JPS59108024A - Manufacture of large-sized rigid urethane slab stock foam having excellent strength and flame-retardancy - Google Patents

Abstract

PURPOSE:To manufacture a large-sized rigid urethane slab having excellent strength and flame retardancy, by using specific amounts of an aromatic polyester polyol, a reactive flame-retardant, a specific polyether polyol, a tolylene diisocyanate prepolymer, etc. CONSTITUTION:The objective large-sized rigid urethane slab stock foam is manufactured by using (A) 30-70pts. of an aromatic polyester polyol, 5- 25pts. of a reactive flame-retardant, and 5-70pts. of a sucrose-type polyether polyol as polyols and (B) 30-80%, based on the whole isocyanate, of a tolylene diisocyanate prepolymer and the rest part of crude diphenylmethane diisocyanate (prepolymer) is isocyanates, adding a foaming agent (e.g. trichloromonofluoromethane), a surface active agent, and a catalyst (e.g. triethylenediamine) to the mixture, and reacting the components.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing large-sized rigid urethane slabs with excellent strength and flame retardancy.

In recent years, a high-quality lettuce slab stock buoy Kl-j...
With the increase in demand and diversification of applications, various performances have come to be required. For example, in addition to its properties and excellent heat insulating properties, examples include various strengths, flame retardance, high temperature properties, low temperature properties, non-water absorption properties, etc. Moreover, there are an increasing number of applications that require a combination of these features or require large slabs with similar performance. However, when trying to obtain a large-sized product with these properties, cracks and scorches are likely to occur inside the foam. In particular, as will be described later, when trying to obtain a slab with excellent strength and flame retardancy, cracks are likely to occur, so only a smaller slab than usual can be foamed, resulting in low productivity and yield.

If you want to obtain a hard urethane kuichi swog that has excellent strength and combustibility and is as large as possible, the following methods can be used. That is, if not only halogenated carbon but also water is used as a blowing agent, there is a tendency to obtain a larger slab with higher strength, but the thermal conductivity becomes significantly higher. Also,
Slowing the reaction rate has some effect on increasing the foam height, but increases the variation in density.Using all TD Eprebo Poly as the isocyanate component yields a large slab with relatively good strength; Making it flame retardant will be extremely difficult.

The use of crude MD speeds up the reaction and tends to cause cracks, so if crude MDI is made into a prepolymer, the reactivity will be milder and the shape of the slab can be made a little larger, but this is not sufficient.

When an additive type flame retardant is used for flame retardancy, the strength decreases and cracks and scorches are more likely to occur. Furthermore, when a reactive flame retardant is used, there is almost no decrease in strength, but the tendency to generate cracks and scorches remains.

The present inventors investigated the effects of the above-mentioned raw materials and foaming methods on the foam properties and processability, and as a result of intensive research into the production of large slabs with excellent strength and flame retardancy, we found that aromatic By using a polyester polyol, a reactive flame retardant, and a sucrose polyether polyol, and using TD Eprepolymer and crude MDI or crude MD Nibrevo M-mer as incyanates within specific ranges, strength and resistance can be improved. It was discovered that a slab with excellent combustibility and a surprising size could be obtained, and the present invention was completed. Next, the present invention will be explained in detail.

Examples of aromatic polyester polyols that can be used in the present invention include those derived from polycarbomethoxy-substituted diphenyl, polyphenyl, and benzyl esters of hydruic acid series, and those having a hydroxyl value of about 250 to 450 are particularly suitable. ing.

Historically, the first rigid polyurethane foams considered were based on alkyd polyesters, such as those shown in US Pat. No. 2,574,299. Next, mustard oil and lactone esters have also been considered.

While polyester polyols generally provide foam with good mechanical properties and flame retardancy, they cannot compete with polyether polyols in terms of price.

However, as recently described in U.S. Pat. It can be used for manufacturing purposes and contributes to the mechanical properties of the foam such as compressive strength, flame retardance, operational temperature rise, cell integrity, closed cell content and compatibility with isocyanates, as well as raw materials. Since it is a by-product, it is extremely cheap. An example of its use is Journal Opcello Plastics (J〇-urnal
of CKLLTJLARPI, AST Engineering 08) 5/
June issue, 1980.152N+27th U.S. Plastic Suede Association Urethane Subcommittee Lecture (S, P Engineering 27th
Annual Teohnioa], /paa, rke
It is also shown on page 244 of the tlngConference) preliminary lecture collection. As an aromatic polyester, there are examples of the use of phthalic anhydride, as previously shown in US Pat. No. 2,654,244.
Its proportion in polyester polyol is extremely low.
What is a substantial aromatic polyester polyol?

If the aromatic ring content of polyester, which already has a high viscosity, is increased, the viscosity will further increase or the polyester will become solid, which is impractical in terms of processing. However, the residue, which is a raw material for the polyester polyol that can be used in the present invention, is a complex mixture, mainly containing methyl and benzyl esters of diphenyldicarboxylic acid and tricarboxylic acid, in which ethylene glycol is used in combination, and its viscosity is 1500 at 25°C.
~65,000 centivoise.

As a flame retardant, in order to obtain high strength and high flame retardancy, it is preferable to use a reactive flame retardant containing halogen, phosphorus, etc. Examples thereof include Fyrol-6, Star 17
77- Ket Ka/I/(Stauff8r Chem
(manufactured by Dow Chemical), 60 to FR-1 (manufactured by Dow Chemical (f
Low Ch-emi, Cal), Fl, -4
50, FL-500, FL-550 (manufactured by Asahi Denka Kogyo Co., Ltd.)
, 0DX-699 (manufactured by Dainippon Ink Chemical Industries, Ltd.) DPG
-phosphone-) (DPG -Phospb, onat
e, tsuxx We-ston Qhem
There is a company number etc.

When additive flame retardants such as halogen-containing phosphoric acid esters are used, the strength of the resulting foam decreases, and depending on the type, cracks, scorch, etc. are likely to occur.

However, if a high level of flame retardancy is required, it is preferable to use both the reactive type and the additive type. In addition, to improve mechanical properties such as compressive strength, highly functional polyols,
In particular, it is effective to use sucrose polyether polyols, and those with an average functional group number of 4.5 or more and a hydroxyl value of 500 or more are preferable, but if high levels of strength and flame retardance are not required, it is preferable to use polyether polyols containing a large amount of hashiol, triol, etc. Sucrose polyether polyols can also be used.

Generally speaking, when using TD yarn type incyanate, MD
Compared to ID isocyanate, the foam is whiter, cracks and scorches are less likely to occur, and the foam shape is easier to maintain when producing slabs. Use together must be considered. Therefore, as the polyisocyanate, TD Eprepolymer is used in an amount of 60 to 80% of the total amount of isocyanate. The remaining isosibnate is preferably a crude MD or a crude MD prepolymer, but the latter is preferred because it has milder reactivity and is less likely to cause cracks or scorches. Incidentally, it is preferable to use a polyol used in the synthesis of the prepolymer, a sucrose-based polyol, or a reactive IJI@flame agent. Crude MDI
If using foam, a foam with a viscosity of 500 centiboise or higher is suitable.Blowing agents include low boiling point inert solvents, substances that react with isocyanate to generate hypocarbon dioxide, and foams that are thermally decomposed by the heat of reaction during foam formation. Any compound that generates a gas can be used, but among them, temo)lichloromonofluoromethane is the most preferred.

As the surfactant, nonionic surfactants, anionic surfactants, cationic surfactants, etc. can all be used, but L-5+! 540 (manufactured by Nippon Unicar), 5H
Polydimethylsiloxane-polyalkylene oxide block copolymers such as -193 (manufactured by Toshi Silicone Co., Ltd.) are preferred.

As the catalyst, any catalyst such as a gold catalyst or an amine catalyst can be used, but a 6th class amine catalyst such as triethylenediamine or dimethylcyclohexane is preferred.

According to the above recipe, it is possible to obtain a large, inexpensive slab with excellent strength and flame retardancy. That is, it is thought that the benzene ring and ester bond in the aromatic polyester polyol contribute to the flame retardancy and high strength of the foam, and also prevent the occurrence of cracks. The use of highly functional polyols also contributes to high strength and flame retardancy. The combined use of TDI and MD isocyanates makes the foam flame retardant, increases its strength, and improves crack prevention.The reactive flame retardant contributes to high strength, and together with the additive flame retardant, it contributes to flame retardancy. ing.

Next, an example will be shown.

As a foaming device, a continuous production fin made of hard urethane slabs is used, and the isocyanate index is 1°05 and the width is 100.
9. Foam the α slab. The injection machine used was a low pressure injection machine UMD-212 manufactured by Polyurethane Engineering Co., Ltd. The test method is W degree: AST! vj-D-1622, compressive strength: ASTM-D-1621, flammability: J Engineering SA
-9514 was used. 2. "Slab height" means the maximum height at which foaming can occur without cracking or scorching.

Examples 1-6, Comparative Examples 1-2 Terate 206 as aromatic polyester polyol
(Terate 20 bottles manufactured by Vercules, hydroxyl value 3
10), 5O-800 (manufactured by Asahi Denka Kogyo Co., Ltd., hydroxyl value 550) as a sucrose polyether polyol,
FyrOl-6 (FyrOl-6) is used as a reactive flame retardant.
, manufactured by Stouffer Chemical Company, hydroxyl value 440), L-5640 (manufactured by Nippon Unicar Company) as a surfactant,
Trichloromonofluoromethane (hereinafter F-
11), using dimethylcyclohexylamine (hereinafter abbreviated as DMCHA) as a catalyst, TDID
The repolymer was prepared by reacting T-80 and 52-460 (sucrose polyol, hydroxyl value 460 manufactured by Futou Yakuhin Co., Ltd.) to have an NCO form of 60%, and the crude gMD Egrepolymer was prepared using MR-100 (manufactured by Nippon Polyurethane Co., Ltd.). ) and Fyr○1-6 to adjust the NO[]% to 26% were used to foam slabs according to the formulations shown in Table 1.

Tatsu 1 As can be seen from Table 1, in Examples 1 to 6 of the present invention, large slabs with excellent strength and flame retardance were obtained, but in Comparative Example 1, which was outside the scope of the present invention, cracks occurred. It is easy to obtain relatively large slabs.

Comparative Example 2 yields a large slab with excellent flame retardancy, but
The strength is considerably inferior to Examples 1 to 6. In the conventional rigid foam manufacturing recipe, for example, the compressive strength is approximately 6.5% at a density of 50 Wy, considering the size and flame retardance of the foam.
5 or less were obtained, and large slabs with excellent strength and flame retardancy as shown in Examples 1 to 6 were not obtained. In Examples 1 to 6, although the flame-retardant formulations made it difficult to increase the size of slabs, slabs comparable in size to flame-retardant formulations were obtained without reducing strength.

Examples 4-6, Comparative Examples 6-4 Shoe rose polyester polyol TS-
450 (manufactured by Sumitomo Bayer Urethane, hydroxyl value 450)
, FL-500 (manufactured by Asahi Denka Kogyo Co., Ltd.,
Table 2 shows the recipe and results when the same raw materials as in Table 1 were used except that hydroxyl value was 450) t-.

As can be seen from Table 2, in Examples 4 to 6 of the present invention, large-sized slabs with excellent strength and flame retardance were obtained. @Considering flammability, the density is about 70Wvf, which is about 6kg or less, which is extremely excellent for the present invention series.

In Comparative Example 6, which is outside the scope of the present invention, cracks were likely to occur and only small slabs were obtained. In Comparative Example 4, a large slab was obtained, but the combustibility was very poor.

Comparative Examples 5 to 7 Comparative Example 5 uses a non-aromatic polyester polyol, Plaxel 606, instead of the aromatic polyester polyol.
(Placce 606, manufactured by Daicel Chemical Industries, Ltd., hydroxyl value 540) is used. Comparative Example 6.7 uses polyol RQ of pentaerythritol bene instead of the sucrose polyol.

650 (manufactured by Dainippon Ink Chemical Industry Co., Ltd. 1-hydroxyl value 600)
To・5P-700 (manufactured by Asahi Denka Kogyo Co., Ltd., hydroxyl value 490)
This is an example using .

Table 6 TD Eprebopoly/crude gMD Eprepolymer = 7/6
In Comparative Example 5, cracks tend to occur and a large slab cannot be obtained. In Comparative Examples 6 and 7, the flame retardance is much inferior to that of the foam obtained with the claimed formulation.

The technological development of transportation and storage of liquefied natural gas, which has been put into full-scale use in recent years, owes a great deal to insulation technology, and the development of ultra-low-temperature insulation materials is particularly desired.

Regarding the importance of insulation materials, see, for example, High Pressure Gas Vol. 15, No. 9 (197B) P, 10, No. 10 (1978) P,
15, and physical property studies are given in Industrial Materials, Vol. 17, No. 5 (
It is described in 1968'J P, 76, etc.

The thermal conductivity of rigid polyurethane foam was reported in the Ashrae Journal, October (
1966), p. 84, KLL, technj-kKl:L mat
J-si, erung) Volume 12 (1966), 0°02 koa over a wide range of temperatures.
'VmkXfo or less, which is the lowest value among existing heat insulating materials. Therefore, hard urethane 7 ohm can be applied in the field of ultra-low temperature insulation, but extremely low temperature properties are required along with flame retardancy, high strength, good processability-1 low cost, etc. 40OX400X50ff for Jin
40OX40 with urethane adhesive on both sides of the form.
Examples 1 to 6 were obtained by bonding a plywood board with a diameter of 12 ff and immersing it in liquid nitrogen (-196°C) for 1 hour after 24 hours and leaving it at room temperature for 1 hour for 5 cycles.
All of them passed this low temperature test without any deformation or cracking. 2 In this field, products with even higher density, such as about 10 ohms, are required, but the 7 ohm product obtained by the formulation of the present invention has a density of 1.
It was able to withstand even 10 hawks. Second, high-density products are difficult to form well when foamed, and the difference from general foams other than those of the present invention becomes more and more noticeable. For example, density 9014
/ptl, considering strength and flame retardancy, the height of normal rigid foam is 20CI! Although it is difficult to increase the height to 1 or more, the foam height obtained by the formulation of the present invention can be 60 cM or more. Therefore, the present invention exhibits greater effects in the field of producing ultra-low temperature insulation materials that require high density.

Claims (1)

[Claims] 60% aromatic polyester polyol as polyol
~70 parts, 5 to 25 parts of reactive flame retardant, 5 to 70 parts of sucrose polyether polyol, and tolylene diisocyanate (TD Engineering) as the isocyanate.
A large material with excellent strength and flame retardancy, characterized in that the prepolymer is used in an amount of 60 to 80% of the total isocyanate amount, and the remaining isocyanate is crude diphenylmethane diisocyanate (MDI) or a prepolymer of crude MDI. A method of manufacturing a shaped hard urethane foam.