JP2015117275A - Use of cashew nutshell liquid as raw material for polyurethane resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for using raw material derived from a plant, suitable for the production of a polyurethane resin.SOLUTION: A Cashew Nut Shell Liquid (CNSL) for industrial use as a renewable resource material is used as the polyol raw material for a polyurethane resin, containing a polyurethane reaction mixture including: (A) a polyol component including a Cashew Nut Shell Liquid; (B) a polyisocyanate component; and (C) an inorganic filler and/or an emulsifier.

Description

  The present invention relates to a method for producing a polyurethane resin using a plant-derived renewable resource material.

  The method for producing the polyurethane resin is a technique well known to those skilled in the art.

The polyols used in current polyurethane production are typically derived from petrochemical products.
In recent years, those skilled in the art have attempted to achieve substitution of petroleum-derived polyols with components obtained from renewable resources in view of global environmental problems. Plastics and foams developed using fatty acid triglycerides derived from vegetable oils including castor oil, sunflower oil, rapeseed oil, linseed oil, cottonseed oil, corn oil, poppy oil, peanut oil and soybean oil and their derivatives have been developed Yes. Also, as interest in renewable and environmentally friendly resources increases, cashew nut shell liquid (also referred to as Cashew Nut Shell Liquid, CNSL) is gaining attention as a potential ingredient for plastic manufacturing.
Cashew nut shell liquid has a great advantage that it is derived from non-edible plants, is relatively stable in supply, and has a lower price than general-purpose polyols.

Until now, cashew nut shell liquid has been studied or used as a resin raw material in the following applications.
For example, the cashew paint, which was invented in 1948 and is still famous, is a high molecular weight cardanol that is the main component of cashew nut shell liquid.
If it relates to polyurethane raw materials,
Japanese Patent Publication No. 48-029530 (Patent Document 1) discloses that a aldehyde condensate or aldehyde cocondensate of cashew nut shell liquid or cardanol is reacted with ethylene oxide or propylene oxide to form a polyol compound. Yes.
Japanese Patent Application Laid-Open No. 2008-144171 (Patent Document 2) discloses that a polyether polyol obtained by alkoxylation based on components of cashew nut shell liquid is used as a raw material for flexible urethane foam.

Japanese Patent Publication No. 48-029530 JP 2008-144171 A

As described above, the polyurethane raw materials are all used by adding some modification to the cashew nut shell liquid.
Cashew nut shell oil (CNSL) is an oily liquid contained in cashew nut tree husks. Cashew nut shell oil mainly contains anacardic acid, cardanol, cardol, and methyl cardol as its components. There are two methods for preparing cashew nut shell oil: the heating method and the solvent extraction method. Usually, industrial cashew nut shell oil is heat-treated (decarboxylated) at the cashew nut production site to convert anacardic acid into cardanol. It is used.

Industrial CNSL is based on a heating method, and its main components are cardanol, cardol (also called curdle), and methyl cardol (also called methyl curdle). The composition ratio of industrial cashew nut shell liquid is generally as follows.
The structural formula and the number (F) of isocyanate-reactive functional groups calculated from the structural formula are also shown.

Cardanol (hydroxyl value 187, F1) 70-90%, especially 75-85%
Cardol (hydroxyl value 355, F2) 8-25%, especially 15-20%
Methyl cardol (hydroxyl value 340, F2) 0.2-10%, especially 1-5%
Anacardic acid (hydroxyl value 164, F1) 1% or less, especially 0.2% or less Average hydroxyl value: 180 to 260, especially about 220
Mole average functionality: 1.08 to 1.35, especially about 1.18
Average molecular weight: 250-350, especially about 303

[上記式中、Ｒは、二重結合を０、１、２または３個有する直鎖の炭素数１５のアルキル基(およびアルケニル基）の組み合わせ、特にＣ₁₅Ｈ₂₇である。]

[In the formula, R represents a combination of double bonds 2 or 3 having straight-chain alkyl group of 15 carbon atoms (and alkenyl groups), in particular C ₁₅ H _27. ]

  Cardanol, which is the main component of cashew nut shell liquid, is a compound having one phenolic hydroxyl group and one isocyanate-reactive functional group (F). Further, the accessory components cardol and methylcardol are compounds having two phenolic hydroxyl groups and two isocyanate-reactive functional groups (F). These phenolic hydroxyl groups can be urethanated with polyisocyanates to form polyurethane resins.

  Usually, in order to obtain a polyurethane resin having useful physical properties, it is necessary to have two or more isocyanate-reactive active hydrogens (two or more functional groups) in one molecule. This is because, when the number of functional groups is 2 or more, urethane crosslinking is linked to form a high molecular weight product when reacted with polyisocyanate. When the number of functional groups is less than 2, the increase in the molecular weight stops in the middle, so that the effective physical properties expected as a polyurethane resin often do not appear.

  Cardanol, the main component of cashew nut shell liquid, is a compound having one phenolic hydroxyl group and one isocyanate-reactive functional group. Usually, the use of such a material as a raw material is avoided in order to cause deterioration of physical properties for the above-mentioned reason. Furthermore, since the phenolic hydroxyl group has low activity, it is disadvantageous in terms of reactivity. It is surmised that these reasons have so far been hardly considered as raw materials for polyurethane resins in the state of industrial cashew nut shell liquid.

The present inventor shows that industrial cashew nut shell liquid can be used as a raw material for polyurethane resin as it is without modification.

  The present inventor has found that industrial cashew nut shell liquid can be used as a raw material for polyurethane resin as it is without being modified.

The present invention
A) Polyol component containing industrial cashew nut shell liquid,
B) Polyisocyanate component and a polyurethane reaction mixture comprising

The present invention
A) polyol component,
B) polyisocyanate component,
C) optionally present polyurethane reaction mixture consisting of inorganic fillers and / or reinforcements, component A) comprising a), b), c), d),
Component A) -a) contains 1 to 80 parts by weight of industrial cashew nut shell liquid (CNSL) per 100 parts by weight of component A),
A) -b) is component A) an isocyanate-reactive component containing 18 to 98 parts by weight of hydroxy groups per 100 parts by weight,
A) -c) is component A) 0-20 parts by weight of water or blowing agent per 100 parts by weight,
A) -d) are optionally present additives,
B) is a polyisocyanate component,
C) optionally contains inorganic fillers and / or reinforcements,
A polyurethane reaction mixture consisting of

  Non-edible plant-derived renewable resource materials that are inexpensive and stable in supply can be used in a wide range of applications as polyurethane materials with a high content.

  The polyurethane molded product may be non-foamed or foamed. Foaming may be chemical foaming or physical foaming.

  Component A) -a) is the aforementioned industrial cashew nut shell liquid (CNSL). The amount of industrial cashew nut shell liquid (CNSL) may be 1 to 80 parts by weight, for example 15 to 60 parts by weight, in particular 30 to 50 parts by weight per 100 parts by weight of component A).

A) -b) Isocyanate-reactive components containing hydroxy groups are divided into two types: 1) relatively high molecular weight compounds and 2) low molecular weight compounds called crosslinking agents.

The comparatively high molecular weight compound of A) -b) -1) is a base polyol for producing a polyurethane resin, which is widely used in the industry.
Examples thereof include, but are not limited to, polyether polyol, polyester polyol, polycarbonate polyol, polyester ether polyol, polycaprolactone polyol, polybutadiene polyol, and polymer polyol. Other renewable resource based polyols not derived from CNSL can also be used.
These polyols preferably have a molecular weight of about 500-10000, an OH number of about 20-800, and a functionality of about 2-8.

The low molecular weight compound called the crosslinking agent of A) -b) -2) includes a compound having a molecular weight of about 30 to 499 and containing at least two groups capable of reacting with an isocyanate group. Examples of usable compounds include polyhydric alcohols. For example, alcohols such as ethylene glycol (EG), diethylene glycol (DEG), triethylene glycol (TEG), propylene glycol (PG), dipropylene glycol (DPG), tripropylene glycol (TPG), butanediol, hexanediol, etc. preferable.

  The amount of component A) -b) is 18 to 98 parts by weight, preferably 20 to 80 parts by weight, for example 30 to 75 parts by weight, in particular 50 to 70 parts by weight per 100 parts by weight of component A).

A) -c) is water or other blowing agent.
As the foaming agent other than water, various foaming agents that are known in the art can be used. Examples include chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), hydrofluorocarbon (HFC), hydrofluoroolefin (HFO), normal pentane, cyclopentane, amine carbonate, formic acid, liquid carbon dioxide, and the like.
The amount of component A) -c) may be 0 to 20 parts by weight, for example 1 to 10 parts by weight per 100 parts by weight of component A).

A) -d) are various additives. Polymerization reaction catalysts, surfactants, bubble regulators, organic and inorganic pigments, colorants, UV and heat stabilizers, plasticizers or substances having antifungal or antibacterial effects, etc., known in this field can be used.
The amount of component A) -d) may be 0-30 parts by weight, for example 1-10 parts by weight per 100 parts by weight of component A).

  The average functionality of the polyol component A) is preferably 1.2 to 4.0, for example 1.5 to 3.5, in particular 2.0 to 3.0.

  As the polyisocyanate of component B), those usually used in the production of polyurethane foams are used. Examples of such isocyanate include aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic polyisocyanate, modified products thereof (for example, urethane group, carbodiimide group, allophanate group, urea group, burette group, isocyanurate group, or Oxazolidone group-containing modified products) and mixtures of two or more thereof.

  As aromatic polyisocyanate, 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), polymeric TDI (also referred to as crude TDI or crude TDI). ), 2,4′- and / or 4,4′-diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (also referred to as crude MDI or crude MDI), polyaryl polyisocyanate (PAPI), and the like.

Examples of the aliphatic polyisocyanate include aliphatic diisocyanates having 2 to 18 carbon atoms. Specific examples include 1,6-hexamethylene diisocyanate and lysine diisocyanate.
Examples of the alicyclic polyisocyanate include alicyclic diisocyanates having 4 to 16 carbon atoms. Specific examples include isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate, norbornane diisocyanate, and the like.

  The amount of component B) is preferably such that the isocyanate index [equivalent ratio of isocyanate groups in component B) to active hydrogen in component A) is 85-130, for example 95-110.

Component C) is an inorganic filler and / or reinforcement that may optionally be included. Component C) is a material known in the art, for example barium sulfate, porous diatomaceous earth, whiting, mica, in particular glass fiber, LC fiber, glass flake, glass sphere, aramid fiber or carbon fiber. These components are preferably added to the polyol component which is component A) and may be inserted into the mold in the case of a continuous toughener. In order to reduce the bulk density, materials such as pumice and other low density synthetic or natural inorganic materials may also be utilized.
The amount of component C) may be 0 to 30 parts by weight, for example 1 to 10 parts by weight per 100 parts by weight of component A).

A polyurethane molded article is obtained by reacting the polyol component A) and the polyisocyanate component B). The reaction is preferably performed at a temperature of 20 to 60 ° C. The reaction is preferably performed in a mold.
After molding, the polyurethane molded product is removed from the mold.

Hereinafter, the method of the present invention will be described in more detail by way of examples.
Unless otherwise specified, temperatures are in degrees Celsius and percentages are percentages by weight.
In the examples, the following components were used.

Industrial cashew nut shell liquid (CNSL)
Appearance: Dark brown liquid Specific gravity: 0.96
Viscosity: 550 mPa · s / 30 ° C
Moisture: 0.05%
Iodine number: 250 (Wiis method)

Polyol 1: Polyether polyol having a hydroxyl value of 45 mg KOH / g obtained by adding 85% by weight of propylene oxide (PO) to propylene glycol and then 15% by weight of ethylene oxide (EO), F2, molecular weight 2500
Polyol 2: Polyether polyol having a hydroxyl value of 35 mg KOH / g obtained by adding 87% by weight of PO and then 13% by weight of EO to glycerin, F3, molecular weight 4800
Polyol 3: A polyether polyol having a hydroxyl value of 455 mg KOH / g, a mixture of sugar, propylene glycol and water (functionality 6.4) as a starting material and having only PO added thereto, F6.4, molecular weight 790
Polyol 4: Polyether polyol having a hydroxyl value of 350 mgKOH / g obtained by adding only PO to TDA (toluenediamine), F4, molecular weight 640
Polyol 5: Mannich compound obtained by reacting 1.6 mol of formaldehyde and 2.4 mol of diethanolamine with 1 mol of nonylphenol, and having a hydroxyl value of 350 mgKOH / g with PO added by 40 wt% and then EO 60 wt% Mannich polyol, F3, molecular weight 480

Crosslinker 1: Diethylene glycol, F2, molecular weight 106
Cross-linking agent 2: ethylene glycol, F2, molecular weight 31

Foaming agent 1: water
Foaming agent 2: cyclopentane

Catalyst 1: DABCO 33LV (Air Product)
Catalyst 2: Dibutyltin dilaurate catalyst 3: Kao Riser No. 3
Catalyst 4: Kao Riser No. 10
Catalyst 5: Kao Riser No. 14
Catalyst 6: Tosoh ET manufactured by Tosoh Corporation

Foam stabilizer 1: Nippon Unicar SZ1627
Foam stabilizer 2: Tegostab B8462 manufactured by Evonik

Polyisocyanate 1: Polymeric MDI (Sumijur 44V20 NCO% = 31.7, manufactured by Sumika Bayer Urethane Co., Ltd.)
Polyisocyanate 2: Carbodiimide-modified monomeric MDI (SBU Isocyanate 0632 NCO% = 29.0, manufactured by Sumika Bayer Urethane Co., Ltd.)

The evaluation was performed by the following method.
The reactivity index of the reaction mixture in the table is as follows.
Cream time: Time (seconds) from mixing the isocyanate and polyol mixture until the liquid starts to rise
Rise time: Time (seconds) from the mixing of the isocyanate and polyol mixture to the end of foam rise

  As the RIM molding machine, a high pressure foaming machine Asystem 40std type manufactured by CANNON was used, and the molds and molding conditions are shown in Tables 1 to 3.

The physical properties were evaluated by the following methods.
Density (according to JIS K 7222: 1999),
Hardness (based on JIS K 6400-2: 2004 D method),
Elongation (according to JIS K 6400-5: 2004),
Tensile strength (according to JIS K 6400-5: 2004),
Tear strength (conforms to JIS K 6400-5: 2004)

Hardness (Asker C)
Using a type C durometer conforming to JIS K6253-3, measurement was performed by a method conforming to JIS K6253-3.
Compressive strength Measured according to JIS A9511.

Thermal conductivity (unit: mW / m · K (23 ° C))
Based on JIS A 1412-2, it measured using the thermal conductivity measuring apparatus (Product name: Auto-Lambda HC-074 (200) type | mold, Eihiro Seiki company make).

  The evaluation method was determined by the fact that the physical property values did not change significantly compared to the reference composition and that there was no problem with the appearance.

Evaluation with non-foamed urethane system (Reference Example 1 and Example 1):
Each component was prepared according to the formulation shown in Table 1 and molded by a RIM molding machine. The physical properties were evaluated and the results are shown in Table 1 (lower part). Example 1 showed the same physical property value as Reference Example 1, and it was found that CNSL can be used as a polyol component in a non-foamed urethane system.

Evaluation with a semi-rigid urethane system (Reference Example 2 and Example 2):
Each component was prepared according to the formulation shown in Table 2 and molded by a RIM molding machine. The physical properties were evaluated, and the results are shown in Table 2 (lower part). Example 2 showed the same physical property value as Reference Example 2, and it was found that CNSL can be used as a polyol component in a semi-rigid urethane system.

Evaluation with rigid urethane system (Reference Example 3 and Examples 3 and 4):
Each component was prepared according to the formulation in Table 3 and molded by hand foaming. The physical properties were evaluated and the results are shown in Table 3 (lower part). Examples 3 and 4 showed physical property values equivalent to those of Reference Example 3, and it was found that CNSL can be used as a polyol component in a hard urethane system.

  From the above, it can be seen that industrial cashew nut shell liquid can be used in a wide range of non-foamed, semi-rigid and rigid foam fields.

  According to the present invention, industrial cashew nut shell liquid can be used as a polyol component in urethane production. Industrial cashew nut shell liquid can be used in a wide range of non-foamed materials, semi-rigid materials and rigid foams made of polyurethane or urea.

Claims (6)

A) Polyol component containing industrial cashew nut shell liquid,
B) Polyurethane reaction mixture comprising a polyisocyanate component, and The polyurethane reaction mixture according to claim 1, wherein the amount of industrial cashew nut shell liquid (CNSL) is 1 to 80 parts by weight per 100 parts by weight of component A). A) polyol component,
B) polyisocyanate component,
C) optionally present polyurethane reaction mixture consisting of inorganic fillers and / or reinforcements, component A) comprising a), b), c), d),
Component A) -a) contains 1 to 80 parts by weight of industrial cashew nut shell liquid (CNSL) per 100 parts by weight of component A),
A) -b) is component A) an isocyanate-reactive component containing 18 to 98 parts by weight of hydroxy groups per 100 parts by weight;
A) -c) is component A) 0-20 parts by weight of water or blowing agent per 100 parts by weight,
A) -d) are optionally present additives,
B) is a polyisocyanate component,
C) optionally contains inorganic fillers and / or reinforcements,
A polyurethane reaction mixture comprising: The polyurethane reaction mixture according to claim 1, wherein a foamed material is obtained. The polyurethane molded product obtained by making the polyurethane reaction mixture in any one of Claims 1-4 react. A method for producing a polyurethane molded article, comprising a step of reacting the component A) and the component B) in the polyurethane mixture according to claim 1.