TWI419906B - Biomass material having multi isocyanate groups and method for manufacturing the same - Google Patents

Description

Polyisocyanate based biomass material and method of forming same

The present invention relates to a polyisocyanate-based biomaterial, and more particularly to a method and application thereof.

Polyurethane (hereinafter referred to as PU) foam is an important material for people's livelihood or industry, and is widely used in transportation, sports equipment, furniture, packaging, fabrics, and insulation materials industries. The annual production of PU foam in North America, Europe, Japan and other places is more than 2.3 million tons, and the global annual growth rate is 2-3%. Taiwan's foam factory produces nearly 100,000 tons per year. The competition is fierce and new technologies are needed to upgrade the quality of foam and develop high value-added products.

With the development of PU industry and the changing times, modern foam products have developed various technologies such as selecting new foaming agents, developing yellowing/stable additives, forced foaming cooling technology, variable pressure foaming technology, carbon dioxide system, and two different Isophorone diisocyanate (IPDI) is a PU foam material and process. The current research focus is more environmentally friendly (the choice of halogen-free materials), non-yellow changes, and high quality.

The structure of a diisocyanate such as isophorone diisocyanate (IPDI) or hexamethylene diisocyanate (HDI) does not contain an aromatic ring, and is less prone to yellowing and the like. It has been applied to foaming fabrics such as underwear, sanitary equipment, transportation equipment, sports equipment, and cushioning materials. The global output value is about NT$3 to 3.5 billion.

At present, the commercially available foam prepolymers are all bifunctional linear molecules, which cannot form a three-dimensional three-dimensional structure by themselves, and an additional cross-linking agent is required to achieve a three-dimensional cross-linking hardening effect. In addition, in order to meet the environmental protection needs, many countries have enacted regulations to encourage manufacturers to apply raw materials to various petrochemical products. Taking lignin as an example, its structure has a large amount of hydroxyl groups and can be used as a prepolymer in a foam formulation. However, the hydroxyl group on the alkyl group in lignin is much less reactive than the hydroxyl group on the benzene ring, and the result of uneven reaction will greatly reduce the physical properties of the product. Therefore, how to make the reactivity of hydroxyl groups at different substitution positions in lignin consistent is a problem that needs to be overcome in the art.

The present invention provides a method for forming a polyisocyanate-based green material, comprising formulating a diisocyanate solution; and dissolving a raw material having a plurality of hydroxyl groups, adding a diisocyanate solution, and reacting a hydroxyl group of the green material to form an isocyanate group; Among them, the diisocyanate includes an aliphatic diisocyanate, an aromatic diisocyanate, or a combination thereof.

The present invention also provides a polyisocyanate-based green material in which each isocyanate group is formed by reacting a hydroxyl group of a raw material with a diisocyanate, and the diisocyanate includes an aliphatic diisocyanate, an aromatic diisocyanate, or a combination thereof.

The present invention provides a method of forming a polyisocyanate based biomass material. First, a diisocyanate solution is prepared, and a solution of a raw material having a plurality of hydroxyl groups is added to the diisocyanate solution to react the hydroxyl groups of the raw material to form an isocyanate-based prepolymer. Taking the most common raw material lignin as an example, the above reaction is represented by Formula 1, and the above diisocyanate may be an aliphatic diisocyanate or an aromatic diisocyanate.

In Formula 1, one monomeric lignin (Ligin) contains different aliphatic and aromatic hydroxyl groups. The molecular weight of lignin is known by molecular weight identification and titration, and several monomers and hydroxyl groups are derived. Next, the amount of the diisocyanate used is determined by the number of the above hydroxyl groups. Each of the hydroxyl groups of the lignin can be reacted with an isocyanate group on one side of the diisocyanate to form an isocyanate group as shown in Formula 2.

It must be stated here that the hydroxyl groups of the lignin have different reaction rates. For example, a hydroxyl group located on an aliphatic chain has a reaction rate about 5 times faster than a hydroxyl group on a benzene ring. In order to allow all of the hydroxyl groups to react to form an isocyanate group, it is necessary to add an isocyanate group of two or more hydroxyl groups.

Diisocyanates suitable as the present invention are aliphatic isocyanates, including isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), methene bis(4-cyclohexyl isocyanate), ring An aliphatic diisocyanate such as 4,4'-dicyclohexylmethane diisocyante (hereinafter abbreviated as H ₁₂ MDI) or an aromatic diisocyanate or a combination thereof. In one embodiment of the invention, the molar ratio of the isocyanate groups of the diisocyanate to the hydroxyl groups of the lignin is between 2:1 and 2.6:1. If the amount of the diisocyanate is too small, it is impossible to react all the hydroxyl groups of the wood to form an isocyanate group. If the amount of the diisocyanate is too large, the unreacted diisocyanate will remain in the product, and the hard properties of the raw material will be lowered.

It should be noted that the above method is not limited to modified lignin, and can also be applied to other raw materials such as cellulose, hemicellulose, or starch containing two or more different reactive hydroxyl groups.

The above-mentioned raw material containing a large amount of isocyanate groups, a surfactant, a foaming agent, a glycol, and a mixture of water are subjected to a foaming reaction and a crosslinking polymerization reaction, and finally, the foam is foamed and solidified into a foam. cotton. Compared with the prior art, since the raw material of the present invention has previously reacted all the hydroxyl groups to form an isocyanate group, the problem of uneven reactivity of hydroxyl groups at different positions of the biomass material can be effectively improved, and the solution can be completed in a short time at room temperature. Foaming reaction. In addition, the above modified biomass material itself has a plurality of isocyanate groups, so that the foam formulation can form a three-dimensional structure without adding a crosslinking agent.

In one embodiment of the present invention, the diol is a polymer having a hydroxyl group at both ends of the head, such as a polyester having a weight average molecular weight of 500 to 3,000, or a polyol such as polyethylene glycol ( PEG), polypropylene glycol (PPG), or the like. The above polyols may also be referred to as polyether alcohols.

In one embodiment of the invention, the weight of the prepolymer and water is preferably between 100:0.1 and 100:10. If the proportion of water is too high, the foam will crack. If the proportion of water is too low, the expansion ratio will be insufficient.

The mixture is stirred at high speed at a high speed, and after about 1-300 seconds, the mixture can be poured into a mold or a continuous production line such as a conveyor belt. After foaming for 0.1-10 minutes, it can be solidified into foam. The foaming reaction can be carried out at room temperature to 200 ° C, preferably between 20 and 100 ° C, and most preferably between 20 and 50 ° C. After the foam formed by the above method is irradiated with UV, the yellowing resistance level can reach 5 levels.

Compared with the conventional art, the foaming time of the foam of the present invention takes only 1-300 seconds, preferably 5-100 seconds, more preferably 10-50 seconds, and cross-linking polymerization time (gelling). Time) only 0.1-10 minutes, preferably 0.5-5 minutes, more preferably 0.5-2 minutes; and the crosslinking reaction does not require high temperature heating, and can also be carried out between room temperature and 200 ° C, preferably between 20-100 ° C, best done at 20-50 ° C. Since the prepolymer of the present invention has high reactivity, the process can be simplified.

In addition to the foaming reaction to form a foam, the raw material containing a plurality of isocyanate groups of the present invention may also be directly cross-linked with a glycol to form a non-foaming product such as a film.

The above and other objects, features, and advantages of the present invention will become more apparent and understood. as follows:

[Examples] Example 1

In the present invention, 200 g of lignin (LS-103 available from Borregaard LignoTech) was dissolved in 100 ml of Polyol 1000 (Bayer Co.) to form a lignin solution, and 100 g of HDI (Desmodur H from Bayer Co.) was taken. Then, the lignin solution was slowly dropped into a HDI solution at 100 ° C to stir the reaction, and after the completion of the dropwise addition, the reaction was further carried out for 6 hours, and it was confirmed by NCO titration that all the hydroxyl groups of the lignin reacted to form an isocyanate group.

160 g of the above modified lignin, 40 g of glycol (PPG-400 available from Bayer Co., Ltd.), 2 g of pentane (foaming agent), 1 g of L580 (surfactant, product of Union Carbide, USA), After thoroughly mixing with 2g of water for 20 seconds, it is poured into an open space mold to carry out foaming cross-linking polymerization reaction. After 1 minute, the finished foam product is obtained. The foamed finished product has good mechanical strength, hardness of 70, and compression modulus. 90 kgf/cm ² , a bubble density of 50 holes/inch, a yellowing resistance grade of 5, and a density of 0.3 g/cm ³ .

Comparative example 1

Take 80g lignin (LS-103 from Borregaard LignoTech), 40g of HDI (Desmodur H from Bayer), 40ml of Polyol 1000, 40g of glycol (PPG-400 from Bayer), 2g Pentane (foaming agent), 1 g of L580 (surfactant, product of Union Carbide, USA), and 2 g of water were thoroughly mixed for 20 seconds, poured into an open space mold, and directly subjected to foaming crosslinking polymerization for 1 minute. After that, the finished foam product has a hardness of 55, a compression modulus of 75 kgf/cm ² , a bubble density of 30 holes/inch, a yellowing resistance grade of 5, and a density of 0.3 g/cm ^{3 .} . Compared with Example 1, since the lignin of Comparative Example 1 was subjected to a foaming reaction without modification, the reaction was uneven and the cells were coarse.

While the invention has been described above in terms of several preferred embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

Claims (8)

A method for forming a polyisocyanate-based green material, comprising: preparing a diisocyanate solution; and dissolving a raw material having a plurality of hydroxyl groups, adding the diisocyanate solution to react a hydroxyl group of the raw material to form an isocyanate group Wherein the diisocyanate comprises an aliphatic diisocyanate, an aromatic diisocyanate, or a combination thereof, wherein a molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the lignin is between 2:1 and 2.6:1. The method for forming a polyisocyanate-based green material according to claim 1, wherein the aliphatic diisocyanate comprises isophorone diisocyanate, hexamethylene diisocyanate, and dimethylene (4-ring). Alkyl isocyanate), cyclohexylmethane diisocyanate, or a combination thereof. A method of forming a polyisocyanate-based green material as described in claim 1, wherein the plurality of hydroxyl-containing biomaterials comprise lignin, cellulose, hemicellulose, or starch. A polyisocyanate-based green material, wherein an isocyanate group is formed by reacting a hydroxyl group of the biomass material with a diisocyanate, and the diisocyanate comprises an aliphatic diisocyanate, an aromatic diisocyanate, or a combination thereof, wherein the plurality of The hydroxygenic material comprises lignin, cellulose, hemicellulose, or starch; wherein the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the lignin is from 2:1 to 2.6:1. Polyisocyanate-based raw material as described in claim 4 And wherein the aliphatic diisocyanate comprises isophorone diisocyanate, hexamethylene diisocyanate, methene bis(4-cyclohexyl isocyanate), cyclohexylmethane diisocyanate, or a combination thereof . The polyisocyanate-based green material as described in claim 4 is applied to a foam, PU resin, and coating formulation. The polyisocyanate-based green material as described in claim 6, wherein the foam formulation further comprises a surfactant, a blowing agent, a glycol, and water. The polyisocyanate-based green material as described in claim 4 is applied to a non-foaming material formulation.