JP3763010B2 - Flame-retardant olefin resin molding - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flame-retardant olefin resin molded article that is improved so as to suppress generation of smoke accompanying thermal decomposition during a fire.
[0002]
[Prior art]
Olefin resins, especially polypropylene, are resins that have good thermoformability and high mechanical strength, are available at low cost, have good chemical resistance, and do not generate corrosive halogen gas during decomposition. Is widely used as a material for industrial purposes, in particular, a liquid tank, a container, a piping member and other materials of a semiconductor manufacturing apparatus.
[0003]
However, since polypropylene is easy to burn and pyrolyzes during combustion to generate smoke and gas, if a polypropylene molded body is used in a semiconductor manufacturing device, the air cleanliness is reduced by the generated smoke in the event of a fire, There is a problem that various devices, devices, and semiconductor parts are contaminated. Therefore, it is desired to impart flame retardancy to a polypropylene molded body so that it does not easily burn even in the event of a fire and to reduce the amount of smoke generated.
[0004]
The assessment standards set by Factory Mutual Research Corporation, which constitutes the Factory Mutual System, an industry mutual insurance organization based in North America, are effective for this flame retardant assessment. It's being used. This evaluation standard is a flame retardant index FPI indicating a flame retardance based on a flame retardant test of a clean room material (FMRC Clean Room Material Flammability Test Protocol) (hereinafter referred to as FM standard) listed as Class Nomber 4910, It is required that the smoke index SDI indicating smoke generation is 0.4 or less and the corrosion index CDI indicating generation of corrosive gas is 1.1 or less.
[0005]
For reference, equations for obtaining the flame retardant index FPI, smoke index SDI, and corrosion index CDI are shown below.
[0006]
FPI = (0.4QCH) ^1/3 / TRP (1)
However, QCH = ΔHCO ₂ · GCO ₂ + ΔHCO · GCO (Chemical · release · rate)
TRP = ΔTig ・ (κ ・ ρ ・ CP) ^1/2 (Thermal ・ response parameter)
Here, ΔTig: ignition temperature, κ: heat transfer coefficient, ρ: specific gravity, and CP: specific heat, and ΔHCO ₂ and ΔHCO are the amounts of heat generated during CO ₂ complete combustion and CO complete combustion, respectively. ₂ and GCO represent the ratio of gas generated between CO ₂ and CO, respectively.
[0007]
SDI = FPI · ys (2)
However, ys = G / m (amount of smoke generated)
G = (1.1 · V · D · χ) / (7 / A) (Smoke generation ratio)
Here, V: Smoke flow ratio, D: Optical specific gravity, χ: Light source wavelength, A: Combustion area, m: Mass reduction ratio.
[0008]
CDI = FPI · CI (3)
However, CI = (δ / Δte) / (W / VT · ΔtTEST) (corrosion index)
Here, δ: copper thickness, Δte: test time, W: gas passage speed, VT: gas generation flow ratio to air, ΔtTEST: gas generation time.
[0009]
[Problems to be solved by the invention]
Since the molded body of the olefin resin does not contain halogen in the polymer itself and hardly generates corrosive gas such as chlorine gas by combustion, among the requirements based on the FM standard, the corrosion index CDI is 1. It is easy to make it 1 or less.
[0010]
However, since the molded product of olefin resin is easy to burn and generates a large amount of smoke and gas during combustion, it is difficult to make the flame retardant index FPI 6 or less of the evaluation standard and the smoke index SDI 0.4 or less of the evaluation standard. Met.
[0011]
The present invention has been made in view of the above problems , and has excellent flame resistance satisfying all evaluation standards of FPI, SDI, and CDI based on FM standards , and has good chemical resistance and corrosion resistance inherent to olefin resins. There has been an object that you provide a flame-retardant olefin resin molded article not to decrease most.
[0012]
As a result of various studies, the present inventors have found the fact that titanium oxide is extremely effective for improving the flame retardancy of an olefin resin molded article, and have completed the present invention.
[0013]
[Means for Solving the Problems]
In order to achieve the above object , a flame-retardant olefin resin molded product according to claim 1 of the present invention is 20 to 80 parts by weight of titanium oxide coated with alumina with respect to 100 parts by weight of olefin resin, and other inorganic materials. As described above, at least one side of a base layer having a thickness of 2 to 30 mm containing 30 to 100 parts by weight of a metal hydrate is less than the titanium oxide content of the base layer with respect to 100 parts by weight of the olefin resin. A surface layer having a thickness of 0.3 to 2 mm contained within a range of 20 to 80 parts by weight is formed .
[0014]
It is not clear why the inclusion of titanium oxide coated with alumina in this way improves the flame retardancy and reduces the amount of smoke generated. (1) Titanium oxide, a nonflammable inorganic material The amount of olefin resin, which is an organic substance, is greatly reduced by blending a large amount of (2) Titanium oxide has higher thermal conductivity than other inorganic materials, and (3) Titanium oxide has a high temperature of 1200 to 1300 ° C. It is presumed that the main reasons are that it remains as inorganic particles without being decomposed to the region, and that (4) titanium oxide has a carbonization promoting action of the olefin resin. In particular, when titanium oxide coated with alumina is included, the carbonization promoting action of the olefin resin is synergistically enhanced by the titanium oxide and the alumina during combustion, and smoke and gas are adsorbed by the alumina. And a compact with a small smoke index SDI can be obtained. And, when the metal hydrate is contained in the base layer as another inorganic material, it has the action of releasing the bound water, delaying the thermal decomposition of the olefin, and suppressing the smoke generation, so the flame retardant index FPI and the smoke index SDI are lowered. Sufficient flame retardancy can be imparted to the molded body.
[0015]
When the base layer contains less than 20 parts by weight of titanium oxide coated with alumina and less than 30 parts by weight of metal hydrate, which is another inorganic material, it is difficult to satisfy the evaluation criteria of FPI, SDI, and CDI at the same time. When it becomes difficult to obtain a flammable olefin resin molded body, on the other hand, when titanium oxide is more than 80 parts by weight and the metal hydrate which is another inorganic material is more than 100 parts by weight, the mechanical strength of the molded body Inadequate chemical resistance, corrosion resistance and the like are caused.
[0016]
Moreover, since this flame-retardant olefin resin molded product contains titanium oxide coated with alumina in the surface layer within a range of 20 to 80 parts by weight so as to be less than the titanium oxide content of the base layer, The density of the titanium oxide exposed on the body surface is low, and the surface of the molded body (surface layer) has chemical resistance and corrosion resistance that are almost the same as the good chemical resistance and corrosion resistance inherent to the olefin resin.
[0017]
In addition, a molded body in which titanium oxide is a powder having an average particle size of 0.1 to 0.5 μm has an advantage that titanium oxide is kneadable with an olefin resin and can be contained in a uniform dispersed state. .
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, specific embodiments of the present invention will be described.
[0019]
Flame-retardant olefin resin molded article of the present invention, the composition to each other physician is a molded body of the multilayer structure with different base layer and surface layer.
[0020]
The base layer of this molded body contains 20 to 80 parts by weight of titanium oxide coated with alumina and 30 to 100 parts by weight of metal hydrate as another inorganic material with respect to 100 parts by weight of the olefin resin. . Additives such as pigments, dyes, ultraviolet absorbers and antioxidants are appropriately added to the base layer .
[0021]
As the material olefin resin, polypropylene, polyethylene, or the like is used. Among these, polypropylene is preferably used because it has a high heat distortion temperature, good chemical resistance, and high mechanical strength.
[0022]
Moreover, as titanium oxide, a powder having an average particle diameter of about 0.1 to 0.5 μm is preferably used. This is because the titanium oxide powder having such a particle size has good kneadability with the olefin resin and can be contained in a uniform dispersed state. In particular, when the powder of titanium oxide whose surface is coated with alumina is included, the carbonization promoting action of the olefin resin is synergistically enhanced by the titanium oxide and alumina during combustion, and smoke and gas are adsorbed by the alumina. It is extremely effective for improving flame retardancy.
[0023]
As described above, when a large amount of titanium oxide coated with alumina is contained, the amount of olefin resin, which is an organic substance, is greatly reduced, and the carbonization promoting action of the olefin resin is enhanced by titanium oxide. That is, titanium oxide has a thermal conductivity about 100 times higher than that of other inorganic materials such as calcium carbonate, has a function of quickly transmitting heat and promoting carbonization, and titanium oxide has a high temperature range of 1200 to 1300 ° C. Since the inorganic particles remain as they are without being decomposed, the flame retardancy of the base layer and thus the flame retardancy of the molded body are remarkably improved, and the amount of smoke generated is reduced.
[0024]
As other inorganic materials to be contained together with titanium oxide, alkaline earth metal hydrates, metal carbonates, metal oxides, talc, barium sulfate, potassium titanate and the like can be used. Preferred alkaline earth metal hydrates are used. Examples of such metal hydrates include aluminum hydroxide (including hydrous alumina) and magnesium hydroxide.
[0025]
Powders of metal hydrates such as aluminum hydroxide (including hydrous alumina) and magnesium hydroxide not only reduce the amount of olefin resin in the molded product to lower the combustion rate, but also act as a halogen scavenger. When a flame retardant is used in combination, the generation of corrosive gas is suppressed and the corrosion index CDI is reduced.
[0026]
Since the metal hydrate has the above-described action, sufficient flame retardancy is obtained when it is used in combination with titanium oxide at a ratio of 30 to 100 parts by weight of the metal hydrate with respect to 100 parts by weight of the olefin resin. the can be applied to the substrate thus formed body, in this way a combination of metal hydrate, even 20 to 80 parts by weight and the content of the titanium oxide relative to 100 parts by weight of olefin resin, FPI, SDI, CDI It is possible to obtain a flame-retardant olefin resin molded article that satisfies all the evaluation criteria.
[0027]
When the amount of titanium oxide is less than 20 parts by weight and the amount of metal hydrate is less than 30 parts by weight, it becomes difficult to obtain a flame-retardant olefin resin molded article that simultaneously satisfies the evaluation criteria of FPI, SDI, and CDI. When the amount of titanium is more than 80 parts by weight and the amount of metal hydrate is more than 100 parts by weight, the mechanical strength, chemical resistance, corrosion resistance and the like of the base layer are greatly reduced, resulting in a molded article that is difficult to put into practical use. Titanium oxide and metal hydrate are particularly preferably contained so that the total content thereof is 70 to 150 parts by weight, and if so contained, a molded product that sufficiently satisfies FPI, SDI, and CDI can be obtained. .
[0028]
The base layer is preferably formed to a thickness of about 2 to 30 mm depending on the application and the like, and a molded body having a base layer thinner than 2 mm is insufficient in strength as an industrial material. Moreover, since the molded body with a base layer thicker than 30 mm has few uses, it is not necessary to mass-produce. In addition, the shape of a molded object can be made into a desired planar shape or three-dimensional shape according to a use.
[0029]
In some cases, the base layer may contain 5 to 30 parts by weight of a halogen-based or phosphorus-based flame retardant with respect to 100 parts by weight of the olefin resin. As the halogen-based flame retardant, brominated flame retardants such as decabromodiphenylene ether and brominated epoxy compounds, and chlorinated flame retardants such as chlorinated polyethylene are used. Halogen flame retardants have the effect of delaying combustion by generating flame retardant halogen gas by thermal decomposition.
[0030]
In addition, as the phosphorus-based flame retardant, compounds such as red phosphorus, organic phosphate ester-based, halogen-containing ester-based, and polyphosphate-based compounds are used. Phosphorus flame retardants produce phosphoric acid by oxidation or thermal partitioning during combustion, and remain on the surface of the olefin resin to suppress oxygen migration and promote carbonization of the surface to suppress combustion. In particular, red phosphorus is preferably used because it has a higher phosphorus content than other phosphorus-based flame retardants and exhibits flame retardancy only by adding a small amount. Among organic phosphorus flame retardants, organic phosphates such as triphenyl phosphate, tricresyl phosphate, tris (chloroethyl) phosphate, tris (chloropropyl) phosphate are preferably used. In addition, when using red phosphorus, it is preferable to reduce content to 5 to 20 weight part and to prevent a molded object from coloring red with white titanium oxide.
[0031]
When a halogen-based flame retardant is contained, the corrosion index CDI of the molded article is added by simultaneously adding a scavenger that traps corrosive gases such as chlorine, bromine, hydrogen chloride, and hydrogen bromide generated from the halogen-based flame retardant. Is preferably reduced. Examples of the halogen scavenger include metal carbonates (eg, magnesium carbonate, lithium carbonate, calcium carbonate), metal oxides (eg, calcium oxide, magnesium oxide), zeolite, etc. Or, an inorganic substance that adsorbs and captures halogen is used. In addition, the aforementioned metal hydrate also exhibits an action as a halogen scavenger. The preferred content of the halogen scavenger is 20 to 70 parts by weight with respect to 100 parts by weight of polyolefin when it is a metal carbonate or metal oxide, and 0.5 to 5 parts by weight when it is zeolite. Part.
[0032]
Further, the base layer may contain a flame retardant aid together with the above flame retardant. Flame retardant aids work to improve flame retardancy, suppress fuming, and suppress corrosive gases by synergistic effects with the above flame retardants.For example, they are excellent when used in combination with halogenated flame retardants. Antimony trioxide that exhibits excellent combustion-suppressing action, zinc stannate, zinc hydroxystannate, zinc borate, zinc hydroxyborate, and powdery silicone polymers that exhibit excellent smoke reduction effects are preferably used. . The preferable content of these flame retardant auxiliaries varies slightly depending on the type, but all are within the range of 1 to 20 parts by weight with respect to 100 parts by weight of the polyolefin.
[0033]
Flame-retardant olefin resin molding of the multilayer structure of the present invention, at least one side, 20 and the titanium oxide to be less than the titanium oxide content of the base with respect to 100 parts by mass of the olefin resin of the base layer It is formed by forming a surface layer contained within the range of 80 parts by weight, and (1) a two-layer molded product in which the surface layer is formed only on one side of the base layer, and (2) a surface layer is formed on both sides of the base layer There are three-layered molded products, and (3) three-layered molded products in which a surface layer is formed on one side of the base layer and various functional layers (for example, antistatic layers) are formed on the other side.
[0034]
This surface layer is formed to improve the physical properties of the surface of the base layer, in particular to suppress a decrease in chemical resistance and corrosion resistance due to a large amount of titanium oxide and metal hydrate, so titanium oxide is added to 100 parts by weight of olefin resin. against it must be contained in the range of 20 to 80 parts by weight, it is necessary to contain as towards the titanium oxide content in the surface layer than the titanium oxide content of the base layer is reduced.
[0035]
When the content of titanium oxide in the surface layer exceeds 80 parts by weight, the density of titanium oxide exposed on the surface becomes high, and it is difficult to suppress so that the good chemical resistance and corrosion resistance inherent to the olefin resin are not greatly reduced. Become. On the other hand, if the surface layer titanium oxide is less than 20 parts by weight, the chemical resistance and the corrosion resistance can be sufficiently suppressed, but the amount of the olefin resin on the surface layer increases, resulting in a disadvantage that the flame retardancy is decreased. The more preferable titanium oxide content in the surface layer is in the range of 30 to 70 parts by weight with respect to 100 parts by weight of the olefin resin.
[0036]
Such a surface layer is preferably formed to a thickness of about 0.3 to 2 mm, and a molded body in which the surface layer is formed thinner than 0.3 mm may be attacked by chemicals, etc., and the surface layer is formed thicker than 2 mm. Since the molded body has a large amount of the olefin resin in the surface layer, there is a possibility that the flame retardancy is lowered and the smoke generation amount is increased. A more preferable thickness of the surface layer is 0.4 to 0.8 mm.
[0037]
This surface layer is preferably formed of the same olefin resin as that of the base layer. Needless to say, additives such as pigments, dyes, ultraviolet absorbers, and antioxidants are also appropriately added to the surface layer.
[0038]
The molded body in which the surface layer as described above is formed on at least one surface of the base layer has a low density of titanium oxide exposed on the surface, and the surface of the molded body (surface layer) is hardly different from the original good chemical resistance and corrosion resistance of the olefin resin. Because it has chemical resistance and corrosion resistance, there is no worry of being attacked by chemicals, etc. , and the base layer contains titanium oxide coated with alumina and metal hydrate at a specific content as described above. Since the above-mentioned titanium oxide that imparts flame retardancy to the surface layer is contained in a specific range, this molded product has good flame retardancy as a whole, and emits smoke and corrodes. The amount of generation of the property gas is small, and the evaluation standards of the combustion index FPI, the smoke generation index SDI, and the corrosion index CDI required by the FM standard are satisfied at the same time.
[0039]
The flame retardant olefin resin molded article having the multilayer structure as described above is composed of titanium oxide coated with alumina, metal hydrate, and in some cases, halogen-based or phosphorus-based flame retardant, halogen scavenger, and other additives. Prepare the blended olefin resin composition for base layer molding and the surface layer olefin resin composition blended with titanium oxide coated with alumina, and apply these resin compositions to multilayer extrusion molding, calendar press, laminate and other by means, which is produced by laminating molded into a desired shape, FPI, SDI, as well as satisfy each criteria CDI at the same time, chemical resistance of the surface, the corrosion resistance is good, it is, or, further secondary processing to applications that chemical resistance of the surface is required, first the cleaning vessel for example is part of a semiconductor manufacturing device, a liquid tank, a container, such as a piping member It is preferably used as charges.
[0040]
In addition, the flame-retardant olefin resin molded article having the above-mentioned multilayer structure is one in which titanium oxide is contained in the surface layer. In addition, a molded article provided with a surface layer of an olefin resin alone containing no titanium oxide, , A molded body provided with a surface layer containing titanium oxide and metal hydrate (however, the total content of titanium oxide and metal hydrate is less than that of the base layer), titanium oxide and halogen-based or phosphorus-based It can also be set as the molded object which provided the surface layer (however, the content rate of a titanium oxide is smaller than that of a base layer) containing a flame retardant.
[0041]
Next, reference examples and comparative examples of the present invention will be given.
[0042]
[ Reference Example 1]
To 100 parts by weight of commercially available polypropylene, 50 parts by weight of the above titanium oxide, 45 parts by weight of magnesium hydroxide, 45 parts by weight of aluminum hydroxide and 5 parts by weight of red phosphorus are added and kneaded uniformly to 0.5 mm. Got the sheet. And 20 sheets of this sheet | seat were piled up and hot-pressed, and the flame-retardant propylene resin board of thickness 10mm used as the base layer of the flame-retardant olefin resin molding which concerns on this invention was obtained.
[0043]
When this flame retardant propylene resin plate was subjected to a flame retardant test according to FM standards, FPI was 5.7, CDI was 0.2, and SDI was 0.4, which satisfies all the evaluation criteria. there were.
[0044]
[ Reference Example 2]
Using the same polypropylene as in Reference Example 1, 60 parts by weight of the above-mentioned titanium oxide, 70 parts by weight of magnesium hydroxide and 10 parts by weight of red phosphorus were added to 100 parts by weight of this polypropylene, and the same as in Reference Example 1. Thus, a flame-retardant propylene resin plate having a thickness of 10 mm, which becomes the base layer of the flame-retardant olefin resin molded article according to the present invention, was obtained.
[0045]
When this flame-retardant propylene resin plate was subjected to a flame retardancy test according to FM standards as in Reference Example 1, the FPI was 4.0, the CDI was 0.4, and the SDI was 0.3. The board also satisfied all the evaluation criteria.
[0046]
[Comparative Example 1]
For comparison, a sheet having a thickness of 0.5 mm is prepared using the same commercially available polypropylene as in Reference Examples 1 and 2, and 20 sheets of these are stacked and hot pressed to obtain a propylene resin plate having a thickness of 10 mm. It was.
[0047]
This propylene resin plate was subjected to a flame retardancy test according to the FM standard in the same manner as in Reference Examples 1 and 2. As a result, FPI was 58, CDI was 0.8, and SDI was 3.4. Evaluation of FPI and SDI The standard could not be satisfied.
[0048]
【The invention's effect】
As is clear from the above description, the flame-retardant olefin resin molded article of the present invention has significantly improved flame retardancy and a small amount of smoke generation and corrosive gas. smoke index SDI, all criteria of the corrosion index CDI can be satisfied, Rutotomoni with sufficient practical strength as an industrial material, such as a decrease in chemical resistance and corrosion resistance by the table layer can be sufficiently suppressed, many Has a remarkable effect.

Claims (2)

On at least one side of a base layer having a thickness of 2 to 30 mm containing 20 to 80 parts by weight of titanium oxide coated with alumina with respect to 100 parts by weight of olefin resin and 30 to 100 parts by weight of metal hydrate as another inorganic material And forming a surface layer having a thickness of 0.3 to 2 mm containing 20 to 80 parts by weight of the titanium oxide with respect to 100 parts by weight of the olefin-based resin so as to be less than the titanium oxide content of the base layer. A flame-retardant olefin resin molded article. The flame-retardant olefin resin molded article according to claim 1 , wherein the titanium oxide is a powder having an average particle diameter of 0.1 to 0.5 µm.