JPH0453891B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention uses a foam sheet as a base material, which maintains its characteristic elasticity to an appropriate level and has excellent sound absorption, sound insulation, and heat insulation properties. The present invention relates to a method for manufacturing a composite sheet.

[Technical background of the invention]

An example of a composite sheet based on a foam sheet is a urethane foam with open cells impregnated with molten asphalt or asphalt emulsion to impart water repellency and slow restoring force, and can be used as a joint material, etc. It has been widely used in the past (hereinafter, a product with the water repellency of asphalt and the resilience of foam will be referred to as asphalt foam).

In addition to the asphalt foam mentioned above,
Asphalt foam is known, which is formed by adding and mixing a urethane prepolymer obtained by reacting a polyether polyol with an ethylene oxide content of 15% or more with an organic isocyanate to an aqueous asphalt emulsion, and then foaming the mixture. This manufacturing method was proposed in Japanese Patent Application No. 57-125373 by the applicant of the present application, and unlike the above-mentioned impregnation method, the asphalt particles are uniformly dispersed throughout, resulting in uniform quality. Since it is composed of a foam base, it has the excellent feature that the asphalt does not separate from the foam base and cause quality deterioration.

Furthermore, the applicant aims to make effective use of the asphalt foam processing waste and defective products proposed above, by impregnating open-cell urethane foam with a recycled solution obtained by melting these defective products.
We have previously proposed a method for remanufacturing asphalt foam. The properties of the asphalt foam thus obtained are similar to those produced by the impregnation method described at the beginning. However, since the impregnated melt contains a urethane component in addition to asphalt, it has good affinity for the urethane foam, and the asphalt component separates and seeps out relatively little.

[Problems with background technology]

It has become clear that all of the above-mentioned asphalt foams not only have properties suitable for joint materials, but also have excellent sound absorbing and sound insulating properties, as well as earthquake proofing properties. Therefore, in recent years, floor materials for automobiles, etc.
It is effectively used in applications that take advantage of its sound and earthquake insulation properties.

However, when the amount of asphalt component is increased in order to increase the sound absorption and sound insulation properties, there is a problem in that the elasticity is significantly reduced. Further, it is difficult to control the viscosity of the impregnating solution, and especially when a large amount of asphalt is desired to be impregnated, the viscosity becomes high, making it difficult to uniformly impregnate the solution, resulting in uneven impregnation.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and provides a method for manufacturing a composite material that can uniformly impregnate an asphalt component into a foam base material and impart appropriate elasticity to the product. It is something to do.

[Summary of the invention]

The method for producing a composite material according to the present invention is to add and mix a urethane prepolymer produced by a reaction between a polyether polyol having an ethylene oxide content of 15% or more and an organic isocyanate into an aqueous emulsion of asphalt, and then foam the composite material. A step of preparing a regenerated solution of asphalt foam by adding an inorganic carbonate to the asphalt foam and heating and dissolving the same; and a step of adding polyurethane foam to a solvent containing an amine-based catalyst and/or a tin-based catalyst. , a step of preparing a urethane foam regeneration solution by heating, stirring and dissolving; the urethane foam regeneration solution;
The method is characterized by comprising the steps of impregnating an appropriate amount of a mixed solution of the asphalt foam regenerating solution and heavy oil into a foam sheet having open cells, impregnating it with an organic isocyanate, and heating and curing it.

Another production method of the present invention is the above production method, in which the organic isocyanate is mixed together with the asphalt foam regeneration solution, urethane foam regeneration solution, and heavy oil and impregnated at the same time, without separately impregnating the organic isocyanate afterwards.

When the manufacturing method according to the present invention is compared with the method previously proposed by the applicant in which only an asphalt foam regeneration solution is impregnated, the difference is that the urethane foam regeneration solution and heavy oil are mixed and impregnated. The details of the present invention will be explained below.

In the present invention, the step of preparing a regenerating solution of asphalt foam is carried out by the applicant in the patent application filed in
The method previously proposed as No. 200668 is used. In this method, inorganic carbonates such as calcium carbonate, sodium carbonate, magnesium carbonate, barium carbonate, etc. are added and heated together, and the addition ratio is 0.5 to 20 parts by weight of carbonate per 100 parts by weight of asphalt foam. . By adding these inorganic carbonates, the heating time required for melting the asphalt foam can be reduced to about half.

In the present invention, the method previously proposed by the applicant (Japanese Patent Application No. 59-176190, etc.) is also used in the step of preparing the urethane foam regeneration solution. In this case, as a solution for dissolving the urethane foam, for example, a polyhydroxy compound or a phosphoric acid ester plasticizer can be used. Tin chloride, tin hydroxide, tin oxide, tin metal, etc. are added as a catalyst to these solvents, and urethane foam is added thereto and heated to dissolve, thereby cutting the polyurethane linkage and allowing another polymerization reaction and A regeneration solution is obtained which has the ability to carry out a foaming reaction.
In the present invention, this urethane foam regeneration solution is mixed with the asphalt foam regeneration solution in order to impart appropriate elasticity to the final product. The mixing ratio is preferably 20 to 200 parts by weight per 100 parts by weight of the asphalt foam regeneration solution.

The reason why heavy oil is mixed into the asphalt foam regeneration solution in the present invention is to adjust the viscosity of the impregnation solution. The mixing ratio thereof is preferably 15 to 75 parts by weight per 100 parts by weight of the asphalt foam regenerating solution.

As the organic isocyanate used in the present invention,
It may be a single isocyanate such as 4,4-diphenylmethane diisocyanate or tolylene diisocyanate, or it may be a urethane prepolymer having a terminal NCO group.

As the foam sheet having open cells used in the present invention, a urethane foam sheet is most suitable, but any foam sheet other than urethane foam may be used as long as it is an open cell foam. Further, the thickness may be arbitrary, but generally 5 mm to 30 mm is used.

In carrying out the present invention, the above-mentioned asphalt foam regeneration solution, urethane foam regeneration solution, and heavy oil are mixed, and the above-mentioned open-cell foam sheet is impregnated with this mixed liquid. At that time, the viscosity is low because heavy oil is added to the impregnation solution.
Can be impregnated uniformly and easily. As the impregnation method, a dipping method using a bathtub, a spray method, a transfer method, etc. can be used. At that time, add 50% of the mixed impregnating liquid.
If heated to about 150°C to 150°C, the viscosity will further decrease significantly, making it easier to impregnate. Since heating for adjusting the viscosity is easy, a method using a transfer method or a dipping method is particularly preferable. After impregnating the mixed solution in this way, the organic isocyanate is impregnated and heated, and the organic isocyanate reacts with the components contained in the asphalt foam regeneration solution and the urethane foam regeneration solution, and polymerizes and hardens to form the desired composite. wood is obtained.

The composite material manufactured in this manner has excellent sound absorption and sound insulation properties similar to conventional asphalt foam, and also has excellent water-stopping properties. Furthermore, appropriate elasticity is imparted through the polymerization reaction of organic isocyanate.

[Embodiments of the invention]

Examples of the present invention will be described below.

(1) First, punching waste formed when asphalt foam was punched was cut into pieces using a crusher, and 200 g of the pieces were weighed into a stainless steel container.
Add to this 20g of calcium carbonate and 100 asphalt.
When the mixture was heated and stirred at 220° C., the asphalt foam melted into a liquid state. Subsequently, while maintaining the temperature at 220° C., small pieces of asphalt foam were added little by little, and a total of 1000 g of asphalt foam was dissolved without any problem, thereby obtaining an asphalt foam regenerating solution.

(2) Separately from the above, weigh 700 g of a trifunctional polyether polyol with a molecular weight of 3000, 15 g of dibutyltin dilaurate, and a total of 5 g of a cationic surfactant and a quaternary ammonium salt and place them in a stainless steel container. Mixed. Subsequently, while heating this solution using a heater, 1000 g of soft polyurethane foam strips were added little by little and dissolved therein. The final temperature is
It was 200℃.

The polyurethane foam regeneration solution thus obtained was a highly viscous liquid at room temperature.

(3) To 100 parts by weight of the asphalt foam regenerating solution prepared as above, add 30 parts by weight of the polyurethane foam regenerating solution and
The mixture was stirred and mixed at ℃. Subsequently, heavy oil was added at a ratio of 40 parts by weight to 100 parts by weight of the asphalt foam regeneration solution and stirred to obtain a mixed solution.

Next, this mixed solution was heated to 80°C, and a 10 mm thick flexible polyurethane foam sheet was immersed in it to impregnate it with the mixed solution.The amount of the mixed solution impregnated was then reduced by passing it through a squeezing roll. The amount was adjusted to 700 parts by weight based on 100 parts by weight of the polyurethane foam. Thereafter, 4,4'-diphenylmethane diisocyanate was sprayed onto the surface, impregnated with a pressure roll, and introduced into an oven, followed by heating and curing at 120 DEG C. for 7 minutes to produce a composite material.

The composite material thus obtained had excellent sound absorbing and sound insulating properties, as well as moderate elasticity.

〔Effect of the invention〕

As detailed above, according to the present invention, it is possible to produce a composite material in which the asphalt component is uniformly impregnated into the foam base material, and it is also possible to impart appropriate elasticity to the product. It is possible to obtain the following effects.

Claims (1)

[Claims] 1. Asphalt foam obtained by adding and mixing a urethane prepolymer produced by the reaction of a polyether polyol having an ethylene oxide content of 15% or more with an organic isocyanate into an aqueous asphalt emulsion and foaming the mixture. A step of preparing a regenerated solution of asphalt foam by adding an inorganic carbonate to the mixture and heating and dissolving the same, and adding polyurethane foam into a solvent containing an amine-based catalyst and/or a tin-based catalyst;
A step of preparing a urethane foam regeneration solution by heating, stirring and dissolving it, and impregnating an appropriate amount of the mixture of the urethane foam regeneration solution, the asphalt foam regeneration solution and heavy oil into a foam sheet having open cells, 1. A method for producing a composite material, comprising the steps of impregnating the material with an organic isocyanate, heating and curing the material. 2 Adding an inorganic carbonate to an asphalt foam obtained by adding and mixing a urethane prepolymer produced by a reaction between a polyether polyol with an ethylene oxide content of 15% or more and an organic isocyanate into an aqueous asphalt emulsion and foaming the mixture. preparing a regenerated solution of asphalt foam by heating and dissolving the asphalt foam together;
A step of preparing a urethane foam regeneration solution by dissolving it by heating and stirring, and impregnating an appropriate amount of a mixture of the urethane foam regeneration solution, the asphalt foam regeneration solution, heavy oil, and organic isocyanate into a foam sheet having open cells. After letting
A method for producing a composite material, comprising the steps of heating and curing.