WO2024135690A1 - Polyurethane foam and composition for producing polyurethane foam - Google Patents

Abstract

[Problem] To provide a technology for producing a novel polyurethane foam that can reduce the load on the environment. [Solution] The present technology provides a polyurethane foam having a biodegradation degree after 45 days of at most 15% and a biodegradation degree after 180 days of at least 30%, as measured in the biodegradation degree test of ISO 14885-2. Moreover, the present technology provides: a composition for producing a polyurethane foam, the composition comprising a polyol and a biomass-derived isocyanate; and a polyurethane foam formed using said composition for producing a polyurethane foam.

Description

Polyurethane foam and composition for producing polyurethane foam

This technology relates to polyurethane foams and compositions for producing polyurethane foams.

Polyurethane foams are used in a wide variety of fields, from furniture such as sofas and chairs, bedding such as mattresses and pillows, clothing such as underwear, daily necessities such as dish sponges and cleaning sponges, interior products for vehicles and aircraft such as car seats, toys, and miscellaneous goods. Various developments are being carried out to improve quality and add new functions according to each field and purpose.

In addition, in recent years, technologies for producing foams using biomass resources have been proposed to contribute to the creation of a sustainable society. For example, Patent Document 1 discloses a rigid polyurethane foam produced using a prepolymer that is a reaction product of at least one polyisocyanate component, at least one hydroxy-functional acrylate component, and at least one polyol component that is a biopolymer containing castor oil, soybean oil, etc.

In addition, techniques for producing highly biodegradable foams have been proposed for the purpose of being environmentally friendly. For example, Patent Document 2 discloses a technique for producing biodegradable polyurethane foams using a composition containing a mixture based on poly(hydroxybutyrate) polymer, renewable polyol, isocyanate, and additives.

Special Publication No. 2007-522325 Special Publication No. 2009-527598

As mentioned above, technologies that use biomass resources and impart biodegradability to foams are being developed, but the reality is that further consideration for the environment is desired. Therefore, the main objective of this technology is to provide a technique for producing new polyurethane foams that can reduce the environmental burden.

In this technology, first, in the biodegradability test of ISO14885-2,
The biodegradability after 45 days is 15% or less,
To provide a polyurethane foam having a biodegradability of 30% or more after 180 days.
The polyurethane foam according to the present technology can use a biomass-derived ester polyol as a raw material.
The polyurethane foam according to the present technology may also use a primary amine as a raw material.

In the present technology, next, a polyol and
Biomass-derived isocyanate;
The present invention provides a composition for producing polyurethane foam, comprising:
The polyol used in the composition for producing a polyurethane foam according to the present technology can include a biomass-derived polyol.
The present technology also provides a polyurethane foam formed using the composition for producing a polyurethane foam according to the present technology.
The biomass content of the polyurethane foam according to the present technology can be 50% or more.

1 is a graph showing the change in biodegradability over time for 180 days in Experimental Example 1.

Below, a preferred embodiment for implementing this technology will be described. The embodiment described below is an example of a representative embodiment of this technology, and any of the embodiments can be combined. Furthermore, the scope of this technology should not be interpreted narrowly because of these.

[First embodiment]
1. Polyurethane foam The polyurethane foam according to the present technology is characterized in that, in the ISO 14885-2 biodegradability test, the biodegradability after 45 days is 15% or less and the biodegradability after 180 days is 30% or more. Since the polyurethane foam according to the present technology has a biodegradability of 15% or less after 45 days, it is possible to prevent early deterioration and maintain quality for a certain period of time. Furthermore, since the polyurethane foam according to the present technology has a biodegradability of 30% or more after 180 days, it is possible to exhibit good biodegradability in a general environment.

The polyurethane foam according to the present technology may be any of flexible, rigid, and semi-rigid polyurethane foams, but is preferably flexible. Specifically, it is preferable for the polyurethane foam to have an elongation of 50% or more, and more preferably, it is preferable for the polyurethane foam to have an elongation of 90% or more. A polyurethane foam having an elongation in this range is sufficiently flexible compared to semi-rigid and rigid polyurethane foams, and can be said to be a flexible polyurethane foam.

The hardness of the polyurethane foam according to the present technology is not particularly limited as long as it does not impair the purpose and effect of the present technology, but the lower limit is, for example, 10 or more, preferably 20 or more, more preferably 30 or more, and even more preferably 40 or more. The upper limit of the hardness of the polyurethane foam is, for example, 100 or less, preferably 90 or less, more preferably 80 or less, and even more preferably 70 or less. In the present technology, the hardness is a value measured using an Asker rubber hardness tester type F.

The foam density of the polyurethane foam according to the present technology is not particularly limited as long as it does not impair the purpose and effects of the present technology, but the lower limit is, for example, 20 kg/m ³ , preferably 40 kg/m ³ , more preferably 60 kg/m ³ , and even more preferably 70 kg/m ^3. The upper limit of the foam density of the polyurethane foam is, for example, 200 kg/m ³ , preferably 150 kg/m ³ , more preferably 100 kg/m ³ , and even more preferably 90 kg/m ^3. By setting the foam density within this range, the appearance of the polyurethane foam is further improved.

In conventional technology, yeast fungi that break down polyurethane were being developed, but these fungi were specialized decomposition fungi and had the problem of not being biodegradable in general environments. On the other hand, conventional foams that were highly biodegradable even in general environments also had the problem of rapid deterioration and poor quality retention. However, the polyurethane foam related to this technology has good quality retention, despite being biodegradable even in general environments.

The polyurethane foam of this technology can be used for a wide variety of purposes in a wide variety of fields, taking advantage of its high quality. For example, it can be used favorably in furniture such as sofas and chairs, bedding such as mattresses and pillows, clothing such as underwear, daily necessities such as tableware and cleaning sponges, vehicle and aircraft interior products such as car seats, architectural joint materials, architectural cushioning materials, architectural sealing materials, home appliance sealing materials, soundproofing materials, packaging materials, vehicle insulation materials, condensation prevention materials, interior materials, home appliance insulation materials, pipe insulation materials, various covers, cushioning materials, toys, miscellaneous goods, etc.

2. Composition for Producing Polyurethane Foam The polyurethane foam according to the present technology can use biomass-derived ester polyols and primary amines as raw materials. In addition, other materials that can be used as raw materials for general polyurethane foams can be freely selected and used as long as they do not impair the purpose and effects of the present technology. The composition for producing the polyurethane foam according to the present technology will be described below.

The polyurethane foam manufacturing composition used in this technology can contain biodegradable polyols, isocyanates, primary amines, blowing agents, catalysts, foam stabilizers, biodegradation accelerators, etc. Each component is described in detail below.

(1) Biodegradable polyols As the biodegradable polyols that can be used in the present technology, one or more biodegradable polyols that can be used in the production of polyurethane foams can be freely selected and used as long as the purpose and effect of the present technology are not impaired. For example, polyglycolic acid (PGA), polylactic acid (PLA), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate terephthalate (PBAT), polycaprolactone (PCL), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyhydroxyalkanoic acid (PHA), cellulose, cellulose acetate, chitosan, starch, modified starch, xylitol, sorbitol, mannitol, maltitol, castor oil-based polyols, and other hydroxyl-containing biomass-derived ester-based polyols can be mentioned. Among these, in the present technology, it is preferable to use a biomass-derived ester-based polyol having a hydroxyl group, such as a castor oil-based polyol represented by the following chemical formula (1), and polycaprolactone (PCL) represented by the following chemical formula (2) may be used in combination. Note that, although it is preferable to use all biodegradable polyols as polyols, other polyols may be mixed and used. The other polyols will be described in the second embodiment described later.

(m and n are integers of 1 or more)

In the polyurethane foam manufacturing composition according to the present technology, the content of the biodegradable polyol per 100 parts by mass of polyol is, for example, 50 parts by mass or more, preferably 55 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 65 parts by mass or more. By setting the content of the biodegradable polyol per 100 parts by mass of polyol within this range, the effect of reducing the environmental load can be improved.

In the polyurethane foam manufacturing composition according to the present technology, the upper limit of the content of biodegradable polyol per 100 parts by mass of polyol is not particularly limited as long as it does not impair the action or effect of the present technology, and in consideration of biodegradability, it is preferable to use all biodegradable polyols. The upper limit of the content of plant-derived polyol per 100 parts by mass of polyol can be set, for example, to 100 parts by mass or less, 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, etc.

(2) Isocyanate The isocyanate that can be used in the present technology can be freely selected from one or more isocyanates that can be used in the production of polyurethane foam, as long as the purpose and effect of the present technology are not impaired. Examples of the isocyanate that can be used in the present technology include aromatic isocyanates, aliphatic isocyanates, and alicyclic isocyanates.

Aromatic isocyanates that can be used in this technology include, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, and 3,3'-dimethoxy-4,4'-biphenylene diisocyanate.

In this technology, it is preferable to use an aliphatic isocyanate and/or an alicyclic isocyanate as the isocyanate. Aliphatic isocyanates and alicyclic isocyanates have the characteristic of being highly degradable, and therefore can contribute to the environment. The polyurethane foam of this technology is decomposed into an isocyanate-derived amine and a polyol by hydrolysis of the ester bond portion derived from the polyol and the urethane bond derived from the polyol and isocyanate. In this technology, by using aliphatic isocyanates and/or alicyclic isocyanates, which have degradability, as the isocyanate, a highly degradable polyurethane foam can be produced.

Aliphatic isocyanates include, for example, trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate), hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate, These include isocyanate methyl caproate, lysine diisocyanate, trimethylhexamethylene diisocyanate, 1,5-pentamethylene diisocyanate (PDI), decamethylene diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, and lysine triisocyanate (LTI (2,6-Diisocyanato hexanoic acid 2-isocyanatoethyl ester)).

Alicyclic isocyanates include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate), 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), dimer acid diisocyanate, transcyclohexane 1, Examples of such isocyanates include monocyclic alicyclic isocyanates such as 4-diisocyanate, hydrogenated tolylene diisocyanate (hydrogenated TDI), and hydrogenated tetramethylxylylene diisocyanate (hydrated TMXDI); and crosslinked cyclic alicyclic isocyanates such as norbornene diisocyanate, norbornane diisocyanate methyl, diisocyanatomethyl bicycloheptane, bicycloheptane triisocyanate, and di(diisocyanatomethyl)tricyclodecane.

Among these, in this technology, it is preferable to select HDI isocyanurate (HDI trimer, 2,4,6-trioxo-1,3,5-triazine-1,3,5-triyltris(6,1-hexanediyl)triisocyanate) represented by the following chemical formula (3), which is a trimer of hexamethylene diisocyanate (HDI), 1,5-PDI isocyanurate represented by the following chemical formula (4), which is a trimer of 1,5-pentamethylene diisocyanate (PDI), and lysine triisocyanate (LTI (2,6-Diisocyanato hexanoic acid 2-isocyanatoethyl ester)) represented by the following chemical formula (5).

There is no particular limit to the number of carbon atoms in the isocyanate used in this technology, but for example, when using a trimer of isocyanate, it is preferable that the number of carbon atoms in the monomeric isocyanate is 6 or more.

The isocyanate group (NCO group) content (NCO%) in the isocyanate used in this technology can be, for example, 50% or less, 40% or less, preferably 35% or less, and more preferably 30% or less.

The amount of isocyanate used in this technology can be freely set as long as it does not impair the purpose and effects of this technology. In this technology, the lower limit of the isocyanate in the composition is, for example, 20 parts by mass or more, preferably 40 parts by mass or more, more preferably 50 parts by mass or more, even more preferably 60 parts by mass or more, and particularly preferably 70 parts by mass or more, per 100 parts by mass of polyol. By setting the lower limit of the isocyanate content in the composition within this range, the foam shape of the polyurethane foam produced can be further improved.

In this technology, the upper limit of the isocyanate content in the composition is, for example, 200 parts by mass or less, preferably 150 parts by mass or less, more preferably 130 parts by mass or less, and even more preferably 100 parts by mass or less, per 100 parts by mass of polyol. Setting the upper limit of the isocyanate content in the composition within this range has the advantage of reducing costs.

In this technology, the isocyanate index can also be freely set as long as it does not impair the purpose and effect of the technology. In this technology, the lower limit of the isocyanate index is, for example, 60 or more, preferably 70 or more, and more preferably 80 or more. By setting the lower limit of the isocyanate index of the polyurethane foam within this range, the strength of the polyurethane foam produced can be improved.

In this technology, the upper limit of the isocyanate index is, for example, 130 or less, preferably 120 or less, and more preferably 110 or less. Setting the upper limit of the isocyanate index content of the polyurethane foam within this range has the benefit of reducing costs, and also prevents the polyurethane foam from becoming too hard, making it brittle and losing its flexibility, thereby improving the elasticity of the polyurethane foam.

In this technology, the isocyanate index is a value calculated by [(isocyanate equivalent in the composition for producing polyurethane foam/active hydrogen equivalent in the composition for producing polyurethane foam) x 100].

(3) Primary amines In the present technology, primary amines can be used. In particular, primary amines having at least one primary amino group and an active hydrogen group such as a hydroxyl group and having two to four functional groups can be used in the present technology.

When manufacturing polyurethane foam, the balance between the resinification reaction and the foaming reaction is very important. For example, if the resinification reaction is slower than the foaming reaction, the thickening of the polyurethane foam manufacturing composition is also slower, which means that the gas generated in the foaming reaction is more likely to escape, resulting in unstable foaming behavior. In addition, the cure time is longer, which makes it unsuitable for general molding, making it difficult to mass-produce, and causing problems such as poor design of the manufactured polyurethane foam. However, this technology uses primary amines to hasten the initial thickening (cream time), promote internal heat generation, improve the reactivity of the resinification reaction, and increase the reactivity of the foaming reaction to shorten the rise time. As a result, a good balance between the resinification reaction and the foaming reaction can be maintained even when raw materials with low reactivity during manufacturing, such as aliphatic isocyanates and/or alicyclic isocyanates and biodegradable polyols, are used to improve biodegradability.

When manufacturing polyurethane foam using raw materials with low reactivity during production, one method is to increase the amount of catalyst to increase reactivity, but increasing the amount of catalyst causes problems such as destabilizing the resinification reaction and foaming reaction. Another method is to use a prepolymer that has been partially reacted with polyol and/or isocyanate in advance as a raw material to shorten the reaction time, but because prepolymers have a high viscosity, there is a problem that the increase in viscosity of the raw material mixture reduces the stirrability. However, with this technology, by using a primary amine, there is no need to increase the amount of catalyst, and the resinification reaction and foaming reaction are stabilized. Furthermore, because the reactivity is high even without using a prepolymer, it is possible to suppress the increase in viscosity of the raw material mixture and prevent a decrease in stirrability.

The amount of primary amine used in the polyurethane foam production composition according to the present technology can be freely set as long as it does not impair the purpose and effect of the technology. In the present technology, the lower limit of the content of primary amine in the polyurethane foam production composition is, for example, 0.5 parts by mass or more, preferably 1 part by mass or more, and more preferably 2 parts by mass or more, per 100 parts by mass of polyol. By setting the lower limit of the content of primary amine in the polyurethane foam production composition within this range, the reactivity of the resinification reaction and the foaming reaction can be improved. As a result, even when a raw material with poor reactivity is used, a good balance between the resinification reaction and the foaming reaction can be maintained, and ultimately, a polyurethane foam with excellent mechanical properties and design properties can be obtained.

In this technology, the upper limit of the content of the primary amine in the composition for producing polyurethane foam is, for example, 20 parts by mass or less, preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 7 parts by mass or less, per 100 parts by mass of polyol. By setting the upper limit of the content of the primary amine in the composition for producing polyurethane foam within this range, it is possible to prevent instability of the resinification reaction and the foaming reaction due to excessively high reactivity during production, and to prevent a decrease in stirrability due to an increase in viscosity during prepolymerization. In addition, if the resinification reaction is too fast compared to the foaming reaction, curing may progress before the foaming reaction progresses, resulting in uneven foaming and hardness, or poor foaming. However, by setting the upper limit of the content of the primary amine in the composition for producing polyurethane foam within this range, it is possible to maintain a good balance between the resinification reaction and the foaming reaction, and to prevent uneven foaming, hardness, poor foaming, and the like.

The number average molecular weight of the primary amine that can be used in this technology is not particularly limited as long as it does not impair the purpose and effect of this technology. The lower limit of the number average molecular weight of the primary amine that can be used in this technology is, for example, 800 or more, preferably 1800 or more, and more preferably 2400 or more. The weight average molecular weight of the primary amine that can be used in this technology is not particularly limited as long as it does not impair the purpose and effect of this technology. The lower limit of the weight average molecular weight of the primary amine that can be used in this technology is, for example, 800 or more, preferably 1800 or more, and more preferably 2400 or more. By setting the lower limit of the number average molecular weight and/or weight average molecular weight of the primary amine that can be used in this technology within this range, it is possible to prevent instability of the resinification reaction and the foaming reaction due to excessively high reactivity during production, and also to prevent a decrease in stirrability due to an increase in viscosity during prepolymerization. In addition, it is possible to maintain a good balance between the resinification reaction and the foaming reaction, and to prevent uneven foaming, uneven hardness, and poor foaming, etc.

The upper limit of the number average molecular weight of the primary amine that can be used in this technology is, for example, 12,000 or less, preferably 8,000 or less, and more preferably 6,000 or less. The upper limit of the weight average molecular weight of the primary amine that can be used in this technology is, for example, 12,000 or less, preferably 8,000 or less, and more preferably 6,000 or less. By setting the upper limit of the number average molecular weight and/or weight average molecular weight of the primary amine that can be used in this technology within this range, the reactivity during production can be improved. As a result, even when a raw material with low reactivity is used, a good balance between the resinification reaction and the foaming reaction can be maintained, and ultimately, a polyurethane foam with excellent mechanical properties and design properties can be obtained.

The number of oxyalkylene repeat units in the primary amine that can be used in this technology is not particularly limited as long as it does not impair the purpose and effect of this technology. The lower limit of the number of oxyalkylene repeat units in the primary amine that can be used in this technology is, for example, 10 or more, preferably 20 or more, more preferably 30 or more, and even more preferably 40 or more. By setting the lower limit of the number of oxyalkylene repeat units in the primary amine that can be used in this technology within this range, it is possible to prevent instability of the resinification reaction and the foaming reaction due to excessively high reactivity during production, and to prevent a decrease in stirrability due to an increase in viscosity during prepolymerization. In addition, it is possible to maintain a good balance between the resinification reaction and the foaming reaction, and to prevent uneven foaming, uneven hardness, and poor foaming, etc.

The upper limit of the number of oxyalkylene repeat units in the primary amine that can be used in this technology is, for example, 200 or less, preferably 160 or less, more preferably 120 or less, and even more preferably 100 or less. By setting the upper limit of the number of oxyalkylene repeat units in the primary amine that can be used in this technology within this range, the reactivity during production can be improved. As a result, even when a raw material with poor reactivity is used, a good balance between the resinification reaction and the foaming reaction can be maintained, and ultimately a polyurethane foam with excellent mechanical properties and design properties can be obtained.

The kinetic viscosity of the primary amine that can be used in this technology is not particularly limited as long as it does not impair the purpose and effect of this technology. The lower limit of the kinetic viscosity of the primary amine that can be used in this technology is, for example, 100 cSt or more, preferably 200 cSt or more, and more preferably 300 cSt or more at 25°C.

The upper limit of the kinetic viscosity of the primary amine that can be used in this technology is, for example, 2000 cSt or less, preferably 1500 cSt or less, and more preferably 1000 cSt or less at 25°C.

The amine hydrogen equivalent (AHEW) of the primary amine that can be used in this technology is not particularly limited as long as it does not impair the purpose and effect of this technology. The lower limit of the amine hydrogen equivalent (AHEW) of the primary amine that can be used in this technology is, for example, 100 or more, preferably 200 or more, and more preferably 300 or more. By setting the lower limit of the amine hydrogen equivalent (AHEW) of the primary amine that can be used in this technology within this range, it is possible to prevent instability of the resinification reaction due to excessively high reactivity during the resinification reaction, and also to prevent a decrease in stirrability due to an increase in viscosity during prepolymerization. In addition, it is possible to maintain a good balance between the resinification reaction and the foaming reaction, and to prevent uneven foaming, uneven hardness, and poor foaming, etc.

The upper limit of the amine hydrogen equivalent (AHEW) of the primary amine that can be used in this technology is, for example, 2000 or less, preferably 1500 or less, and more preferably 1000 or less. By setting the upper limit of the amine hydrogen equivalent (AHEW) of the primary amine that can be used in this technology within this range, the reactivity of the resinification reaction can be improved. As a result, even when a raw material with low reactivity is used, a good balance between the resinification reaction and the foaming reaction can be maintained, and ultimately a polyurethane foam with excellent mechanical properties can be obtained.

In this technology, the amine hydrogen equivalent weight (AHEW) of a primary amine is defined as the molecular weight of a polyetheramine divided by the number of active amine hydrogens per molecule. The amine hydrogen equivalent weight (AHEW) of a primary amine can be calculated according to conventional techniques known to those skilled in the art, but preferably, it can be calculated by determining the content of amine group nitrogen using the procedure described in ISO 9702.

Specific examples of primary amines that can be used in this technology include one or more primary amines selected from polyester primary amines, polyether triamines obtained by addition polymerization of oxyalkylene represented by the following chemical formula (6), polyether primary amines such as poly(propylene glycol) triamine and polyoxypropylene diamine, and one or more of these primary amines can be freely selected and used.

(n, x, y, and z are each an integer of 1 or more)

In addition to primary amines, secondary amines and tertiary amines can also be used in the polyurethane foam manufacturing composition according to the present technology, so long as they do not impair the purpose and effect of the present technology. In this case, the proportion of primary amines in all amines is preferably 90% or more, and more preferably 94% or more. By setting the proportion of primary amines in all amines within this range, the reactivity of the resinification reaction can be improved. As a result, even when a raw material with poor reactivity is used, a good balance can be maintained between the resinification reaction and the foaming reaction, and ultimately a polyurethane foam with excellent mechanical properties can be obtained.

(4) Foaming Agent A foaming agent can be used in the composition for producing polyurethane foam according to the present technology. As the foaming agent that can be used in the present technology, one or more foaming agents that can be used in the production of polyurethane foam can be freely selected and used as long as the purpose and effect of the present technology are not impaired.

Examples of the foaming agent include water, hydrocarbons, and halogenated compounds. Examples of the hydrocarbons include cyclopentane, isopentane, and normal pentane. Examples of the halogenated compounds include methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, pentafluoroethyl methyl ether, and heptafluoroisopropyl methyl ether. Among these, it is preferable to use water as the foaming agent in this technology. The water may be any of ion-exchanged water, tap water, and distilled water.

The amount of blowing agent used in the polyurethane foam production composition according to the present technology can be freely set as long as it does not impair the purpose and effect of the technology. In the present technology, the lower limit of the blowing agent content in the polyurethane foam production composition is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more, per 100 parts by mass of polyol. By setting the lower limit of the blowing agent content in the polyurethane foam production composition within this range, it is possible to improve the foamability, and as a result, it is possible to obtain a polyurethane foam with excellent mechanical properties and appearance.

In this technology, the upper limit of the blowing agent content in the polyurethane foam production composition is, for example, 10 parts by mass or less, preferably 8 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of polyol. By setting the upper limit of the blowing agent content in the polyurethane foam production composition within this range, it is possible to suppress formation defects due to excessive foaming, and also to contribute to cost reduction.

(5) Catalyst A catalyst can be used in the composition for producing polyurethane foam according to the present technology. As the catalyst that can be used in the present technology, one or more catalysts that can be used in the production of polyurethane foam can be freely selected and used, as long as the purpose and effect of the present technology are not impaired.

Examples of catalysts include tin catalysts such as tin neodecanoate, dibutyltin dilaurate, and stannous octoate, and metal catalysts (organometallic catalysts) such as phenylmercury propionate and lead octenate. In addition, triethylamine, triethylenediamine (TEDA), tetramethylguanidine, diethanolamine, bis(2-dimethylaminoethyl)ether, N,N,N',N",N"-pentamethyldiethylenetriamine, imidazole-based compounds, piperazine-based amines such as dimethylpiperazine, N-methyl-N'-(2-dimethylamino)ethylpiperazine, and N-methyl-N'-(2-hydroxyethyl)piperazine, morpholine-based amines such as N-methylmorpholine and N-ethylmorpholine, and 1,8-diazabicyclo[4,5-diamine]pyrazine. Amine catalysts such as amines called DBU homologues, such as 1,5-diazabicyclo-[4,3,0]-nonene-5 (DBN), 1,8-diazabicyclo-[5,3,0]-decene-7 (DBD), and 1,4-diazabicyclo-[3,3,0]octene-4 (DBO), can also be used, but among these amine catalysts, tertiary amine catalysts and secondary amine catalysts are preferred, and those with a molecular weight of less than 700 are more preferred, those with a molecular weight of less than 500 are even more preferred, and those with a molecular weight of less than 300 are even more preferred.

The amount of catalyst used in the polyurethane foam production composition according to the present technology can be freely set as long as it does not impair the purpose and effect of the technology. In the present technology, the lower limit of the catalyst content in the polyurethane foam production composition is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more, per 100 parts by mass of polyol. By setting the lower limit of the catalyst content in the polyurethane foam production composition within this range, the resinification reaction and the foaming reaction can be promoted, and as a result, a polyurethane foam with excellent mechanical properties and appearance can be obtained.

In this technology, the upper limit of the catalyst content in the composition for producing polyurethane foam is, for example, 30 parts by mass or less, preferably 25 parts by mass or less, and more preferably 20 parts by mass or less, per 100 parts by mass of polyol. By setting the upper limit of the catalyst content in the composition for producing polyurethane foam within this range, it is possible to prevent destabilization of the resinification reaction and the foaming reaction, and to maintain a good balance between the resinification reaction and the foaming reaction. As a result, it is possible to obtain a polyurethane foam with excellent mechanical properties and appearance.

(6) Foam stabilizer A foam stabilizer can be used in the composition for producing polyurethane foam according to the present technology. As the foam stabilizer that can be used in the present technology, one or more foam stabilizers that can be used in the production of polyurethane foam can be freely selected and used as long as they do not impair the purpose and effect of the present technology.

Examples of foam stabilizers include silicone-based foam stabilizers, fluorine-containing compound-based foam stabilizers, surfactants, etc. Examples of silicone-based foam stabilizers include those that are mainly composed of siloxane chains, those in which the siloxane chain and polyether chain have a linear structure, those that are branched and unbranched, and those in which the polyether chain is modified to be pendant to the siloxane chain.

The amount of foam stabilizer used in the polyurethane foam production composition according to the present technology can be freely set as long as it does not impair the purpose and effect of the technology. In the present technology, the lower limit of the foam stabilizer content in the polyurethane foam production composition is, for example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, and more preferably 0.5 parts by mass or more, per 100 parts by mass of polyol. By setting the lower limit of the foam stabilizer content in the polyurethane foam production composition within this range, the foaming reaction can be stabilized, and as a result, a polyurethane foam with excellent mechanical properties and appearance can be obtained.

In this technology, the upper limit of the foam stabilizer content in the polyurethane foam production composition is, for example, 10 parts by mass or less, preferably 7 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of polyol. Setting the upper limit of the foam stabilizer content in the polyurethane foam production composition within this range can contribute to cost reduction.

(7) Biodegradation Accelerator A biodegradation accelerator can be used in the composition for producing a polyurethane foam according to the present technology. By using a biodegradation accelerator, when a biodegradable raw material is used as a raw material for the polyurethane foam according to the present technology, the biodegradability can be improved.

As for the biodegradation promoter that can be used in this technology, one or more types of biodegradation promoter that can be used in polyurethane foam can be freely selected and used, as long as it does not impair the purpose and effect of this technology.

Examples of biodegradation promoters include sugars such as glucose, xylose, galactose, maltose, sucrose, chitin, and cellulose; starches; amino acids; peptides; gums such as tamarind gum; and lignin.

The amount of biodegradation promoter used in the polyurethane foam production composition according to the present technology can be freely set as long as it does not impair the purpose and effect of the present technology. In the present technology, the lower limit of the content of the biodegradation promoter in the polyurethane foam production composition is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more, per 100 parts by mass of polyol.

In this technology, the upper limit of the content of the biodegradation accelerator in the composition for producing polyurethane foam is, for example, 10 parts by mass or less, preferably 7 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of polyol.

(8) Others In the composition for producing polyurethane foam according to the present technology, one or more other components that can be freely selected depending on the purpose from various components that can be used in compositions for producing polyurethane foam may be used as other components, as long as the purpose and effects of the present technology are not impaired.

Ingredients that can be used in the polyurethane foam manufacturing composition according to this technology include, for example, flame retardants, stabilizers, plasticizers, colorants, antioxidants, crosslinking agents, antibacterial agents, dispersants, and ultraviolet absorbers.

3. Method for Producing Polyurethane Foam The polyurethane foam according to the present technology can be produced by preparing a composition by mixing each component of the composition for producing polyurethane foam according to the present technology described above, and proceeding with a resinification reaction and a foaming reaction. As for the method for the resinification reaction and the foaming reaction, any general method can be freely combined and used as long as it does not impair the purpose and effect of the present technology.

In the polyurethane foam manufacturing method according to the present technology, either slab foaming or mold foaming can be used for the foaming. Slab foaming is a method in which a polyurethane foam manufacturing composition (raw material for polyurethane foam) is mixed and discharged onto a belt conveyer, and foamed at atmospheric pressure and room temperature. On the other hand, mold foaming is a method in which a polyurethane foam manufacturing composition (raw material for polyurethane foam) is mixed and injected into the cavity of a mold (metal mold), and foamed to the shape of the cavity. In this technology, mold foaming is preferably used from the viewpoint of ease of manufacturing. As mentioned above, in this technology, by using a primary amine, it is possible to perform mold molding even when a large amount of biomass-derived raw material is used.

[Second embodiment]
1. Composition for producing polyurethane foam The composition for producing polyurethane foam according to the present technology contains a polyol and an isocyanate derived from biomass. In addition, a primary amine, a blowing agent, a catalyst, a foam stabilizer, a biodegradation promoter, etc. can be contained as necessary. Each component will be described in detail below. The details of the primary amine, the blowing agent, the catalyst, the foam stabilizer, and the biodegradation promoter are the same as those of the first embodiment described above, so that the description will be omitted here.

(1) Polyol In the present technology, one or more polyols that can be used in the production of polyurethane foam can be freely selected and used in combination. Examples of polyols include polyester polyols, polycarbonate polyols, polyester ether polyols, polycaprolactone polyols, and polylactic acid polyols.

Polyether polyols include, for example, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc., which are obtained by polymerizing cyclic ethers such as ethylene oxide, propylene oxide, etc., respectively, and copolyethers thereof. They can also be obtained by polymerizing the cyclic ethers using polyhydric alcohols such as glycerin, trimethylolethane, etc. Commercially available polyether polyols may also be used.

Also, a polymer polyol can be used as the polyether polyol. A polymer polyol is one obtained by polymerizing an ethylenically unsaturated monomer in a polyether polyol, or one obtained by emulsifying and dispersing a polymer of an ethylenically unsaturated monomer in a polyether polyol. Specific examples include those obtained by graft polymerizing acrylonitrile, styrene, etc. onto a polyether polyol, and those obtained by dispersing polystyrene or polyacrylonitrile in a polyether polyol.

Examples of polyester polyols include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid; aliphatic carboxylic acids such as ricinoleic acid; aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as hexahydrophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid; and acid esters or acid anhydrides of these with ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, Examples of the polyester polyol include polyester polyols obtained by dehydration condensation reaction with 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, or a mixture thereof; polylactone polyols and polycaprolactone polyols obtained by ring-opening polymerization of lactone monomers such as ε-caprolactone and methylvalerolactone. In addition to these, examples of polyester polyols include polyols having naturally occurring ester groups.

Examples of polycarbonate polyols include those obtained by reacting at least one of polyhydric alcohols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, and diethylene glycol with diethylene carbonate, dimethyl carbonate, diethyl carbonate, etc.

Examples of polyester ether polyols include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid; aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid; alicyclic dicarboxylic acids such as hexahydrophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid; and those obtained by dehydration condensation reaction of acid esters or acid anhydrides of these with glycols such as diethylene glycol or propylene oxide adducts, or mixtures of these.

In this technology, it is preferable to use a biomass-derived polyol as the polyol. As the biomass-derived polyol that can be used in this technology, one or more types of biomass-derived polyol that can be used in the production of polyurethane foam can be freely selected and used, as long as the action and effect of this technology are not impaired.

Examples of biomass-derived polyols that can be used in this technology include polyols derived from natural fats and oils. Natural fat-derived polyols are natural fats and oils such as castor oil, soybean oil, rapeseed oil, and coconut oil, or derivatives thereof (modified natural fat and oil polyols, unmodified natural fat and oil polyols, etc.), which contain hydroxyl groups on the hydrocarbon chain and have two or more hydroxyl groups per molecule. In this technology, two or more of these may be used in combination. Other biomass-derived polyols include, for example, corn-derived polyols and cashew nut shell liquid-derived polyols. Commercially available biomass-derived polyols may also be used.

Among these, it is preferable to use castor oil in this technology. "Castor oil" includes unmodified castor oil, modified castor oil, dehydrated castor oil, hydrogenated castor oil, etc. More specifically, it is preferable to use the castor oil-based polyol represented by the above chemical formula (1).

In the polyurethane foam manufacturing composition according to the present technology, the content of biomass-derived polyol per 100 parts by mass of polyol is, for example, 45 parts by mass or more, preferably 65 parts by mass or more, more preferably 85 parts by mass or more, and even more preferably 95 parts by mass or more. By setting the content of biomass-derived polyol per 100 parts by mass of polyol within this range, the effect of reducing the environmental load can be improved.

In the polyurethane foam manufacturing composition according to the present technology, the upper limit of the content of biomass-derived polyol per 100 parts by mass of polyol is not particularly limited as long as it does not impair the action or effect of the present technology, and in consideration of reducing the environmental load, it is preferable to use all biomass-derived polyols. The upper limit of the content of biomass-derived polyol per 100 parts by mass of polyol can be set, for example, to 100 parts by mass or less, 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, etc.

In this technology, a biodegradable polyol can also be used in consideration of the environment. Details of the biodegradable polyol are the same as those of the biodegradable polyol used in the first embodiment described above, so a detailed explanation will be omitted here.

(2) Biomass-derived isocyanate The composition for producing a polyurethane foam according to the second embodiment is characterized in that a biomass-derived isocyanate is used as the isocyanate. By using the biomass-derived isocyanate, the biomass content of the polyurethane foam produced can be increased, which can contribute to reducing the environmental load.

As the biomass-derived isocyanate, one or more types of biomass-derived isocyanates that can be used in the production of polyurethane foam can be freely selected and used, so long as they do not impair the action and effect of this technology. Examples include 1,5-pentamethylene diisocyanate (PDI), lysine triisocyanate (LTI (2,6-Diisocyanato hexanoic acid 2-isocyanatoethyl ester)), lysine diisocyanate (LDI (Hexanoic acid, 2,6-diisocyanato)), dimer acid diisocyanate (DDI (3,4-dihexyl-5-(10-isocyanatodec-1-en-1-yl)-6-(8-isocyanatooctyl)cyclohex-1-ene)), etc. Among these, in this technology, it is preferable to select 1,5-PDI isocyanurate, which is a trimer of 1,5-pentamethylene diisocyanate (PDI) and is represented by the above chemical formula (4), and lysine triisocyanate (LTI (2,6-Diisocyanato hexanoic acid 2-isocyanatoethyl ester)), which is represented by the above chemical formula (5).

In this technology, in addition to biomass-derived isocyanates, it is also possible to use other commonly used isocyanates, such as petroleum-derived isocyanates. Details of the other isocyanates are the same as those that can be used in the first embodiment described above, so a description is omitted here.

In the polyurethane foam manufacturing composition according to the present technology, the content of biomass-derived isocyanate per 100 parts by mass of isocyanate is, for example, 40 parts by mass or more, preferably 45 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 55 parts by mass or more. By setting the content of biomass-derived isocyanate per 100 parts by mass of isocyanate within this range, the effect of reducing the environmental load can be improved.

In the polyurethane foam manufacturing composition according to the present technology, the upper limit of the content of biomass-derived isocyanate per 100 parts by mass of isocyanate is not particularly limited as long as it does not impair the action and effect of the present technology, and in consideration of reducing the environmental load, it is preferable to use all biomass-derived isocyanate. The upper limit of the content of biomass-derived isocyanate per 100 parts by mass of isocyanate can be set, for example, to 100 parts by mass or less, 90 parts by mass or less, 85 parts by mass or less, 80 parts by mass or less, 75 parts by mass or less, 70 parts by mass or less, etc.

The amount of biomass-derived isocyanate used in this technology can be adjusted to the amount of isocyanate and isocyanate index described in the first embodiment above, and when used in combination with other isocyanates, the amount of the other isocyanates can be taken into consideration.

2. Polyurethane Foam The polyurethane foam of the second embodiment is a polyurethane foam produced using the composition for producing a polyurethane foam of the second embodiment described above.

The degree of biodegradability of the polyurethane foam according to the second embodiment is not particularly limited, but similar to the polyurethane foam according to the first embodiment described above, in the ISO 14885-2 biodegradability test, it is preferable that the degree of biodegradability after 45 days is 15% or less, and that the degree of biodegradability after 180 days is 30% or more.

The biomass degree of the polyurethane foam according to the present technology can be freely set as long as it does not impair the action and effect of the present technology. The lower limit of the biomass degree of the polyurethane foam according to the present technology is, for example, 20% or more, preferably 25% or more, more preferably 30% or more, even more preferably 35% or more, and particularly preferably 40% or more. The higher the biomass degree of the polyurethane foam according to the present technology, the more it can contribute to the environment, so there is no upper limit to the biomass degree.

In this technology, the "biomass degree" is a value calculated using the following formula.
Biomass ratio (%)={(weight of biomass material×biomass ratio of biomass material/100)/weight of total raw materials}×100

The hardness, density, and other properties and uses of the polyurethane foam according to the second embodiment are the same as those of the polyurethane foam according to the first embodiment described above, so a description thereof will be omitted here.

3. Method for Producing Polyurethane Foam The polyurethane foam according to the second embodiment can be produced by mixing the components of the composition for producing polyurethane foam according to the second embodiment described above to prepare a composition, and then allowing a resinification reaction and a foaming reaction to proceed. Details of the production method are the same as those of the method for producing polyurethane foam according to the first embodiment described above, and therefore will not be described here.

The present technology will be described in more detail below with reference to examples. Note that the examples described below are representative examples of the present technology, and should not be construed as narrowing the scope of the present technology.

Unless otherwise specified, the materials used in the present examples are as follows.
Petroleum-derived polypropylene glycol polyol: Sanyo Chemical Industries, Ltd. "KC737"
Petroleum-derived polycaprolactone polyol 1: Daicel Corporation "Placcel 308"
Petroleum-derived polycaprolactone polyol 2: Daicel Corporation "Placcel 205U"
Biomass-derived refined castor oil (ricinoleic acid triglyceride): Ito Oil Mills, Ltd. "H-30"
Biomass-derived sebacic acid ester polyol: Ito Oil Mills "SE-2013C"
Petroleum-derived polyetheramine: Mitsui Fine Chemicals Co., Ltd. "T5000"
Tin neodecanoate: "Neostan U50" by Nitto Chemical Industries Co., Ltd.
TEDA (triethylenediamine): Evonik Japan Co., Ltd. "DABCO Crystal"
DBU (diazabicycloundecene): San-Apro Co., Ltd. "U-CAT SA-102"
1,2-Dimethylimidazole (70%) + EG (30%): Evonik Japan Co., Ltd. "DABCO 2040"
Silicone foam stabilizer: Evonik Japan Co., Ltd. "B-8742LF2" (Comparative Examples 1 to 4, Examples 4 and 6), Momentive Performance Materials Japan LLC "L594plus" (Examples 1 to 3, 5, 7 and 8)
Diphenylmethane diisocyanate: Tosoh Corporation "Millionate NM"
Hexamethylene diisocyanate (HDI) trimer: Asahi Kasei Corporation "Duranate TLA-100"
Pentamethylene diisocyanate (PDI) trimer: Mitsui Chemicals, Inc. "STABIO D-376N"

<Experimental Example 1>
In Experimental Example 1, the biodegradability of polyurethane foam was examined.

(1) Production of polyurethane foams After preparing compositions by mixing the raw materials shown in Table 1 below, the compositions were first poured into a foaming box (open without a lid) and allowed to foam freely, and the reactivity and foam moldability (appearance and foam condition) were confirmed. Next, after preparing compositions by mixing the raw materials shown in Table 1 below, the compositions were transferred to a mold and allowed to foam, to produce each polyurethane foam.

(2) Biodegradability Test The produced polyurethane foams were subjected to a biodegradability test using the following method.

[Soil burial test]
Compost was prepared by mixing 4 kg of chicken manure compost, 1 kg of cow manure compost, 20 g of superphosphate, and 100 g of bacteria, and then water was added at a weight ratio of compost:water = 1:1, and the mixture was then covered and cultured at room temperature for 24 hours, and then further cultured at 58°C for 24 hours. If the fully matured compost after culture had lost weight due to water evaporation, water was replenished to adjust the moisture content to 50-75%, and if the pH was 9 or higher, it was neutralized with acetic acid to adjust the pH to 7-9, thereby preparing fully matured compost.

The polyurethane foam test pieces (100 x 150 x 20 mm) were mixed with the prepared fully matured compost in a weight ratio of fully matured compost:test pieces = 15:1 (dry weight ratio 6:1), sealed and left at 58°C. The weight and pH were checked periodically, and if there was a weight loss due to water evaporation, water was replenished to keep the moisture content at 50-75%, and if a decrease in compost was observed, a mixture of vermiculite and water (weight ratio 1:1) was added. If the pH was 9 or higher, it was neutralized with acetic acid to keep the pH at a constant 7-9, and the inside was stirred at least once a week.

After 45 days from burying the test specimens, the specimens were removed while taking care not to collapse. After washing off any attached soil with water, the specimens were dried in a thermostatic chamber at 60°C for 24 hours, and the weight loss rate was calculated using the following formula.
{(weight before burial - weight after 45 days) / (weight before burial)} x 100 = weight loss rate (%)

[Biodegradability]
The biodegradability of Example 1, Comparative Examples 1 and 2, and Example 5 produced in Experimental Example 2 described later was measured for 180 days in accordance with ISO 14855-2.

(3) Results The results are shown in Table 1. The change in biodegradability over 180 days is shown in the graph of Figure 1.

<Experimental Example 2>
In Experimental Example 2, the influence of differences in raw materials used in the production of polyurethane foam on various physical properties was investigated.

(1) Production of Polyurethane Foams Each of the polyurethane foams was produced by mixing the raw materials shown in Table 2 below to prepare a composition, which was then transferred to a mold and foamed.

(2) Evaluation The produced polyurethane foams were evaluated for various physical properties using the following methods.

[Reactivity]
The raw materials shown in Table 2 below were mixed to prepare a composition, which was then poured into a foaming box (open without a lid) and allowed to foam freely, and the rise time was confirmed.
×: Rise time exceeds 180 seconds, or thickening is insufficient, air bubbles escape, and foaming does not progress.
△: Rise time 120 to 180 seconds.
◯: Rise time less than 120 seconds.

[Form shape]
The raw materials shown in Table 2 below were mixed to prepare a composition, which was then poured into a foaming box (open and without a lid) and allowed to foam freely, and the state of the foam was confirmed.
×: The foam collapses during foam expansion molding, or cracks appear on the exterior, resulting in poor appearance, or the cells on the cut surface inside the foam become rough.
△: Slight deformation during foam expansion molding.
◯: The foam moldability, appearance, and cells are almost uniform, all of which are good.

[density]
After the molding, the mold was cut into a sample having a size of 100 mm square and a thickness of 20 mm, and the density of the obtained sample was measured in accordance with JIS K7222:2005.

[Hardness]
The hardness was measured using an Asker rubber hardness tester, type F.

(3) Results The results are shown in Table 2 below.

(4) Observations As shown in Table 2, the reactivity tended to decrease in Examples 6 to 8 using a biomass-derived ester-based polyol, but the reactivity was improved by using a primary amine as shown in Examples 2, 4, and 5. In addition, as shown in Example 3, the reactivity could also be improved by using a polycaprolactone-based polyol and a biomass-derived ester-based polyol in combination as the polyol.

Furthermore, by using isocyanate derived from biomass, the biomass content could be increased to 75%.

Claims (7)

1. In the ISO14885-2 biodegradability test,
   The biodegradability after 45 days is 15% or less,
   A polyurethane foam having a biodegradability of 30% or more after 180 days.
2. The polyurethane foam according to claim 1, which uses a biomass-derived ester polyol as a raw material.
3. The polyurethane foam according to claim 1 or 2, which uses a primary amine as a raw material.
4. A polyol,
   Biomass-derived isocyanate;
   A composition for producing polyurethane foam comprising:
5. The composition for producing polyurethane foam according to claim 4, wherein the polyol includes a biomass-derived polyol.
6. 　Polyurethane foam formed using the composition for producing polyurethane foam according to claim 4 or 5.
7. The polyurethane foam according to claim 6, having a biomass content of 50% or more.