JP7336538B2 - Sheet for blasting method - Google Patents

Description

The present invention relates to a sheet for blasting method.

BACKGROUND ART When repainting a coating film on a structure such as a bridge, the old coating film is once removed by blasting, and then a new coating is applied. This blasting process generates dust on the paint film, and the paint film may contain hazardous substances such as polychlorinated biphenyls and lead. , Efforts should be made to prevent scattering of dust.

In order to prevent the scattering of dust during blasting, it is common to separate the work environment from the outside with a panel and cover the inside of the panel with a blasting sheet. Sheets for construction work are used. This sheet for construction work is obtained by coating the surface of a woven fabric made of flat yarn with a resin, and polyethylene or polyvinyl chloride is used as the resin (see, for example, Patent Document 1).

Further, for example, sheets for construction work have been proposed which are excellent in post-processability by thermal bonding. More specifically, as a sheet for the blasting method, a sheet for construction work is used in which the surface of a woven fabric made of flat yarn is coated with flame-retardant vinyl chloride. In order to enhance the flame retardancy of this sheet, the flat yarn is coated with a vinyl chloride coating containing a halogen-based flame retardant as a flame retardant and antimony trioxide as a flame retardant aid. It is a sheet for blasting method as a sheet for construction work (see Patent Document 2, for example).

In addition, transparent flame-retardant films having self-extinguishing properties (flame retardancy) and excellent transparency have been proposed for applications such as partition curtains used in factories, terraces, and the like. More specifically, 0.01 to 5 parts by mass of antimony trioxide having an average particle diameter (D50) of 20 to 800 nm is added to 100 parts by mass of synthetic resin. In addition, a transparent flame-retardant film containing 1 to 60 parts by mass of a flame-retardant plasticizer such as a phosphate ester-based flame-retardant plasticizer with respect to 100 parts by mass of a synthetic resin (for example, Patent Document 3 reference).

JP-A-3-36367 JP-A-10-245739 JP 2012-102303 A

However, when the sheet for construction work is used as the sheet for the blasting method, holes may be formed by scattered objects such as cutting materials rebounded from the surface to be treated during the blasting process. In particular, when blasting is performed in a low-temperature environment such as in winter, holes are likely to form. If the blasting sheet is perforated, there is concern that dust containing harmful substances may leak outside.

In addition, the sheet for blasting using polyvinyl chloride described in Patent Document 1 may undergo brittle fracture in a low-temperature environment such as outdoors in winter, making it more likely to break. In addition, polyethylene is known as a general-purpose plastic that is resistant to low temperatures, but the energy applied to the sheet for blasting by flying debris during blasting is strong, so there is a risk of tearing (chipping) even at room temperature due to flying debris. was there.

In addition, antimony trioxide is used as a flame retardant aid or flame retardant in the blasting method sheet as the architectural curing sheet described in Patent Document 2, the partition curtain described in Patent Document 3, and the like. There was a problem that the laws and regulations on use were strictly applied.

In other words, in 2015 and 2016, the Ministry of Health, Labor and Welfare held the 2016 Investigative Committee on Measures to Prevent Health Impairment of Workers Due to Chemical Substances, and diantimony It has been designated as a Class 2 Controlled Substance under the Preventive Regulations.

Therefore, as long as diantimony trioxide is used, it is obligatory to take measures to control emission in accordance with the "Ordinance on Prevention of Hazards from Specified Chemical Substances", implement work environment measurements, implement special health examinations, etc., and strictly observe the usage conditions. There is a problem of having to

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a blasting method sheet that can achieve both cold resistance (chipping resistance in a low temperature environment) and flame retardancy.

In order to achieve the above object, the blasting sheet of the present invention comprises a soft vinyl chloride resin composition containing a vinyl chloride resin and a plasticizer, the plasticizer containing an aliphatic dibasic acid ester plasticizer. , The impact resistance energy by the film impact tester test is 1.99 J or more at -15 ° C., and the flame retardancy satisfies Category 3 in accordance with JIS L1091 (A-1 method). .

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the sheet|seat for blasting methods excellent in cold resistance and flame retardance.

FIG. 2 is a diagram showing an example of TG-DTA curves of a vinyl chloride resin and an endothermic inorganic compound used in a blasting method sheet. It is a figure which shows the usage method of the sheet|seat for blasting methods of 1 sheet type. It is a figure which shows the usage method of the sheet|seat for blasting methods of a 2 sheet type. It is a figure for demonstrating the blast test (chipping resistance test) in an Example.

Hereinafter, the sheet for blasting method of the present invention will be specifically described. In addition, the present invention is not limited to the following embodiments, and can be appropriately modified and applied without changing the gist of the present invention.

The blasting sheet of the present invention is a sheet formed of a soft vinyl chloride resin composition containing at least a vinyl chloride resin and a plasticizer.

<Vinyl chloride resin>
Examples of vinyl chloride resins include polyvinyl chloride and copolymers mainly composed of vinyl chloride. Examples of copolymers mainly composed of vinyl chloride include ethylene-vinyl chloride copolymers, vinyl acetate-vinyl chloride copolymers, vinyl chloride-halogenated olefin copolymers, and the like.

In addition, copolymers mainly composed of vinyl chloride include other compatible resins mainly composed of these vinyl chloride resins (for example, polyester resins, epoxy resins, acrylic resins, vinyl acetate resins, urethane resins, acrylonitrile- Also included are blends with styrene-butadiene copolymers, partially saponified polyvinyl alcohol, etc.).

The proportion of vinyl chloride units in the vinyl chloride resin is preferably 80% by mass or more with respect to the total resin components. The polymerization method of the vinyl chloride resin is not particularly limited, and conventional polymerization methods such as bulk polymerization method, emulsion polymerization method, suspension polymerization method and solution polymerization method can be mentioned. Any one of these vinyl chloride resins may be used alone, or two or more thereof may be used in combination.

The vinyl chloride resin preferably has an average degree of polymerization of 800 to 2,500, more preferably 1,000 to 2,000. When the average degree of polymerization is at least the lower limit of the above range, the film does not stretch excessively when pulled, and does not impair handleability. Further, if the average degree of polymerization is equal to or less than the upper limit value of the above range, it is not too hard, and holes are less likely to form during blasting.

<Plasticizer>
The plasticizer of the present invention contains an aliphatic dibasic ester plasticizer. Examples of the aliphatic dibasic acid ester plasticizer include di-n-butyl adipate, diisobutyl adipate, dioctyl adipate (hereinafter sometimes abbreviated as "DOA"), bis(2-ethylhexyl) adipate, and diisononyl adipate. , diisodecyl adipate, bis [2-(2-butoxyethoxy) ethyl] adipate (hereinafter sometimes abbreviated as "BXA-N"), bis (2-ethylhexyl) azelate, dibutyl sebacate, bis (2- It is preferably at least one compound selected from the group consisting of ethylhexyl) sebacate (hereinafter sometimes abbreviated as "DOS"), diethyl succinate, di-n-butyl malate, and monobutyl itaconate. .

The reason for this is that such an aliphatic dibasic ester plasticizer can remarkably improve the cold-temperature properties of the obtained flame-retardant sheet compared to the aromatic dibasic ester plasticizer. It's for.

In particular, at least one of dioctyl adipate (DOA), bis [2-(2-butoxyethoxy) ethyl] adipate (BXA-N), and bis (2-ethylhexyl) sebacate (DOS) significantly improves cold resistance. can be improved. Furthermore, these aliphatic dibasic acid ester plasticizers are relatively inexpensive, and are excellent in terms of economy and availability, and are thus preferable.

In addition, the amount of the aliphatic dibasic ester plasticizer is preferably a value within the range of 15 to 55 parts by mass, more preferably 35 to 50 parts by mass, with respect to 100 parts by mass of the vinyl chloride resin. .

This is because if the content of the aliphatic dibasic ester plasticizer is less than 15 parts by mass, the cold resistance may decrease. On the other hand, if the amount of the aliphatic dibasic acid ester plasticizer exceeds 55 parts by weight, the blasting sheet may become too soft, resulting in deterioration of mechanical properties and handling properties.

In addition, from the viewpoint of ensuring cold resistance, the amount of the aliphatic dibasic ester plasticizer with respect to the entire plasticizer is preferably 50% by mass or more, and the aliphatic dibasic ester plasticizer It is more preferred to use plasticizers consisting of agents only.

Further, if the amount is small relative to the blending amount (100 parts by mass) of the aliphatic dibasic ester plasticizer, for example, an aromatic dibasic ester plasticizer such as dioctyl phthalate (DOP) may be blended. good.

More specifically, from the viewpoint of suppressing a decrease in cold resistance of the sheet for blasting, the amount of the aromatic dibasic ester plasticizer is preferably 50 parts by mass or less, more preferably 30 parts by mass or less. , 10 parts by mass or less are particularly preferred.

In addition, the soft vinyl chloride resin composition of the present invention may optionally contain components other than the vinyl chloride resin and plasticizer described above, such as flame retardants and heat-absorbing inorganic compounds shown below.

<Flame retardant>
Examples of flame retardants include phosphate ester flame retardants, phosphorus-nitrogen composite flame retardants, and halogen flame retardants.

Among them, the phosphoric acid ester flame retardant includes trimethyl phosphate (sometimes referred to as TMP, hereinafter the same), triethyl phosphate (TEP), tributyl phosphate (TBP), trilith (2-ethylhexyl) phosphate (TOP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), trixylenyl phosphate (TXP), cresyl diphenyl phosphate (CDP), 2-ethylhexyl at least one of tylhexyldiphenyl phosphate and the like.

In particular, if at least one of tri-cresyl phosphate (TCP), trixylenyl phosphate (TXP), and cresyl diphenyl phosphate (CDP) is used, the phosphorus content (P) per unit weight is relatively large. Therefore, even in a relatively small amount, it exhibits excellent flame retardancy and is relatively easy to obtain, which is more preferable.

Further, it is preferable that the amount of the phosphate ester-based flame retardant compounded is 8 to 12 parts by mass with respect to 100 parts by mass of the vinyl chloride resin. This is because if the amount of the phosphate ester-based flame retardant compounded is less than 8 parts by mass, the desired flame retardancy may not be obtained reliably in the sheet for the blasting method. Moreover, if the amount of the phosphate ester-based flame retardant compounded exceeds 12 parts by mass, the cold resistance of the sheet for blasting method may be remarkably lowered.

<Endothermic inorganic compound>
Also, as an auxiliary agent for the flame retardant, an endothermic inorganic compound may be blended together with the above flame retardant. Here, the endothermic inorganic compound is defined as an inorganic compound that causes an endothermic reaction when heated to a predetermined temperature. is a compound. Examples include at least one of metal hydroxides, ores, metal compounds, inorganic hydrates, inorganic carbonates, and the like.

More specific examples include magnesium hydroxide, aluminum hydroxide, hydrotalcite, and zinc borate. In addition, these can be used individually by 1 type or in combination of 2 or more types.

In addition, among these endothermic inorganic compounds, magnesium hydroxide, hydrotalcite, and zinc borate are used in particular, so that the decomposition initiation temperature is 260 ° C. or higher, and the unit when hydrolyzing Since the amount of heat absorption per weight is extremely high, 500 J/mg or more, the heat absorption effect can be exhibited by combining with a phosphate ester flame retardant, and as a result, good flame retardancy can be exhibited.

More specifically, by including an endothermic inorganic compound exhibiting such decomposition initiation temperature and decomposition endothermic amount, as shown by curve B in the TG-DTA chart of FIG. It is known that the main chain is thermally decomposed at around 400°C.

In such cases, it has also been found that the phosphate ester flame retardant is dehydrated to form a so-called char, which is a carbonized layer of phosphorus and carbon.

In addition, as shown by curve A in the TG-DTA (thermogravimetric-differential thermal analysis) chart of FIG. 1, it has been found that a given endothermic inorganic compound causes an endothermic reaction at a given temperature.

Therefore, according to the soft vinyl chloride resin composition of the present invention, by utilizing the endothermic reaction of the predetermined endothermic inorganic compound, decomposition of the vinyl chloride resin is delayed and char formation by the phosphate ester flame retardant is prevented. can be promoted, and as a result, good flame retardancy can be exhibited.

The above-described decomposition initiation temperature and decomposition endotherm can be measured with an analysis device such as a TG-DTA device (differential thermal-thermogravimetry device) or a DSC device (differential scanning calorimeter).

The amount of the endothermic inorganic compound is preferably 5 to 30 parts by mass, more preferably 5 to 15 parts by mass, based on 100 parts by mass of the vinyl chloride resin. This is because if the blending amount of the endothermic inorganic compound is less than 5 parts by mass, the desired flame retardancy may not be obtained reliably in the blasting sheet. On the other hand, if the blending amount of the endothermic inorganic compound exceeds 30 parts by mass, the mechanical properties are remarkably deteriorated, uniform mixing and dispersion becomes difficult, and the specific gravity of the blasting sheet becomes heavy. This is because there is a case where the handleability is deteriorated.

In addition, the ratio represented by the compounding amount of the phosphate ester compound/the compounding amount of the endothermic inorganic compound is preferably 1/5 to 5, more preferably 1/1.5 to 2.4. . This is because if the ratio is less than 1/5, the mechanical properties may significantly deteriorate. Also, if the ratio exceeds 5, the desired flame retardancy may not be obtained with certainty.

<Other ingredients>
At least one compound such as an epoxy stabilizer, liquid stabilizer, powder stabilizer, anti-blocking agent, or lubricant may be added to the soft vinyl chloride resin composition as an additive.

For example, in order to improve the heat resistance of the sheet for blasting and to suppress the hydrolyzability, an epoxy-based stabilizer, a liquid stabilizer, a powder stabilizer, or the like may be blended.

At least one antiblocking agent such as crosslinked vinyl chloride resin particles, polyolefin resin powder, fatty acid ester, etc. may be blended in order to prevent blocking between sheets for the blasting method.

Furthermore, in order to prevent the blasting sheets from sticking together, fatty acid amides such as ethylenebisstearic amide, stearic amide, palmitic amide, and oleic amide, polyethylene wax, stearic acid, silica, etc. are added as lubricants. May be blended.

<Sheet for blasting method>
The blasting sheet of the present invention formed from the soft vinyl chloride resin composition described above has an impact resistance energy of 1.99 J or more at -15°C in a film impact tester (FIT) test.

Therefore, even if the blasting sheet is subjected to blasting in a low-temperature environment, it is possible to suppress the occurrence of holes, cracks, etc., so that the cold resistance of the blasting sheet can be improved. becomes possible.

The reason why it is possible to suppress the occurrence of holes and cracks is that the sheet for blasting is soft even at low temperatures, so it can be easily deformed when a cutting material collides with it, and the impact is mitigated. it is conceivable that. In addition, it is thought that the conventional sheet for construction work, which has been used as a sheet for the blasting method, is likely to have holes and cracks because it becomes hard at low temperatures.

In particular, when an aliphatic dibasic ester plasticizer is used as the plasticizer, the glass transition point (Tg) of the soft vinyl chloride resin composition is lowered by the aromatic ring-free dibasic ester, and the temperature is as low as -15°C. The flexibility of the sheet for the blasting method is maintained even in the environment. As a result, it is possible to realize a sheet for blasting that does not break even in a blast irradiation test at -15°C and has excellent low-temperature properties.

In addition, since the sheet for blasting method of the present invention is formed of the soft vinyl chloride resin composition capable of exhibiting the above-mentioned good flame retardancy, the flame retardancy is JIS L1091 (A-1 method). Satisfies Category 3 in accordance with

Therefore, it is possible to indicate the specified flame retardancy, and to exhibit the specified flame retardancy quantitatively, practically, and with good reproducibility.

The impact energy resistance and flame retardancy described above can be determined by the methods described in Examples below. Thus, in the sheet for blasting method of the present invention, both cold resistance and flame retardancy can be achieved.

The blasting sheet of the present invention has a Young's modulus in the machine direction of 5 to 200 MPa, preferably 5 to 100 MPa, more preferably 5 to 50 MPa, even more preferably 10 to 30 MPa.

If the Young's modulus is 5 Mpa or more, the productivity and workability of the blasting sheet are good. If the Young's modulus is 200 MPa or less, holes are less likely to form during blasting.

Such Young's modulus can be adjusted by the content of the plasticizer in the soft vinyl chloride resin composition, the degree of polymerization of the vinyl chloride resin, and the like. For example, Young's modulus tends to decrease as the plasticizer content increases.

The elongation at break in the machine direction of the blasting sheet of the present invention is 100 to 500%, preferably 150 to 450%, more preferably 200 to 400%. If the elongation at break is 100% or more, holes are less likely to form during blasting. If the elongation at break is 500% or less, the productivity and workability of the sheet are good.

The elongation at break can be adjusted by the content of the plasticizer in the soft vinyl chloride resin composition, the degree of polymerization of the vinyl chloride resin, and the like. For example, the higher the plasticizer content, the higher the elongation at break.

The blasting sheet of the present invention preferably has a thickness of 110 to 300 μm, more preferably 150 to 250 μm. If the thickness is 110 μm or more, it is possible to suppress the occurrence of holes or the like during blasting even in a low-temperature environment. In addition, if the thickness is 300 μm or less, the handleability and workability are improved.

The shape of the blasting sheet is not particularly limited, and may be, for example, tape-like, triangular, quadrangular (rectangular), polygonal, circular, elliptical, irregular shape, or the like.

In particular, since it is necessary to adhere to the inner side of each panel that covers the periphery of a structure such as a bridge, a generally rectangular shape is preferable.

The blasting sheet of the present invention is for blasting. In blasting, a cutting material (e.g., plastic, By spraying sand-based, steel-based), the coating film, etc. on the surface to be treated is turned into dust and removed. The blasting sheet of the present invention is used to prevent dust generated during blasting from scattering outside from the working environment.

The specific usage of the blasting sheet of the present invention may be the same as the usage of the blasting sheet conventionally used for blasting. For example, inside the panel surrounding the surface to be treated of the structure and the scaffolding for blasting, the surface of the present invention is applied so that dust does not scatter outside from the gap between the panels and the gap between the panel and the scaffolding. A blasting sheet can be placed.

FIG. 2 shows a method of using a single type blasting sheet. , the tucker 40 is used to position and fix in place. In addition, FIG. 3 shows a method of using a two-sheet type blasting method sheet. Two blasting method sheets 31 are placed on the base material 20 at once using a tacker 40 at a predetermined position. Indicates positioning and fixing. Therefore, when blasting the surface of a bridge or the like, it is possible to effectively prevent external leakage of environmental impact substances generated in the space of the working room structure.

<Manufacturing method>
The blasting method sheet of the present invention is produced by kneading and molding the soft vinyl chloride resin composition containing the vinyl chloride resin and the plasticizer using, for example, test rolls (two rolls). . The blasting method sheet of the present invention may be produced using a known calendar roll, extrusion device, knife coater, roll coater, or the like.

The present invention will be described below based on examples. The present invention is not limited to these examples, and these examples can be modified and changed based on the spirit of the present invention, and they are excluded from the scope of the present invention. isn't it.

The materials used to prepare the sheets for the blasting method are shown below.
(1) Vinyl chloride resin: Polyvinyl chloride having an average degree of polymerization of 1400 (PVC, manufactured by Taiyo Vinyl Co., Ltd., trade name: TH1400)
(2) Plasticizer: Aliphatic dibasic acid ester: Dioctyl adipate (DOA, manufactured by Daihachi Chemical Industry)
(3) Plasticizer: Aliphatic dibasic acid ester: Bis (2-ethylhexyl) sebacate (DOS, manufactured by Daihachi Chemical Industry)
(4) Plasticizer: Aliphatic dibasic acid ester: Bis[2-(2-butoxyethoxy)ethyl]adipate (BXA-N, manufactured by Daihachi Chemical Industry)
(5) Plasticizer: Aromatic dibasic acid ester: Dioctyl phthalate (DOP, manufactured by J-Plus)
(6) Flame retardant: Phosphate ester flame retardant: tricresyl phosphate (TCP, manufactured by Daihachi Chemical Industry)
(7) Endothermic inorganic compound: magnesium hydroxide (manufactured by Kyowa Chemical Industry, trade name: Kisuma 5B)
(8) Endothermic inorganic compound: aluminum hydroxide (manufactured by Showa Denko Hygilite, trade name: H-42M)
(9) Endothermic inorganic compound: hydrotalcite (manufactured by Kyowa Chemical Industry, trade name: MHT-PD)
(10) endothermic inorganic compound: zinc borate (manufactured by Mizusawa Chemical Industry, trade name: FRC-500)
In addition, using TG-DTA, in a nitrogen atmosphere, the temperature is raised from room temperature to 600 ° C. (heating rate: 20 ° C./min), and each of the above endothermic inorganic compounds contained in the soft vinyl chloride resin composition ( When the decomposition initiation temperature (the peak decomposition initiation temperature on the chart) and the total endothermic amount of 7) to (10) were measured, the decomposition initiation temperature was 260 ° C. or higher for all endothermic inorganic compounds, and the total The amount of endotherm was 500 J/mg or more.

(Example 1)
<Preparation of sheet for blasting method>
The above-described materials were mixed according to the formulation (parts by mass) shown in Table 1, kneaded at 185 ° C. for 5 minutes with a test roll machine (two-roll mill), and peeled off from the rolls to obtain the sheet of Example 1 (blasting method sheet) was prepared.

<Film impact tester (FIT) test>
A strip having a width of 10 cm was cut from the produced sheet to obtain a sample for measurement. Then, the sample was placed in a constant temperature layer (−15° C.) and kept at a constant temperature. Each sample for measurement was struck with a pendulum-type hammer having an impact energy of 3 J to measure the impact energy resistance of the sample. A film impact tester (manufactured by Toyo Seiki Co., Ltd., a film impact tester with a constant temperature bath) was used to measure the impact resistance energy described above. Table 1 shows the above results.

<Blast test (chipping resistance test)>
Next, a chipping resistance test was performed on the produced sheet.
Test equipment: Mighty Mini R (manufactured by SNM Asia Co., Ltd.)
Test temperature: 25°C, 0°C, -10°C, -15°C, -20°C, -25°C
Test pressure: 0.3MPA
Test time: 10 seconds Test distance (distance between injection nozzle tip and sample surface): 35 cm
Cutting material: Steel grid Specimen table: Iron plate

More specifically, as shown in FIG. 4, in the chipping resistance test, an iron plate 22 serving as a sample table was provided in a chamber 21, and a sample (that is, the produced sheet) S was placed on the iron plate 22. Then, the cutting material C was injected into the chamber 21 from the cutting material supply part 23 . Then, it was visually confirmed whether the injected cutting material C caused damage such as a hole in the sample S, and evaluation was made according to the following evaluation criteria. Table 1 shows the above results.
◯: No through hole was observed.
x: A through-hole was generated.

<Flame retardant evaluation>
The produced sheet was subjected to an evaluation test according to JIS L1091 (A-1 method): 1999, and the flame retardancy (flame resistance) was evaluated according to the following evaluation criteria. Table 1 shows the above results.
◯: The sample satisfies Category 3.
×: The sample did not satisfy Category 3.

(Examples 2 to 15, Comparative Examples 1 to 9)
A blasting sheet having a thickness shown in Table 2 was produced in the same manner as in Example 1 above, except that the resin component was changed to the formulation (parts by mass) shown in Tables 1 and 2.

The thickness was adjusted by changing the gap between the two rolls. Further, as Comparative Example 2, a flat yarn-containing vinyl chloride coated sheet (a sheet in which both sides of polyester flat yarn are coated with polyvinyl chloride), which is diverted to a blasting method sheet, was used.

Then, film impact tester test, blast test, and flame retardancy evaluation were performed in the same manner as in Example 1 described above. The above results are shown in Tables 1 and 2.

As shown in Table 1, the blasting method sheets of Examples 1 to 15 have an impact resistance energy of 1.99 J or more at -15 ° C. in the film impact tester test, so no through holes are formed in the blasting test. It turns out that it is excellent in cold resistance. In addition, since it satisfies Category 3 in accordance with JIS L1091 (A-1 method), it is found to be excellent in flame retardancy.

On the other hand, in the blasting method sheets of Comparative Examples 1, 3, 7, and 8, the plasticizer does not contain an aliphatic dibasic acid ester plasticizer, so the impact resistance energy in the film impact tester test is - At 15°C, it was less than 1.99 J, and as a result, through holes were formed in the blast test, indicating poor cold resistance.

In addition, in the blasting method sheet of Comparative Example 2, since the flat yarn-containing vinyl chloride coated sheet is used, the impact resistance energy in the film impact tester test is less than 1.99 J at -15 ° C. As a result, Through holes were formed in the blast test, indicating poor cold resistance.

In addition, in the blasting method sheets of Comparative Examples 4 and 5, the amount of the aliphatic dibasic acid ester plasticizer (DOA, BXA-N) is less than 15 parts by mass with respect to 100 parts by mass of the vinyl chloride resin. Since the amount of the aliphatic dibasic ester plasticizer is less than 50% by mass with respect to the total plasticizer, the impact resistance energy in the film impact tester test is less than 1.99 J at -15 ° C. As a result, Through holes were formed in the blast test, indicating poor cold resistance.

As shown in Comparative Example 6, when the blasting sheet is thin (that is, the thickness is less than 110 μm), it is not possible to suppress the formation of through holes during blasting in a low-temperature environment. I understand.

In addition, it can be seen that the sheet for blasting method of Comparative Example 9 is poor in flame retardancy because the phosphoric acid ester-based flame retardant is not blended.

INDUSTRIAL APPLICABILITY As described above, the present invention is suitable for blasting sheets.

Claims (7)

Made of a soft vinyl chloride resin composition containing a vinyl chloride resin, a plasticizer, a phosphate ester flame retardant, and an endothermic inorganic compound,
The plasticizer includes an aliphatic dibasic acid ester plasticizer,
The impact resistance energy in the film impact tester test is 1.99 J or more at -15 ° C.,
A sheet for blasting, characterized by satisfying Class 3 flame retardancy according to JIS L1091 (method A-1). The aliphatic dibasic ester plasticizer is blended in an amount of 15 to 55 parts by mass with respect to 100 parts by mass of the vinyl chloride resin, and the aliphatic dibasic ester plasticizer is blended with respect to the entire plasticizer. The sheet for blasting method according to claim 1, characterized in that the amount is 50% by mass or more. 2. The blasting sheet according to claim 1, wherein the amount of the phosphoric acid ester flame retardant compounded is 8 to 12 parts by mass with respect to 100 parts by mass of the vinyl chloride resin. The sheet for blasting according to claim 1, wherein the amount of the endothermic inorganic compound is 5 to 30 parts by mass with respect to 100 parts by mass of the vinyl chloride resin. The aliphatic dibasic ester plasticizer is at least one selected from the group consisting of dioctyl adipate, bis[2-(2-butoxyethoxy)ethyl]adipate, and bis(2-ethylhexyl) sebacate. The sheet for blasting method according to claim 1 or 2, characterized by the above-mentioned. 3. The phosphoric acid ester flame retardant is at least one selected from the group consisting of tri-cresyl phosphate, trixylenyl phosphate and cresyl diphenyl phosphate. The sheet for the blasting method described in . 5. The endothermic inorganic compound according to claim 1 or 4 , wherein the endothermic inorganic compound is at least one selected from the group consisting of magnesium hydroxide, aluminum hydroxide, hydrotalcite, and zinc borate. Sheet for blasting method.

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