JP2021194785A - Fireproof laminate sheet - Google Patents

Abstract

To provide a fireproof laminate sheet excellent in fireproof and heat shielding properties when exposed to high heat.SOLUTION: The fireproof laminate sheet is obtained by laminating a first hard PVC sheet, a soft PVC sheet, and a second hard PVC sheet in this order, where the soft PVC sheet is composed of a soft polyvinyl chloride composition, the first hard PVC sheet and the second hard PVC sheet are composed of hard polyvinylchloride compositions, and the soft PVC sheet contains a phosphoric acid ester-based plasticizer, phosphorous acid aluminum, and heat-expandable graphite.SELECTED DRAWING: None

Description

The present invention relates to a refractory laminated sheet containing polyvinyl chloride.

A secondary battery such as a lithium ion secondary battery is often used by arranging a plurality of cells side by side in a housing. If one of the plurality of cells ignites abnormally, there is a problem that the adjacent cells are burnt and the cells in the housing are completely damaged. In order to prevent such burning, Patent Document 1 proposes arranging a laminated body of sheets containing a flame retardant between cells.

Japanese Unexamined Patent Publication No. 2019-96410

In the fire-resistant laminated body of Patent Document 1, an insulating heat-foaming layer and a heat-expanding layer are laminated, and the insulating heat-foaming layer foams at around 400 ° C. to change from a powdery state to a porous body. It contains aluminum and a resin, and the heat-expanding layer contains a heat-expandable graphite and a resin that expands at around 200 ° C. When this refractory laminate is heated by a flame or the like, the thermal expansion layer expands rapidly in advance, so that the laminated structure of the refractory laminate is not maintained and the arrangement should be before the insulating thermal foam layer foams. There was a problem that it fell off from the surface or the outer shape was greatly deformed (problem with low fire resistance).

The present invention provides a refractory laminated sheet having excellent fire resistance and heat shielding properties when exposed to high heat.

In order to solve the above problems, the present inventors have examined as follows.
If the only purpose is to mitigate the deformation of the outer shape of the thermal expansion layer laminated on the insulating thermal foam layer (improve the fire resistance), reduce the content of the thermal expansion graphite contained in the thermal expansion layer and make it relative. It is conceivable to increase the amount of resin. However, doing so reduces the heat-shielding property of the thermal expansion layer after expansion.

Therefore, as a flame retardant to be contained in the heat-expanding layer, not only heat-expandable graphite but also aluminum phosphate, which is relatively less deformed by expansion, is sufficiently contained, and polyvinyl chloride is adopted as a resin. However, the viscosity and fluidity of the resin composition obtained by dispersing the flame retardant in the resin are not stable, and it is difficult to mold the resin composition into a sheet. After diligently investigating the cause of this, a resin composition containing heat-expandable graphite and aluminum phosphite was obtained by setting the average degree of polymerization of polyvinyl chloride within a predetermined range and adding a sufficient amount of a plasticizer in a predetermined amount. It has become possible to mold it into a shape.

When the fire resistance and heat-shielding property of the soft PVC sheet obtained by molding the above resin composition were evaluated, the fire resistance (suppression of deformation of the outer shape) was improved, but the heat-shielding property (thermal expansion) to the expected degree was improved. No heat-shielding property was obtained as compared with the case where no graphite was contained and only aluminum phosphite was contained. As a result of further diligent investigation of the cause, it is sufficient to keep the total content of the flame retardant with respect to the total amount of polyvinyl chloride and the plasticizer within a predetermined range and to adopt a phosphoric acid ester-based plasticizer as the plasticizer. It was found that a good heat-shielding property can be obtained.

Furthermore, they have found that by laminating a hard PVC sheet containing aluminum phosphite on both sides of a soft PVC sheet, deformation due to expansion of the soft PVC sheet can be further reduced, and the present invention has been completed. The present invention has the following aspects.

[1] A refractory laminated sheet in which a first hard PVC sheet, a soft PVC sheet, and a second hard PVC sheet are laminated in this order.
The soft PVC sheet is formed of a polyvinyl chloride composition for soft, and is formed.
The first hard PVC sheet and the second hard PVC sheet are refractory laminated sheets formed of a hard polyvinyl chloride composition.
[The polyvinyl chloride composition for soft contains polyvinyl chloride, a phosphoric acid ester-based plasticizer, aluminum phosphite, and heat-expandable graphite, and the average degree of polymerization of the polyvinyl chloride is 1300 or more. It is 4000 or less, and the phosphoric acid ester-based plasticizer is contained in an amount of 5 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the polyvinyl chloride, and the total of the polyvinyl chloride and the phosphoric acid ester-based plasticizer. It is a composition containing 50 parts by mass or more and 200 parts by mass or less of the total of the aluminum phosphite and the heat-expandable graphite with respect to 100 parts by mass of the above.
The polyvinyl chloride composition for hardness contains polyvinyl chloride and aluminum phosphite, and the aluminum phosphite is 5 parts by mass or more and 250 parts by mass or less with respect to 100 parts by mass of the polyvinyl chloride. Included is the composition. ]
[2] The soft polyvinyl chloride composition according to [1], wherein the heat-expandable graphite is contained in an amount of 60 parts by mass or more and 250 parts by mass or less with respect to 100 parts by mass of the phosphoric acid ester-based plasticizer. Fireproof laminated sheet.
[3] The refractory laminated sheet according to [1] or [2], wherein the polyvinyl chloride composition for hardness has an average degree of polymerization of 500 or more and 1300 or less.

The refractory laminated sheet of the present invention is excellent in fire resistance and heat shielding property when exposed to high heat.

≪Fireproof laminated sheet≫
The fire-resistant laminated sheet of the first aspect of the present invention is a fire-resistant laminated sheet in which a first hard PVC sheet, a soft PVC sheet, and a second hard PVC sheet are laminated in this order.
Hereinafter, a soft polyvinyl chloride composition for forming a soft PVC sheet and a rigid polyvinyl chloride composition for forming a hard PVC sheet will be described.

<Polychlorinated vinyl chloride composition for soft>
The polyvinyl chloride composition for soft according to this embodiment contains polyvinyl chloride, a phosphoric acid ester-based plasticizer, aluminum phosphite, and heat-expandable graphite, and the average degree of polymerization of the polyvinyl chloride is 1300. The amount is 4000 or less, and the polyvinyl chloride-based plasticizer is contained in an amount of 5 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the polyvinyl chloride. It is a composition containing 50 parts by mass or more and 200 parts by mass or less of the total of the aluminum phosphite and the heat-expandable graphite with respect to 100 parts by mass of the total.

Hereinafter, aluminum phosphate and heat-expandable graphite may be collectively referred to as a flame retardant. Further, polyvinyl chloride may be described as an abbreviation for PVC, and a polyvinyl chloride composition may be described as a PVC composition. Further, the lower limit value and the upper limit value of the numerical value range indicated by "~" shall be included in the numerical value range.

The average degree of polymerization of PVC in the PVC composition for soft materials is 1300 to 4000, preferably 1700 to 3000, and more preferably 2000 to 2500.
When it is at least the lower limit of the above range, the viscosity of the PVC composition for soft material is increased, the dispersibility of the flame retardant is also improved, and it becomes easy to mold into a sheet.
When it is not more than the upper limit of the above range, the fluidity of the PVC composition for soft material is increased, the dispersibility of the flame retardant is also improved, and it becomes easy to mold into a sheet.
Here, the average degree of polymerization of PVC is the average degree of polymerization measured according to JIS K6720-2. The average degree of polymerization is obtained by converting from the K value. The K value is a value measured in accordance with JIS K7367-2 (ISO1628-2).

The PVC of the PVC composition for soft material may be a homopolymer of vinyl chloride or a copolymer. Examples of the monomer copolymerizable with PVC include ethylene, propylene, acrylonitrile, vinyl acetate, maleic acid or an ester thereof, acrylic acid or an ester thereof, methacrylic acid or an ester thereof, vinylidene chloride and the like.
The PVC of the PVC composition for soft material is preferably a vinyl chloride homopolymer.
The PVC of the PVC composition for soft may be a chlorinated vinyl chloride resin.

The content of PVC with respect to the total mass of the PVC composition for soft material is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, still more preferably 20 to 30% by mass.
Within the above range, the dispersibility of the flame retardant in the soft PVC composition is enhanced, and it becomes easier to mold the soft PVC composition into a sheet.

The PVC composition for soft may contain a resin other than PVC, but from the viewpoint of sufficiently obtaining the effect of the present invention, the content of the resin other than PVC with respect to 100 parts by mass of PVC is 50 parts by mass or less. If there is, it may be added.

Examples of resins other than PVC include polyolefin resins such as polypropylene trees and polyethylene resins, polystyrene resins, acrylonitrile-butadiene-styrene (ABS) resins, polycarbonate resins, polyphenylene ether resins, (meth) acrylic resins, polyamide resins, and novolak. Examples thereof include thermoplastic resins such as resins, polyurethane resins, polyisobutylene, polyvinyl acetate, and ethylene-vinyl acetate (EVA).

The phosphoric acid ester-based plasticizer of the PVC composition for soft materials is a known plasticizer having a phosphoric acid ester structure. Here, the phosphoric acid ester structure is a structure in which all or part of the three hydrogens of _{phosphoric acid (O = P (OH) 3) is substituted with an organic group.}
Suitable phosphate ester plasticizers include, for example, tricresyl phosphate (TCP), Tetra-C12-15-alkyl (propane-2,2-diylbis (4,1-phenylene)) bis (phosphite). Be done.
The phosphoric acid ester-based plasticizer contained in the PVC composition for soft may be one kind or two or more kinds.

In the PVC composition for soft materials, the content of the phosphoric acid ester-based plasticizer with respect to 100 parts by mass of PVC is 5 to 150 parts by mass, preferably 30 to 120 parts by mass, more preferably 50 to 100 parts by mass, and 60 parts by mass. ~ 90 parts by mass is more preferable.
When it is at least the lower limit of the above range, the fluidity of the PVC composition for soft material is increased, the dispersibility of the flame retardant is also improved, and it becomes easy to mold into a sheet.
When it is not more than the upper limit of the above range, the viscosity of the PVC composition for soft material is increased, the dispersibility of the flame retardant is also improved, and it becomes easy to mold into a sheet.

The heat-expandable graphite contained in the PVC composition for soft materials is a known carbon material. It is preferable that the heat-expandable graphite has a property of expanding at 200 ° C. or higher and rapidly expanding when exposed to high heat such as a flame.
Examples of known heat-expandable graphite include those obtained by treating graphite powder with an inorganic acid and a strong oxidizing agent to form a graphite interlayer compound. Here, examples of graphite include natural scaly graphite, pyrolytic graphite, quiche graphite and the like. Examples of the inorganic acid include concentrated sulfuric acid, nitric acid, selenic acid and the like. Examples of the strong oxidizing agent include concentrated nitric acid, perchloric acid, perchlorate, permanganate, permanganate, dichromate, hydrogen peroxide and the like. The heat-expandable graphite obtained by the above treatment may be further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound or the like. Commercially available heat-expandable graphite can be used.

The content of the heat-expandable graphite with respect to the total mass of the PVC composition for soft material is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, still more preferably 20 to 30% by mass.
Within the above range, it becomes easier to mold the soft PVC composition into a sheet, and the fire resistance and heat shielding property of the obtained soft PVC sheet are enhanced.

In the PVC composition for soft materials, the content of the heat-expandable graphite with respect to 100 parts by mass of PVC is preferably 5 to 200 parts by mass, more preferably 50 to 150 parts by mass, still more preferably 75 to 125 parts by mass.
Within the above range, it becomes easier to mold the soft PVC composition into a sheet, and the obtained soft PVC sheet has an excellent balance of fire resistance and heat shielding property.

In the PVC composition for soft materials, the content of the heat-expandable graphite with respect to 100 parts by mass of the phosphoric acid ester-based plasticizer is preferably 60 to 250 parts by mass, more preferably 80 to 200 parts by mass, and 100 to 150 parts by mass. More preferred.
Within the above range, it becomes easier to mold the soft PVC composition into a sheet, and the obtained soft PVC sheet has an excellent balance of fire resistance and heat shielding property.

Aluminum phosphate contained in the PVC composition for soft materials is a known compound. It is preferable that aluminum phosphite has a property that the composition changes at around 400 ° C. and foams to change from a powdery state to a porous body. Commercially available aluminum phosphite can be used.

The content of aluminum phosphate with respect to the total mass of the PVC composition for soft material is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, still more preferably 20 to 30% by mass.
Within the above range, it becomes easier to mold the soft PVC composition into a sheet, and the fire resistance and heat shielding property of the obtained soft PVC sheet are enhanced.

In the PVC composition for soft materials, the content of aluminum phosphate with respect to 100 parts by mass of PVC is preferably 5 to 200 parts by mass, more preferably 50 to 150 parts by mass, still more preferably 75 to 125 parts by mass.
Within the above range, it becomes easier to mold the soft PVC composition into a sheet, and the obtained soft PVC sheet has an excellent balance of fire resistance and heat shielding property.

When the total content of polyvinyl chloride and phosphate ester plasticizer is 100 parts by mass in the PVC composition for soft materials, the total content of aluminum phosphite and heat-expandable graphite with respect to 100 parts by mass. Is 50 to 200 parts by mass, preferably 60 to 180 parts by mass, more preferably 70 to 160 parts by mass, further preferably 80 to 140 parts by mass, and particularly preferably 90 to 120 parts by mass.
Within the above range, it becomes easy to mold the soft PVC composition into a sheet, and the balance between the fire resistance and the heat shielding property of the obtained soft PVC sheet is excellent.

In the PVC composition for soft materials, the content of the heat-expandable graphite is preferably 50 to 200 parts by mass, more preferably 70 to 150 parts by mass, and 80 to 100 parts by mass with respect to 100 parts by mass of aluminum phosphate. Parts by mass are more preferred.
Within the above range, the balance between the fire resistance and the heat shielding property of the soft PVC sheet obtained from the soft PVC composition is excellent.

<Other optional ingredients>
The soft PVC composition may contain any component other than PVC, a phosphoric acid ester-based plasticizer, aluminum phosphite, and heat-expandable graphite, if necessary.

Further, stabilizers, lubricants, modifiers, fillers, colorants and the like generally used for PVC resins can be added and mixed within a range that does not impair the object of the present invention.
Stabilizers include, for example, lead tribasic lead sulfate, lead dibasic phosphite, basic lead sulfite, lead dibasic phthalate, lead white, lead-based stabilizers such as laurate or stearate of lead; butyl. Tin maleate, octyl tin maleate, di-n-alkyl tin mercaptide, di-n-alkyl tin dilaurate, dibutyl tin dimalate, dibutyl tin lauryl mercaptide, di-octyl tin-S, S'-bis- (isooctyl-mercaptoacetate) ), Dibutyltin bis-isooctylthioglycolate, di- (n-octyl) tin maleate polymer, tin-based stabilizers such as dibutyltin mercaptopropionate; laurate or stearate of calcium, cadmium, barium or zinc, etc. Organic metal salt stabilizers and metal soap stabilizers; antimony stabilizers such as antimony mercaptocarboxylates or ester salts; phosphate stabilizers; epoxidized oils such as epoxidized soybean oil and epoxidized flaxseed oil. Stabilizers; these are used alone or in combination of two or more.
Examples of the lubricant include aliphatic hydrocarbon-based lubricants such as low-molecular-weight wax, polyethylene wax, paraffin wax, and liquid paraffin; higher aliphatic alcohol-based lubricants such as stearyl alcohol; fatty acid-based lubricants such as stearic acid, palmitic acid, and myristic acid. Lubricants; aliphatic amide lubricants such as stearic acid amide, palmitate amide, methylene bisstearoamide; fatty acid ester lubricants such as glycerin monostearate, ethyl diaminostearate, butyl stearate; or metal soap, silicone oil, etc. These are used alone or in combination of two or more.
Examples of the modifier include ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, chlorinated polyethylene, methyl methacrylate / butadiene / styrene copolymer, acrylonitrile / butadiene / styrene copolymer, and acrylic rubber. Impact resistance improvers such as; Gelation accelerators such as polymethylmethacrylate; Acrylonitrile / butadiene / α-methylstyrene copolymers, methylmethacrylate / acrylic acid ester copolymers, etc., which may be used alone or in combination of two or more. Used in combination of.

<Manufacturing method of PVC composition for soft material>
The PVC composition for soft material is obtained by mixing each component according to a conventional method.
First, a PVC compound containing PVC, a phosphoric acid ester-based plasticizer, and an optional component is obtained, and then aluminum phosphite and heat-expandable graphite are added to the PVC compound and kneaded to disperse the flame retardant. It is preferable because it has excellent properties.

<Hard polyvinyl chloride composition>
The polyvinyl chloride composition for hardness of this embodiment contains polyvinyl chloride and aluminum phosphite, and the aluminum phosphite is 5 parts by mass or more and 250 parts by mass with respect to 100 parts by mass of the polyvinyl chloride. It is a composition contained below.

The average degree of polymerization of PVC in the hard PVC composition is preferably 500 to 1300, more preferably 600 to 1000, and even more preferably 700 to 800.
Within the above range, a hard sheet having excellent fire resistance can be easily molded.
Here, the average degree of polymerization of PVC is a value measured by the same method as the average degree of polymerization of PVC in the PVC composition for soft materials.

The PVC of the PVC composition for hardness may be a homopolymer of vinyl chloride or a copolymer. Examples of the monomer copolymerizable with PVC include ethylene, propylene, acrylonitrile, vinyl acetate, maleic acid or an ester thereof, acrylic acid or an ester thereof, methacrylic acid or an ester thereof, vinylidene chloride and the like.
The PVC of the PVC composition for hardness is preferably a vinyl chloride homopolymer.
The PVC of the hard PVC composition may be a chlorinated vinyl chloride resin.

The content of PVC with respect to the total mass of the PVC composition for hard is preferably 10 to 50% by mass, more preferably 20 to 45% by mass, still more preferably 30 to 40% by mass.
Within the above range, the rigidity of the rigid PVC sheet is further increased, and the fire resistance of the refractory laminated sheet is improved.

The hard PVC composition may contain a resin other than PVC, but from the viewpoint of sufficiently obtaining the effects of the present invention, the content of the resin other than PVC with respect to 100 parts by mass of PVC is 10 parts by mass or less. It is preferably 5 parts by mass or less, more preferably 1 part by mass or less, and most preferably not substantially contained.

Examples of resins other than PVC include polyolefin resins such as polypropylene trees and polyethylene resins, polystyrene resins, acrylonitrile-butadiene-styrene (ABS) resins, polycarbonate resins, polyphenylene ether resins, (meth) acrylic resins, polyamide resins, and novolak. Examples thereof include thermoplastic resins such as resins, polyurethane resins, polyisobutylene, polyvinyl acetate, and ethylene-vinyl acetate (EVA).

The PVC composition for hardness may or may not contain a phosphoric acid ester-based plasticizer.

The hard PVC composition may contain heat-expandable graphite, but from the viewpoint of enhancing the rigidity and fire resistance of the hard PVC sheet, the content of the heat-expandable graphite with respect to 100 parts by mass of PVC is 10 parts by mass. The following is preferable, 5 parts by mass or less is more preferable, 1 part by mass or less is further preferable, and it is most preferable that it is substantially not contained.

Aluminum phosphate contained in the hard PVC composition is a known compound as described above.
The content of aluminum phosphate with respect to the total mass of the hard PVC composition is preferably 30 to 70% by mass, more preferably 40 to 65% by mass, still more preferably 50 to 60% by mass.
Within the above range, it becomes easier to mold the hard PVC composition into a sheet, and the fire resistance and heat shielding property of the obtained hard PVC sheet are enhanced.

In the hard PVC composition, the content of aluminum phosphate with respect to 100 parts by mass of PVC is 5 to 250 parts by mass, preferably 50 to 200 parts by mass, more preferably 75 to 150 parts by mass, and 100 to 125 parts. Parts by mass are more preferred.
Within the above range, it becomes easier to mold the hard PVC composition into a sheet, and the balance between the fire resistance and the heat shield of the obtained hard PVC sheet is excellent.

<Other optional ingredients>
The hard PVC composition may contain PVC and an optional component of aluminum phosphite, if necessary.
Examples of the optional component include other optional components exemplified in the PVC composition for soft materials.

<Manufacturing method of PVC composition for hardness>
The hard PVC composition is obtained by mixing each component according to a conventional method.
First, a PVC compound containing PVC and arbitrary components is obtained, and then a method of adding aluminum phosphite to the PVC compound and kneading is preferable.

<Laminated structure of refractory laminated sheet>
The size of the vertical × horizontal × thickness of the refractory laminated sheet of this embodiment is not particularly limited, and examples thereof include a size of 1 to 100 cm in length, 1 to 100 cm in width, and 1 to 10 mm in thickness.
In the refractory laminated sheet of this embodiment, the thickness of the soft PVC sheet is not particularly limited, and is appropriately set in the range of 0.1 to 10 mm, for example, depending on the application.
In the refractory laminated sheet of this embodiment, the thickness of the hard PVC sheet is not particularly limited, and is appropriately set in the range of 0.1 to 10 mm, for example, depending on the application.
The thickness h1 of the first hard PVC sheet and the thickness h2 of the second hard PVC sheet may be the same or different from each other, for example, h1: h2 = 2: 1-1: 1. It can be in the range of 2.
The thickness h1 of the first hard PVC sheet and the thickness h3 of the soft PVC sheet may be the same or different from each other, for example, h1: h3 = 2: 1-1: 2. Can be a range.
In the refractory laminated sheet of this embodiment, any one of the two rigid PVC sheets may be considered as the first rigid PVC sheet.

In the fire-resistant laminated sheet of this embodiment, another resin layer may be provided between the first hard PVC sheet and the soft PVC sheet, but from the viewpoint of enhancing the fire resistance and heat-shielding property of the fire-resistant laminated sheet of this embodiment. It is preferable that the first hard PVC sheet and the soft PVC sheet are directly adhered to each other. The same applies to the relationship between the second hard PVC sheet and the soft PVC sheet.

The composition of the first hard PVC sheet and the second hard PVC sheet constituting the refractory laminated sheet of this embodiment may be the same or different from each other.

<Manufacturing method of refractory laminated sheet>
A refractory laminated sheet is obtained by forming a soft PVC sheet from a soft PVC composition, forming a hard PVC sheet from a hard PVC composition, and then laminating the hard PVC sheet and the soft PVC sheet according to a conventional method. be able to. As a method of laminating a soft PVC sheet on a hard PVC sheet, a method of welding while heating and pressurizing is preferable.

Examples of the method for producing a soft PVC sheet include a method of melt-extruding a soft PVC composition with an extruder such as a single-screw extruder or a twin-screw extruder, or calendar forming / press forming according to a conventional method.
The melting temperature of the PVC composition for soft material needs to be low so that the PVC does not burn and the heat-expandable graphite does not expand, and is preferably 130 to 170 ° C.
The hard PVC sheet can be manufactured in the same manner as the soft PVC sheet.

<Use of refractory laminated sheet>
The use of the refractory laminated sheet of this embodiment is not particularly limited, and is suitable for, for example, shielding, storing, or packing flammable articles such as batteries and various power supply devices.

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

The details of the raw materials shown in Table 1 are as follows.
"TK-1000": Polyvinyl chloride with an average degree of polymerization of 1000 manufactured by Shin-Etsu Chemical Co., Ltd. "TK-2500HS": Polyvinyl chloride with an average degree of polymerization of 2500 manufactured by Shin-Etsu Chemical Co., Ltd .: Shin-Etsu Chemical Co., Ltd. Polyvinyl chloride "Leofos 65" with an average degree of polymerization of 5000: Ajinomoto Fine Techno Co., Ltd., Triaryl isopropyl phosphate "DINP": Shin-Etsu Chemical Co., Ltd., Diisononyl phthalate "W-100EL": DIC Co., Ltd. "Adecastab NPS-309": Made by ADEKA "Adecastab 1500": Made by ADEKA, Tetra-C12-15-alkyl (propane-2,2-diylbis (4,1-phenylene)) bis (phosphite)
"CS-6": Nitto Kasei Kogyo Co., Ltd., calcium stearate "NSF": Taihei Kagaku Sangyo Co., Ltd. "Expanded Graphite N9950300": Nishimura Graphite Co., Ltd.

[Preparation of PVC composition for soft material]
A PVC composition for softness was obtained by mixing each raw material with a biaxial kneader in the amount (part by mass) shown in Table 1. For example, in Example 1, 75 parts by mass of a phosphoric acid ester plasticizer and about 5 parts by mass of other additives are blended with 100 parts by mass of PVC, and 90.05 parts by mass of aluminum phosphite and heat are added. 90.05 parts by mass of expandable graphite was added to obtain the desired soft PVC composition.

[Creation of soft PVC sheet]
(Example 1)
80 g of the soft PVC composition of Example 1 was put into a labplast mill (manufactured by Toyo Seiki Co., Ltd .: model number: 4C150, rotor: R30) and kneaded at 30 rpm at 150 ° C. for 7 minutes. The obtained kneaded product was passed through a 6-inch roll set at 150 ° C. for 3 minutes within 1 minute to prepare a soft PVC sheet having a thickness of about 1 mm. This soft PVC sheet was cut into a size of 10 cm × 5 cm to obtain a test piece.

(Comparative Example 1)
Using the soft PVC composition of Comparative Example 1, an attempt was made to prepare a soft PVC sheet in the same manner as in Example 1, but the fluidity of the soft PVC composition was excessively high and it could not be formed into a sheet. rice field.

(Comparative Example 2)
Using the soft PVC composition of Comparative Example 2, an attempt was made to prepare a soft PVC sheet in the same manner as in Example 1, but the soft PVC composition was poorly organized, had an excessively high viscosity, and was molded into a sheet shape. I couldn't.

(Comparative Examples 3 to 5)
Using the soft PVC compositions of Comparative Examples 3 to 5, a soft PVC sheet was prepared in the same manner as in Example 1 to obtain a test piece.

(Comparative Example 6)
Using the soft PVC composition of Comparative Example 6, an attempt was made to prepare a soft PVC sheet in the same manner as in Example 1, but the soft PVC composition was poorly organized and could be molded into a barely thick sheet (plate). It could not be thinned to the same thickness as in Example 1.

[Evaluation of fire resistance and heat insulation of soft PVC sheet]
The test piece of the soft PVC sheet prepared in each example was fixed horizontally and placed on a wire mesh heated to 900 ° C. and heated for 120 seconds. The temperature change on the upper surface of the test piece at this time was measured by thermography.

(Example 1)
The maximum temperature of the upper surface of the test piece was 350 ° C. In addition, changes in the outer shape such as warpage and thinning (shrinkage) were small.

(Comparative Example 3)
The maximum temperature of the upper surface of the test piece reached 405 ° C., and then ignited.

(Comparative Example 4)
Immediately after heating, the outer shape of the test piece was significantly deformed, so heating was stopped.

(Comparative Example 5)
The maximum temperature of the upper surface of the test piece reached 400 ° C.

<Discussion 1>
The soft PVC sheet of Example 1 showed excellent heat-shielding properties, had little deformation in the outer shape, and had excellent fire resistance.
Since the average degree of polymerization of PVC in the soft PVC composition of Comparative Example 1 was small, the soft PVC composition was not in a state suitable for sheet molding.
In the soft PVC composition of Comparative Example 2, the average degree of polymerization of PVC was large, so that the soft PVC composition was not in a state suitable for sheet molding.
Since the soft PVC sheet of Comparative Example 3 did not contain a phosphoric acid ester-based plasticizer and contained a phthalic acid-based plasticizer, it was inferior in heat-shielding property and ignited.
Since the total amount of the flame retardant was small in the soft PVC sheet of Comparative Example 4, the outer shape was severely deformed immediately after heating, and the heat-shielding property could not be exhibited.
The soft PVC sheet of Comparative Example 5 contained a large amount of aluminum phosphite within the range in which the sheet could be molded, but did not contain heat-expandable graphite, so that the heat-shielding property was inferior.
The soft PVC composition of Comparative Example 6 could not be pressed to obtain a sheet having a desired thickness due to the large amount of the flame retardant.
From the above results, it is clear that the soft PVC composition used in the present invention can form a sheet with a desired thickness, and the obtained soft PVC sheet is excellent in both fire resistance and heat shielding properties. Is.

The details of the raw materials shown in Table 2 are as follows.
"TK-700": Polyvinyl chloride "S-111" manufactured by Shin-Etsu Chemical Co., Ltd. with an average polymerization degree of 700: "ADEKA STAB 1500" manufactured by Katsuta Kako Co., Ltd .: "Kaneka B-564" manufactured by ADEKA Corporation: "Kaneka Ace" manufactured by Kaneka Corporation. B-56 ": Kaneka's" Metabren P-700 ": Mitsubishi Chemical's" Metabren P-501A ": Mitsubishi Chemical's" Roxyol G-72 ": Emery Oleochemicals'"F-3 ": Kawaken Fine Chemicals "Roxyol G-70S" manufactured by Emery Oleochemicals: "Roxyol G-15" manufactured by Emery Oleochemicals: "CS-6" manufactured by Emery Oleochemicals: Calcium stearate "W-100EL" manufactured by Nitto Kasei Kogyo Co., Ltd .: "NSF" manufactured by DIC : Made by Taihei Chemical Industry Co., Ltd.

[Preparation of PVC composition for hardness]
A PVC composition for hardness was obtained by mixing each raw material with a biaxial kneader in the amount (part by mass) shown in Table 2. For example, in Example 2, various arbitrary components are blended in an amount of 18.95 parts by mass with respect to 100 parts by mass of PVC, and 118.95 parts by mass of aluminum phosphate is further blended to obtain a desired hard PVC composition. rice field.

[Creation of hard PVC sheet]
(Example 2)
85.9 g of the hard PVC composition of Example 2 was put into a lab plast mill (manufactured by Toyo Seiki Co., Ltd .: model number: 4C150, rotor: R30) and kneaded at 30 rpm at 180 ° C. for 7 minutes. The obtained kneaded product was passed through a 6-inch roll set at 180 ° C. for 3 minutes within 1 minute to prepare a hard PVC sheet having a thickness of about 0.5 mm. This rigid PVC sheet was cut into a size of 10 cm × 5 cm to obtain a test piece.

(Comparative Example 7)
Using the hard PVC composition of Comparative Example 7, an attempt was made to prepare a hard PVC sheet in the same manner as in Example 2, but the fluidity of the hard PVC composition was poor and it could not be formed into a sheet.

(Comparative Example 8)
Using the hard PVC composition of Comparative Example 8, a hard PVC sheet was prepared in the same manner as in Example 2 to obtain a test piece.

[Evaluation of fire resistance and heat insulation of hard PVC sheet]
The test piece of the soft PVC sheet prepared in each example was fixed horizontally and placed on a wire mesh heated to 900 ° C. and heated for 90 seconds. The temperature change on the upper surface of the test piece at this time was measured by thermography.

(Example 2)
The temperature of the upper surface of the test piece after heating for 90 seconds was 521 ° C. In addition, there was almost no change in the outer shape such as warpage or thinning (shrinkage).

(Comparative Example 8)
The temperature of the upper surface of the test piece after heating for 90 seconds was 581 ° C.

<Discussion 2>
The rigid PVC sheet of Example 2 showed excellent heat-shielding properties as compared with Comparative Example 8, and had almost no deformation in the outer shape and was also excellent in fire resistance.
Since the hard PVC composition of Comparative Example 7 contained a large amount of aluminum phosphite, the hard PVC composition was not in a state suitable for sheet molding.
The hard PVC sheet of Comparative Example 8 had a poor heat-shielding property because the content of aluminum phosphite was low.
From the above results, it is clear that the hard PVC composition used in the present invention can form a sheet with a desired thickness, and the obtained hard PVC sheet is excellent in both fire resistance and heat shielding properties. Is.

[Creation of refractory laminated sheet]
(Example 3)
By superimposing the hard PVC sheet (0.5 mm thick) prepared in Example 2 on the front surface and the back surface of the soft PVC sheet (0.5 mm thick) prepared in the same manner as in Example 1, and heating and pressurizing the two sheets. A refractory laminated sheet (1.5 mm thick) having a soft PVC sheet sandwiched between the hard PVC sheets of the above was prepared. This refractory laminated sheet was cut into a size of 10 cm × 5 cm to obtain a test piece.

(Comparative Example 9)
By superimposing the soft PVC sheet (0.5 mm thick) prepared in the same manner as in Example 1 on the front surface and the back surface of the hard PVC sheet (0.5 mm thick) prepared in Example 2, heating and pressurizing the two sheets. A refractory laminated sheet (1.5 mm thick) was prepared by sandwiching a hard PVC sheet between the soft PVC sheets. This refractory laminated sheet was cut into a size of 10 cm × 5 cm to obtain a test piece.

[Evaluation of fire resistance and heat insulation of fire resistant laminated sheet]
The test piece of the refractory laminated sheet prepared in each example was fixed horizontally and placed on a wire mesh heated to 770 ° C. and heated for 120 seconds. The temperature change on the upper surface of the test piece at this time was measured by thermography.

(Example 3)
The maximum temperature of the upper surface of the test piece was 300 ° C. In addition, there was almost no change in the outer shape such as warpage or thinning (shrinkage).

(Comparative Example 9)
The maximum temperature of the upper surface of the test piece was suppressed to 300 ° C., but the change in the outer shape such as warpage and thinning was large as compared with Example 3.

From the above results, it is clear that the refractory laminated sheet of the present invention is excellent in both fire resistance and heat shielding property.

Claims (3)

A refractory laminated sheet in which a first hard PVC sheet, a soft PVC sheet, and a second hard PVC sheet are laminated in this order.
The soft PVC sheet is formed of a polyvinyl chloride composition for soft, and is formed.
The first hard PVC sheet and the second hard PVC sheet are refractory laminated sheets formed of a hard polyvinyl chloride composition.
[The polyvinyl chloride composition for soft contains polyvinyl chloride, a phosphoric acid ester-based plasticizer, aluminum phosphite, and heat-expandable graphite, and the average degree of polymerization of the polyvinyl chloride is 1300 or more. It is 4000 or less, and the phosphoric acid ester-based plasticizer is contained in an amount of 5 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the polyvinyl chloride, and the total of the polyvinyl chloride and the phosphoric acid ester-based plasticizer. It is a composition containing 50 parts by mass or more and 200 parts by mass or less of the total of the aluminum phosphite and the heat-expandable graphite with respect to 100 parts by mass of the above.
The polyvinyl chloride composition for hardness contains polyvinyl chloride and aluminum phosphite, and the aluminum phosphite is 5 parts by mass or more and 250 parts by mass or less with respect to 100 parts by mass of the polyvinyl chloride. Included is the composition. ] The fireproof lamination according to claim 1, wherein the polyvinyl chloride composition for soft contains 60 parts by mass or more and 250 parts by mass or less of the heat-expandable graphite with respect to 100 parts by mass of the phosphoric acid ester-based plasticizer. Sheet. The refractory laminated sheet according to claim 1 or 2, wherein in the hard polyvinyl chloride composition, the average degree of polymerization of the polyvinyl chloride is 500 or more and 1300 or less.