JPS5928357B2 - Highly filled flame-resistant sealant - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly filled flame-resistant sealing material using a liquid chloroprene polymer and a liquid butadiene polymer, particularly a liquid chloroprene polymer having a terminal hydroxyl group and a liquid butadiene polymer having a terminal hydroxyl group. The present invention relates to a high-filler flame-resistant sealing material that contains a large amount of inorganic filler in the combined mixture and has improved workability and on-site workability despite extremely high filling.

Traditionally, flame-resistant ``Tefu Konno Wood'', which is made by blending liquid chloroprene polymers with alkylzanthate end groups with hydrated alumina and other inorganic fillers, is used to prevent fires in buildings, ships, etc., or to penetrate walls. It is known to be effective in preventing the spread of fire from the inside.

When this liquid chloroprene-based polymer is used, the amount of inorganic filler that can be mixed into a workable putty-like sealing material is substantially limited, and is 450 parts by weight per 100 parts by weight of the liquid polymer.
If the weight part was exceeded, the resulting compound would be extremely hard, resulting in a marked decline in sealing performance as a sealant, as well as poor workability, making it impossible to apply it on-site as a flat sealing material. . In addition, when blending with a high loading exceeding 450 parts by weight, the viscosity or hardness of the blend becomes extremely high, making it practically difficult to uniformly disperse the polymer and the inorganic filler. The amount of filler is limited to parts by weight. However, the flame resistance of the sealing material improves as the amount of inorganic filler is increased, and the higher the amount of inorganic filler, the more economically advantageous it becomes. A new flame-resistant sealing material with improved workability has long been desired by those skilled in the art.

In order to solve the problems of conventional putty-covered sealants, the inventor conducted intensive research and discovered a new flame-resistant sealant that has a high filling rate and has improved workability and on-site workability, which was previously impossible. The invention was completed.

The purpose of the present invention is to provide a compound with extremely high filling properties, which has excellent processability and workability, and because of its high filling, it not only has flame resistance that can be called non-combustible, but also has economical properties. The present invention aims to provide a new flame-resistant sealing material that is very advantageous in terms of both the viewpoint of the user and the user, and which could not be expected from the prior art.

The present inventor discovered that liquid polymers having terminal hydroxyl groups have excellent filling properties, and that particularly when using a hydrated inorganic filler, it is possible to achieve a significantly high filling rate, and that liquid polymers having terminal hydroxyl groups It was also confirmed that butadiene-based polymers have particularly excellent high filling properties.

However, the flame-resistant sealing material aimed at by the present inventors is not only highly filled but also requires various properties that are practically required, that is, workability as a putty. In accordance with the specified method, however, the load is 509 (hereinafter simply referred to as penetration).
0 or more, preferably around 100, and the sealing material is required to have flame resistance or noncombustibility (oxygen index of 90 or more), no dripping during combustion, sealing performance, adhesion, and weather resistance. Ru. From this point of view, putty sealing materials made solely from liquid butadiene polymers have excellent workability, but are inferior in weather resistance, sealing properties during combustion, and adhesion; It was confirmed that the high filling property was inferior to that of butadiene-based liquid polymer. Based on the above, the novel flame-resistant sealing material that is the object of the present invention is specified to be a specific liquid chloroprene polymer, that is, 80 to 30 parts by weight of a chloroprene polymer having a terminal hydroxyl group with a number average molecular weight of 1,000 to 6,000. liquid butadiene-based polymer, that is, number average molecular weight 1,000 to 6,0
Butadiene polymers having 00 terminal hydroxyl groups 20-7
A highly filled composition containing more than 500 parts by weight and up to 900 parts by weight of an inorganic filler per 100 parts by weight of the mixture with 0 parts by weight, and at least 50% by weight of the inorganic filler is alumina hydrate. It is a thing.

The chloroprene polymer used in the present invention can be used at room temperature (25
It is a chloroprene homopolymer or chloroprene copolymer that maintains fluidity in a liquid state at temperatures (°C) and can be handled as a viscous liquid, has at least one hydroxyl group at the end of its molecule, and has a number average molecular weight. is 1,000 to 6
,000.

If the number average molecular weight is less than 1,000, high filling properties tend to be impaired, and if it exceeds 6,000, processability tends to decrease and the penetration of the flame-resistant sealing material tends to decrease. A chloroprene-based copolymer is a copolymer of a chloroprene monomer and a monomer copolymerizable with it, but the polymer composition is such that the polymerization unit based on the chloroprene monomer is 50% by weight or more. be. Monomers copolymerizable with chloroprene include styrene, methacrylic acid, methyl methacrylate, vinyl compounds such as acrylonitrile, 1,3-butadiene, isoprene,
1-chlorobutadiene, 2,3-dichlorobutadiene-
conjugated dienes such as 1 and 3, and are arbitrarily selected from mixed monomers containing these.

In addition, the butadiene-based polymer used at the same time was kept at room temperature (25
It is a butadiene homopolymer or butadiene copolymer that maintains fluidity in a liquid state and can be handled as a viscous liquid at ℃), and has at least one hydroxyl group at the end of its molecule, and has a number average Molecular weight is 1,000-6,
000 range.

If the number average molecular weight is less than 1000, the high filling properties will be impaired, the penetration of the flame-resistant sealing material will be too large, sag will easily occur during processing or combustion, and the sealing performance in the event of a fire will be poor. If it exceeds 6000, the workability is poor. A butadiene-based copolymer is a copolymer of butadiene-1,3 monomer and a monomer copolymerizable with it.
As for the polymer composition, the polymerization unit based on butadiene-1,3 monomer accounts for 50% by weight or more. Examples of monomers that can be copolymerized with butadiene include styrene, methacrylic acid, vinyl compounds such as methyl methacrylate, and acrylonitrile, and conjugated dienes such as isoprene and chloroprene. be done. Apart from the mechanistic elucidation of why ordinary inorganic fillers can be highly loaded extremely easily by using a liquid polymer having terminal hydroxyl groups, there are other problems when using the liquid polymer specified in the present invention. Compared to the case where a liquid polymer having no terminal hydroxyl group is used, the blend is characterized by a lower viscosity and softer when the viscosity of the polymer and the level of filler amount are kept the same.

Therefore, in order to obtain a formulation having the same level of viscosity and hardness as conventional formulations using other liquid chloroprene-based polymers, when using the polymer of the present invention, the loading amount must be 50 to 10.
It is possible to increase it by about 0%. Further, it is sufficient that the number of terminal hydroxyl groups in the polymer used in the present invention is at least one, and usually about 1 to 2.5 terminal hydroxyl groups are used. However, if the number of terminal hydroxyl groups is extremely small, the high filling property tends to decrease, which is not preferable. In addition, if the number average molecular weight of the polymer is extremely small, the polymer molecules will be incorporated into the inorganic filler particles, making it difficult to achieve high loading.If the molecular weight is too high, the viscosity of the polymer will be significantly This results in a decrease in workability. In the present invention, the mixing ratio of the chloroprene polymer and the butadiene polymer is limited to 80 to 30 parts by weight of the chloroprene polymer and 20 to 70 parts by weight of the butadiene polymer.

If the chloroprene polymer exceeds 80 parts by weight, high filling properties tend to be impaired, while if it is less than 30 parts by weight, workability is good, but the weather resistance of the compound decreases and it tends to sag when burned. It is unsuitable as a sealing material because it has a strong tendency to have poor sealing properties. The amount of the inorganic filler used in the present invention is more than 500 parts by weight and 900 parts by weight based on 100 parts by weight of the liquid polymer mixture having terminal hydroxyl groups.

If the filling amount is lower than this range, the flame resistance of the obtained compound will be reduced, deformation due to sagging after on-site construction will likely occur, and it will also be economically disadvantageous. Moreover, if it exceeds this range, the compound will no longer be a putty-like sealing material and will tend to be hard and lose workability, making it difficult to compound. The inorganic fillers used here are at least 5
There is no particular restriction other than that 0% or more of the alumina hydrate is contained, and any known one may be arbitrarily selected. The reason why the above amount of alumina hydrate is used is that it is difficult to obtain a substantially non-combustible flame-resistant sealing material simply by highly filling a typical inorganic filler. Therefore, the inorganic filler used in the present invention is either alumina hydrate alone or a combination of alumina hydrate 5001) or above and other inorganic fillers. As the filler other than alumina hydrate, commonly used fine powder powders such as hydrated magnesia, hydrated calcium silicate, calcium carbonate, clay, talc, and titanium dioxide are used, but in particular, inorganic fillers containing hydrated water are used. It is particularly preferable to use an agent because it has excellent compatibility with the polymer having a terminal hydroxyl group and facilitates high-filling compounding. The highly filled flame-resistant sealing material of the present invention uses a heat-retardant chloroprene polymer and a nonflammable inorganic filler containing alumina hydrate, as well as a liquid butadiene polymer containing terminal hydroxyl groups, so it can be more highly filled than conventional sealants. The sealing material has an extremely high degree of flame resistance and is substantially non-flammable in air, and has appropriate fluidity.

That is, when an installer embeds the sealing material, it is easily deformed, adheres closely to the covering, and does not sag due to its own weight after installation or during combustion. Additionally, because this sealant is a highly filled formulation, the economic benefits are of great practical significance. In the present invention, if practically required, in addition to the above-mentioned essential components, metal oxides such as zinc oxide, magnesium oxide, and lead oxide, which are common compound components (however,
Glass fiber containing alumina hydrate as an essential ingredient,
It is also possible to blend inorganic or metallic fibers such as stainless steel fibers and softeners such as trinonyl phosphate, tricresyl phosphate, chlorinated paraffin, dioctyl phthalate, and dioctyl sebacate.

Workability can be further improved by incorporating a softener into the sealing material of the present invention.

In particular, a large amount of inorganic filler, e.g.
In the case of high-filling blending using 700 parts by weight or more relative to 0 parts by weight, the workability is significantly improved. That is, the softener is mixed with the liquid chloroprene-based and butadiene-based polymers used in the present invention, and has the effect of increasing the fluidity of the resulting sealing material. However, when only these softeners are used as binders for inorganic fillers without using the liquid polymer, the softeners tend to be incorporated into the inorganic filler particles. It is impossible to form a putty-based sealing material by incorporating a large amount of inorganic filler, such as 900 parts by weight. It is difficult to make a general statement because it depends on the type of softener and inorganic filler, but softener 1
Only about 200 to 300 parts by weight of inorganic filler can be added to obtain a sealant composition per 00 parts by weight. Moreover, the sealing material made of the softener and inorganic filler obtained in this way is immediately thermally deformed by contact with flame, has a strong tendency to drip, and cannot be an effective flame-resistant sealing material. The present invention will be explained in more detail below using Examples and Comparative Examples.

However, all "parts" are based on weight. Polymer A used in Examples and Comparative Examples: Chloroprene and 2, in the presence of 2-mercaptoethanol.
A number average molecular weight of 2,50 having an average of 1 hydroxyl end group obtained by copolymerizing 3-dichlorobutadiene-1,3
0 chloroprene-based liquid polymer (85% by weight of chloroprene-based polymerization units, 2,3-dichlorobutadiene-
15% by weight of polymerization units based on 1,3).

Polymer B: Chloroprene and 2-mercaptoethanol in the presence of 2-mercaptoethanol.
Number average molecular weight 1, having an average of 1.6 hydroxyl end groups obtained by copolymerizing hydroxyethyl methacrylate,
920 chloroprene-based liquid polymer (96% by weight of polymer units based on chloroprene, 4% by weight of polymer units based on 2-hydroxyethyl methacrylate).

Polymer C: A polymer having a number average molecular weight of 3,000 and having an isopropyl xanthate end group obtained by polymerizing chloroprene and 2,3-dichlorobutadiene-1,3 in a toluene solvent in the presence of diisopropyl xantogen disulfide. Chloroprene-based liquid polymer (85% by weight of polymerized units based on chloroprene)
, 15% by weight of polymerization units based on 2,3-dichlorobutadiene-1,3).

Polymer D: A liquid chloroprene polymer having no terminal hydroxyl group and having a number average molecular weight of 2,330 obtained by polymerizing chloroprene in a toluene solvent in the presence of n-dodecylmercaptan.

Polymer E: Product name of Idemitsu Petrochemical Co., Ltd. “POlybdR-45H”
T'': A butadiene polymer having an average of 2.2 to 2.4 hydroxyl end groups and a number average molecular weight of about 2,700.

(Note) The content of terminal hydroxyl groups and the number average molecular weight were measured by infrared absorption spectrum analysis of the purified polymer and an engineering briometer, and the number of terminal groups per molecule was determined from these results.

Example 1 Soft clay 200% in polymer A6O part and polymer E4O part
When the mixture was mixed with 450 parts of alumina hydrate and kneaded using a paint mill, a putty-like compound that was easily uniformly dispersed was obtained.

The penetration was 130, and it had good workability as a putty.
Further, this compound was placed in a sheet and accelerated deterioration was performed in a weather-o-meter at 50° C. for 200 hours. As a result, there was no deformation due to flow, no coloration, no surface cracking, and the weather resistance was good. Example 2 Hydrated magnesia 20 in polymer A8O and polymer E2O
0 parts and 300 parts of alumina hydrate were kneaded in a paint mill to obtain a putty-like compound.

The penetration was 102, and this product had extremely good workability. Example 3 90% of alumina hydrate was added to the polymer B3O part and the polymer E7O part.
0 parts was added and kneaded on a paint mill to obtain a putty compound.

The penetration rate of this compound was 64, and the workability as a putty was good. And this compound 100
1.5 parts of tricresyl phosphate as a softening agent
The needleability of the Nomate compound obtained by adding 50% of the mixture and kneading it on a paint mill was 86, and the workability as a Nomate was extremely good.

Comparative Example 1 A compound obtained by kneading 400 parts of alumina hydrate into a polymer ClOO portion on a paint mill had a penetration degree of 11.

This material was so hard that it could no longer be called a putty-like material. It was recognized that high loading exceeding 400 parts of alumina hydrate was impossible. Comparative Example 2 50 parts of alumina hydrate in polymer D5O part and polymer E5O part
0 parts were kneaded on a paint mill to obtain a compound.

This compound was a hard, slightly brittle compound with a penetration degree of 15, and did not have workability as a putty. Comparative example
3. A compound obtained by kneading 450 parts of alumina hydrate and 300 parts of soft clay with the polymer AlOO part had a penetration of 25 and was extremely poor in workability as a putty.

Reference Example In order to evaluate the flame retardancy of the flame-resistant sealing material according to the present invention, oxygen index measurements and vertical combustion tests were conducted on the putty-like bodies obtained in Examples 1 to 3.

The results are summarized in a table. As is clear from the results, the sealing material according to the present invention was nonflammable, and no drippings were observed. Comparative Example 4 A compound was obtained by kneading 800 parts of alumina hydrate into a polymer ElOO part on a paint mill.

Although this material had a penetration degree of 69 and had good workability as a putty, it sagged during combustion and had poor sealing and adhesion properties. Further, as in Example 1, a test using a weather-o-meter revealed that there was deformation due to flow and discoloration to yellow-brown, and surface cracks were also observed, indicating poor weather resistance. Test result measurement method 1 Penetration...JISA5
The load was set at 509 in accordance with the method specified in 754.

2 Oxygen index: Based on the method specified in JIS K72Ol.

3 Vertical combustion test: Conformed to the US UL-94 standard.

The same evaluation method: The time (seconds) from ignition for 10 seconds until extinguishment was measured using an ignition source.

Claims (1)

[Claims] 1 Chloroprene-based polymer having at least one terminal hydroxyl group and having a number average molecular weight of 1,000 to 6,000 80 to
Number average molecular weight 1,00 with 30 parts by weight and terminal hydroxyl group
More than 500 parts by weight and up to 900 parts by weight of an inorganic filler of which at least 50% by weight is alumina hydrate per 100 parts by weight of a mixture with 20 to 70 parts by weight of a butadiene-based polymer of 0 to 6,000% by weight. Highly filled flame-resistant sealing material characterized by comprising: