JPH06908A - Propylene-based resin laminated foam sheet - Google Patents

Abstract

PURPOSE:To provide propylene-based resin laminated foam sheet, which is excellent in physical properties such as formability, shape retention after forming, heat insulating properties and mechanical strength, heat resistance, water resistance, oil resistance, chemical resistance and the like and suitable for fruit container, heat resistant heat insulating material for building, packaging sheet and the like. CONSTITUTION:The propylene-based resin foam sheet 1 consists of foam sheet 2, the base material of which is non-crosslinked propylene-based resin having long chain branching and, at the same time, drawdown properties of 60m/min or less and which has the thickness of 1.2-30mm and the specific gravity of not less than 0.02g/cm<3> and under 0.06g/cm<3>, and propylene-based resin film 3 of sheet, which has the thickness of 3-1,000mum and is laminated at least on one side of the foam sheet 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propylene-based resin laminated foam sheet excellent in moldability, shape retention after molding, heat insulation, mechanical strength and the like.

[0002]

2. Description of the Related Art As a method for producing a foamed sheet for molding a container or the like, an extrusion foaming method in which a thermoplastic resin is melt-kneaded with a foaming agent in an extruder and then extruded under low pressure to foam is widely adopted. Has been done.

In the extrusion foaming method of an olefin resin, when a melt-kneaded product of a resin and a foaming agent is extruded from the extruder under a low pressure, the foaming agent in the melt-kneaded product expands to foam. However, when the temperature of the resin is raised, the viscosity drops sharply and the resin cannot hold the foaming agent and escapes from the resin to form a foamed sheet of open cells. Conversely, in order to increase the viscosity of the resin, the resin temperature must be increased. If it is lowered, crystallization of the resin will proceed, and as a result, the foaming sheet will not be sufficiently and uniformly foamed, and the surface of the foamed sheet will become uneven. For this reason, the extrusion foaming needs to be carried out at a temperature at which the resin has sufficient viscous foaming and has viscoelasticity capable of holding the foaming agent in the resin. The temperature range in which viscoelasticity suitable for foaming is obtained differs depending on the type of resin, and this temperature range is generally referred to as the foaming suitable temperature range.

[0004]

However, the propylene-based resin having a higher degree of crystallinity than that of low density polyethylene has a large viscoelasticity of the resin due to a slight temperature change, and the foaming temperature range is very narrow. It is very difficult to carry out extrusion foaming while maintaining the resin temperature within such a narrow temperature range, and when the extrusion foaming temperature fluctuates and is outside the foaming suitable temperature range, the foamed part has an open cell structure. However, it was difficult to obtain a foamed sheet having good and uniform properties as a whole. Conventionally, in the case of non-crosslinked propylene-based resin, a relatively good foamed sheet can be obtained only when the density is low expansion ratio exceeding 0.2 g / cm ³ or when the density is 0.013 g / cm ³ It has a high expansion ratio of less than.

The above-mentioned problems are considered to be caused by the high crystallinity of the propylene-based resin, and the density of the propylene-based resin is 0.
The reason why a foamed sheet with a low expansion ratio of more than 2 g / cm ³ can be obtained relatively well is that the resin temperature during extrusion foaming is higher than the crystallization temperature of the resin because the proportion of the resin is higher than the amount of the foaming agent. It is considered that this is because the temperature can be set to a considerably high temperature. The density is 0.013 g / cm ³
The reason why a foamed sheet having a high expansion ratio of less than 10% can be relatively well obtained is as follows.

Generally, the olefin resin being foamed during extrusion foaming is subjected to an external cooling operation using a cooling means, thereby solidifying the cell walls to obtain a good foamed sheet. However, since propylene-based resin has a higher degree of crystallinity than low-density polyethylene, the amount of heat generated during crystallization is large. This heat hinders the cooling and thus the solidification of the cell walls, and destroys or deforms the cells of the propylene-based resin in the process of foaming.

Therefore, a large amount of a foaming agent is blended to foam, so that the heat of vaporization (expansion heat) of the foaming agent is used to drastically lower the temperature of the propylene resin during foaming, thereby solidifying the cell wall. Promote. Further, a large amount of foaming agent has a function of delaying the crystallization of the resin in the extruder. As a result, a relatively good foamed sheet can be obtained. However, in this case, the resulting foamed sheet inevitably has a high expansion ratio of less than 0.013 g / cm ³ because of the necessity of blending a large amount of the foaming agent. Also in this case, the foaming suitable temperature range is only about 0.6 ° C.

The present inventors have been
In view of the fact that only an extruded foamed sheet having a high expansion ratio or a low expansion ratio can be obtained, the use of a propylene-based resin having a specific drawdown property makes the density 0.3 to 0.
In addition to finding a method for easily producing even a propylene-based resin extruded foamed sheet of 06 g / cm ^{3, in} a foamed sheet of a specific thickness, the skin thickness, the film thickness of the cells, and the number of cell films in the thickness direction have a specific relationship. Filed under the heading that the foamed sheet in 1) is suitable for thermoforming (Japanese Patent Application No. 4-
72876).

Since this foamed sheet is excellent in heat resistance, water resistance and chemical resistance, it can be used as a packaging material, but its density is low.
If it is less than 0.06 g / cm ^3, it is not always satisfactory in terms of deep drawability, mechanical strength and shape retention. In addition, as a product that is expected to have a high heat-resistant heat insulating material that can be easily installed with a tucker or the like in the field of construction, which has a density of less than 0.06 g / cm ³ , as another application, from the viewpoint of heat insulation and flexibility of polyolefin. Can be mentioned. However, they were also unsatisfactory in terms of mechanical strength.

The present invention has been made in view of the above points,
An object of the present invention is to provide a propylene-based resin laminated foam sheet which is an improvement of the invention of the applicant of the present invention, and further has improved moldability, shape retention after molding, heat insulating properties, and mechanical strength.

[0011]

Means for Solving the Problems That is, the propylene-based resin laminated foam sheet of the present invention is based on a non-crosslinked propylene-based resin having a long chain branch and a drawdown property of 60 m / min or less, and has a thickness of 1.2-30 mm, density 0.02 g /
A foamed sheet having a cm ³ or more and less than 0.06 g / cm ³ and a thickness of 3 to 1000 laminated on at least one surface of the foamed sheet.
It is characterized by comprising a propylene-based resin film or sheet of μm.

In the propylene-based resin laminated foam sheet of the present invention, at least one of the base resin of the foam sheet and the base resin of the film or sheet laminated on the foam sheet is
It is preferably a propylene-based resin containing 0.5 to 30% by weight of an ethylene component.

As shown in FIG. 1, a propylene-based resin laminated foam sheet 1 of the present invention comprises a propylene-based resin foam sheet 2 and a propylene-based resin film or sheet 3 (hereinafter referred to as a propylene-based resin film or sheet 3) laminated on at least one side of the foam sheet 2. , Simply referred to as film 3.).

In the present invention, as the propylene-based resin which is the base resin of the foamed sheet 2, a non-crosslinked propylene-based resin having long chain branching and a drawdown property of 60 m / min or less is used. Drawdown property is preferably 3
It is 0 m / min or less, particularly preferably 15 m / min or less.

The drawdown property means that the molten propylene resin heated to 230 ° C. is extruded into a cord at a constant speed of 10 mm / min from a nozzle of the melt indexer (caliber 2.095 mm, length 8 mm), and then the After passing the string-like object through the feed roll located above the tension detection pulley located below the nozzle, the tape is wound by the take-up roll while gradually increasing the take-up speed of the take-up roll. The string-like material is cut, and the winding speed of the string-like material at the time of this cutting is referred to.

The above-mentioned resin may be a homopolymer, a block copolymer or a random copolymer, but a copolymer excellent in deep drawability is preferable.

The propylene-based resin constituting the foamed sheet 2 must have a long-chain branch in the main chain, unlike ordinary propylene-based resins. The propylene-based resin may be any of a homopolymer, a block copolymer, and a random copolymer, but a block copolymer is preferable from the viewpoint of easiness of forming long chain branches and the like, and particularly a propylene-ethylene block copolymer. Polymers are preferred.

In the case of the copolymer, a copolymer of propylene and a small amount of olefin other than propylene is preferable, and examples of the olefin include ethylene and α-olefins having 4 to 10 carbon atoms. Two or more kinds can be used in combination. Examples of the α-olefin having 4 to 10 carbon atoms include 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, 3-
Methyl-1-hexene and the like can be mentioned.

The above-mentioned olefin is usually contained in the copolymer in an amount of 0.5.
It is preferably contained in a proportion of ˜30 wt%, especially 1 to 10 wt%. From the viewpoint of ease of forming long chain branches,
A block copolymer is preferable to a random copolymer, and a propylene-ethylene block copolymer is particularly preferable.

The propylene resin used in the present invention is
An ordinary crystalline linear propylene-based resin (usually having a weight average molecular weight of 100,000 or more), and a resin containing an atactic component and / or an isotactic but non-crystalline component (hereinafter referred to as "the present invention"). In order to distinguish it from the propylene-based resin used in (1), this resin is referred to as “normal propylene-based resin. Note that when simply referred to as propylene-based resin, it means the resin used in the present invention. Decomposition type (decomposition temperature: room temperature to about 120 ° C.) peroxide is mixed and heated to 120 ° C. or lower to branch an atactic or / and non-crystalline isotactic component into the main chain of a normal propylene resin. It can be obtained by a method such as binding as a chain, and is usually considered to have a branched structure mainly having a long chain branch at the end.

Examples of the low temperature decomposition type peroxide include di (s-butyl) peroxydicarbonate and bis (2-
Ethoxy) peroxydicarbonate, dicyclohexyl peroxydicarbonate, di-n-propylperoxydicarbonate, di-n-butylperoxydicarbonate, diisopropylperoxydicarbonate,
Examples thereof include t-butyl peroxy neodecanoate, t-amyl peroxy neodecanoate and t-butyl peroxypivalate.

It has a long-chain branch and a drawdown property of 6
The propylene-based resin having a rate of 0 m / min or less is a conventional propylene-based resin, which is stirred in a reactor equipped with a stirrer while substituting the inside of a reaction vessel with an inert gas such as argon, and then the above-mentioned peroxide is used as a resin. Usually, 5 to 50 mmol is added per 1 kg, and the mixture is heated to about 120 ° C., preferably about 70 to 105 ° C. while continuing stirring to react (usually 30 to 1
20 minutes), after which the reaction is stopped and obtained. In stopping the reaction, a method of introducing a reaction terminator such as methyl mercaptan into the reaction vessel, or heating the reaction product at about 130 to 150 ° C. for 20 to 40 minutes is adopted.

The drawdown property can be adjusted by the number and length of the long chain branches. Generally speaking, the greater the number of long chain branches and the longer the branch length, the lower this value tends to be. Therefore, in order to obtain a copolymer having a desired drawdown property, it is necessary to set the reaction conditions in consideration of these things.

In the case of having no long-chain branching, or having branching too short or too little, or in the case of a normal propylene resin, the drawdown property exceeds 60 m / min. Performing extrusion foaming using such conventional propylene resin, the present invention foam sheet similar density 0.02 g / cm ³ or more, even to obtain a foamed sheet of less than 0.06 g / cm ^3, The resulting foamed sheet has many corrugated surfaces and surface irregularities, and has no commercial value.

The propylene-based resin used in the present invention preferably has a semi-crystallization time at the crystallization temperature + 15 ° C. of 800 seconds or longer, and particularly preferably 1000 seconds or longer. A crystallization rate measuring device can be used for the measurement of the half crystallization time.

In order to measure the semi-crystallization rate, first, the support holding the film-like sample is placed in the air bath of the crystallization rate measuring instrument to completely melt the sample, and then the molten sample is put together with the support. Immersion in an oil bath maintained at the crystallization temperature of the sample + 15 ° C so as to block the optical path between the light source and the optical sensor, and always keep constant at the optical sensor until the melted sample solidifies again. The voltage of the light source is adjusted so that the light intensity of the light source is detected, and the voltage-time curve shown in FIG. 2 is obtained. When the voltage when the voltage in this curve has a constant value is V ₀ , the time until the voltage becomes 1/2 V ₀ is the half-crystallization time.

In the present invention, not only the above propylene-based resin can be used alone, but also other resins can be mixed and used. As the resin to be mixed and used, for example, a propylene-based resin other than the above, or high-density polyethylene, low-density polyethylene, linear low-density polyethylene,
Linear ultra low density polyethylene, ethylene-butene copolymers, ethylene-maleic anhydride copolymers and other ethylene resins, butene resins, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers and other vinyl chloride resins Examples thereof include resins and styrene resins.

When the other resin is mixed, the amount of the resin to be mixed is limited to 40% by weight of the total weight of the polymer after mixing, and the drawdown property of the mixture does not exceed 60 m / min. There is a need.

On the other hand, as the propylene-based resin, which is the base resin of the film 3 laminated on the foamed sheet 2, in addition to the same resin as the propylene-based resin forming the foamed sheet 2, conventionally used resins. It is possible to use a common propylene resin. This propylene-based resin may be either a propylene homopolymer or a copolymer with a monomer having an unsaturated bond capable of copolymerizing with propylene, and in the case of a copolymer, a block copolymer or a random copolymer. Either may be used. Examples of the monomer having an unsaturated bond copolymerizable with propylene include ethylene and α-olefins having 4 to 10 carbon atoms, and these may be used alone or in combination of two or more. The α-olefin having 4 to 10 carbon atoms is, for example, 1
-Butene, isobutylene, 1-pentene, 3-methyl-
1-butene, 1-hexene, 4-methyl-1-pentene, 3,4-dimethyl-1-butene, 1-heptene, 3
-Methyl-1-hexene and the like can be mentioned.

In the laminated foam sheet 1 of the present invention, it is preferable that at least one base resin of the foam sheet 2 and the film 3 is a propylene-based resin having an ethylene content of 0.5 to 30% by weight.

The propylene-based resin having an ethylene component content of 0.5 to 30% by weight may be a mixture of polyethylene with polypropylene or a copolymer obtained by copolymerizing an ethylene component with a propylene component. Further, in the case of a copolymer, it may be a block copolymer or a random copolymer, but a block copolymer is preferable.

In the laminated foam sheet 1 of the present invention, it is preferable that the propylene resin constituting the foam sheet 2 and the propylene resin constituting the film 3 are the same kind of resin. That is, when the propylene-based resin forming the foamed sheet 2 is a propylene homopolymer, the propylene-based resin forming the film 3 is also preferably a propylene homopolymer, and the propylene-based resin forming the foamed sheet 2 is In the case of a copolymer, for example, in the case of a propylene-ethylene block copolymer or a propylene-ethylene random copolymer, the propylene-based resin forming the film 3 is also a propylene-ethylene block copolymer or propylene-ethylene, respectively. It is preferably a random copolymer.

The most preferable combination of the resin forming the foamed sheet 2 and the resin forming the film 3 is a combination of propylene-ethylene block copolymers or a combination of propylene-ethylene random copolymers.
When the resin forming the foamed sheet 2 and the resin forming the film 3 are made of the same type of resin, the laminated sheet and a molded product obtained from the laminated sheet can be recycled, which is preferable.

Even when the propylene-based resin forming the foamed sheet 2 and the propylene-based resin forming the film 3 are the same type of propylene-based resin, the resin forming the film 3 has long-chain branching and 60 drawdown
It does not have to be a propylene-based resin of m / min or less.

In the laminated foam sheet 1 of the present invention, the thickness of the foam sheet 2 is 1.2 to 30 mm, preferably 1.5 to 10.
mm, and the density of the foamed sheet is 0.02 g / cm ³ or more and less than 0.06 g / cm ³ , preferably 0.03 g / cm ^3.
As described above, it is less than 0.06 g / cm ³ . The thickness of the film 3 is 3 to 1000 μm, preferably 30 to 250 μm. The foam sheet 2 may be obtained by laminating the foam sheets.

In the laminated foamed sheet of the present invention, when the thickness of the foamed sheet is less than 1.2 mm, the deep-drawing formability, cushioning property, mechanical strength and heat insulating property are poor, and the thickness of the foamed sheet is 3
If it exceeds 0 mm, the moldability will be poor.

When the thickness of the film is less than 3 μm, it is difficult to laminate and the laminated foamed sheet is inferior in mechanical strength, deep drawability and shape retention. When the thickness of the film exceeds 1000 μm, the film cannot be efficiently laminated on the foamed sheet, the cushioning property of the foamed sheet is impaired, and the mechanical strength is controlled by the film, which is not practical.

When the density of the foamed sheet is less than 0.02 g / cm ³ , the shape retention is poor and it is difficult to use it as a fruit container or the like. If the density of the foamed sheet is 0.06 g / cm ³ or more, it is not satisfactory in terms of heat insulating property for construction.

As a method for laminating the foamed sheet 2 and the film 3, a general method such as an extrusion laminating method (extrusion laminating), a thermal laminating method (thermal laminating), laminating with a hot melt adhesive or the like may be adopted. You can

As a method for obtaining the foamed sheet 2 used in the present invention, a non-crosslinked propylene resin having a long chain branch and a drawdown property of 60 m / min or less is melt-kneaded in an extruder and then A method in which a melt-kneaded product is attached to the end of an extruder and a circular die having an annular lip is used to extrude foam from the lip of the die to obtain a tubular foam, and then the tube is cut open to form a sheet is Usually adopted.

In this method, the mandrel (the inner surface side of the cylindrical foam) for cooling (narrowing) the resin flow path near the opening of the circular die or for cooling the cylindrical foam extruded from the circular die. It is provided so as to be cooled from the inside of the tubular foam body.) If a method such as blowing cooling air onto the outer surface of the tubular foam body is adopted, a foamed sheet with less uneven thickness can be obtained. It is possible and preferable.

An inorganic foaming agent, a volatile foaming agent, a decomposable foaming agent or the like can be used as the foaming agent in the production of the foamed sheet 2. Examples of the inorganic foaming agent include carbon dioxide, air and nitrogen.

As the volatile foaming agent, aliphatic hydrocarbons such as propane, n-butane, i-butane, pentane and hexane, cycloaliphatic hydrocarbons such as cyclobutane and cyclopentane, trichlorofluoromethane and dichlorodifluoromethane. , Dichlorotetrafluoroethane, methyl chloride,
Examples thereof include halogenated hydrocarbons such as ethyl chloride and methylene chloride.

Examples of the decomposition type foaming agent include azodicarbonamide, dinitrosopentamethylenetetramine, azobisisobutyronitrile, sodium bicarbonate and the like. These foaming agents can be appropriately mixed and used.

The amount of the foaming agent used varies depending on the kind of the foaming agent, the desired expansion ratio, etc., but the density is 0.02 g / cm ³
As described above, the amount of the foaming agent used to obtain the foamed sheet 2 of less than 0.06 g / cm ³ is about 5 to 12 parts by weight (converted to butane) of the volatile foaming agent per 100 parts by weight of the resin, and the inorganic foaming agent. It is about 1.5 to 5.0 parts by weight (in terms of carbon dioxide) and about 10 to 30 parts by weight for the decomposing foaming agent.

If necessary, a cell regulator may be added to the melt-kneaded product of the resin and the foaming agent when the foamed sheet 2 is manufactured. Examples of the air bubble modifier include inorganic powders such as talc and silica, acidic salts of polyvalent carboxylic acids, and reaction mixtures of polyvalent carboxylic acids with sodium carbonate or sodium bicarbonate. It is preferable to add about 13 parts by weight or less of the cell regulator per 100 parts by weight of the resin (except when a large amount of the inorganic filler is contained in the resin). Further, if necessary, additives such as a heat stabilizer, an ultraviolet absorber, an antioxidant and a colorant may be added.

Further, the resin may contain an inorganic filler up to 40% by weight based on the total weight. Examples of the inorganic filler include talc, silica, calcium carbonate, clay, zeolite, alumina, barium sulfate and the like. The average particle size of these is preferably 1 to 70 μm. When a large amount of such an inorganic substance is contained, the obtained foamed sheet has improved heat resistance and can reduce calories burned during incineration.

The laminated foam sheet 1 of the present invention is suitable as a fruit container, a heat-resistant heat insulating material for construction, a packaging sheet and the like. The molding method for molding and using the laminated foam sheet 1 of the present invention includes vacuum molding, pressure molding, and free drawing molding, plug and
Ridge molding, ridge molding, matched mold molding, straight molding, drape molding, reverse draw molding, air slip molding, plug assist molding, plug assist reverse draw molding, and the like, and a combination thereof may be used.

[0049]

EXAMPLES The present invention will be described in more detail with reference to examples. In addition, a melt indexer and a melt tension tester type II manufactured by Toyo Seiki Seisakusho Co., Ltd. were used in combination to measure the drawdown property and melt tension of the resin used, and Kotaki Corporation ( A crystallization rate measuring instrument MK-801 type manufactured by K.K. was used.

The resins used in the examples and comparative examples are as follows.

Base resin for foamed sheet Resin A: Propylene / ethylene block copolymer having long-chain branch ("SD-632" manufactured by Highmont Co., USA: melting point 159.9 ° C, crystallization temperature 130.1 ° C, half) Crystallization time 13
53 seconds, MI = 2.0g / 10 minutes, drawdown 3.1m
/ Min, melt tension 13.0gf)

Resin B: Propylene homopolymer having a long chain branch ("PF-814" manufactured by Highmont, USA: melting point 15)
9.0 ° C, crystallization temperature 127.4 ° C, semi-crystallization time 3220
Second, MI = 2.2g / 10min, drawdown property 3.5m /
Min, melt tension 17.4gf)

Base resin for film or sheet Resin 1: Propylene homopolymer ("PF814" manufactured by Highmont Co., USA)

Resin 2: Propylene-ethylene block copolymer ("SD632" manufactured by Highmont USA)

Resin 3: Propylene homopolymer ("E120G" manufactured by Nippon Petrochemical Co., Ltd.)

Examples 1 to 6 and Comparative Examples 1 to 3 The foamed sheets and films shown in Table 1 were laminated by the method shown in the table to obtain laminated foamed sheets. The density of the sheet after laminating the film is also shown in Table 1 (in the comparative example, since the film is not laminated on the foamed sheet, only the example shows the density of the laminated sheet). Using this sheet, a container having an opening diameter (outer diameter) of 135 mm and a depth (outer shape) of 85 mm and a hemispherical outer shape was formed.

The presence or absence of cracks or holes in the obtained container was observed and the properties of the laminated sheet were measured. The results are also shown in Table 1.

[0058]

[Table 1]

* 1: The "texture" of the foamed sheet is the number of bubbles per surface of the foamed sheet, 3 mm × 3 mm = 9 mm ² (cells / 9 mm ² ), and the number was measured using a microscope.

* 2: Moldability was judged according to the following criteria. ⊚: No cracks or holes are observed and the elongation is uniform. ○: No cracks or holes are observed, but there is unevenness in elongation. Δ: Holes or cracks having a diameter of less than 10 mm are present at 1 to 2 places. ×: There is a hole with a diameter of 10 mm or more, or a diameter of 10 m
There are 3 or more holes or cracks of less than m.

* 3: Tensile strength was measured according to JIS K6767.

* 4: Tear strength was measured according to JIS K6767.

* 5: The heat insulating property was measured according to JIS A141Z, and the sheets were piled up to a thickness of about 20 mm and measured, and evaluated according to the following criteria. ○: Thermal conductivity is 0.035 (kcal / m ・ hour ・ ° C)
Less than × ・ ・ ・ Thermal conductivity is 0.035 (kcal / m ・ hour ・ ° C)
that's all

* 6: The foamed sheets of Examples 4 and 5 have a thickness of 3.
It is a laminate of three 4 mm foam sheets.

[0065]

As described above, the laminated foamed sheet of the present invention comprises a propylene-based resin foamed sheet and a propylene-based resin film or sheet laminated on the propylene-based resin foamed sheet, and constitutes a foamed sheet. Since a specific propylene-based resin having a long chain branch and a drawdown property of 60 m / min or less was used as the resin, the laminated foamed sheet of the present invention has good moldability, and is obtained by molding the sheet. The molded product is excellent in heat resistance, water resistance, oil resistance, chemical resistance and the like, and also excellent in heat insulation, shape retention, mechanical strength and the like.

Thus, the laminated foamed sheet of the present invention uses a foamed sheet having a high expansion ratio (low density) of a density of 0.02 g / cm ³ or more and less than 0.06 g / cm ³ and specified for this foamed sheet. By stacking thick films or sheets, it can be used as a packaging material for fruit containers such as peaches, pears, and melons, as a packaging material for packaging sheets, as a heat-resistant heat-insulating roofing base material, and as a building material for pipe coating materials. it can.

Further, as the resin constituting the foamed sheet or at least one of the resins constituting the film or sheet laminated on the foamed sheet, the ethylene content is 0.
By using 5 to 30% by weight of the propylene resin, there is an effect that the flexibility of the entire sheet is increased, there is no sagging of the sheet during heat molding, and the moldability is particularly good.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a laminated foam sheet of the present invention.

FIG. 2 is a voltage-time curve obtained by crystallization rate measurement.

[Explanation of symbols]

 1 Propylene resin laminated foam sheet 2 Propylene resin foam sheet 3 Propylene resin film

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 20, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

It has a long-chain branch and a drawdown property of 6
The propylene-based resin having a rate of 0 m / min or less is a conventional propylene-based resin, which is stirred in a reactor equipped with a stirrer while substituting the inside of a reaction vessel with an inert gas such as argon, and then the above-mentioned peroxide is used as a resin. Usually, 5 to 50 mmol is added per 1 kg, and the mixture is heated to 120 ° C., preferably 70 to 105 ° C. with continuous stirring to react (usually 30 to
120 minutes), after which the reaction is stopped and obtained.
In stopping the reaction, a method of introducing a reaction terminator such as methyl mercaptan into the reaction vessel, or heating the reaction product at about 130 to 150 ° C. for 20 to 40 minutes is adopted. Long chain branching in the propylene resin molecular chain
You can check for the presence of
It That is, an extensional flow measuring device (eg, rheometric
Sustainable extension flow measurement device: product name RER-9000)
Using, make a measurement sample from propylene resin,
Elongational viscosity at the strain rate (sec ^-1 ) of the sample
Graph the relationship between (poise) and time (seconds).
On this graph, the propylene type with long chain branching
A resin and a propylene-based resin having no long-chain branch are long-chain
A branched propylene-based resin has a slope of extensional viscosity curve
It grows with time, but has no long-chain branching
In propylene resin, the slope of the extensional viscosity curve changes with time.
It can be distinguished from being small. Leo above
Extension flow measuring device (RER-900
0) shows that propylene having a long-chain branch
Of resin and propylene resin without long chain branch
The figure shows the relationship between elongational viscosity and time at apparent speed.
3 is a graph of 3. Curve A in the graph has long chain branching
Curve B has no long chain branching.
Shows a propylene resin. From this graph, long-chain branch
With a propylene-based resin having
It grows with time, but has no long-chain branching
With propylene-based resins, the slope of the extensional viscosity curve varies with time.
You can see that it gets smaller. The measurement sample and measurement
The fixed conditions are as follows. ・ Size and shape of measurement sample: length 30 mm, diameter 5
mm columnar ・ Strain rate: 1.0 sec ■ -1 ・ Measuring temperature: Base resin melting point + 20 ° C (However, the melting point is
Material resin 1-5 mg by differential scanning calorimeter at 10 ° C / min
Of the endothermic peak of the DSC curve obtained when the temperature is raised by
Temperature. )

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 3

[Correction method] Added

[Correction content]

FIG. 3 is a graph showing the relationship between elongational viscosity and time at strain rate for a propylene-based resin having a long-chain branch and a propylene-based resin having no long-chain branch.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 3

[Correction method] Added

[Correction content]

[Figure 3]

Claims (2)

[Claims] 1. A base material is a non-crosslinked propylene-based resin having long chain branching and a drawdown property of 60 m / min or less, a thickness of 1.2 to 30 mm, a density of 0.02 g / cm ³ or more,
A propylene-based resin laminated foam sheet, comprising a foamed sheet of less than 0.06 g / cm ³ and a propylene-based resin film or sheet having a thickness of 3 to 1000 μm laminated on at least one surface of the foamed sheet. 2. A base material resin of at least one of a foamed sheet or a film or sheet laminated on the foamed sheet,
The propylene-based resin laminated foam sheet according to claim 1, which is a propylene-based resin having an ethylene component content of 0.5 to 30% by weight.