JPS5943307B2 - Nonflammable reinforced plastics - Google Patents

Description

[Detailed Description of the Invention] This invention relates to reinforced plastics (hereinafter referred to as FRP).
Regarding the composition of the conventional so-called flame retardant FR
This invention relates to a composition that can dramatically improve the combustion resistance of P.

In general, it is known that the use of various hydrated inorganic substances is effective in making unsaturated polyester resin flame retardant, and the present inventor previously discovered that unsaturated polyester resin 1
00 parts (weight ratio) and 180 parts (weight ratio) or less of alum powder mixed together and thoroughly stirred to produce a non-flammable unsaturated polyester molded product that has excellent flame resistance. (Tokuko Sho 52-431)
7. The above are referred to as published inventions). In the published invention, the part of the test plate that was in direct contact with the flame only "became a rough surface like bursting alum" and there was no ignition flame (column 4, line 43 to column 5, line 3 of the same publication).

On the other hand, aluminum aqua regia has approximately the same amount of crystallized water as that of alum (for example, the ratio of crystallized water contained is 48%/35%''■, 1.4, so aluminum
In the case of alum, the filler is 140 parts of aluminum hydroxide compared to 140 parts of aluminum aqua regia. However, while it just "pops" silently, in the case of aluminum aqua regia, dozens or more of minute cracks (approximately 1 to 3 u) are generated on the surface.
With a cracking sound, the epidermis curls up a little, and red-orange flames gush out. Therefore, alum is clearly superior as a filler for noncombustible FRP, but at present, fine powder with a particle size of 10 x 104 m or less is not industrially produced. , and its melting point is around 95 degrees Celsius, which may pose a practical problem. Therefore, we decided not to use alum and worked diligently to develop a nonflammable FRP that improves the drawbacks of aluminum hydroxide. As a result of research, we arrived at this invention. First, in order to pass the test (hereinafter referred to as the Ministry of Transport flammability test) according to the Ministry of Transport flammability test method (Notice of the Ministry of Transport Railway Supervision Bureau dated May 15, 1970, Railway Transport No. 81 Annex). IA) 1. There is no steady ignition.

There should be little smoke. (during test) (2) 2 No carbonization,
Discoloration should remain below 100U.

(After the test) CA) 3 The deformation is only superficial,
Its length shall be 100 mTIL or less.

(after the exam), etc. must be satisfied. Now, FR using aluminum trihydroxide powder as a flame retardant filler.
The combustion resistance of P according to the Ministry of Transport type combustion test was as shown in Table 1.

(All of the tests in Table 1 were conducted by the applicant of this patent, who created the test plates and conducted them at the Ministry of Transport's Traffic Safety and Pollution Research Institute. ) B(2), B(4) in Table 1
), the ignition time is 50 seconds and 25 seconds, respectively.
(Comparative Example) has no ignition flame (incomplete ignition), but the carbonization deformation is 50 VIL 145 mm and 80 m 1 L in the order of B(2), B(4), and (Comparative Example), respectively.

(There was very little smoke in either case.) As shown above, aluminum trihydroxide has a smaller carbonized deformation area than alum, but it is problematic in that it has ignition flame. In other words, as mentioned above,
In the case of aluminum trihydroxide, there is a problem that micro-cracks form on the surface of the test material, causing the skin to curl up and emit flames. This invention focuses on this point, and in order to satisfy condition A (1), which is one of the conditions for passing the nonflammability test in the Ministry of Transport combustion test mentioned above, as a result of numerous experiments, we first applied a gel coat layer. is required to be filled with at least 130 parts of aluminum trihydroxide and at least 25 parts of fine glass fiber powder, and then, under the conditions that the above gel coat is used, an inorganic substance having crystal water in the laminated part must be filled with at least 130 parts of aluminum trihydroxide and at least 25 parts of fine glass fiber powder. The crystal water retention coefficient (the water content (parts) as crystal water per 100 parts of resin, the value determined by the number of parts of the inorganic material blended with the resin (Phr) x the crystal water content of the inorganic material) is approximately 45. Knowing that the above is necessary,
completed this invention.

That is, in the present invention, glass is added to 100 parts of gel coat resin, which is composed of 10 parts or less of triethyl phosphate and 130 parts or more of aluminum trihydroxide powder per 100 parts of unsaturated polyester resin, by weight in the blend. A gel coat resin mixture containing 25 parts or more of fiber fine powder and 25 parts or less of acetone is used to form a gel coat layer, and crystallization water is added per 100 parts of unsaturated polyester resin having a cast plate elongation of 3% or more after curing. A reinforced plastic that has been molded and cured using an unsaturated poly(I) ester resin mixture containing aluminum trihydroxide powder with a retention coefficient of 45 or more, 10 parts or less of talolstyrene, and 5 parts or less of acetone as a laminating resin. Styrene residual amount is 0.2
% or less by post-curing at a high temperature of 80 to 100° C. for a long period of time.

The main compositional differences between this invention and the published invention are as follows.

C(1) A gel coat is prepared by using the filler of the published invention in which 180 parts or less of alum is mixed with 130 parts or more of aluminum trihydroxide.

C(2) Further add glass fiber fine powder to the above gel coat 1.
00 parts, 25 parts or more was added.

C(3) Under the condition of using the above (1×2) gel coat, the filler in the laminated portion was aluminum trihydroxide powder having a crystal water retention coefficient of 45 or more.

Next, the gel coat resin mixture and the lamination resin mixture constituting this invention will be separated and explained in detail.

In addition, in the following description, parts indicate parts by weight. <Gel coat resin mixture> The fine glass fiber powder used in this invention is not granular, but has a diameter of 13 x 10-6 m and a length of 20 to 20 m.
Since it has a cylindrical shape of approximately 300 x 10-6 m, when it receives heat and reaches a temperature of approximately 200°C or higher, the aluminum trihydroxide dehydrates, ruptures the thin wall of unsaturated polyester that surrounds it, and spews out steam. (If the wall ruptures, the thin unsaturated polyester wall that loses cooling water will ignite.)

Just as long glass fibers strengthen the unsaturated polyester matrix in FRP from a macroscopic point of view, fine glass fiber powder from a microscopic point of view is a cell that envelops aluminum trihydroxide powder. It strengthens the unsaturated polyester wall and delays the release of crystal water held in aluminum trihydroxide, which acts as a cooling and fire extinguisher, greatly contributing to the initial fire extinguishing of FRP boards. Become. The lower limit of the amount of glass fiber fine powder added is 25 parts per 100 parts of gel coat resin, as shown in Reference Example 1 of the present invention below.

However, in other experimental examples, even 20 parts passed the non-flammability test, but considering stability, the lower limit is 25 parts, and considering the variation during mass production, it is desirable to set it to 35 parts or more. . Reference Example 1 0 to 30 parts of fine glass fiber powder (Surf Ace Strand) was blended per 100 parts of gel coat resin made of the following, and a transportation combustion test was conducted.

The results are shown in b) without the drug. By the way, if a large amount of filler is blended as in Reference Example 1, the resin content will be extremely low (in the bottom row of the table in Reference Example 1, the resin content is approximately 25.6%), so the viscosity will be extremely low. The drawback is that the dispersion of each compound is not uniform.

Therefore, in reference example 1, as mentioned above, even 20 parts of glass fiber fine powder may pass the nonflammability test, but considering stability, 25 parts is the lower limit ($
, because the filler was not well dispersed, the glass fiber fine powder was
When it was 0, it is thought that the test happened to be on a dense surface and good results were obtained. The lower limit was set at 25 parts in consideration of uniformity of dispersion.

In this way, the filler is blended in a much larger amount than normal FRP, and the resin content is only around 20%, so mixing and molding cannot be done at this point, so we first use triethyl phosphate (as a plasticizer). It is desirable to use and mix 10 parts or less of TEP) per 100 parts of unsaturated polyester resin, and add 5 to 2 parts of acetone immediately before molding.
It is necessary to mix and dilute 5 parts and mold (using a spatula or spray gun).

There are many different kinds of plasticizers, but first of all, it has one of the lowest viscosity among plasticizers and is also flame retardant.
TEP is preferred.

This TEP contributes to flame retardancy with phosphorus 17 (fl) and has a low viscosity of 1.55 cps, so it is mainly used as a diluent. It also has the effect of imparting flexibility to the aforementioned unsaturated polyester as the cell wall and relieving thermal stress. When using TEP, the maximum amount added is 10 parts per 100 parts of unsaturated polyester resin; 15 parts may cause cracks in the curing furnace, and 20 parts or more may cause numerous cracks on the entire surface. do.

Conventionally, when adding acetone to gel coat resin, it was common knowledge to add at most 5 parts, or at most 8 parts, because of the generation of minute cracks after curing, but in this invention, glass fiber The fine powder has a reinforcing effect, and since it is completely post-cured at high temperatures, the acetone added during molding and in the curing furnace will completely volatilize, as shown in Reference Example 2 below. Depending on the filling amount, a large amount can be added, and 2
It was found that there is no problem in adding up to 5 parts.

Reference example 2 Unsaturated polyester resin (Polymer 630
4. Add 200 parts of aluminum trihydroxide (Hygilite H-31) to 100 parts of (450 cps (25°C)) and thoroughly knead the gel coat resin. To 100 parts of gel coat resin, add glass fiber fine powder ( surf nice strand)
When the mixture was added and kneaded, the appropriate amount of acetone to be added to the amount of glass fiber fine powder added to enable spraying with a pressure gun was as follows.

In addition to acetone, chlorstyrene may also be used as a diluent for surface deformation after the combustion test, but as shown in Reference Example 2 (comparison), chlorstyrene is not preferred because it induces flaming.

This concludes the explanation of the gel coat resin mixture of this invention.
Next, the resin mixture for lamination will be explained.

<Resin mixture for lamination> In order for the resin mixture for lamination to pass the Ministry of Transport type flammability test as nonflammable, the water-of-crystal retention coefficient of the inorganic substance must be about 45 or more, as described above.

For example, in Reference Example 1, the amount of alum in the laminated part is 100 (parts (Phr)) x 0.45 = 45, and in Reference Example 2, the amount of aluminum trihydroxide is 130 (parts (Phr)) x
It was 0.35=45.5. Also, since a large amount of inorganic powder is mixed in, the viscosity of the resin becomes high, making pan lay-up molding difficult, for example. If molding is difficult, 5 parts or less of acetone may be mixed.

Next, the embodiment thereof is shown in Reference Example 3. Reference example 3 1'? 'l'VV 4Pf It was sufficiently moldable, and there were no abnormalities even after the resin was cured.

There were no problems in the combustion test. fully moldable;
There were no abnormalities after the resin was cured. There were no problems in the combustion test. It is difficult to mold, but it is possible. There were no abnormalities after the resin was cured.

There were no problems in the combustion test. In addition, when molded using an unsaturated polyester resin mixture containing a large amount of filler,
Since the mixture as a whole inevitably becomes hard and brittle, it is desirable to use a highly elongated resin as the matrix. Reference example 4 is a glass fiber mat (C
This shows the tensile strength of an FRP board hand-laid and molded using a resin mixture containing 100 parts of resin and 150 parts of alum, with two layers of M45O) as a reinforcing material. I know it's stronger. Reference example
4 On the other hand, unsaturated polyester resin is a mixture of unsaturated linear polyester and vinyl monomer (hereinafter referred to as styrene) that undergoes a crosslinking reaction with the addition of a curing agent, solidifying into a three-dimensional network structure. However, depending on the degree of crosslinking, the following outline is shown.

That is, after normal hardening, FRP retains at least several percent of unreacted styrene as residual styrene, which is why FRP has a styrene odor. This means that styrene, which is a type of organic solvent and is highly flammable, remains inside the FRP at all times. This invention focuses on this point, which has not been noticed by those skilled in the art, and uses a larger amount of chlorstyrene (flame-retardant styrene) than usual to reduce the amount of filler that contributes to nonflammability to its ultimate limit. After molding and curing the FRP, it is post-cured at high temperature for a long time until the styrene and volatile substances remaining in the FRP are nearly completely removed.
By expelling the material during this period, the amount of filler that contributes to non-combustibility can be increased to a much larger amount than normally thought, without reducing strength or sacrificing formability, which was previously impossible. I was successful in doing so.

The table below shows an example of the measurement results of the amount of styrene remaining in FRP (4) by heating in air for a long time at high temperatures. This concludes the explanation of the resin mixture for lamination of the present invention.

Next, a process for molding the nonflammable reinforced plastic of the present invention will be explained.

First, unsaturated polyester resin (
Coloring) 100 parts, if necessary, add up to 1 part of TEPlO to dilute it, then add 130 parts of aluminum trihydroxide.
2 parts or more, thoroughly kneaded and used as a gel coat resin.

During mass production, the amount of aluminum trihydroxide added is preferably 180 parts or more. Next, to 100 parts of this gel coat resin, 25 parts or more of glass fiber fine powder is added, and 25 parts of acetone is added.
Spray mold by diluting 1 part or less.

During mass production, the amount of glass fiber fine powder added is preferably 35 parts or more. The laminated part that backs up this is
First, for 100 parts of unsaturated polyester resin whose elongation after curing is around 301) or more, the crystal water retention coefficient (as described above)
5' Blending inorganic material powder with crystal water of 45 or more (for example, 130 parts or more of aluminum trihydroxide).

), which is then diluted with 10 parts or less of chlorstyrene and 5 parts or less of acetone, and laminated using glass fiber cloth (including mat, etc.). After the resin has almost completely cured,
Finally, post-curing is performed at a temperature of 80 to 100° C. until the amount of styrene remaining in the FRP becomes 0.2 (:fl) or less.

The temperature is preferably 100° C., and the post-curing time is usually 10 hours or more, although it depends on the amount of styrene remaining at the beginning. Example Results of high-temperature long-term post-curing and combustion test results of FRP molded according to the above-mentioned process using gel coat resin mixture (a) and lamination resin mixture (b) having the following compositions (c)
) are shown in comparison.

As described above, according to the present invention, it is possible to add an inorganic filler containing a large amount of crystal water, which is unthinkable in the conventional FRP industry. (5-10 parts) much more than (
25 parts or more) and can be molded in the same way as before using conventional molding equipment and methods. This has the great effect of making it easier to mass-produce non-combustible FRP, which had previously been the case.

Furthermore, in the pursuit of non-combustibility, conventional non-combustible FRP generally has a porous, brittle, or soft outermost layer, so most of them have a surface hardness (Barcol hardness) close to O, and the hardness is very low. Even the more expensive ones cost no more than 35
Below (40 to 50 for normal FRP), it was impractical.

Claims (1)

[Claims] 1. By weight, per 100 parts of unsaturated polyester resin, 100 parts or less of triethyl phosphate and 130 parts or more of aluminum trihydroxide powder, 25 parts or more of glass fiber powder and 100 parts of gel coat resin. An unsaturated polyester resin 1 containing 25 parts or less of acetone as a gel coat resin mixture to form a gel coat layer and having a cast plate elongation of 3% or more after curing.
An unsaturated polyester resin mixture prepared by blending aluminum trihydroxide powder with a crystal water retention coefficient of 45 or more per 00 parts, 10 parts or less of chlorstyrene, and 5 parts or less of acetone is used as a lamination resin, and the reinforcement is completed by molding and curing. Nonflammable reinforced plastics made by post-curing plastics at high temperatures of 80 to 100°C for a long time so that the residual amount of styrene is 0.2% or less.