SI23803A - Foamed materials based on combinations of polymers derived from renewable natural sources, and amino resins and process for their manufacture - Google Patents

Abstract

The present invention relates to polymer foam materials based on a cross-linked combination of liquefied natural plastic materials from renewable sources that are not used in the food chain of humans and amino resins and the process for their manufacture. The invention particularly relates to a method of making foamed material, wherein a combination of liquefied wood and melamine-formaldehyde resin or modified melamine-formaldehyde resin is used in the foaming emulsion. Foam material, based on a new crosslinked combination of liquefied natural plastic materials from renewable sources not used in the food chain of humans and amino resin, is suitable for use as an insulating material, especially for thermal and / or acoustic insulation.

Description

Foamed materials based on a combination of polymers obtained from renewable sources of natural origin and amino resins and process for their manufacture

The present invention relates to polymer foamed materials based on a cross-linked combination of liquefied polymeric materials from renewable sources of natural origin not used in the human food chain and amino resins and to a process for their manufacture. The invention relates in particular to a process for the production of foam material, wherein a combination of liquefied wood and melamine-formaldehyde resin or modified melamine-formaldehyde resin is used in the foaming emulsion.

The foamed material, based on a novel cross-linked combination of liquefied polymeric materials of natural origin, not used in the human food chain, and amino resins, is suitable for use as insulating material, in particular for thermal and / or sound insulation.

State of the art and technical problem

Today, there are many insulating materials on the market that are foam-based and meet some or most of the requirements for insulation materials. Examples are, for example. foamed polyurethane, foamed polystyrene, phenolic foams, foamed polyolefins or foamed glass.

The problem with some insulation materials is that they do not meet individual requirements for practical use, such as fireproofness, weather resistance, chemical resistance or resistance to biological pests. They are also mostly made on the basis of non-renewable resources, such as oil or natural gas.

There are also many traditional renewable insulation materials that do not meet individual technical and safety requirements. Typically, they are combustible, weatherproof, resistant to various pests and are not completely • suitable for modern construction such as eg. straw, wine saw, various cellulosic materials.

The problem of not meeting the individual requirements of insulating materials is solved by adding various additives to the product, by impregnating e.g. with flame retardants or with external product protection, e.g. with non-combustible lining.

Recently, basic polymer materials based on renewable sources, such as liquefied wood, liquefied lignocellulosic materials and natural polysaccharides, are available. The production of liquefied wood from scrap wood and similar materials such as cellulose, cotton, paper or starch is described e.g. in patent SI 21883.

JP 11029957 discloses the production of a lignocellulosic foamed product from a liquefied lignocellulosic raw material, which is foamed and cured by a foam stabilizer such as polydimethylsiloxane, a catalyst such as pyridine, a foaming agent such as methylene chloride, a polyisocyanate such as toluene similar. JP 6172477 further discloses the production of polyurethane foam, wherein the foam useful as a thermal insulation material is prepared from a liquefied lignocellulosic material by reaction with a polyisocyanate such as phenylene diisocyanate in the presence of a foaming agent such as water.

Patents US 3,085,085, US 3,153,002, US 3,222,357 and US 4,430,490 address the process of manufacturing rigid polyurethane foams, which, however, do not utilize a significant amount of renewable materials that are not used in the food chain.

DE 3 432 381 describes the preparation of a hard or semi-rigid polyurethane foam in which a mixture of polyisocyanate, polyol, filler and foaming agent is foamed, using a powdered waste fluid obtained from wood pulp digestion as a filler.

GB 1443024 relates to hard closed-cell foams, in particular to hard foams based on melamine-formaldehyde resins, optionally containing various inorganic or organic fillers which burn slowly or are highly flammable. Organic fillers include, inter alia, coconut or sisal fibers. However, the purpose of the present invention is not to use renewable resources for the purpose of making hard foam products for use as insulating material, nor are fillers in the form of fibers used.

The purpose of the present invention was therefore to produce a foam material which would be particularly suitable as an insulating material and which would combine the good technical properties of synthetic materials such as polystyrene foams, polyurethane foams, phenolic foams, and foam made from amino resins, such as e.g. from melamine-formaldehyde resins and urea-formaldehyde resins, and mineral fiber insulation such as e.g. glass and stone wool, and would be at least partly made from liquefied polymeric materials from renewable sources not used in the human food chain.

We wanted to use a renewable source of natural origin that is not used in the human food chain as one of the raw materials for the production of environmentally friendly, non-combustible, quality and usable insulation material, while also ensuring sustainable development and competitiveness in the market by using a renewable source as a raw material .

DETAILED DESCRIPTION OF THE INVENTION

We have found that such insulating material can be represented by new foamed materials based on a crosslinked combination of liquefied polymers obtained from renewable sources of natural origin not used in the human food chain and amino resins, preferably based on a crosslinked combination of liquefied wood and melamine formaldehyde resins, or modified melamine-formaldehyde resins.

Such foamed materials can be prepared by a new process of the invention, wherein a combination of raw materials based on the preparation of the foaming emulsion is used

liquefied polymers of natural origin from renewable sources not used in the human food chain and amino resins. The foamed material produced by the process of the invention has suitable properties as insulating material, such as good thermal and sound insulation properties, good sound absorption, non-combustibility, inertness, chemical resistance, UV stability, weather resistance and has a high proportion materials from renewable sources not used in the food chain, which can range up to about 60% by weight % of liquefied wood in the finished product.

The process of making foamed material according to the invention comprises:

a) preparing a foaming emulsion comprising:

0.1-60% by weight of liquefied polymers of natural origin from renewable sources not used in the human food chain, 20-99.9% by weight of amino resin, 0.1-20% by weight of foaming agent, 0.5-10% by weight % surfactant, 0.5-10 wt% hardener, 0-20 wt% emulsion viscosity control component and, optionally, one or more different additives known in the art to achieve the desired properties of the foamed material selected from the group comprising pigments, plasticizers, flame retardants and fillers to achieve specific mechanical properties, followed by

b) thermal curing of the emulsion obtained in step a) at a temperature between 50 ° C and 200 ° C for a period of 2 minutes to 60 minutes to obtain foamed material.

The foamed material obtained can optionally be subsequently heat treated at a temperature of from 50 ° C to 200 ° C to a constant weight in a further step of the process.

For the preparation of the foaming emulsion as a liquefied polymer of natural origin from renewable sources not used in the human food chain, we preferably use liquefied wood. The term liquefied wood as used herein means liquefied wood derived from waste wood or wood waste, lignocellulose containing waste materials or similar materials such as cellulose, cotton, paper or starch. Especially preferred is liquefied wood obtained from accessible sources of wood - waste wood or wood waste.

According to the invention, e.g. liquefied wood up to 50% wood content, with a height in the range of 100 mPas to 15000 mPas.

A non-limiting example is e.g. use of liquefied wood obtained by the method described in patent SI 21883. Modified liquid wood could also be used, e.g. esterified (plasticizer).

Urea-formaldehyde resins, melamine-formaldehyde resins, or modified melamine-formaldehyde resins are particularly suitable as amino resins.

By the term melamine-formaldehyde resin or modified melamine-formaldehyde resin as used herein, we mean a resin having a melamine: formaldehyde ratio of 1: 1.5 to 1: 4.0, which, in the case of a modified resin, may be modified by amines, amides, starches , sugars, acrylates, aliphatic and aromatic glycols, Na-bisulfite, aliphatic and aromatic polyols or alcohols. Preferred modified resin is Na-bisulfite modified melamine formaldehyde resin in a molar ratio of melamine: Na-bisulfite from 1: 0.05 to 1: 0.5. The resins used may have a concentration of 50% to 100% of the melamine-formaldehyde component or modified melamine-formaldehyde component.

Particularly preferred according to the invention is the use of melamine-formaldehyde resins with a melamine: formaldehyde ratio of 1: 1.7 to 1: 3.5 and a concentration of at least 60%.

In non-limiting cases, Meldur® MP is a melamine-formaldehyde resin having a melamine: formaldehyde ratio of 1: 1.7 to 1: 3.5, with a concentration of 60% to 80% and a viscosity of 100 mPas to 15000 mPas, partially soluble in water, and said Meldur® MPS is a modified Na-bisulfite modified melamine-formaldehyde resin with a molar ratio of melamine; Na-bisulfite from 1: 0.2 to 1: 2.0, with a concentration of 60% to 80% and a viscosity of 100 mPas to 15000 mPas, partially or completely soluble in water.

Water-miscible organic solvents such as aliphatic and cyclic alkanes, in particular aliphatic alkanes such as pentane and hexane, in particular n-pentane and n-hexane, may be used as the foaming agent.

Surfactants may be used to prepare the emulsion, which may be anionic, cationic or neutral, in particular anionic surfactants such as sodium salts of alkyl sulfates and sulfonates. The surfactant used may be selected from the group consisting of e.g. sodium lauryl sulfate (SLS, sodium lauryl sulfate) and sodium lauryl ether sulfate (SLES, sodium lauryl ether sulfate).

Organic and inorganic acids or their salts with organic and inorganic bases can be used as a hardener. A non-limiting example of suitable organic acid is formic acid, in particular concentrated formic acid.

As solvent component for emulsion viscosity, solvent poles are suitable, water is preferred.

The degree of thermal curing of the emulsion prepared in step a) of the process is carried out at 50 ° C and 200 ° C. Temperature can be achieved through various modes of heat transfer such as convection, conduction, IR radiation, high frequency heating or microwave heating, or any combination of flying. The curing time is from 2 minutes to 60 minutes and depends on the heating rate, the set temperature, the amount of material, the thickness of the material and the mode of heat transfer.

Optionally, the foam material resulting from the thermal curing step can be subsequently heat treated (cured) at temperatures from 50 ° C to 200 ° C to constant weight.

In a preferred embodiment of the invention, the process of making foamed material comprises:

a) preparing a foaming emulsion comprising:

0.1-60% by weight of liquefied wood, 20-99.9% by weight of melamine-formaldehyde resin or modified melamine-formaldehyde resin, 0.1-20% by weight of foaming agent, 0.5-10% by weight of surfactant, 0.5 -10 wt% hardener and 0-20 wt% emulsion viscosity control component, followed by

b) thermal curing of the emulsion obtained in step a) at a temperature between 50 ° C and 200 ° C for a period of 2 minutes to 60 minutes to obtain foamed material.

The foamed material obtained can optionally be subsequently heat treated at a temperature of from 50 ° C to 200 ° C to a constant weight in a further step of the process.

The process of the invention may be continuous or batch-wise.

The foamed material of the invention is made on the basis of a new crosslinked foaming emulsion, which may comprise a combination of liquefied wood and melamine-formaldehyde resin by weight of liquefied wood: melamine-formaldehyde resin in the range of 0.1: 99.9 to 60: 40. Instead of melamine-formaldehyde resin modified melamine-formaldehyde resin may also be used.

In a particularly preferred embodiment of the invention, the foamed material is made on the basis of a crosslinked foaming emulsion comprising 0.1-60% by weight of liquefied wood, 20-99.9% by weight of melamine-formaldehyde resin or modified melamine-formaldehyde resin, 0.1-20% by weight % foaming agent, preferably n-pentane,

0.5-10% by weight of the surfactant, preferably sodium lauryl ether sulfate, 0.5-10% by weight of hardener, preferably formic acid, 0-20% by weight of the emulsion viscosity control component, preferably water and, optionally, one or several different additives known in the art to achieve the desired foam material properties. Such additives are, for example, pigments, plasticizers, flame retardants, fillers to achieve specific mechanical properties.

The foamed material obtained by the process of the present invention may have a density in the range of about 2 kg / m ³ to about 150 kg / m ³ , a compressive strength in the range of 0 kPa to 2000 kPa, as measured according to EN 826, and a thermal conductivity from 0,025 to 0,05 W / mK, as measured according to EN 12667.

The properties determined depend on the type and ratio of the ingredients used, the method of preparation of the emulsion and the type of heat transfer during the foaming and curing process.

The process of the invention allows one to control the morphology of the finished product - the foamed material. Upon completion of the process, an inert organic material is obtained which does not subsequently release volatiles from the material. The process can produce both flexible (soft) and rigid (hard) foams.

The foamed material of the invention is useful as an insulating material for thermal and acoustic insulation, especially where chemical inertia, temperature resistance, weather resistance, flame retardability, vapor permeability and good sound absorption of the material are required. It can be produced in the form of e.g. blocks, e.g. insulating panels, which may be further used as such or transformed into the desired or required shape. The foaming emulsion can also be cured in the molding process in an arbitrarily shaped mold of a predetermined shape.

According to a preferred embodiment of the invention, rigid foams having suitable properties for use as insulating material, e.g. strength, thermal conductivity, especially for sound and / or thermal insulation

The examples below are intended merely to illustrate the invention and are in no way intended to limit in any way the scope of the present invention.

Unless otherwise stated, the percentages given in the description refer to weight%.

Implementation examples

Example 1

Prepare an emulsion of 4.3% by weight of liquefied wood, 5.7% by weight of Meldur® MP, 0.4% by weight of SLES, 0.3% by weight of concentrated formic acid, 0.13% by weight of n-pentane.

The ingredients were stirred for 3 minutes to give a homogeneous emulsion. The emulsion is then poured into a Teflon-lined model and cured for 30 minutes at 135 ° C by conduction heat transfer. The foam is then finalized at 50 ° C to constant weight. The foam thus obtained has a density of 110 kg / m ³ , a compressive strength of 125 kPa.

Example 2

Prepare an emulsion of 2.5% by weight of liquefied wood, 7.5% by weight of Meldur® MP, 0.4% by weight of SLES, 0.3% by weight of concentrated formic acid, 0.15% by weight of n-pentane.

The ingredients were stirred for 3 minutes to give a homogeneous emulsion. The emulsion is then poured into a Teflon-lined model and cured for 30 minutes at 135 ° C by conduction heat transfer. The foam is then finalized at 50 ° C to constant weight. The foam thus obtained has a density of 90 kg / m ³ and a compressive strength of 105 kPa.

Example 3

Prepare an emulsion of 1.25 parts by weight of liquefied wood, 8.75 parts by weight of Meldur® MP, 0.4 parts by weight of SLES, 0.3 parts by weight of concentrated formic acid, 0.17 parts by weight of n-pentane.

The ingredients were stirred for 3 minutes to give a homogeneous emulsion. The emulsion is then poured into a Teflon-coated model and cured for 30 minutes at 135 ° C by conduction heat transfer. The foam is then finalized at 50 ° C to constant weight. The foam thus obtained has a density of 75 kg / m ³ and a compressive strength of 260 kPa.

Example 4

Prepare an emulsion of 0.1% by weight of liquefied wood, 9.9% by weight of Meldui® MP, 0.4% by weight of SLES, 0.3% by weight of concentrated formic acid, 0.16% by weight of n-pentane.

The ingredients were stirred for 3 minutes to give a homogeneous emulsion. The emulsion is then poured into a Teflon-lined model and allowed to heat for 30 minutes at 135 ° C by conduction heat transfer. The foam is then finalized at 50 ° C to constant weight. The foam thus obtained has a density of 75 kg / m ³ and a compressive strength of 315 kPa.

Example 5

The process of preparing the emulsion for the foam proceeds as in Example 4, except that 0.2 weight percent n-pentane is added in the preparation of the emulsion. The foam thus obtained has a density of 60 kg / m ³ and a compressive strength of 250 kPa.

Example 6

Prepare an emulsion of 0.1% by weight of liquefied wood 9.9% by weight of Meldur® MP, 0.5% by weight of SLES, 0.25% by weight of concentrated formic acid, 0.8% by weight of n-pentane.

The ingredients were stirred for 3 minutes to give a homogeneous emulsion. Then the emulsion is poured into a model lined with Teflon foil and cured with a microwave heat transfer mode for 10 minutes. The foam is then finalized at 50 ° C to constant weight. The foam thus obtained is flexible and has a density of 5 kg / m ³ .

Example 7

The process of preparing the foaming emulsion is as in Example 6, except that when preparing the foaming emulsion, 9.9 parts by weight of Meldur® MPS and 0.4 parts by weight of concentrated formic acid are added as melamine-formaldehyde component. The foam thus obtained is flexible and has a density of 3 kg / m ³ .

Claims (23)

Patent claims A process for the manufacture of foamed materials, characterized in that it comprises: a) preparing a foaming emulsion comprising: 0.1-60% by weight of liquefied polymers of natural origin from renewable sources not used in the human food chain, 20-99.9% by weight of amino resin, 0.1-20% by weight of foaming agent, 0.5-10% by weight % surfactant, 0.5-10 wt% hardener, 0-20 wt% emulsion viscosity control component, followed by b) thermal curing of the emulsion obtained in step a) at a temperature between 50 ° C and 200 ° C for a period of 2 minutes to 60 minutes to obtain foamed material. Method according to claim 1, characterized in that the preparation of the foaming emulsion in step a) of the process as a liquefied polymer of natural origin from renewable sources not used in the human food chain, uses liquefied wood derived from waste wood or wood waste, lignocellulose-containing waste or similar materials such as cellulose, cotton, paper or starch. Process according to claim 1 or 2, characterized in that the liquefied polymer of natural origin from renewable sources is liquefied wood obtained from waste wood or wood waste. Process according to any one of claims 1 to 3, characterized in that the liquefied wood is liquefied wood with a wood content up to 50% and a viscosity in the range of 100 mPas to 15000 mPas. Process according to any one of claims 1 to 4, characterized in that urea-formaldehyde resin, melamine-formaldehyde resin or modified melamine-formaldehyde resin is used as the amino resin to prepare the foaming emulsion in step a) of the process. Process according to any one of claims 1 to 5, characterized in that the amino resin is a melamine-formaldehyde resin or a modified melamine-formaldehyde resin with a melamine: formaldehyde ratio of 1: 1.5 to 1: 4.0. Process according to any one of claims 1 to 6, characterized in that the amino resin is a melamine-formaldehyde resin or a modified melamine-formaldehyde resin with a melamine: formaldehyde ratio of 1: 1.7 to 1: 3.5 and a concentration of at least 60% . A method of manufacturing foamed material according to any one of claims 1 to 7, characterized in that it comprises: a) preparing a foaming emulsion comprising: 0.1-60% by weight of liquefied wood, 20-99.9% by weight of melamine-formaldehyde resin or modified melamine-formaldehyde resin, 0.1-20% by weight of foaming agent, 0.5-10% by weight of surfactant, 0.5 -10 wt% hardener, 0-20 wt% emulsion viscosity control component, followed by b) thermalising the emulsion obtained in step a) at a temperature between 50 ° C and 200 ° C for a period of 2 minutes to 60 minutes to obtain foamed material. A method according to any one of claims 1 to 8, characterized in that in step a) of the process, the foaming emulsion further comprises one or more additives selected from the group comprising pigments, plasticizers, flame retardants and fillers to achieve specific mechanical properties. • · · A method according to any one of claims 1 to 9, characterized in that the temperature in the stage of thermal hardening of the emulsion prepared in step a) of the process is achieved by convection, conduction, IR radiation, high frequency heating or microwave heating or any a combination of these. Process according to any one of claims 1 to 10, characterized in that it is continuous or batch-wise. A method according to any one of claims 1 to 11, characterized in that the foamed material obtained is further heat treated at a temperature from 50 ° C to 200 ° C to a constant weight in the further process step. Method according to any one of claims 1 to 12, characterized in that the process prepares foamed material for use as insulating material, preferably for sound and / or thermal insulation. Foamed material, prepared by the process according to any one of claims 1 to 11, having a density in the range of about 2 kg / m ³ to about 150 kg / m ³ , a compressive strength in the range of 0 kPa up to 2000 kPa as measured according to EN 826 and thermal conductivity from 0.025 to 0.05 W / mK as measured according to EN 12667. 15. Foamed material, prepared on the basis of a cross-linked combination of liquefied polymers of natural origin from renewable sources not used in the human food chain and amino resins. Foamed material according to claim 15, characterized in that the liquefied polymer is of natural origin from renewable sources not used in the human food chain, liquefied wood obtained from waste wood or wood waste, waste materials containing lignocellulose, or similar materials such as cellulose, cotton, paper or starch. • « Foamed material according to claim 16, characterized in that the liquefied wood is obtained from waste wood or wood waste. Foamed material according to any one of claims 15 to 17, characterized in that the amino resins are urea-formaldehyde resins or melamine-formaldehyde resins or modified melamine-formaldehyde resins. Foamed material according to any one of claims 16 to 18, characterized in that it is made on the basis of a crosslinked foaming emulsion comprising a combination of liquefied wood and melamine-formaldehyde resin or modified melamine-formaldehyde resin by weight of liquefied wood: melamine -formaldehyde resin or modified melamine-formaldehyde resin in the range of 0.1: 99.9 to 60: 40. Foamed material according to any one of claims 18 to 19, characterized in that it is made on the basis of a crosslinked foaming emulsion comprising 0.1-60% by weight of liquefied wood, 20-99.9% by weight of melamine-formaldehyde resin or modified melamine-formaldehyde resin, 0.1-20% by weight of n-pentane, 0.5-10% by weight of sodium lauryl ether sulfate, 0.5-10% by weight of formic acid and 0-20% by weight of water. 21. Foamed material according to any one of claims 19 to 20, characterized in that it has a density in the range of from about 2 kg / m ³ to about 150 kg / m ³ , a compressive strength in the range from 0 kPa to 2000 kPa, as measured according to EN 826, and thermal conductivity from 0,025 to 0,05 W / mK as measured according to ENI2667. Foamed material according to any one of claims 19 to 21, characterized in that it is flexible or rigid foam. Foamed material according to any one of claims 20 to 22, characterized in that it is a rigid foam suitable for use as insulating material for sound and / or thermal insulation.