JPH04266919A - Production of polyurethane foam for flame lamination - Google Patents

Abstract

PURPOSE:To produce polyurethane foam for flame lamination, having excellent bond strength, especially initial bond strength even by using a general purpose polyether polyol. CONSTITUTION:In production of polyurethane foam for flame lamination by using a polyol and tolylene diisocyanate(TDI), at least 2,4-TDI among 2,4-TDI and 2,6-TDI is used as the TDI and the content of isocyanate group at the 4-position of 2,4-TDI is characteristically 42-50% based on the whole isocyanate groups.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyurethane foam for frame lamination having excellent initial adhesion.

0002

[Prior Art] Traditionally, ester foam has been mainly used for urethane foam for frame lamination, but today it is widely used because of its high quality properties such as moisture-heat deterioration prevention performance, good elasticity, and low manufacturing cost. For a reason, etheric forms are being used instead. However, frame laminated laminates using this ether foam generally have low adhesive strength, particularly low initial adhesive strength, and may cause problems such as poor adhesion during the manufacturing process of the laminate. For this reason, it has been proposed to produce ether foam using a special polyol developed based on polyether polyol (
Special Publication No. 46-30309, Special Publication No. 1388-1973
Publication No. 0, etc.). Further, as the isocyanate group used in the ether foam, those having an isomer ratio of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate of 80:20 or 65:35 are generally used.

0003

[Problems to be Solved by the Invention] However, when the above-mentioned special polyol is used, the manufacturing process increases and becomes complicated, and the special polyol itself is expensive. It has a special composition that contains an organic phosphorus compound in a special polyol. Further, even if these special polyols are used, sufficient adhesive strength, especially initial adhesive strength, may not be obtained depending on the skin material used. The present invention solves the above-mentioned problems, and provides a frame that has sufficient adhesive strength, especially excellent initial adhesive strength, regardless of the type of skin material used, even when inexpensive general-purpose polyol is used. It is an object of the present invention to provide a method for producing polyurethane foam for lamination.

0004

[Means for Solving the Problems] The method for producing a polyurethane foam for flame lamination according to the first aspect of the present invention uses a polyol and tolylene diisocyanate (hereinafter referred to as "TDI").
”. ), in which the tolylene diisocyanates include 2,4-TDI and 2,4-TDI;
It is characterized in that at least 2,4-TDI is used among the 6-TDIs, and the isocyanate group at the 4-position of the 2,4-TDI accounts for 42 to 50% of the total isocyanate groups. Examples of the polyol include polyether polyols such as polyoxypropylene ether polyol and polyoxyethylene ether polyol, as well as Japanese Patent Publication No. 46-3030
Special polyols such as polyether polyester polyols as shown in Japanese Patent No. 9 may be used, or polyols containing organic phosphorus compounds may be used. Here, 2
, 4-TDI (hereinafter referred to as "4-position isocyanate group") refers to an isocyanate group that substitutes hydrogen at the 4-position of the benzene ring skeleton of TDI. The reason why the isocyanate group at the 4-position is required to account for 42 to 50% of the total isocyanate groups in TDI is as follows. That is, the isocyanate group reacts with the active hydrogen in the polyol, the urethane bond, and the active hydrogen in the urea bond to form urethane, allophanate, and biuret bonds, respectively. And these connections are
The urethane polymer is decomposed by heat, and this thermal decomposition allows the urethane polymer to melt and function as an adhesive. In this case, the bond formed by the reaction of the isocyanate group at the 4-position with active hydrogen is less stable against heat than the bond formed by the reaction of the isocyanate group at the 2-position or the isocyanate group at the 6-position. Yes, it is easily thermally decomposed. Further, in the cooling process after lamination, the dissociated isocyanate groups react again with hydroxyl groups or with active hydrogen of the skin material to form a strong adhesive layer. Therefore, the higher the ratio of the 4-position isocyanate group to all the isocyanate groups, the better. As shown in the examples below, when this ratio is 42% or more, thermal decomposition easily occurs, resulting in excellent initial adhesion and
Final adhesion is obtained. On the other hand, the maximum ratio of the 4-position isocyanate group to all isocyanate groups is 50
%. Therefore, the isocyanate group at position 4 is TD
It is required that the total amount of isocyanate groups in I be 42 to 50%. Furthermore, 2,4-TDI and 2,6-TD
When the isomer ratio of I is 84:16 to 100:0%,
This is the ratio.

Furthermore, as shown in the second aspect of the present invention, a prepolymer obtained by reacting a part of the isocyanate group of TDI having an isocyanate group at the 4-position with a polyol in such a ratio may be used. In this case as well, since the isocyanate group at the 4-position is contained in the same amount as above, the same effect can be obtained.

In the production of the urethane foam of the present invention, other known blowing agents, catalysts, auxiliaries, etc. may be used depending on the purpose. Here, as this blowing agent, for example, in addition to water, halogen-substituted aliphatic hydrocarbons (trichloromonofluoromethane, dichlorodifluoromethane,
methylene dichloride, etc.) can be used alone or in combination. Further, as a catalyst, for example, N-methylmorpholine, N,N,N',N'-tetramethyl-1,
Tertiary amines such as 3-butanediamine and triethylenediamine, or organic tin compounds such as dibutyltin dilaurate and stannous octoate, etc. can be used alone or in combination. Further, as the auxiliary agent, for example, a surfactant, an additive type phosphate ester flame retardant, etc. can be used. As the surfactant, for example, silicone oil (polysiloxane-polyoxyalkylene copolymer) is used, and as the additive type phosphate ester flame retardant,
For example, trischloroethylphosphate, trischloropropylphosphate, trisβ-chloropropylphosphate, tetrakis-2-chloroethylethylene diphosphate, etc. can be used.

[0007]

[Examples] The present invention will be explained in detail with reference to Examples below. In this example, the ratio of the 4-position isocyanate group to all isocyanate groups contained in TDI was
(manufactured by Nippon Polyurethane Industries Co., Ltd.) and TDI-100
(manufactured by Nippon Polyurethane Industries Co., Ltd.), various polyurethane foams were produced by varying the mixing ratio, and the adhesive strength of the frame laminate layer of these foams was compared. Here, TDI-80 means TDI with a ratio of 2,4-TDI and 2,6-TDI of 80:20, and TDI-100 means 2,4-TDI.
A TDI consisting only of I is shown. (1) Preparation of test piece 400 g of general-purpose polyol (polyoxypropylene ether polyol with glycerin as an initiator and average molecular weight of 3000), water, and an amine catalyst (product name: DAB
CO 33LV, manufactured by Sankyo Air Products Co., Ltd.), Stanus octoate and surfactant (silicon foam stabilizer, product name:
L-520 (manufactured by Nippon Unicar Co., Ltd.) was added in the proportions shown in Table 1 and stirred. Note that all numerical values regarding each component shown in Table 1 are parts by weight.

[Table 1] Next, to these, 4
TDI having an isocyanate group in position 154, respectively.
g, poured into a foaming box (350 x 350 x 250 mm), and allowed to open and foam. Polyurethane foams 1 to 3 were produced. In addition, in Table 1, TDI-80
and TDI-100 blend ratio (TDI-80/T
DI-100). In addition, in the same table, the ratio of the isocyanate group at the 4th position is "NCO at the 4th position (%)"
is displayed. (2) Performance test ■Physical property test The above test piece No. In order to evaluate the physical properties of polyurethane foams 1 to 3, density (g/cm3), hardness (kg/cm3),
314 cm2) and air permeability (liter/min), and the results are also listed in Table 1. Here, the density is JIS
Hardness was determined according to JIS K6401, and air permeability was determined according to ASTM D1564. ■Flame fusion test The above test piece No. From 1 to 3 polyurethane foam,
Foam pieces (300 mm x 115 mm x 12 mm, foam pieces No. 1 to 3, each corresponding to the test piece No.) were cut out. This piece of foam is then cut to a width of 1
A flame of LP gas adjusted to a length of 10 mm and a height of 70 mm was passed through at a speed of 8 m/min to melt the surface. Immediately after, the fabric was overlaid on the surface and passed through a roll to be crimped. In this case, two cases were conducted: a polyester nonwoven fabric and a polyester knit (15 denier) were used as the fabric. Furthermore, after crimping, the foam piece was immediately cut into pieces of 25 mm in width and 150 mm in length, and the peel strength (g/2
5 mm) was measured over time. Note that this peel strength is J
Measured using IS L1066. The above results are shown in Table 2. In addition, in Table 2, fusion test No. 1, polyester nonwoven fabric was used as the fabric, and fusion test No. 1 was used. 2 shows the case where polyester knit is used as the fabric.

[Table 2] (3) According to the physical property values (density, hardness, and air permeability) in Performance Evaluation Table 1, the products of the present invention (test specimens No. 1 and 2) were the comparative products (test specimen No.
o. It has almost the same performance as 3). On the other hand, according to the flame fusion test shown in Table 2, the product of the present invention (foam piece No. 1 to 2) are far superior in peel strength to the comparative product (foam piece No. 3). In particular, the initial adhesion properties after 2 minutes and 6 minutes were significantly different between the inventive product and the comparative product. Therefore, according to the manufacturing method of this example, even if an inexpensive general-purpose polyether polyol is used without using a special polyol or a special composition containing an organic phosphorus compound, the frame It was possible to manufacture a laminate product with excellent adhesive strength of the laminate layer, especially excellent initial adhesive strength. It should be noted that the present invention is not limited to those shown in the above-mentioned specific embodiments, and may be modified in various ways within the scope of the present invention depending on the purpose and use.

[0008]

[Effects of the Invention] As described above, by specifying the ratio of the 4-position isocyanate group to all isocyanate groups contained in TDI, a special polyol and a special composition containing an organic phosphorus compound can be used. It is possible to produce a polyurethane foam for frame lamination having excellent adhesive strength, especially initial adhesive strength, even if inexpensive general-purpose polyether polyol is used. Further, even in cases where the skin material is difficult to adhere, strong adhesion can be achieved by using TDI as shown in the present invention.

Claims (2)

[Claims] 1. A method for producing polyurethane foam for flame lamination using a polyol and tolylene diisocyanate, wherein the tolylene diisocyanate is at least one of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate. Using 2,4-tolylene diisocyanate, the 2,4
- A method for producing a polyurethane foam for flame lamination, characterized in that the content of isocyanate groups at the 4-position of tolylene diisocyanate is 42 to 50% of the total isocyanate groups. 2. A method for producing a polyurethane foam for flame lamination using a prepolymer obtained by reacting a part of the isocyanate groups of tolylene diisocyanate with a polyol, wherein the tolylene diisocyanate is 2,4 - At least 2,4-tolylene diisocyanate is used among tolylene diisocyanate and 2,6-tolylene diisocyanate, and the content of the isocyanate group at the 4-position of the 2,4-tolylene diisocyanate is 42- to 50%
A method for producing polyurethane foam for frame lamination, characterized by: