JPS6279217A - Production of shock-absorbing foam - Google Patents

Abstract

PURPOSE:To obtain the titled light-weight foam having sound-absorbing property as well as vibration-damping property and having excellent heat-resistance, by using a specific polyether polyol as a polyol component and using specific amounts of a plasticizer and a tackifier soluble in the polyol component. CONSTITUTION:The objective foam can be produced by compounding (A) a mixed polyol composed of (i) >=10wt% poly(oxyalkylene)diol having an average molecular weight of 1,000-3,000 and (ii) a poly(oxyalkylene)triol having an average molecular weight of 2,000-6,000 with (B) 25-200pts.(wt.) (based on 100pts. of the component A) of a tackifier soluble in the component A, (C) 0.25-2pts. (based on 1pt. of the component B) of a plasticizer (e.g. phthalic acid ester), (D) an organic isocyanate, (E) a foaming agent, (F) a catalyst and (G) a foam stabilizer and reacting and foaming the mixture e.g. by one-shot process.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention is applicable to "transport vehicles" such as automobiles, trains, and airplanes.
This article relates to a method of manufacturing @shock absorbing 7 ohm material, which is used as a soundproofing material to reduce noise accompanied by vibrations in factories, machinery, houses, etc.

(Prior art) Flexible polyurethane foam is widely used as a porous sound-absorbing material because it has continuous cell manufacturing, but it has low damping performance and is not suitable as a sound-insulating material for noise generated with vibration noise. Therefore, in order to improve the damping performance (adding filler or asphalt to increase the density), it increased the cost and imitated the deterioration of the physical properties of the 7-ohm itself. Because asphalt contamination occurs during processing and machining, it is difficult to put into practical use.

On the other hand, rubber-like sheets with a large mass, which are made by adding fillers to various rubber-like substances or thermoplastic resins, are used as damping materials, but these have the major disadvantages of being heavy, expensive, and lacking in sound-absorbing properties. I was disappointed. Therefore, in order to solve these problems, a flexible polyurethane foam with sound absorption performance t-'N (= in order to give good vibration distribution performance, various types of polyols, foam stabilizers, polyisocyanates, and other raw materials used should be selected) A flexible polyurethane foam has been developed that has not only sound absorption performance but also vibration damping performance.

(Problems to be Solved by the Invention) A flexible polyurethane foam that has both sound absorption and vibration damping properties was obtained by selecting the raw materials used, but the physical properties of polymers change with temperature changes, Shock absorption of 7 ohms is no exception; mechanical strength such as elongation and tensile strength decreases as the temperature rises, causing inconveniences in molding methods such as thermocompression molding. This invention had the disadvantage of causing a decrease in absorption performance.This invention was developed in consideration of these points, and was developed to create a shock absorbing material that has a small decrease in physical properties of 7 ohm even at high temperatures and can withstand thermal compression molding. The purpose is to obtain a resistance of 7 ohms.

(Means for solving the problem) In other words, this invention uses polyol, organic isocyanate,
1: For the complete production of flexible polyurethane foam from blowing agents, catalysts, foam stabilizers, etc.

(1) The average molecular weight as a polyol is 100 to 300
0 poly(oxyalkylene) diol and a poly(oxyalkylene) triol having an average molecular weight of 2,000 to 6,000, and a polyether polyol in which the diol accounts for 10% by weight or more based on the total polyol.

(2) Add a tackifier that dissolves in polyol to polyol 1
001: 25 to 200 weights are used.

('!I) Plasticizer'f: Tackifier 1 (025 for 2
A method for manufacturing a shock-absorbing 7 ohm, characterized in that: -2 is used.

Polyol is an important element in determining the heat resistance of polymers, and the polyol is said to have heat resistance that allows the elongation rate, which is an important physical property for Samurai, to maintain 100% or more even at 80 degrees Celsius. We have found that this can be achieved with a composition.

Poly(oxyalkylene diol) is a compound with an average molecular weight of 1,000 to 3,000, which is produced by adding ethylene oxide, propylene oxide, etc. alone or in random or block form to two active hydrogen-containing compounds. Examples of the active hydrogen-containing compound include water, ethylene glycol, propylene glycol, ethylene glycol, hexylene glycol, and the like.

Poly(oxyalkylene) triols contain three active hydrogen-containing compounds: ethylene oxide, propylene oxide,
It is a compound with an average molecular weight of 2,000 to 6,000, which can be produced singly or in the form of a block addition of petite/oxide, etc. Examples of the three active hydrogen-containing compounds include glycerin and trimethylolpropane.

The tackifier imparts tackiness to the resulting foam, slowing down recovery from 7 ohm compression, shrinkage, and providing 7 ohm splitting performance. In this invention, it is essential that the tackifier be soluble in the polyol. If undissolved, phase separation may occur during tank storage of mixed raw materials, product quality may become uneven, the foaming state may become unstable, and the viscosity of the foaming stock solution may increase, resulting in production problems. It is unfavorable in terms of quality. Tackifier is polyol 100
It is added in an amount of 25 to 200 parts by weight.

If the amount added is small, the adhesiveness of the foam will be insufficient, the recovery time after compression will be short, and no distribution effect can be expected. As the amount added increases.

The viscosity of the system increases, making one-shot foaming difficult and foaming stability unstable, so about 200 parts by weight is the practical limit.

As a tackifier that can be used in this invention, high-grade hydrocarbon resin 11PTR-6100 (Mitsui Petrochemical Co., Ltd.,
Ester Gum H (Arayo Kagaku Kogyo), which is a hydrogenated rosin ester, is available, but it is not limited thereto as long as it is soluble in polyol. Even if they have a tackifying effect, they have poor solubility in polyols, such as the synthetic polyterpene resin Finton (Mitsui Petrochemical Industries) and the aliphatic cyclic hydrocarbon resin 7-Iretsutsu (Mitsui Petrochemical Industries). , liquid polybutadiene, polybutene, etc., or those with a strong odor, such as asphalt, coumaron resin, aromatic hydrocarbon resin Vetrozin (Mitsui Petrochemical Industries)
etc. are not desirable.

The plasticizer is added in an amount of 0.25 to 2.0 to 1 of the glaze layer imparting agent. If the blending ratio of the plasticizer is too high, the foam itself will become sticky, causing problems with contamination during processing, and the recovery time of the foam after compression will be short, making it impossible to expect an allocation effect. An increase in the amount of plasticizer causes a decrease in the flame retardancy and heat resistance of the foam, so the smaller the amount, the better. However, in order to impart tackiness to the glaze layer imparting agent, it is necessary to use a plasticizer in combination, and t''Lfc is determined from overall viewpoints such as vibration stability and foam stability.

If the amount added is too small, the adhesiveness will be insufficient, the recovery time after compression will be short, and no distribution effect can be expected.

In addition, the elongation of the foam becomes small and it cannot withstand hot compression molding.

Examples of plasticizers that can be used include esters such as phthalate esters and phosphate esters such as tricresyl phosphate. trischloroethyl phosphate,
Halogenated phosphate esters such as tris dichloropropyl phosphate have poor solubility and cannot be used.

The organic isocyanate is generally used for flexible polyurethane foam, and includes 2.4 isomer, 2.6 isomer and mixtures thereof of tolylene diisocyanate.

As the blowing agent, water, low-boiling halogenated hydrocarbons such as Freon-11 and methylene chloride can be used alone or in combination, and other catalyst additives are those generally used for flexible urethane foams.

(Examples and Comparative Examples) Raw material formulations shown in Table 1; Foamed by two-way one-shot method to leave flexible polyurethane foam, density 1 of elasticity, hysteresis loss, elongation
25℃ and 80℃), the recovery time after compression was measured and Table 1-
The results shown in 1 were obtained.

(Effects of the Invention) According to this invention, it is possible to obtain a shock absorption of 7 ohms made of a lightweight flexible polyurethane foam that has both sound absorption and vibration distribution properties, and has excellent heat resistance (excellent), with little decrease in strength and physical properties even at high temperatures. Since it can be thermoformed, combination processing with other materials is also possible, and soundproofing materials of various shapes can be obtained, expanding the range of uses and reducing costs.

The Ya M H imparting agent is polyol-soluble, so the conventional one-shot method can be applied as is, and there is no change in the manufacturing process, so it is economical, and the amount of the viscosity M imparting agent itself is also comparable. Since the allocation performance can be obtained with less target, the cost of the form is also reduced.

Claims (1)

[Claims] When producing flexible polyurethane foam from polyols, organic isocyanates, blowing agents, catalysts, foam stabilizers, etc., (1) polyols with an average molecular weight of 1000 to 300;
0 poly(oxyalkylene) diol and an average molecular weight of 2000 to 6000 poly(oxyalkylene) triol, using a polyether polyol in which the diol is 10% by weight or more based on the total polyol, (2) Add a tackifier that dissolves in polyol to polyol 1
(3) 0.25 to 200 parts by weight of plasticizer to 1 part of tackifier.