JP7103736B2 - Polyvinyl chloride sheet - Google Patents

Description

The present invention relates to a polyvinyl chloride-based sheet having a transparent layer.

A soft polyvinyl chloride sheet obtained by adding a plasticizer such as a phthalate ester to a polyvinyl chloride resin is used as a building material, an industrial film, or the like. In addition, this soft polyvinyl chloride sheet is widely used as an interior material for buildings, railroad cars, aircraft, etc. because of its flexibility, excellent workability and adhesiveness.

Since polyvinyl chloride resin has high transparency, a transparent layer with high transparency is set on the surface to be observed as an appearance, and a design layer with a printed pattern is set under it to have high durability and high design. It is possible to provide sexual interior materials.

On the other hand, polyvinyl chloride resin may have an influence on evacuation and fire extinguishing activities because a large amount of smoke and hydrogen chloride gas are generated at the time of combustion. For this reason, studies have been conducted on reducing smoke emission and reducing hydrogen chloride gasification of polyvinyl chloride, and methods using various flame retardants have been proposed.

For example, polyvinyl chloride resin compositions containing flame retardants such as magnesium hydroxide, antimony oxide compounds, and zinc-based compounds are used (Patent Documents 1 and 2).

However, when the above flame retardant is added to the transparent layer, the transparency is lowered and the printed pattern of the design layer becomes invisible, so that it cannot be used. The amount of smoke generated and the amount of hydrogen chloride gas will increase.

Japanese Unexamined Patent Publication No. 5-5-1504 Japanese Unexamined Patent Publication No. 8-208925

An object of the present invention is to provide a polyvinyl chloride-based sheet having a transparent layer and reducing the amount of smoke generated during combustion and the amount of hydrogen chloride gas.

The gist of the means used in the present invention to solve the above problems is that it is a laminated sheet in which a transparent layer containing a specific plasticizer and a layer containing a specific plasticizer and a flame retardant are laminated.

More specifically, a transparent layer (A) composed of a polyvinyl chloride-based resin composition (a) containing 100 parts by weight of a vinyl chloride-based resin and 5 to 50 parts by weight of a polyester-based plasticizer, and a vinyl chloride-based resin. 100 parts by weight of resin, 5 to 100 parts by weight of polyester-based plasticizer, 5 to 100 parts by weight of flame retardant of at least one of molybdic acid-based compound and zinc nitrate compound, and 50 to 300 parts by weight of inorganic filler. It has a base material layer (B) made of the polyvinyl chloride resin composition (b) contained therein , and the transparent layer (A) is filled with a light-transmitting inorganic material having a refractive index of 1.42 to 1.65. A polyvinyl chloride-based sheet containing 1 to 100 parts by weight of the agent is used.

Further, a transparent layer (A) made of a polyvinyl chloride-based resin composition (a) containing 100 parts by weight of a vinyl chloride-based resin and 5 to 50 parts by weight of a polyester-based plasticizer, and 100 parts by weight of a vinyl chloride-based resin. Polyvinyl chloride containing 5 to 100 parts by weight of a polyester-based plastic, 5 to 100 parts by weight of a flame retardant of at least one of a molybdic acid-based compound and a zinc nitrate compound, and 50 to 300 parts by weight of an inorganic filler. Polyvinyl chloride having a base material layer (B) made of a vinyl resin composition (b) and the flame retardant containing 5 to 95 parts by weight of a molybdic acid-based compound and 5 to 95 parts by weight of a zinc nitrate compound. It is to be a system sheet .

Further, the transparent layer (A) preferably contains 1 to 100 parts by weight of a light-transmitting inorganic filler having a refractive index of 1.42 to 1.65, and the haze of the transparent layer (A) is 70%. The following is preferable, and the total light transmittance is preferably 80% or more.

The polyvinyl chloride-based sheet of the present invention has a transparent layer, and has the effect of reducing the amount of smoke generated during combustion and the amount of hydrogen chloride gas. Further, since it has a transparent layer, a design layer having a printed pattern can be provided under the transparent layer, and a highly durable and highly designed sheet can be provided.

It is sectional drawing of the polyvinyl chloride-based sheet which concerns on embodiment of this invention. It is sectional drawing of the polyvinyl chloride-based sheet which concerns on other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail. The polyvinyl chloride-based sheet of the present invention includes at least a transparent layer and a base material layer. FIG. 1 shows a cross-sectional view of an embodiment of the polyvinyl chloride-based sheet of the present invention having the transparent layer 1 and the base material layer 2. The transparent layer 1 and the base material layer 2 are laminated and integrated to form a sheet.

The transparent layer of the present embodiment is composed of a resin composition containing 5 to 50 parts by weight of a polyester-based plasticizer with respect to 100 parts by weight of a vinyl chloride-based resin, is capable of transmitting visible light, and has a substantially total light transmittance. When the content is 70% or more, the desired transparency can be obtained. By providing this transparent layer on the outermost surface of the polyvinyl chloride-based sheet, it is possible to provide a layer having a design property under the transparent layer. That is, the design layer can be visually recognized from above the transparent layer. The total light transmittance of the transparent layer is preferably 80% or more, more preferably 85% or more. In addition, the visibility changes depending on the degree of cloudiness of the transparent layer, and if the degree of cloudiness is high, the visibility is lowered, resulting in a vague design. The lower the degree of cloudiness, the closer the design to the original design layer is expressed as it is. The haze, which is an index of the cloudiness of the transparent layer, is preferably 70% or less, more preferably 60% or less. Even if the haze exceeds 70%, it can be used as a transparent layer as long as the total light transmittance is 70% or more.
The base material layer of the present embodiment contains 5 to 100 parts by weight of a polyester-based plasticizer and 5 to 100 parts by weight of a flame retardant of at least one of a molybdic acid-based compound and a zinc nitrate compound with respect to 100 parts by weight of a vinyl chloride resin. It is composed of a resin composition containing 50 to 300 parts by weight of an inorganic filler. As a result, a base material layer having appropriate flexibility and excellent adhesiveness to the base material and workability can be obtained.

Further, a resin layer may be provided in addition to the transparent layer (A) and the base material layer (B). The resin layer may be laminated between the transparent layer (A) and the base material layer (B), or may be laminated on the base material layer (B). That is, the transparent layer (A) may be the outermost surface of the polyvinyl chloride-based sheet, and a plurality of resin layers may be laminated. The resin layer includes 100 parts by weight of a vinyl chloride resin, 5 to 80 parts by weight of a polyester plasticizer, 5 to 100 parts by weight of a flame retardant of at least one of a molybdic acid compound and a zinc nitrate compound, and an inorganic filler. It is preferably composed of the polyvinyl chloride resin composition (c) containing 10 to 100 parts by weight. FIG. 2 shows a cross-sectional view of an embodiment of the polyvinyl chloride-based sheet of the present invention having an intermediate layer 3 which is a resin layer provided between the transparent layer 1 and the base material layer 2.

Examples of the vinyl chloride-based resin include polyvinyl chloride homopolymerized resin, polyvinyl chloride vinyl chloride resin, and polyvinyl chloride copolymer resin (for example, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl chloride copolymer, etc.). , Vinyl chloride graft copolymer (for example, ethylene-vinyl acetate-vinyl chloride graft copolymer, polyurethane-vinyl chloride graft copolymer, etc.), etc., and these may be used alone or in combination of two or more. Can be done.

As the plasticizer, a polycondensate of an aliphatic dibasic acid and a diol of a polyester-based plasticizer can be used. By adopting a polyester-based plasticizer, the amount of smoke generated during combustion can be suppressed.
Examples of the aliphatic dibasic acid include succinic acid, maleic acid, fumaric acid, glutamic acid, adipic acid, azelaic acid, sebacic acid, dodecandicarboxylic acid and the like. The diols include 1,2-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-. Pentandiol, 2,2-diethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-butyl-2-ethyl- Examples thereof include 1,3-propanediol, 2-methyl-1,8-octanediol, and 1,12-octadecanediol.
Of these, adipic acid-based polyester plasticizers are preferably used. This is because it has an effect of excellent plasticization efficiency and a small amount of smoke.

The amount of these polyester-based plasticizers added is 5 to 50 parts by weight, preferably 15 to 45 parts by weight, and more preferably 20 to 40 parts by weight in the transparent layer with respect to 100 parts by weight of the vinyl chloride resin. The base material layer is 5 to 100 parts by weight, preferably 40 to 80 parts by weight, and more preferably 50 to 75 parts by weight.

Further, it is possible to add a plasticizer other than the polyester-based plasticizer as long as it does not affect the performance of the polyvinyl chloride-based sheet of the present invention. For example, a phthalate ester-based plasticizer, a sulfonic acid ester-based plasticizer, a phosphoric acid ester-based plasticizer, an adipic acid ester-based plasticizer, an epoxy-based plasticizer, and the like.

At least one flame retardant of molybdate-based compound or zinc-tinate compound is added to the base material layer of the polyvinyl chloride-based sheet.
Examples of the zinc sulfate compound include zinc tinate and zinc hydrosikistinate.
Examples of molybdic acid compounds include molybdenum oxide, molybdenum trioxide, molybdic acid, potassium molybdate, sodium molybdate, calcium molybdate, zinc molybdate, zinc molybdate, ammonium molybdate, ammonium dimolybdate, and ammonium hepta molybdate. , Ammonium octamolybdate, ammonium decamolybdate, molybdenum disulfide, phosphomolybdate, potassium phosphomolybdate, calcium phosphomolybdate, zinc molybdate, melamine β molybdate, etc. , Or a mixture of two or more in an appropriate combination can be used.

The amount of the flame retardant added to the base material layer is 5 to 100 parts by weight, preferably 8 to 80 parts by weight, and more preferably 10 to 60 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. be. If it is less than 5 parts by weight, the effect of suppressing smoke generation during combustion and the generation of toxic gas such as hydrogen chloride is not sufficient, and even if it is added in excess of 100 parts by weight, the effect of suppressing smoke generation and generation of toxic gas does not change much. There is an increase in cost and deterioration in workability and physical properties.
Further, the molybdate-based compound and the zinc nitrate compound may be used alone, but it is particularly preferable to use them in combination because the effect of suppressing hydrogen chloride gas is improved. When these are used in combination, the amount of the molybdic acid-based compound added is preferably 5 to 95 parts by weight, and the amount of the zinc nitrate compound added is preferably 5 to 95 parts by weight, and the molybdic acid-based compound is added. It is more preferable that the amount is 5 to 50 parts by weight and the amount of the zinc nitrate compound added is 5 to 50 parts by weight.

Further, flame retardants other than the above molybdenum-based compound and zinc nitrate compound can also be added within a range that does not affect the performance of the polyvinyl chloride-based sheet of the present invention. Such flame retardants include organic and inorganic types, and examples of the organic type include halogen type such as bromine type and phosphorus type such as phosphoric acid ester, and inorganic type includes ammon carbonate and boron nitride. Examples include nitrogen-based materials, metal hydroxides such as magnesium hydroxide and aluminum hydroxide, and antimony-based materials such as antimony oxide.

The base material layer of the polyvinyl chloride-based sheet contains an inorganic filler other than the above flame retardant. By containing the inorganic filler in the base material layer, the dimensional stability, heat resistance, flame retardancy, etc. of the polyvinyl chloride-based sheet are improved, and there is an effect of cost reduction.
Examples of the inorganic filler added to the base material layer include carbonates such as calcium carbonate and magnesium carbonate, layered silicates such as clay, talc and mica, fly ash balloons, silas balloons and glass balloons. Hollow balloons and the like can be mentioned.

The amount of the filler added to the base material layer is preferably 50 to 300 parts by weight, more preferably 75 to 275 parts by weight, still more preferably 100 to 250 parts by weight, based on 100 parts by weight of the vinyl chloride resin. If it is less than 50 parts by weight, the effect of improving physical properties such as dimensional stability, heat resistance, and flame retardancy cannot be sufficiently obtained, and the cost reduction effect is small. If it exceeds 300 parts by weight, the strength of the sheet may decrease.

A light-transmitting inorganic filler having a refractive index of 1.42 to 1.65 can be added to the transparent layer. As such a light-transmitting inorganic filler, for example, silica, silicon oxide, silica sand, quartz, nepheline syensis, mica, feldspar, feldspathoid, hydrotalcite, glass beads, glass fiber and the like can be used. can. When a general inorganic filler is added to a polyvinyl chloride resin sheet, the sheet becomes turbid and the transparency is lowered, but the light-transmitting inorganic filler as described above does not significantly reduce the transparency of the transparent layer. It can be added and has the effect of reducing smoke and toxic gas during combustion.
Among the above-mentioned light-transmitting inorganic fillers, nepheline syenite is preferable because the sheet does not become turbid when added to the transparent layer and the transparency can be maintained. Further, it is preferable that the light-transmitting inorganic filler has a fine particle size because it tends to be less turbid when added to the transparent layer. Specifically, the average particle size is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less.

The amount of the light-transmitting inorganic filler added to the transparent layer is preferably 1 to 100 parts by weight, more preferably 3 to 80 parts by weight, still more preferably 5 to 50 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin. preferable. If it is less than 1 part by weight, the smoke emitting property at the time of combustion and the effect of reducing toxic gas cannot be sufficiently obtained, and if it exceeds 100 parts by weight, the filling amount of inorganic particles in the transparent layer increases and it becomes difficult to maintain transparency. ..
Further, the light-transmitting inorganic filler can be added to each layer other than the transparent layer as long as it does not affect the performance of the polyvinyl chloride-based sheet of the present invention.

Stabilizers, lubricants, ultraviolet absorbers, pigments, light stabilizers, antioxidants, antibacterial agents, foaming agents and the like may be added to the polyvinyl chloride-based sheet, if necessary.

The thickness of the polyvinyl chloride-based sheet is preferably 0.5 mm to 5.0 mm, more preferably 0.7 mm to 4.5 mm, still more preferably 1.0 mm to 4.0 mm.

The thickness of the transparent layer (A) is preferably 0.1 mm to 1.0 mm. When used as an interior sheet, the thickness can be set according to the wear characteristics of the surface. In addition, it is transparent in flooring materials for heavy walking such as public facilities, commercial facilities, trains, buses, aircraft, ships, etc. that require more wear resistance, or for heavy walking such as trolleys and stretchers. The layer is preferably thicker.

The thickness of the base material layer (B) is preferably 0.4 mm to 4.0 mm. When used as an interior sheet, 1.0 mm to 3.0 mm is preferable in consideration of durability, workability, and the like.

When a resin layer is provided in addition to the transparent layer (A) and the base material layer (B), the thickness of the resin layer is preferably 0.1 mm to 0.5 mm. When the resin layer is provided as an intermediate layer, a colored layer in which the resin layer itself is colored with a pigment or the like, a printing layer in which transfer printing or the like is applied to the surface of the resin layer, or a design layer that can be visually recognized from above the transparent layer. It is preferable to do so.

A reinforcing layer may be provided on the polyvinyl chloride-based sheet. A woven fabric, a non-woven fabric, or the like is used as the reinforcing layer. As the fibers constituting the woven fabric and the non-woven fabric, natural fibers, chemical fibers, synthetic fibers, inorganic fibers such as glass and the like can be used. The reinforcing layer may be provided below the base material layer, or may be provided between the base material layer and an layer such as a surface layer or an intermediate layer. Further, a reinforcing layer may be provided in the middle of the base material layer to form a structure such as a surface layer, a base material layer, a reinforcing layer, or a base material layer.

Each layer such as a transparent layer, a base material layer, and a resin layer constituting a polyvinyl chloride-based sheet is obtained by mixing predetermined materials and molding by a molding machine such as an extruder or a calendar. Then, the polyvinyl chloride-based sheet can be obtained by laminating each of these layers with heat or an adhesive. It can also be obtained by molding and laminating each layer at once using a multi-layer extruder. Further, when laminating the reinforcing layers, a manufacturing method such as laminating the reinforcing layers when molding each layer with an extruder or a calendar, or laminating the reinforcing layers when laminating each layer can be used. ..

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to the following examples.

The materials used in the test examples and examples are as follows.
Vinyl chloride resin: Polyvinyl chloride Degree of polymerization 1000
Phthalate-based plasticizer: DOP
Polyester-based plasticizer: Adipic acid-based polyester plasticizer Viscosity 150 mPa · s / 25 ° C. Molecular weight 750
Stabilizer: Barium zinc-based stabilizer Light-transmitting inorganic filler 1: Nepheline syensis Average particle size 1.5 μm (50% diameter of cumulative particle size distribution by laser diffraction method)
Light-transmitting inorganic filler 2: Silicon oxide Average particle size 4.9 μm (50% diameter of cumulative particle size distribution by laser diffraction method)
Inorganic filler: Calcium carbonate average particle size 3.5 μm (50% diameter of cumulative particle size distribution by laser diffraction)
Zinc molybdate compound: Zinc molybdate hydroxy molybdate compound: A mixture of calcium molybdate and zinc molybdate

Test Example 1
<Sheet manufacturing method>
The formulations were kneaded based on the formulations shown in Table 1, and the obtained compound was used in two rolls at 175 ° C. to prepare a 0.5 mm sheet.
<Measurement of total light transmittance and haze>
Total light transmittance by Haze Meter NDH-2000 of Nippon Denshoku Industries Co., Ltd. according to JIS-K7361-1 "Test method of total light transmittance of plastic-transparent material-Part 1: Single beam method" Was evaluated by a test in accordance with JIS-K7136 "Plastic-How to obtain haze of transparent material". A 50 mm square test piece was used for the test.

In Test Examples 1-1 and 1-2 to which the light-transmitting inorganic filler and other inorganic fillers were not added, the haze was low, the total light transmittance was close to 90%, and the transparency was excellent. Can be used as a transparent layer of. On the other hand, in Test Example 1-3 using calcium carbonate, which is a normal inorganic filler, the haze is high, the total light transmittance is less than 50%, and the appearance is cloudy and opaque. On the other hand, in Test Examples 1-4 to 1-8 using the light-transmitting filler, the haze is suppressed as compared with Test Example 1-3, and the total light transmittance is as high as 80% or more. Can be used as a transparent layer of. Comparing Test Examples 1-5 to 1-8, the haze tends to increase as the amount of the light-transmitting filler added increases, but the total light transmittance does not change significantly.

Test Example 2
<Sheet manufacturing method>
The formulations were kneaded based on the formulations shown in Table 2, and the obtained compound was used in two rolls at 175 ° C. to prepare a 1.0 mm sheet.

<Measurement of smoke amount>
The amount of smoke emitted in the present specification conforms to the test method specified in ASTM E662, and the amount of smoke emitted in flame combustion and non-flame combustion was measured. Specifically, the sample was placed in a closed chamber and burned for 20 minutes with an electric heater and a gas burner (flame combustion only). The dimming coefficient was obtained from the intensity of the transmitted light from the phototube during combustion, the specific optical density when this dimming coefficient was the largest value was calculated, and the maximum smoke concentration was obtained based on this value (Ds (max)). ).

The smaller the value of the maximum smoke concentration, the smaller the amount of smoke emitted, and it was evaluated as unfavorable when it exceeds 450 (×), preferable when it is 450 or less (○), and more preferable when it is 300 or less (◎). ..

<Measurement of hydrogen chloride gas amount>
The amount of hydrogen chloride gas in the present specification conforms to the test method specified in ASTM E662, and the amount of hydrogen chloride gas in flame combustion and non-flame combustion was measured. Specifically, the sample was placed in a closed chamber and burned for 20 minutes with an electric heater and a gas burner (flame combustion only). Four minutes after the start of combustion, 100 cc of air in the chamber was passed through the detector tube, and the concentration of toxic gas (hydrogen chloride gas) was measured (HCl (ppm)).

The smaller the value of the hydrogen chloride gas concentration, the smaller the amount of hydrogen chloride gas. When it exceeds 500 ppm, it is not preferable (×), when it is 500 ppm or less, it is preferable (○), and when it is 300 ppm or less, it is more preferable (◎). ).

As is clear from Table 2, the amount of smoke generated and the amount of hydrogen chloride gas are reduced by using a polyester-based plasticizer than by using a phthalate ester-based plasticizer. It was confirmed that the amount of poisonous gas decreased.

Test Example 3
<Sheet manufacturing method>
The formulations were kneaded based on the formulations shown in Table 3, and the obtained compound was used in two rolls at 175 ° C. to prepare a 1.0 mm sheet.
Similar to Test Example 2, the amount of smoke generated and the amount of hydrogen chloride gas in flame combustion were evaluated.

As is clear from Table 3, it was confirmed that the amount of smoke generated and the amount of hydrogen chloride gas were reduced by using the molybdenum acid-based compound and the zinc nitrate compound. Comparing Test Examples 3-2 and 3-3, the content of inorganic compounds (inorganic fillers and flame retardants) in the formulation was lower in Test Example 3-3 than in Test Example 3-2, but smoke was emitted. The amount and the amount of toxic gas generated are smaller in Test Example 3-3. From this, it is considered that the performance is improved by increasing the number of copies of the molybdate-based compound and the zinc nitrate compound, which are flame retardants, and using them in combination.

Example and Comparative Example <Sheet manufacturing method>
The formulations of each layer were kneaded based on the formulations shown in Tables 4 and 5, and the obtained compound was prepared into a sheet using two rolls at 175 ° C. Then, the obtained sheet of each layer was press-processed (170 ° C.) to obtain a polyvinyl chloride-based sheet shown in Tables 4 and 5.
The amount of smoke generated and the amount of hydrogen chloride gas were evaluated in the same manner as in Test Example 2.

As is clear from Tables 4 and 5, it was confirmed that the amount of smoke and hydrogen chloride gas generated can be significantly reduced even in the structure by using the polyester-based plasticizer, the molybdenum acid-based compound, and the zinc nitrate compound.

1 Transparent layer 2 Base material layer 3 Resin layer (intermediate layer)

Claims (6)

A transparent layer (A) made of a polyvinyl chloride resin composition (a) containing 100 parts by weight of a vinyl chloride resin and 5 to 50 parts by weight of a polyester plastic agent, and 100 parts by weight of a vinyl chloride resin. , Polyvinyl chloride containing 5 to 100 parts by weight of a polyester-based plastic, 5 to 100 parts by weight of a flame retardant of at least one of a molybdic acid-based compound and a zinc nitrate compound, and 50 to 300 parts by weight of an inorganic filler. 1 to 100 light-transmitting inorganic fillers having a base material layer (B) made of the based resin composition (b) and the transparent layer (A) having a refractive index of 1.42 to 1.65. A polyvinyl chloride-based sheet containing parts by weight . A transparent layer (A) made of a polyvinyl chloride-based resin composition (a) containing 100 parts by weight of a vinyl chloride-based resin and 5 to 50 parts by weight of a polyester-based plasticizer, 100 parts by weight of a vinyl chloride-based resin, and the like. A polyvinyl chloride-based plastic containing 5 to 100 parts by weight of a polyester-based plastic, 5 to 100 parts by weight of a flame-retardant agent of at least one of a molybdic acid-based compound and a zinc nitrate compound, and 50 to 300 parts by weight of an inorganic filler. It has a base material layer (B) made of the resin composition (b), and the flame retardant is a polyvinyl chloride-based compound composed of 5 to 95 parts by weight of a molybdic acid-based compound and 5 to 95 parts by weight of a zinc nitrate compound. Sheet. The polyvinyl chloride-based sheet according to claim 2 , wherein the transparent layer (A) contains 1 to 100 parts by weight of a light-transmitting inorganic filler having a refractive index of 1.42 to 1.65. The polyvinyl chloride-based sheet according to claims 1 to 3, wherein the haze of the transparent layer (A) is 70% or less, and the total light transmittance is 80% or more. Claim 1 to claim 1 to which the maximum smoke concentration (Ds (max)) in the flame combustion smoke test measured in accordance with ASTM E662 is 300 or less, and the hydrogen chloride gas concentration in the flame combustion toxic gas test is 300 ppm or less. The polyvinyl chloride-based sheet according to 4. The thickness of all layers of the sheet is 0.5 mm or more and 5.0 mm or less.
The polyvinyl chloride-based sheet according to claim 1 to 5, wherein the thickness of the transparent layer (A) is 0.1 mm or more and 1.0 mm or less, and the thickness of the base material layer (B) is 0.4 mm to 4.0 mm.

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