is reduced, and when the total thickness is reduced, the mechanical strength such as bending strength is reduced. Therefore, 2 to 10 mm is preferable.

When the thickness Ts of one propylene resin layer of the olefin-based laminated sheet is increased, the lightness of the olefin-based laminated sheet may be reduced. Is preferably 0.1 to 1 mm, since the mechanical strength of the steel may decrease. When the total solid thickness of the two crosslinked foamed sheet layers and the heat-sealing layer is Tf, Ts / Tf is preferably 0.5 to 20. This is because, as Ts / Tf increases, the proportion of the propylene-based resin layer in the olefin-based laminated sheet increases, and the heat insulation and soft feeling of the olefin-based laminated sheet may decrease. The molding distortion of the crosslinked foamed sheet may act to increase the heat shrinkage of the entire molded article obtained from the olefin-based laminated sheet, and the propylene-based resin layer becomes locally thin and the back side can be seen through or cracked. This is because necking, which causes cracks, is likely to occur.

The solid thickness Tf in the present invention is a thickness when air is extracted from the two crosslinked foamed sheets and the heat-sealing layer.

When the thickness Tl of the heat-sealing layer of the olefin-based laminated sheet is large, the heat insulating property and softness of the olefin-based laminated sheet may be reduced. Reduce remaining molding distortion,
Since the effect of annealing the molding strain is reduced, the formability of the olefin-based laminated sheet may be reduced.
1 to 0.5 mm is preferred. Further, from the relationship between the expansion ratio and the thickness of the crosslinked foamed sheet, Tl is preferably 1 to 25% of the total thickness of the two crosslinked foamed sheet layers and the heat sealing layer.

When the total thickness of the olefin-based laminated sheet is large, the lightness may decrease, and when the thickness is small, the mechanical strength such as bending strength may decrease. 12 mm is preferred. Further, from the above-described conditions, the olefin-based laminated sheet has a Ts / Tf of 0.5 to 0.5.
It is particularly preferable that Tl is 0.1 to 0.5 mm and 1 to 25% of the total thickness of the two crosslinked foamed sheet layers and the heat-sealing layer.

[0054]

EXAMPLES In Examples 1 and 2 and Comparative Examples 1 and 2,
The compounds shown below were used. However, the elution amount is the amount eluted at 94 ° C. or higher by the cross fractionation method, and the elution amount is the resin component eluted at 94 ° C. or higher by the cross separation method.

Propylene resin (A) PE copolymer 1; MI = 2 g / 10 min, elution amount = 75
Propylene-ethylene random copolymer having a weight average molecular weight of 3.4 × 10 ⁵ and an ethylene content of 3.2% by weight.

Ethylene resin (A) LLDPE1; MI = 2.5 g / 10 min, elution amount = 6.
8% by weight, eluted weight average molecular weight = 2.3 × 10 ⁵ ,
Linear low density polyethylene copolymerized with 15% by weight of 1-octene

Propylene resin (B) PE copolymer 2; MI = 4 g / 10 min, melting point = 16
Propylene-ethylene block copolymer at 6.7 ° C

PE copolymer 3: MI = 1 g / 10 min,
Propylene-ethylene block copolymer having a melting point of 166.5 ° C

Low melting point propylene resin PE copolymer 4: MI = 1.5 g / 10 min, melting point = 1
Propylene-ethylene random copolymer having a temperature of 36.2 ° C

PEB terpolymer; MI = 2.0 g
Propylene-ethylene-butylene terpolymer having a melting point of 135.2 ° C./10 minutes

(Example 1) A predetermined amount of PE shown in Table 1
Copolymer 1, LLDPE1, trimethylolpropane trimethacrylate, azodicarbonamide, 2,6-di-t-butyl-p-cresol, dilaurylthiopropionate, and methylbenzotriazole were subjected to 190-screw extruder. After melt-kneading at ℃, a foamable resin sheet having a thickness of 0.9 mm was continuously extruded.

Next, one side of the obtained foamable resin sheet was irradiated with an electron beam having an acceleration voltage of 800 kV at 3 Mrad to crosslink, and then foamed in a vertical foaming furnace maintained at 250 ° C. by hot air and an infrared heater. The expandable resin sheet was continuously supplied to expand the expandable resin sheet to obtain a crosslinked foam sheet. In addition, the thickness of the obtained crosslinked foamed sheet is 2 m.
m, the solid thickness was 0.1 mm, the gel fraction was 60% by weight, the expansion ratio was 20 times, and the appearance was uniform and good.

Next, a method of manufacturing a laminated product will be described with reference to FIG. A propylene-based resin composition comprising a predetermined amount of PE copolymer 2, PE copolymer 4 and talc having an average particle diameter of 10 μm shown in Table 1 was supplied to a single screw extruder (not shown) having a diameter of 90 mm. After melt-kneading, the mixture is extruded from the extrusion mold 2 at a resin temperature of 240 ° C. and an extrusion speed of 8 m / min. Laminate product by pressing with 31 and rubber backup roll 33
1A was obtained. However, the thermocompression bonding roll 31 was set to the propylene-based resin composition side, and the laminated product 1A was taken up by the taking-up rolls 35 at a speed of 8 m / min. The thickness of the propylene-based resin layer of the obtained laminated product 1A is 0.3 m.
m. In FIG. 1, reference numeral 34 denotes a guide roll.

On the other hand, as a propylene resin composition, P-
A laminated product 1B was obtained in the same manner as the laminated product 1A, except that the thermocompression bonding roll 31 was changed to a thermocompression bonding roll 32 having a flat outer peripheral surface using the E copolymer 3. The thickness of the propylene-based resin layer of the laminated product 1B was 0.3 mm.

Next, a method for producing an olefin-based laminated sheet using the above-mentioned laminated articles 1A and 1B will be described with reference to FIG. The laminated articles 1A and 1B are arranged so that the respective crosslinked foamed sheet layers 11 and 11 face each other, and the surfaces of the crosslinked foamed sheet layers 11 and 11 are heated to about 160 ° C. with a propane gas flame 5 and melted. Was immediately supplied between the pressure-bonding rolls 41, 41, and both were pressure-bonded by the pressure-bonding rolls 41, 41, cooled, and taken up by the take-up rolls 42, 42 at a speed of 6 m / min to obtain the olefin-based laminated sheet 1. The obtained olefin-based laminated sheet 1 had a thickness of 4.6 mm and a weight of 730 g / m ² . A heat-sealing layer 14 is formed at a portion where the crosslinked foamed sheets of the obtained olefin-based laminated sheet are pressed together, the thickness Tl is 0.2 mm, and the two crosslinked foamed sheet layers 11, 11 And 5% of the total thickness of the heat-sealing layer 14. The two crosslinked foamed sheet layers 11 and 11 and the heat-sealing layer 14
Has a total thickness of 4 mm, a total solid thickness Tf of 0.2 mm,
The thickness Ts of one propylene-based resin layer 12 is 0.3 mm,
Ts / Tf was 1.5.

The structure of the obtained olefin-based laminated sheet 1 will be described with reference to FIG. The olefin-based laminated sheet 1 is composed of laminated products 1A and 1B,
On one surface of the crosslinked foamed sheet layer 11 of 1A, a propylene-based resin layer 12 containing an inorganic filler was laminated, and on the surface thereof, an uneven pattern composed of concave portions 15 and convex portions 16 was formed. The propylene-based resin layer 13 was laminated on one side of the crosslinked foamed sheet 11 of the laminate 1B, and the surface was flat. A heat sealing layer 14 is provided on the bonding surface of the laminate products 1A and 1B.
Was formed.

The difference h between the concave and convex portions 15 and the convex portions 16 of the concavo-convex pattern on the surface of the propylene-based resin layer 12 shown in FIG. 4 of the obtained olefin-based laminated sheet was measured with an electron microscope, and the minimum value h of h _{0 was} measured.
Are shown in Table 1. Next, the olefin-based laminated sheet 1 is
The propylene-based resin layer 12 containing an inorganic filler has a surface of 13
After heating with a far-infrared heater so that the surface of the propylene-based resin layer 13 containing no inorganic filler is at 155 to 160 ° C., the cross section as shown in FIG. Male mold 61 having a convex shape and female mold having a semicircular concave shape having a radius of 100 mm in cross section
The olefin-based lamination between the male and female molds 61 and 62 is performed using the press mold 6 composed of 62, so that the propylene-based resin layer 13 is on the female mold side 62 and the propylene-based resin layer 12 is on the male mold side 61. The sheet 1 is disposed, and the male and female dies 61 and 62 are pressed at a press die 6 temperature of 40.
The olefin-based laminated sheet 1 was press-molded by closing at 4 ° C. and a clearance of 4 mm to obtain a molded product. The h of the resulting molded article was measured in the same manner as described above, it showed the minimum value h ₁ in Table 1.

Next, the obtained olefin-based laminated sheet 1
The heat resistance and the appearance of molded articles (the moldability of the olefin-based laminated sheet) were evaluated as follows.

(Heat Resistance) The surface of the olefin-based laminated sheet during heating during the molding was visually observed and evaluated as follows. The results are shown in Table 1. ；: The surface was uniform, and no deformation due to heat was observed. Δ: Rippling due to heat was partially observed on the surface. ×: Waving due to heat was observed on the entire surface.

(Appearance) From the above h ₀ and h ₁ , the holding ratio of the concavo-convex pattern was calculated by the following formula, and h ₀ , h ₁ and the holding ratio are shown in Table 1. Retention rate (%) = (h ₁ / h ₀ ) × 100 The higher the retention rate is, the smaller the variation in surface temperature during heating is, the more uniform contact between the mold and the olefin-based laminated sheet during press molding, and Since the molded product is homogeneous without any significant elongation, the moldability of the olefin-based laminated sheet and the appearance of the molded product are excellent.

Example 2 Example 2 was repeated except that the PE copolymer 4 was replaced by a PEB terpolymer as the resin constituting the propylene resin layer of the laminated product 1A. In the same manner as in Example 1, an olefin-based laminated sheet was obtained.

The obtained olefin-based laminated sheet 1 had a thickness of 4.6 mm and a weight of 730 g / m ² . A heat-sealing layer 14 is formed at a portion where the crosslinked foamed sheets of the obtained olefin-based laminated sheet are pressed together, the thickness Tl is 0.2 mm, and the two crosslinked foamed sheet layers 11, 11 And 5% of the total thickness of the heat-sealing layer 14. The total thickness of the two crosslinked foamed sheet layers 11 and 11 and the heat sealing layer 14 was 4 mm,
The total solid thickness Tf was 0.2 mm, the thickness Ts of one propylene-based resin layer 12 was 0.3 mm, and Ts / Tf was 1.5.

The heat resistance of the obtained olefin-based laminated sheet and the appearance of the molded product (the moldability of the olefin-based laminated sheet) were measured in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 1 A foamable resin sheet was continuously extruded in the same manner as in Example 1 except that the thickness was changed to 1.5 mm, and the obtained foamable resin sheet was foamed in the same manner as in Example 1. Thus, a crosslinked foamed sheet 11a was obtained. The thickness of the obtained crosslinked foamed sheet 11a was 4 mm, and the gel fraction was 6
The foaming ratio was 20% by weight and the appearance was uniformly good.

On the other hand, a predetermined amount of PE copolymer 2, PE copolymer 4 and a resin composition comprising talc having an average particle diameter of 10 μm shown in Table 1 were placed in a single screw extruder having a diameter of 90 mm. After melt-kneading, the mixture is extruded at a resin temperature of 240 ° C. and an extrusion speed of 8 m / min to form an olefin resin sheet having a thickness of 0.3 mm.
71 was obtained. Furthermore, an olefin resin sheet 72 having a thickness of 0.3 mm was obtained in the same manner as described above except that the resin composition was changed to the PE copolymer 3.

Then, as shown in FIG. 6, the obtained olefin-based resin sheets 71 and 72 are polymerized on both sides of the crosslinked foamed sheet 11a, respectively.
Is supplied between the thermocompression roll 31 and the backup roll 33 maintained at a temperature of 150 ° C. so that the olefin-based resin layer is laminated and integrated on both surfaces. Pickup roll 35 for sheet 1a,
It was taken at a speed of 8 m / min with 35. The thermocompression roll 31, the backup roll 33, and the guide roll 34 used were the same as those used in Example 1.

The heat resistance of the obtained laminated sheet and the appearance of the molded product (the moldability of the olefin-based laminated sheet) were measured in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Example 2) PE of a predetermined amount shown in Table 1
As shown in FIG. 7, the resin composition composed of copolymer 2, PE copolymer 4 and talc having an average particle size of 10 μm was melt-kneaded in a single screw extruder 91 having a diameter of 90 mm. , P
-E copolymer 3 was melt-kneaded in another single-screw extruder 92 having a diameter of 90 mm, and each was melted at a resin temperature of 240 ° C. to form a sheet 8
1 and 82, and these extruded sheets 81 and 8
2 was polymerized on both sides of the crosslinked foam 11a obtained in the same manner as in Comparative Example 1, and then heated so that the sheet 81 extruded from the single screw extruder 91 was on the thermocompression bonding roll 31 side. The sheet was supplied between the pressure bonding roll 31 and the backup roll 33, these were laminated and integrated, and the laminated sheet 1a in which the olefin-based resin layer was laminated and integrated on both sides was taken up by the take-up rolls 35, 8 at a speed of 8 m / min. The thickness of each of the olefin resin layers 81 and 82 constituting the laminated sheet 1a is 0.3 m.
m. Thermo-compression roll 31, backup roll
33 and the guide roll 34 were the same as those used in Example 1.

The heat resistance of the obtained laminated sheet and the appearance of the molded product (formability of the olefin-based laminated sheet) were measured in the same manner as in Example 1, and the results are shown in Table 1.

[0080]

[Table 1]

[0081]

According to the method for producing an olefin-based laminated sheet of the present invention, a propylene-based resin layer is formed on both sides of a crosslinked foamed sheet by extrusion lamination having excellent moldability and adhesiveness. No wrinkles occur. Moreover, in the present invention, the two laminated products are laminated and integrated by heat fusion to produce an olefin-based laminated sheet, so that the molding distortion remaining in the crosslinked foamed sheet generated during the thermal fusion of the laminated product is reduced. Since the heat shrinkage of the olefin-based laminated sheet obtained by laminating and integrating the two laminated products is averaged, the resulting olefin-based laminated sheet has less heat shrinkage at the time of molding and can be molded. It has excellent properties. Furthermore,
Since the obtained olefin-based laminated sheet uses a cross-linked foamed sheet made of a propylene-based resin and an ethylene-based resin for the central layer, it is excellent in lightness. Moreover, since the propylene-based resin layer laminated on at least one surface of the crosslinked foamed sheet is composed of a homopropylene resin and / or a block propylene resin, a low-melting-point propylene-based resin, and an inorganic filler, the olefin-based laminated sheet is made of homopropylene. While having good grain retention and thermal stability by resin and / or block propylene resin,
It also has excellent moldability due to good elongation of the low melting point propylene resin and excellent thermal stability due to good stress relaxation. Therefore, the olefin-based laminated sheet obtained by the method for producing an olefin-based laminated sheet of the present invention can be formed into a complicated shape while leaving the grain pattern formed on the surface in good condition, and furthermore, the surface is whitened. A molded article having excellent surface properties and thermal stability can be obtained. Furthermore, since the inorganic filler is contained, the olefin-based laminated sheet has excellent thermal stability,
It also has excellent mechanical strength such as impact strength.

[Brief description of the drawings]

FIG. 1 is a schematic process diagram schematically showing a method for producing a laminated product of an example.

FIG. 2 is a schematic process diagram schematically showing a method for producing an olefin-based laminated sheet of an example.

FIG. 3 is a cross-sectional view schematically illustrating a laminated sheet obtained in an example.

FIG. 4 is a cross-sectional view schematically showing an uneven pattern on the surface of a propylene-based resin layer containing an inorganic filler of the olefin-based laminated sheet obtained in each of Examples and Comparative Examples.

FIG. 5 is a perspective view schematically showing a press die used in Examples and Comparative Examples.

FIG. 6 is a schematic process diagram schematically showing a method for manufacturing a laminated sheet of a comparative example.

FIG. 7 is a schematic process diagram schematically showing a method for manufacturing a laminated sheet of a comparative example.

[Explanation of Signs] 1 Olefin-based laminated sheet 11 Cross-linked foamed sheet 12, 13 Propylene-based resin layer 14 Thermal fusion layer 1A, 1B Laminated product

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B60R 13/02 B60R 13/02 A // B29K 23:00 B29L 9:00

Claims (4)

[Claims] 1. A propylene-based resin layer is formed by extrusion lamination on one surface of each of two cross-linked foamed sheets made of a propylene-based resin and an ethylene-based resin to form two laminates. In the method for producing an olefin-based laminated sheet in which a surface on the crosslinked foamed sheet side is melted and pressure-bonded to form a heat-sealing layer on the portion, at least one of the propylene-based resin layers is a homopropylene resin and / or a block propylene resin 100
1. An olefin-based laminated sheet comprising: 1 part by weight, 1 to 50 parts by weight of a low-melting-point propylene resin, and 1 to 50 parts by weight of an inorganic filler, wherein an uneven pattern is formed on the surface of the layer during extrusion lamination. Method. 2. The total solid thickness of the two crosslinked foamed sheet layers and the heat sealing layer is Tf, and the propylene resin layer 1 is
When the thickness of the sheet is Ts and the thickness of the heat sealing layer is Tl, Ts / Tf is 0.5 to 20 and Tl is 0.1 to 0.1.
The method for producing an olefin-based laminated sheet according to claim 1, wherein the thickness is 0.5 mm and 1 to 25% of the total thickness of the two crosslinked foamed sheet layers and the heat-fused layer. 3. The propylene resin constituting the crosslinked foamed sheet has a melt index of 0.2 to 10 g / 10.
Of elution at 94 ° C. or more by cross-fractionation method
5% by weight and the weight-average molecular weight of the eluted portion 2 × 10 ⁵ -1
The method for producing an olefin-based laminated sheet according to claim 1 or 2, wherein the propylene-α-olefin copolymer is 0x10 ⁵ . 4. The ethylene resin constituting the crosslinked foamed sheet has a melt index of 0.5 to 10 g / 10.
5-20 elution amount at 94 ° C or higher by cross fractionation
% By weight and the weight average molecular weight of 1.5 × 10 ^5-
The method for producing an olefin-based laminated sheet according to any one of claims 1 to 3, comprising an ethylene-α-olefin copolymer having a size of 10 × 10 ⁵ .