KR20130094515A - Low temperature curing liquid hydroxymethyl thermoset composition and thermoset plastic material - Google Patents

Abstract

The present invention relates to a low temperature curable liquid hydroxymethyl thermosetting composition (lacking aldehyde or substituted aldehyde) synthesized in the presence of an alkali metal catalyst and / or amine.
The present invention is prepared by combining at least one aromatic compound (A) comprising at least two hydroxyl groups and at least one aldehyde and / or aldehyde substituent (B) in the presence of an alkali metal catalyst (C) and in the presence of water and / or an organic solvent. It is characterized by. Such low temperature curable liquid hydroxymethyl thermosetting compositions can be usefully used in the preparation of composites requiring increased heat resistance, increased fire resistance, increased impact resistance, increased adhesion of resins to fibers and reduced fracture properties. .

Description

LOW TEMPERATURE CURING LIQUID HYDROXYMETHYL THERMOSET COMPOSITION AND THERMOSET PLASTIC MATERIAL}

The present invention relates to a low temperature curable liquid hydroxymethyl thermosetting composition (lacking aldehyde or substituted aldehyde) synthesized in the presence of an alkali metal catalyst and / or amine.

Polymeric (plastic) materials are generally divided into two materials: thermoplastics and thermosets. Thermoplastic resins consist of long molecules, each of which may have side or side chain groups that do not attach (ie, do not crosslink) to other molecules. These resins can be melted and modified so that any residues generated during processing can be reused. In general, no chemical change occurs during molding unless the processing temperature is exceeded. The temperature range of use of the thermoplastic resin is limited by its loss of physical strength and melting at elevated temperatures.

On the other hand, thermosetting resins react during processing to form crosslinked structures that cannot be remelted and reprocessed. The thermosetting resin may be provided in liquid form or in the form of partially polymerized solid phase molding powder. In the uncured state, the thermosetting resin can be molded into the final product shape with or without pressure and polymerized (crosslinked) using chemicals and / or heat.

The difference between thermoplastics and thermosets is not always clear. For example, thermoplastic polyethylene can be extruded as a coating for wires and then crosslinked chemically or via light irradiation to form thermosetting resins that no longer melt upon heating. Some plastic materials may have components belonging to two classes, for example thermosetting and thermoplastic polyester resins.

Reinforced thermosetting resin (RTP) composites are glass plastics known by several names, including glass reinforced plastics (GRP), glass fiber reinforced plastics (FRP) composites and, in short, glass fibers. Specifically, the reinforced thermosetting plastics (RTP) composite contains reinforcing fibers in the reinforcing thermosetting polymer matrix. Most commonly, the reinforcing fibers are glass fibers, but reinforcing materials including high strength fibers such as aramid, basalt, graphite, carbon and the like are sometimes used for advanced applications. The polymer matrix is a thermosetting resin (reinforced resin), and products of this structure are considered as "nonmetallic" reinforced thermosetting plastic (RTP) composites. Useful RTP composite products can be prepared using several manufacturing methods. Such methods are well known to those skilled in the art and include hand lay-up, filament winding, resin transfer molding (RTM), and vacuum assisted resin transfer molding (VARTM). ), Pultrusion, pre-preg, and the like. Polymer products made using this method may be cured (crosslinked) at room temperature or cured (crosslinked) under accelerated conditions including elevated temperature curing, photoinitiated curing, and / or some other advanced curing methods known to those skilled in the art. Can be.

Useful polymer reinforced resins include terephthalate, isophthalate, orthophthalate, bisphenols, vinyl esters, epoxy vinyl esters, epoxides, phenols, resorcinol, and many other organic and inorganic resins. Over the last three decades, many people in the construction, aerospace, shipping and transportation industries, universities, and fire protection and fire insurance industries have found that many of the commonly used nonmetallic products (thermoplastics and thermosets) have been subjected to severe fire, toxicity and It raises the issue of thermal stability.

Organic materials such as benzoxazine, BMI (bismaleimide), cyanate esters, PEEK, phthalonitrile, polyimide and the like are being newly developed for compensation and making significant progress to meet this need. However, these organic materials suffer from some processing difficulties and associated high usage costs. Representative hydroxymethyl compounds such as phenol-aldehydes, resorcinol-aldehydes, phenol-resorcinol-aldehydes, tannins-aldehydes, urea-aldehydes, melamine-aldehyde resins, casein-aldehydes, etc., have lower costs when used for specific applications. Has a special advantage. Various electrophilic compound systems, including phenols and / or resorcinol, are known to have high temperature strength.

Generally, the first part of the phenol-formaldehyde reaction takes place at about 70 ° C. to form hydroxymethyl phenol (resin). Hydroxymethyl phenol crosslinks upon heating to about 120 ° C. to form methylene and methyl ether bridges. The resin then begins to crosslink, forming a highly elongated three-dimensional web consisting of covalent bonds, which represent a polymerized phenolic resin. This highly crosslinked nature of the phenol gives the phenol hardness and good thermal stability and makes the phenol resistant to most acidic chemicals.

Phenols are reactive toward electrophilic compounds (ie, formaldehyde, etc.) in the ortho and para positions (ie, 2, 4, and 6 positions) such that up to three formaldehyde units can be attached to the ring. The hydroxy methyl group can be reacted with another free ortho or para position to form a methylene bridge, or with another hydroxymethyl group to form an ether bridge.

In addition, formaldehyde may react with up to two phenols. The actual functionality found in the final polymer depends on the paraformaldehyde molar ratio to phenol (F: P). When the molar ratio reaches 1 (F: P = 1), theoretically all phenols are bonded via methylene crosslinking to form a single molecule and fully crosslinked. Resins such as phenol-formaldehyde (PF), resorcinol-formaldehyde (RF), phenol-resorcinol-formaldehyde (PRF), phenol-melamine-formaldehyde (PMF) and the like can be catalyzed by acids or bases. It is formed by a step-growth polymerization reaction (also known as a condensation reaction).

The route through which the step-growth polymerization reaction is carried out varies depending on the type of catalyst used. For the production of phenolic resins, phenol, formaldehyde, water and catalyst are mixed in the desired amounts depending on the desired resin to be formed and then reacted through heat. The byproduct of this reaction is water. Various phenolic resins can be produced by adjusting the ratio of formaldehyde to phenol, the reunification temperature, and the catalyst. Resin systems based on phenols and / or modified phenols (ie, resorcinol, etc.) are generally classified into two categories:

1) Novolac: Two-part resins (novolaks) are typically acid catalyzed phenol forms having a molar ratio of formaldehyde (F) to phenol (P) of less than 1 (F: P <1). Aldehyde resin. Since the molar ratio of formaldehyde (F) to phenol (P) is less than 1 (F: P <1), these resins can be fully polymerized without adding a suitable crosslinking agent.

2) Resol: A single-stage resin (resol) is typically an alkali catalyzed phenol formaldehyde (PF) resin having a molar ratio of aldehyde to phenol greater than 1 (F: P> 1), wherein the molar ratio Is generally from 1.1: 1 to 2.5: 1. The lasol completes the curing process in the heating mold without additional catalyst to form three-dimensionally crosslinked insoluble polymer.

Unfortunately, many of these phenols have been found to require higher curing temperatures, tend to be embrittlement, require acid catalysts, and require "free formaldehyde". In some of these phenolic resins, considerable research is being conducted to reduce fire, smoke and toxicity problems, including the use of halogens and fillers such as ATH, MgO and other materials. Many other problems arise from the use of reinforcing materials commonly known as glass fibers in such phenolic resin applications. Such phenolic resins tend not to bind well to glass fiber reinforcements. Generally, the glass fiber reinforcement is treated with chemicals and salts, such as a coupling agent, which makes the glass fiber more flexible and improves the binding of the glass fiber to the resin. For example, water released from condensation reactions tends to react with these salts and binders on glass fibers, causing degradation and brittleness and hindering the general use of such binders. It is also desirable to use tempered glass fibers to achieve strength and durability. It is also desirable to be able to mold glass fibers without the need to cure them at high temperatures and pressures. Representative phenols also tend to have voids generated as a result of step polymerizations performed under high temperature curing. As a result, the final complex is severely weakened. It is desirable to provide suitable composites free of voids.

In addition to the above differences, there are several differences between the various types of thermosetting resins, in particular phenol resins and resorcinol resins. Specifically, the thermosetting resins differ from other thermosetting resins such as thermosetting adhesives and / or tackifying resins in terms of solids and polymer matrix geometry. Thermosetting reinforcement resins have a side chain structure, whereby it is possible to form a three-dimensional polymer matrix to obtain a stronger and thermally more stable structure.

Representative Phenolic Reinforced Resin: Crosslinked Three-Dimensional Matrix

On the other hand, thermosetting adhesives and / or tackifying resins are linear structures.

Representative Novolak Tackifying Resin: Linear Matrix

Thus, thermoset reinforced resins have the ability to withstand greater mechanical loads than those of thermoset adhesives and / or tackifying resins when used in the manufacture of reinforced thermoset plastics (RTP) composites. It is well known to those skilled in the art that such thermoset adhesives and / or tackifying resins do not provide good laminate resins for the purpose of making reinforced thermoset plastics (RTP) composites.

Reinforced thermosetting plastics (RTP) composites are reinforcing plastics known by several names, including glass reinforced plastics (GRP), glass fiber reinforced plastics (FRP) composites, and for short glass fibers, etc. Specifically, reinforced thermosetting Plastic (RTP) composites contain reinforcing fibers in a thermoset reinforcing polymer matrix, most commonly the reinforcing fibers are glass fibers, but reinforcing materials, including high strength fibers such as aramid, base salt, graphite and carbon, etc. The polymer matrix is a thermosetting resin (reinforced resin) and the product of this structure is considered a "nonmetallic" reinforced thermoset plastic (RTP) composite.

Phenolic resols and / or novolacs can be used alone or in combination with various phenolic compounds such as phenol, resorcinol, bisphenol, phloroglucinol, cresol, alkyl phenols, phenol esters, tannins, lignin, melamine, urea and other hydroxyl groups. It is well known to those skilled in the art that they can include in combination.

When phenol (hydroxybenzene) is reacted with an electrophilic compound (ie formaldehyde) in an alkaline solution, a step polymerization reaction takes place, introducing a hydroxy methyl group onto the aromatic nucleus at the ortho or para position to the phenol group. Under alkaline conditions, phenols form phenoxy anions, which are generally believed to be in the form of phenols that react with electrophilic compounds. It can be seen that the reaction between the electrophilic compound and the other phenolic compound in the alkaline solution occurs in a similar form. This alkaline reaction appears to be very beneficial to the present invention.

A step polymerization reaction occurs when resorcinol (1,3-dihydroxybenzene) is reacted with an electrophilic compound (eg formaldehyde). By this reaction, hydroxymethyl groups are introduced on the aromatic nucleus at the ortho position relative to the hydroxy. It is known to those skilled in the art that resorcinol is more reactive than phenol. Incorporation of resorcinol into phenol makes it possible to cure at lower temperatures. Curing at lower temperatures appears to be very beneficial to the present invention. It is also well known to those skilled in the art that resorcinol increases the toughness (impact resistance) of phenol. Impact resistance seems to be very beneficial to the present invention.

It is well known to those skilled in the art that phenols and resorcinol novolac resins lacking electrophilic compounds (e.g., formaldehyde, formaldehyde substituents, etc.) need to be cured (completely crosslinked) by addition of a suitable crosslinking agent.

Useful sources of aldehydes are well known and examples thereof include formaldehyde (CH 2 O), paraformaldehyde (CH 2 O) n, trioxymethylene (C 3 H 6 O 3), hexamethylenetriamine (hexa) (C 6 H 12 N 4), furfural (C 5 H 4 O 2), and fur In addition to compounds such as furyl alcohol (C5H6O2), acrolein (C3H4O). Other formaldehyde-containing compounds such as urea-formaldehyde, melamine-formaldehyde and the like.

It is also well known that formaldehyde may be further substituted using acetaldehyde, propionaldehyde, cyclohexanedicarboxaldehyde, benzaldehyde, furfural, and other aryl or heterocyclic aldehydes and the like.

Phenol-formaldehyde, phenol-resorcinol-formaldehyde, formed in the reaction between an electrophilic compound (e.g., an aldehyde) and a carbonyl containing compound having a reactive hydrogen on a carbon or nitrogen atom adjacent to carbonyl, Thermosetting reinforced resin systems, such as resorcinol-formaldehyde, tannin-formaldehyde, phenol-melamine-formaldehyde, and similar reinforced resins, constitute the multi-billion-dollar requirement for formaldehyde in the reinforced thermosetting plastic (RTP) composite industry. do. Such thermosetting reinforcing resins are used in reinforced thermosetting plastics (RTP) because of their excellent FST (fire, smoke and toxicity) properties and are advantageous for the present invention.

In order to prepare phenol (PF) or resorcinol (PRF) thermosetting reinforced resins with good shelf life, the resins are prepared in a form lacking electrophilic compounds (aldehydes such as aldehydes or paraformaldehydes). In order to react and make these phenol or resorcinol thermosetting strengthening resins complete, additional electrophilic compounds (aldehydes such as aldehydes or paraformaldehydes) are incorporated into the resins when the resins are used. By the completed reaction, the resin is converted to a cured material suitable for the production of reinforced thermosetting resin (RTP) composites (products).

Considerable research has been conducted to produce novolak resin products incorporating various reactive components (e.g., resorcinol, phenol and aldehyde; phenol, melamine and aldehyde; phenol, furfuryl and aldehyde; etc.) and alkaline catalysts. Has been. The novolak resin products have the special advantages of low curing temperature, completely neutral pH level, low embrittlement and cracking during curing, low flame propagation, good heat release rate and low smoke emission. have. Typically, however, such resins have relatively short gelation cycles, long room temperature curing cycles, very brittleness and poor adhesion to fibers. It is advantageous for the present invention to further improve the adhesion of the resin to the fibers.

Over the last few decades, many people in the construction, aerospace, shipping, transportation, universities, wastewater treatment plants, semiconductor plants, fire protection and fire insurance industries have commonly used nonmetallic products (thermoplastics and thermosets). Learned that it poses a serious fire problem. Nearly all of the resin systems (including reinforced resins) used in the late 1960s and 1990s made claims related to flame retardancy. "Flame retardant resin" simply included a flame retarding mechanism that does not easily burn the resin even when it does not contain chemicals. Nevertheless, these resins still burned. It has not changed much, and it is certain that most flame retardant resins are not very flame retardant and are not fire safe.

Phenolic complexes have long been recognized for their potential utility because of their excellent FST (fire, smoke and toxicity). For a wider range of applications where safety against fire is important, flame retardant polyesters, vinyl esters and the like have been studied. Fire safety applications include aircraft, buses, trains, subway cars, and especially those where crowds of people may be crowded if exits are restricted. Unfortunately, conventional phenols are known to be brittle, require special processing, raise some occupational and environmental problems, and increase energy consumption.

Brown (US Pat. No. 4,373,062) discloses a phenol-formaldehyde resin composition having a molar ratio of formaldehyde to phenol of 1.7: 1 to 2.8: 1 at pH 5.6 to 8.5, and then reacting the reaction at 2.1: 1 to 2.8: 1. It is disclosed that phenol-formaldehyde and phenol-resorcinol-formaldehyde thermosetting binders and adhesive (adhesive) resins can be prepared by reaching a aldehyde-phenol ratio of to formaldehyde. The obtained resol resin product is thermosetting. This thermoset resol product is then reacted with a formaldehyde scavenger in an approximately stoichiometric amount relative to the free formaldehyde content of the thermoset product and reacts resorcinol in an amount of 60 to 140% of the phenol. The mixture obtained is reacted for a time-temperature period to achieve copolymerization to obtain a stable phenol-resorcinol liquid resin product that cures to a solid solid upon mixing with additional formaldehyde. As ammonia was added to the stoichiometric amount of formaldehyde, hexamethylene tetramin (hexa) was produced in situ. This resulting liquid resin is a synthetic base-catalyzed phenol-resorcinol-formaldehyde novolak product that is stable and useful as an adhesive when activated by the addition of monomers or polymer formaldehyde. Such resin systems are not useful as thermosetting resins for the production of composite products.

Shea (US Pat. Nos. 4,107,127 and 5,202,189) discloses a reinforced thermosetting plastic composite product that exhibits low flame propagation, good heat release and low smoke emission when exposed to fire and high thermal conditions and is resistant to brittleness and cracking upon curing. In order to prepare room temperature curable compositions useful for the preparation, the production of novolak resorcinol reinforced resin compositions containing at least 60% solids (with or without phenol) and containing formaldehyde or paraformaldehyde are disclosed. Shea discloses that a suitable novolak resin is produced in a single phase, the initial step is to mix phenol and, if necessary, resorcinol with formaldehyde (substantially formaldehyde or paraformaldehyde or mixtures thereof) and form A slight lack of aldehyde preheats the resulting mixture to the point of preventing curing of the resin until termination. Shea also discloses that the resin system is alkaline and based on using various inorganic hydroxides as catalysts. Shea also discloses a viable range of ingredients required in the invention of his novolak invention (Table 1).

ingredient Weight portion Resorcinol 35 to 100 phenol 0 to 40 Formaldehyde 15 to 35 Catalyst + solvent 20 to 115

Specifically, Shea is a resorcinol and phenol lacking the molar amount of formaldehyde relative to resorcinol, or phenol (or modified phenol or combination thereof), 20 to 115 parts by weight of alkaline metal hydroxide catalyst + solvent, and 15 to 35 weight It is disclosed to produce a novolak resin using negative formaldehyde. Shea also discloses that the reactivity of higher solids resins differs from that of lower solids resins. Shea also discloses that certain curing agents may include paraformaldehyde in addition to formaldehyde in solution. Shea also discloses a special thermoset reinforced resorcinol resin of at least 60% solids that exhibits excellent fire resistance and low flame and smoke generation. Shea also claims that the subject invention can be cured at room temperature. Shea, for example, in its Table 5, discloses the casting of a 71% solids resin containing 28 parts by weight of 37% formalin after 24 hours of curing. This claim of room temperature cure is an important part of the Shea invention.

The resin of the Shea patent was commercialized with Fireban® Mark V and Mark VII resins. Several different permutations have been made, all of which follow this principle. Fireban® resin was obtained to evaluate curing. Several casting and lamination experiments were performed to measure the cure cycle of the Shea resin. As a result of these experiments, the ability of the Shea invention to gel (cure) at room temperature was clearly confirmed.

Gelation rate (pot life) is an important consideration for those using the resin. If the gelation rate is too fast, consideration should be given to adequate wetting out of the reinforcement. The gelation time was dependent on the solids of the resin, the aldehyde form used, the pH of the resin, room temperature and the resin temperature, with a gelation time of 15 to 40 minutes being representative. The information in Table 5 of the Shea patent makes me believe that the molds and laminates obtained above at room temperature could be cured within 24 hours.

An important consideration in the composite industry is the degree of cure achieved within a given time. This is often considered in terms of curing against gelling (vs.) and curing (vs.). If the resulting composite product is not sufficiently cured, various important properties (tensile, flexural and compressive strength, etc.) cannot be sufficiently obtained. Inadequately cured products could lead to catastrophic failure. By measuring the hardness of the thermosetting material, the degree of curing can be predicted. By comparing the hardness of known fully cured (final cured) specimens against the hardness of the newly created mold or laminate, the degree of curing of the material can be readily determined. Target measurements (the desire to claim the composite to cure) are often measurements of up to 85% of fully cured specimens. For example, in the applicable data sheet of the Shea patent, a fully cured Shea Fireban® Mark VIITM resin (subject of Shea invention) is shown to have a Barcol Hardness of 45-50 when fully cured. As a result of specific experiments for measuring the degree of curing at room temperature, the Bacol hardness obtained after curing at room temperature for 24 hours was found to be zero (0). Indeed, flat laminates cured at room temperature showed no detectable Bacol hardness up to several days to one week (depending on room temperature). Standard ASTM test results for tension, flexion and compression resulted in substandard results for laminates cured to room temperature up to 8 weeks. However, if curing was finally achieved, whether at room temperature or with the aid of an elevated temperature, the resulting laminate exhibited the claimed mechanical properties. As such, it is evident that the Shea resin is curable at room temperature.

The Shea resin was produced to lack formaldehyde and needed additional formaldehyde to cause crosslinking. Shea discloses the use of Fireban® (55% formaldehyde, 35% methanol and 10% methoxymethanol or water) as one of the preferred curing agents. Unfortunately, this combination (resin + hardener) tends to generate smoke (release free formaldehyde). Shea and Ghiorso have done a great deal of research to prepare useful nonformaldehyde crosslinking substituents (WIPO International Publication No. WO 2004/029119) used to help increase the amount of Shea resin (US Pat. No. 5,202,189). It has been found that gelling time of 1 minute to 1 week (or more) can be taken. Unfortunately, the Shea resin still tends to break (the resulting composite tends to cut and generate dust when exposing the glass fibers), so that the resin's adhesion to the fiber is relatively weak and significant deformation It has been found that modification needs to be used for non-ductwork. The practical limitation of the Shea invention appears to be that of duct piping and other tubular (self-supporting) composite products.

Dailey in U.S. Pat.Nos. 5,075,413 and 5,075,414 is a thermosetting reinforcing resin composition, i. Solid to produce a stable (uncured) resin solution containing component A consisting of at least a lecinol-formaldehyde acid-catalyzed novolak reinforced resin and (b) a crosslinking agent (paraformaldehyde) required to cure component A It is preferably about 55 to 67% and the paraformaldehyde content is preferably 35 to 43%, preferably a two-component type consisting of Part B which is a phenol resol reinforced resin obtained through a reaction carried out in the presence of an alkaline catalyst. A process for preparing a liquid-liquid pre-catalyzed composition is disclosed. Finally, component A and component B are mixed with each other so that the paraformaldehyde (premixed in component B) can react with the resorcinol novolak reinforced resin of component A to obtain a cured (crosslinked) fire resistant composition. Done. The premixed paraformaldehyde of component B is a methylene donor for component A, which causes crosslinking (curing) of the resin composition. Dailey also discloses the use of additional methylene donors for the purpose of increasing the strength of the reinforced plastics by reducing the mixing viscosity (viscosity regulator) to improve the processing and deposition of the reinforcing materials and to increase the crosslinking density. As such, it is evident that Dailey did not consider the use of additional methylene donors in the same definition as the methylene donors used to promote crosslinking (curing) of the thermosetting phenol or resorcinol resin compositions.

Dailey also discloses that the preferred "additional methylene donor" suitable for this purpose (viscosity control) is a material selected from the group consisting of furfural, furfuryl alcohol, oxazolidine, ecrolein and combinations thereof. Furfural, furfuryl alcohol and acrolein are among the well known methylene donors. However, it is well known to those skilled in the art that many oxazoline compounds are available, some of which are reactive (good formaldehyde donors) and others that are not reactive. It is also well known that some oxazoline compounds are reactive at room temperature when thermally activated. Thus, not all oxazoline compounds are known to be useful methylene donors, which may or may not be useful "methylene donors" as defined in Dailey's definition. All examples provided by Dailey used furfural without providing an example for any particular oxazoline compound suitable for use as an "additional methylene donor." Dailey has found that certain reinforcement resin compositions that cure at room temperature can use "additional methylene donors" as density modifiers to reduce the viscosity of fire resistant reinforced thermoset plastic compositions, improve wet out and increase crosslink density. It is disclosed that there is. Dailey also discloses that acid catalyzed novolacs can be used with base catalyzed resols and “additional methylene donors”.

Dailey also discloses that the resin can be cured within 20 hours to 0.06 hours at a temperature of about 16 to 160 ° C. Dailey also discloses that the cure occurs at room temperature (12 ° C. to 35 ° C.) within 8 to 14 hours. In practice, however, such resin systems required elevated temperature thermosetting.

The problem to be solved by the present invention is to provide a low-temperature curing liquid hydroxymethyl thermosetting composition (lacking aldehyde or substituted aldehyde) in the presence of alkali metals and / or amines using aldehydes and / or substituted aldehydes.

In addition, other solutions of the present invention include formaldehyde, paraformaldehyde, "hexa" oxazolidine, nitroalcohol, nitroamine, imine, amine-nitroalcohol, hexahydropyrimidine, nitron, hydroxylamine, nitro- Low temperature curable liquid hydroxymethyl thermoset compositions that can be used with various aldehyde and non-formaldehyde hardeners, including olefins, nitroacetals, and variants, permutations, and variations thereof. In providing.

In addition, another problem of the present invention is to provide a low-temperature curing liquid hydroxymethyl thermosetting composition that can be used with various crosslinking compounds.

The low temperature curable liquid hydroxymethyl thermosetting composition of the present invention comprises a hydroxy group component (A), an aldehyde or a substituted aldehyde (B), an alkali metal catalyst (C) of less than 15 parts by weight, and an alkali metal catalyst having a total weight of less than 15 parts by weight. It is characterized by consisting of a solvent (D).

Preferably, the hydroxy group component is any one selected from phenol, resorcinol, bisphenol, phloroglucinol crasol, alkyl phenol, phenol esters, tannins, lignin, melamine, urea and other hydroxyl group components and mixtures thereof. It is done.

Preferably, the aldehyde or substituted aldehyde is formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, cyclohexanedicarboxaldehyde, benzaldehyde ,. Furfural and other aryl or heterocyclic aldehydes, amines, nitro paraffins (and derivatives), reactive oxazolines and mixtures thereof.

Preferably, the solvent is characterized in that it is water or an organic solvent when used.

In addition, the low-temperature-curable liquid hydroxymethyl thermosetting composition of the present invention is a hydroxy group component (A), less than 15 parts by weight of aldehyde or substituted aldehyde (B), less than 15 parts by weight of an alkali metal catalyst (C), and a total weight of 15 parts by weight. It is characterized by consisting of a reaction product of less than a portion of the alkali metal catalyst + solvent (D).

The present invention can produce synthetic liquid resol / novolak resins (lacking aldehydes or substituted aldehydes) catalyzed in the presence of alkali metal catalysts and / or amines.

In addition, the present invention is formaldehyde. Paraformaldehyde, "hexa" oxazolidine, nitroalcohol, nitroamine, imine, amine-nitroalcohol, hexahydropyrimidine, nitron, hydroxylamine, nitro-olefins, nitroacetals, and variants thereof Synthetic liquid novolac resin systems can be prepared that can be used with a variety of aldehyde and non-formaldehyde hardeners, including permutations, variants, and the like.

In addition, the present invention can produce synthetic liquid novolac resin systems having less than 1 ppm of free formaldehyde that are considered to be free of formaldehyde.

In addition, the present invention can produce a synthetic liquid resin system that can be used with various glass fiber reinforcement and can be cured at various temperatures and pressures.

In addition, the present invention can produce a composite product having high resistance to flame and flame impingement.

In addition, the present invention allows the production of composite products with little tendency to autoignite upon exposure to radiant (indirect) heat.

In addition, the present invention can produce a composite product that generates little smoke upon exposure to direct flame impact conditions and indirect heat radiation sources.

In addition, the present invention can produce a synthetic resin with reduced fractureability and increased adhesion of the resin to the reinforcing material.

In addition, the present invention provides high heat deflection temperature (HDT), high glass transition temperature (Tg), high thermal reaction parameter (TRP), low maximum heat release rate (PHRR), low flame propagation index (FPI) and low smoke damage index ( A curable synthetic liquid novolak resin (lacking aldehyde or substituted aldehyde) can be prepared that can be used to provide with SDI).

The following examples are provided to illustrate certain features and / or embodiments.

The novel synthetic liquid novolac resin, which is one of the low temperature curable liquid hydroxymethyl thermosetting compositions of the present invention, is made by reacting an aldehyde-reactive resin-forming compound with an aldehyde and / or an aldehyde substituted compound and / or an amine and / or combinations thereof. Manufacture. Specifically, the composition is reacted with an alkali metal catalyst in an amount of less than 100% so that the molar ratio of aldehyde and / or aldehyde substituted compound to the hydroxy functional compound is less than 1.

In addition, the novel synthetic liquid novolak resin, another low temperature curable liquid hydroxymethyl thermosetting composition of the present invention, uses less than 15 parts by weight of alkali metal catalyst and / or catalyst + solvent and / or other catalyst based on the total weight. The amount of alkali metal catalyst used to achieve the condensation reaction can vary over a relatively wide range between about 0 to about 15 parts by weight, typically an aldehyde-reactive resin-forming compound (eg, phenol, substitution Less than about 10 parts by weight based on 100 parts by weight of phenol).

An aldehyde-reactive resin-forming compound has two or more aldehyde-reactive hydrogen sites in its molecule. The aldehyde-reactive resin-forming compound includes aminotriazine, urea, phenol and the like.

Phenol is the preferred starting material, but ortho-cresol, meta-cresol, para-cresol, para-tert-butyl-phenol, para-octylphenol, para-nonylphenol, paraphenol, bisphenol, resorcinol, phlogrog Substituted phenols such as rucinol, tannin, lignin, and cashew nut shell liquid can be used without limitation, alone or in combination. Of these, phenol and resorcinol are particularly preferred as starting materials.

Aminotriazines that may be used alone or in combination include, but are not limited to, acetoguanamine, amlides, amelin, benzoguanamine, formmoguanamine, melamine, and the like. Urea compounds include, but are not limited to, urea itself, ethylene urea, and the like. Urea and melamine are particularly preferred.

Aldehyde compounds that can be used alone or in combination include acetaldehyde, acrolein, benzaldehyde, butyraldehyde, cyclohexanedicarboxaldehyde, formaldehyde, furfural, heptaaldehyde, hexamethylenetetramine and other amines (e.g. , 4,4-dimethyl oxazolidine, 7-ethylbicyclooxazolidine), pentaaldehyde, propionaldehyde, other aryl or heterocyclic aldehydes, and the like. For most purposes, formaldehyde is preferred for the resin's reaction in view of its reactivity, availability and cost.

During the discovery of the present invention, resins of various forms and properties were prepared and identified. These embodiments are disclosed by way of example. Typically, the viscosity ranged from 100-cps to 8,000-cps, and the nonvolatile content (solid content) ranged from about 50 to 80% or more. It is known to those skilled in the art that the viscosity and nonvolatile content of such resins can be easily adjusted. In order to effectively prove the gist of the present invention, the examples disclosed herein are carried out from phenol and resorcinol, but other aldehyde-reactive resin forming compounds may also be readily used. The addition of aldehydes (or equivalents) is carried out so that the molar amount of aldehydes relative to phenol, resorcinol or combinations thereof is insufficient. However, it will be apparent to those skilled in the art that an excess of aldehyde prepared in one step can be offset by an insufficient amount of aldehyde produced in another step and the final result is still lacking. These examples are not to be construed as limiting the invention to the features and embodiments described herein.

In all examples, a 500-mL reactor with a stirrer, thermometer, vacuum device, reflux condenser and addition funnel was used. After the reaction is completed, the reaction temperature is adjusted if necessary, and then the water distillate is removed under normal pressure and reduced pressure. Several confirmation steps are used to adjust the nonvolatile content, pH and viscosity. All resins were filtered prior to dispensing into suitable storage containers before use.

To further confirm the control, these novolac resins are crosslinked using the following:

1) aldehyde (formaldehyde or paraformaldehyde).

2) curing agents (as generally described by Swedo and Ghiorso).

It is well known to those skilled in the art that various fire and heat resistance tests can be used to predict the behavior of the composite material during fire conditions. The most common is the ATSM E-84 tunnel test. Another more rigorous test is the FM Approved FM 4910 Flammability Apparatus Test.

The ASTM E-84 (Steiner Tunnel) test is probably the most widely used fire test device in North America. It has many different names and test names, including UL 723, NFPA 255, ANSI 2.5, UBC 8-1, and more generally "tunnel test". The "tunnel test" is performed in a tunneled chamber about 1 foot high, 1.5 feet wide and 25 feet long. A damper and a burner are located at one end, and a damper set and a chimney are located at opposite ends. Closed viewing windows are located along the sides. The material to be tested is fixed to the tip of the tunnel.

Initially, the tunnel is tested by testing the asbestos cement board. The distance the flame travels down the specimen is used in the formula and the result is set to zero flame propagation. Next, the red oak flooring is tested. Use the time required for the flame to travel along the length of the specimen in the equation and record the result as 100 flame propagation. Next, the material to be evaluated is tested in the same way and the results are compared with the test values for asbestos cement board and red oak. This comparison is used to determine the flame propagation class.

The most commonly approved flame spread classification system is the National Fire 6 Protection Association Life Safety Code, NFPA No. 101, which applies to interior wall and ceiling finishes. This code group, namely the class of flame propagation and smoke generation, is shown in Table 2 below:

Bracket Flame propagation Smoke generated A (1) 0-25 0-450 B (2) 26-75 0-450 C (3) 76-200 0-450

Tests according to the FM 4910 test protocol assess the flame propagation behavior of materials, the likelihood of smoke generation, and the possibility of contamination by corrosion products of combustion using FPI and SDI indices. Certain parameters have been set to confirm the ability of the test material to be classified and labeled as a "fire safe" material suitable for use in a semiconductor clean room (Table 3).

Test FM 4910 Limit week Flame Propagation Index (FPI) <6.0 No sustained flame propagation on its own Smoke Damage Index (SDI) <0.4 Almost no smoke during fire

Both test protocols have specific parameters for evaluating the performance of the material. These parameters can be used to indicate whether the test material meets certain desired requirements. Using this test, the fire resistance of the material was evaluated. Although not a limiting factor, the desired results for the novel synthetic liquid novolac resins obtained of the present invention are ASTM E-85 Class A grades. In some cases it is also desirable to use a useful FM 4910 test protocol number. The results of some of the experiments presented here indicate the ASTM E-84 Class rating and indicate whether the FM 4910 limit has been exceeded.

The following examples are provided to illustrate the principles of the invention and are not intended to limit the scope of the invention.

Example 1 Synthesis of Liquid Phenol-Formaldehyde, Resorcinol-Formaldehyde, Melamine-Formaldehyde (etc.) Resol Resins

New synthetic liquids by combining formaldehyde reactive compounds (phenol, substituted phenols (ie resorcinol), urea or melamine) (P) with aldehydes (F) in a molar ratio greater than 1 ((F: P> 1) Preferred examples of phenol-formaldehyde, resorcinol-formaldehyde or melamine-formaldehyde resol resins are prepared.

Charge the material into the reactor and adjust the temperature to a temperature above 45 ° C. Check pH and RI. Less than 15 parts by weight of alkali metal catalyst is slowly added. This composition is reacted at the set temperature. The temperature is then adjusted to at least 70 ° C. and maintained at that temperature until the desired viscosity is achieved. Various viscosity modifiers such as water, methanol or ethanol can be used to reduce the viscosity if necessary. Once the desired viscosity is obtained, the liquid resin is cooled, filtered and stored for later use. Specifically, the amount of alkali metal catalyst + viscosity modifier (solvent) is less than 15 parts by weight. The novel synthetic liquid resol resins prepared in this example are generally phenol-2 formaldehyde (PF), resorcinol-formaldehyde (RF), urea-formaldehyde (UF) and melamine-formaldehyde (MF). Known. The PF resol and RF resol prepared as described above are shown in Tables 4 and 5.

Classification Molar weight mole weight% phenol 94.11 One To 50 Formaldehyde 30.03 > 1 > 13 NaOH 39.99 <0.5 <8

Classification Molar weight mole weight% Resorcinol 110.1 One To 50 Formaldehyde 30.03 > 1 > 13 NaOH 39.99 <0.5 <8

Example 2: Synthesis of Resol Resins of Liquid Phenol-Formaldehyde, Resorcinol-Formaldehyde, Melamine-Formaldehyde (etc.) with Reduced Formaldehyde Release ("Free Formaldehyde")

Preferred examples of novel synthetic liquid phenol-formaldehyde, resorcinol-formaldehyde or melamine-formaldehyde resol resins such that the molar amount of formaldehyde exceeds 1 (F: P> 1) are described in Example 1 Prepare as described. The excess formaldehyde is captured by adding ammonia and / or ammonia-containing compounds (urea, amines, etc.) to a stoichiometric equivalent of formaldehyde. The components of PF resol with reduced free formaldehyde and RF resol with reduced free formaldehyde are shown in Tables 6 and 7.

Classification Molar weight mole weight phenol 94.11 One To 50 Formaldehyde 30.03 > 1 > 13 NaOH 39.99 <0.5 <8 Capture agent variable > 0.05 > 0.5

Classification Molar weight mole weight% Resorcinol 110.1 One To 50 Formaldehyde 30.03 > 1 > 13 NaOH 39.99 <0.5 <8 Capture agent variable > 0.05 > 0.5

Example 3: Synthesis of Liquid Phenol-Resorcinol-Formaldehyde Novolak Resin

A novel synthetic liquid phenol-resorcinol-formaldehyde novolak resin by combining a resol resin as generally described in Examples 1 to 2 with a synthetic liquid novolac resin as generally described in Examples 5 and 6 Another preferred example of is prepared. Specifically, the combination of liquid phenol resol and liquid resorcinol novolac has particular utility in the present invention. Thus, 100 parts by weight of the phenol resin is combined with 5 to 100 parts by weight or more of resorcinol novolac to prepare a synthetic liquid phenol-novolak resin. In particular, R: P> 0.1. It is well known to those skilled in the art that resol can be combined with novolac to obtain a resol resin. For this example, particular attention is paid to the stoichiometric ratio to ensure F: P (or substitution P) <1, and additional crosslinking agents are added.

Example 4 Synthesis of Liquid Phenol-Resorcinol-Formaldehyde Novolak Resin

A preferred example of a novel synthetic liquid phenol-resorcinol-formaldehyde novolak resin is prepared by combining phenol (P) with aldehyde (F) to a molar ratio (F: P <1) of less than one.

Charge the materials into the reactor and adjust the temperature to a temperature above 45 ° C. Check pH and RI. Less than 15 parts by weight of alkali metal catalyst is slowly added. This composition is reacted at the set temperature. The temperature is then raised to a temperature above 70 ° C. and maintained until the desired viscosity is achieved. Next, resorcinol (R) is added. This addition lowers the temperature. The resorcinol is maintained at a temperature close to the initial temperature until dissolved. The composition is heated to reflux and maintained at that temperature. The temperature is then reduced to add aldehyde (F) or substituted aldehyde, with the total amount of aldehyde being an stoichiometrically insufficient amount. After the addition of the aldehyde, the temperature is cycled in stages and maintained at a temperature above 70 ° C. Finally, the temperature is controlled to terminate the reaction and dehydrate. Once the desired viscosity is obtained, the liquid resin is cooled and filtered. Specifically, the amount of alkali metal catalyst + viscosity modifier (solvent) is less than 15 parts by weight based on the total weight of the resin. The total amount of aldehyde added is generally less than 15% by weight based on the weight of the resin. The novel synthetic liquid novolak resins obtained are generally known as phenol-resorcinol-formaldehyde (PRF) resins. It is known to those skilled in the art that other resins such as PMF, PUF, RUF, RMF and the like can also be prepared. Thus prepared PRF novolac, PRF novolac components are shown in Table 8 and Table 9.

Classification Molar weight mole weight% phenol 94.11 One To 50 Resorcinol 110.1 0.12 ~ 5 Formaldehyde 30.03 <1 <15 NaOH 39.99 <0.5 <8 menstruum 18.02 <5 > 25

Classification Molar weight mole weight% phenol 94.11 One ~ 25 Resorcinol 110.1 1.2 ~ 40 Formaldehyde 30.03 <1 <15 NaOH 39.99 <0.5 <5 H ₂ O 18.02 <5 > 10

Example 5: Synthesis of Liquid Phenol-Resorcinol-Formaldehyde Novolak Resin

Another example of a novel synthetic liquid phenol-resorcinol-formaldehyde novolak resin is prepared by combining phenol (P) with aldehyde (F) so that the molar ratio is less than 1 (F: P <1).

The materials are charged to the reactor and the temperature is adjusted to a temperature above 45 ° C. Check pH and RI. Less than 15 parts by weight of alkali metal catalyst is slowly added. This composition is reacted at the set temperature. The temperature is then raised to a temperature above 70 ° C. and maintained at that temperature until the desired viscosity is achieved. Next, RF resin (prepared in Example 1) is added in a desired amount and complexed. Next, the PRF resin is obtained and the temperature and viscosity are adjusted to terminate the reaction. Once the desired viscosity is obtained, the liquid resin is cooled and filtered. Specifically, the amount of alkali metal catalyst + viscosity modifier (solvent) is less than 15 parts by weight based on the total weight of the resin. The total amount of aldehyde added is generally less than 15% by weight based on the weight of the resin. The novel synthetic liquid novolak resins obtained are generally known as phenol-resorcinol-formaldehyde (PRF) resins.

Example 6 Synthesis of Phenol-Resorcinol-Formaldehyde Resin

Another example of a novel synthetic liquid phenol-resorcinol-formaldehyde is prepared from a resin prepared as described in the above examples. Select PF resin and add RF resin to it. The novel synthetic liquid novolak resins obtained are generally known as PRF resins. It can be seen that PMF, PUF and PMRF resins can be prepared using this method.

Example 7 Synthesis of Phenol-Resorcinol-Formaldehyde Novolac Resin from Resol

Another preferred example of a novel synthetic liquid phenol-resorcinol-formaldehyde resin is prepared by using the purchased basic phenol resol and adding the RF resin prepared as described in the above examples. The novel synthetic liquid novolak resins obtained are generally known as PRF resins. It can be seen that the basic PF resin can be easily prepared. It can also be seen that PMF, PUF and PMRF resins can be prepared using this method.

Example 8 Synthesis of Phenol-Resorcinol-Formaldehyde Resin from Resol

Another example of a novel synthetic liquid phenol-resorcinol-formaldehyde resin is prepared by using the purchased basic phenol resol and adding PRF prepared as described in Example 2. The novel synthetic liquid novolak resins obtained are generally known as PRF resins. It can be seen that the basic PF resin can be easily prepared. It can also be seen that PMF, PUF and PMRF resins can be prepared using this method.

Preparation of Standard Composites

One advantage of the fiber reinforced thermoset plastic composites of the present invention is that the composites can be prepared using representative methods for conventional composite preparation. Examples thereof include water lamination, filament winding, vacuum bagging, resin transfer molding (RTM) and vacuum assisted resin transfer molding (VARTM), but all methods of providing fiber reinforced thermosetting plastic resins can be used. Can be. These methods are not mutually exclusive and may be used together. In some cases, the fiber reinforced material is impregnated with a thermoset polymer (prepreg) prior to forming the molded article. Reinforcing fiber (filament) fabrics or mats impregnated with a thermosetting polymer may be made in the form of pre-preg and stored for later use in, for example, molds, windings or water laminations.

Hand lay-up is the simplest and oldest open molding method of the composite manufacturing process. Typically, components of the reinforcement impregnated with the fiber reinforcement or thermosetting polymer or a continuous ply are added to the mold, the composite is made and processed by hand. Curing (crosslinking) generally takes place at room temperature, but if desired, it may be accelerated by heating or by adding a curing initiator. Typically placed manually in a reinforcing mat or reinforcing fiber one side open mold, such as a woven or roving, the thermoset polymer is injected, brushed or sprayed into the fiber (wet lamination). Hand rollers may also be used to penetrate the thermosetting polymer into the thickness portion of the fiber mat. Typically, trapped air or excess thermoset polymer is removed using a rubber mop and / or roller to complete the structure. The structure is cured and then removed from the mold. Since this process is not typically carried out under the influence of heat and pressure, simple apparatus and tools can be used.

The vacuum bag molding method, which is an improvement of the water lamination method, uses vacuum to remove trapped air and excess thermosetting polymer. After fabricating the laminate structure on the male or female mold, typically a non-adhesive film is placed on the laminate structure and sealed at the mold flange. The composite is cured at room temperature or elevated temperature while vacuuming the bag made of the film. In contrast to the water lamination method, the vacuum bag molding method has a higher concentration of reinforcing agent, better adhesion between layers, and a better control of the polymer / fiber ratio.

In the case of the filament winding method, a continuous fiber reinforcement (filament winding glass) is wound on a suitable mandrel. The shape of the final product is determined by the shape of the mandrel. Typically, the resin impregnated strands of the amount and direction required to produce the desired reinforcing structure by the filament winding device are wound on the mandrel. In addition, the filament winding may be carried out dry and the resin may be applied in a later step. Generally, fiber reinforcements are rovings dispensed from creels. Through the guide and the tensioning device, the strand is released under controlled conditions. In some cases, the filament winding method utilizes pre-impregnated filaments. A full bath or transfer roller device impregnates the filament strand with the resin and controls the amount of the resin. Thus, the impregnated strands are wound in several pieces on a rotating mandrel using an automated filament winding machine. After this wet winding step, the mandrel on which the composite structure is wound is cured while rotating. Upon thermosetting, the resin polymerization is complete and the mandrel is removed. Sometimes the mandrel may remain intact in the final composite product ("liner" portion).

The filament winding method may also be used to produce a braided fiber composite material. A unique feature of the braiding method is the ability to bond continuous fibers in an orientation form on a mandrel of any shape or size. The braiding method creates an interlaced structure of continuous fibers, providing stability to the pre-form and providing strength-to-weight properties to the final product. Forming the braid under tension eliminates the possibility of plies and wrinkles or pinching.

Resin transfer molding (RTM), also known as resin injection, is a hermetically sealed mold injection system. This method utilizes a thermoset polymer material system associated with cold forming and is compatible with most reinforcement forms such as continuous strands, cloths, woven rovings, long fibers and chopped strands. This method consists of filling the tight and closed mold cavity by injecting the resin through one or several points depending on the size of the components. After the reinforcement is pre-positioned inside the mold, the mold is sealed and firmly fastened. Depending on the production rate required, different types of molds are available. Heat may be applied to shorten the curing time, in which case a steel mold may be required. The reinforcement may be a continuous filament mat, a composite or a woven fabric, but generally a continuous filament mat is used. With "pre-forms" obtained using continuous strand mats, a significant increase in production rate can be achieved. The use of pre-flags for hardening high performance composite structures has been a state of the art for over 30 years. Recently, the aerospace industry has undertaken cost reduction programs for composite aircraft components to obtain aerospace grade composite structures using vacuum assisted resin transfer molding (VARTM) manufacturing methods. This method has been used in other industries for a while.

Vacuum Assisted Resin Transfer Molding (VARTM) is a method in which liquid fibers are transferred using vacuum only into a dry fiber “pre-form” located within a mold cavity with only one tool surface. VARTM parts are formed in open cavity molds, so not all surfaces are molded with tools. The surface opposite the tool surface is mainly a vacuum bag surface consisting of a transfer medium, a peel ply fabric, a drawer / breather medium, and a sealing tape. Since the one tool can typically be a computer numerical control machined to high tolerances, the shaped surface can be complex in shape and very precise. This is important for many large parts where dimensional control and tolerance of only one surface is required and surface finishing becomes important. For complex shapes, there are methods such as "caul plates" for simultaneously applying vacuum bag pressure (typically about 15 psi) to complex surfaces of different orientations. Mirror plates used in the VARTM method have the primary purpose of controlling areas where thickness is important on the vacuum bag surface of the stack, but cannot achieve tolerances as high as RTM with a pair of metal tools.

Pultrusion is a continuous process for producing various reinforced plastic shapes of uniform cross section. Fiber reinforcements, such as one-way roving and multi-directional glass fiber mats, are guided to all fibers sufficiently wetted through a liquid resin bath. The reinforcement is guided and molded into a profile to be manufactured before entering the die. As the resin material proceeds through the die and is molded to conform to the design profile, the resin turns into a gel in the liquid phase and finally becomes a hardened hard composite. A pulling device secures the cured material and pulls the material laterally through the die. (Hence the name pultrusion). After the cured product has passed through the drawing device, it is cut to the desired length. Drawing is ideally suited to custom shapes, but some standard products include rods, bars, angles, channels, and I-beams.

The following examples are provided to illustrate certain features and / or embodiments. These examples are not to be construed as limiting the invention to the particular features or embodiments described herein.

Experimental Example 1-Lamination

Simple water laminates were prepared using four layers of woven roving and three layers of chopped strand mats. A stoichiometric amount of curing agent was incorporated to promote curing, and the necessary laminates were prepared using the resins obtained in the above examples. Resin of each Example was used. Various reinforcements were tested, including E-glass, ECR-glass, S-glass, S2-glass, carbon, Basalt, stainless steel cloth and various aramids. The gelation time at room temperature was recorded and then the laminate was brought to a "cured state" using elevated temperature. In general, the elevated temperature was less than 100 ° C. However, this temperature was not limited after hard gelation was achieved. The limiting factor of the uncontrolled (open mold) curing process was the release of water during the curing (condensation reaction). The data below is the average of the results for these resins using a number of different curings.

a) formaldehyde-based curing agent; Gelation in 30 minutes; Cured Bacol Hardness: 45-55

b) paraformaldehyde-based curing agent: gelation in 45 minutes; Cured Bacol Hardness: 45-55

c) ZT-55 (ducyclic oxazolidine); Gelation in 30 minutes; Cured Bacol Hardness: 35-40

d) TG-33C (ducyclic oxazolidine); Gelation in 30 minutes; Cured Bacol Hardness: 45-55

e) NFC-2836 (ducyclic oxazolidine); Gelation in 20 minutes; Cured Bacol Hardness: 35-45

f) TG-33CT (modified cyclic oxazolidine); Gel in 45 minutes; Cured Bacol: 45-55

g) TG-30CT (modified bicyclic oxazolidine); Gel in 90 minutes; Cured Bacol: 45-55

h) TG-28CT (modified bicyclic oxazolidine); Gelation in 2 hours; Cured Bacol: 45-55

i) TG-24TN (modified nitroalcohol); Gelation in 4 hours; Cured Bacol: 50-60

j) TG-24CT (modified bicyclic oxazolidine); Gelation in 4 hours; Cured Bacol: 50-60

k) TG-22CT (modified bicyclic oxazolidine); Gelation within 6 hours; Cured Bacol: 45-60

l) TG-20CT (modified bicyclic oxazolidine); Gelation within 12 hours; Cured Bacol: 45-55

m) TG-20TN (modified nitroalcohol); Gelation within 12 hours; Cured Bacol: 50-60

n) TG-100TN (modified nitroalcohol); Gel in 36 hours; Cured Bacol: 45-55

ASTM E-85: Class A (1)

FM-4910: FPI <6.0 & SDI <0.4

Experimental Example 2-Filament Winding

In general, the resin was prepared in the above examples. The appropriate curing agent was selected and the appropriate amount was added to cause crosslinking. Simple filament wound parts were made using circumferential and spiral outer windings. Various reinforcements were tested, including E-glass, ECR-glass, S-glass, S2-glass, carbon, basalt, stainless steel cloth and various aramids. A filament winding product was produced without difficulty according to a conventional procedure. Direct injection filament externalization and more traditional open resin bath methods were used. The pot life of the resin bath was about 30 minutes before gelling for 24 hours at room temperature. The filament winding product was gelled and then cured using heat for 3 hours at a temperature below 100 ° C. Further experiments confirmed that pot life can be further controlled using temperature and / or pH. Some parts were cured at room temperature, while others used heat to promote hardening. The preparation method using the resin obtained in Example 6 confirmed a significant reduction in free formaldehyde emissions after a short mixing cycle. There was no detectable "free formaldehyde" during the manufacturing process.

ASTM E-85: Class A (1)

FM-4910: FPI <6.0 & SDI <0.4 34

Experimental Example 3-VARTM

In general, the resin was prepared in the above examples. The appropriate curing agent was selected and the appropriate amount added to cause crosslinking. Preforms were prepared using a variety of reinforcements including E-glass, ECR-glass, S-glass, S2-glass, carbon, basalt, stainless steel cloth, and various aramids. Simple injections were made. Direct injection infusion and resin pot methods were used. The pot life of the selected resin pot was about 40 minutes before gelation at room temperature and there was no release of free formaldehyde. Curing was promoted using heat for several hours at temperatures below 100 ° C. The obtained Bacol hardness exceeded 85% of the value obtained in the final cured specimen.

ASTM E-85: Class A (1)

FM-4910: FPI <6.0 & SDI <0.4

Experimental Example 4: Drawing

In general, the resins were prepared in Examples except Examples 9 and 10 above. The appropriate curing agent was selected and the appropriate amount added to cause crosslinking. According to a special process, the molded parts were manufactured without any difficulty. The multiphase curing method was used. "Resin bath" and "direct injection" pultrusion methods were used. Barcol hardness exceeded 85% of the value obtained for the fully cured specimen. During the pultrusion process, there was no detectable release of “free formaldehyde”.

ASTM E-85: Class A (1)

FM-4910: FPI <6.0 & SDI <0.4 16

Experimental Example 5: drawing molding using modified resol

In general, the resin was prepared as in Examples 9 and 10 above. The appropriate curing agent was selected and the appropriate amount added to cause crosslinking. According to a special process, the molded parts were manufactured without any difficulty. The crosslinking rate increased compared to standard resol. The multiphase curing method was used. "Resin bath" and "direct injection" pultrusion methods were used. Barcol hardness exceeded 85% of the value obtained for the fully cured specimen. During the pultrusion process, there was no detectable release of “free formaldehyde”.

ASTM E-85: Class A (1)

FM-4910: FPI <6.0 & SDI <0.4 28

Experimental Example 6: Prefrag

In general, the resin was prepared as in the above examples. The curing agent was selected from the combination of oxazoline and / or nitroalcohol compounds. The resin was placed in a "resin bath" and then the selected woven roving (cloth) was drawn through the resin bath, impregnated with the resin, and then cured to the desired B-step. The resulting prepreg was rolled into a package shape using a release film between the layers. The next day, the prepreg was unfolded if necessary, cut to the desired length and shape, and then laminated to the desired preform (removing the release film from the prepreg layers). The preform was then cured in a heated platen press for a predetermined time. Barcol hardness exceeded 85% of the value obtained for the fully cured specimen. During the prefragmentation and curing process, there was no detectable release of free formaldehyde.

ASTM E-85: Class A (1)

FM-4910: FPI <6.0 & SDI <0.4 44

Claims (6)

A low temperature curable liquid phase comprising a hydroxyl group component (A), an aldehyde or a substituted aldehyde (B), an alkali metal catalyst (C) of less than 15 parts by weight, and an alkali metal catalyst + solvent (D) having a total weight of less than 15 parts by weight. Hydroxymethyl thermosetting composition. Consisting of a reaction product of a hydroxy group component (A), less than 15 parts by weight of aldehyde or substituted aldehyde (B), less than 15 parts by weight of an alkali metal catalyst (C), and a total weight of less than 15 parts by weight of an alkali metal catalyst + solvent (D) Low temperature curable liquid hydroxymethyl thermosetting composition, characterized in that. The hydroxy group component according to claim 1 or 2, wherein the hydroxy group component is selected from phenol, resorcinol, bisphenol, phloroglucinol crasol, alkyl phenol, phenol ester, tannin, lignin, melamine, urea and other hydroxy group components and mixtures thereof. Low temperature curable liquid hydroxymethyl thermosetting composition, characterized in that any one. The method according to claim 1 or 2, wherein the aldehyde or substituted aldehyde is formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, cyclohexanedicarboxaldehyde, benzaldehyde ,. Low temperature curable liquid hydroxymethyl thermosetting composition, characterized in that it is one selected from furfural and other aryl or heterocyclic aldehydes, amines, nitro paraffins (and derivatives), reactive oxazolines, and mixtures thereof. The low temperature curable liquid hydroxymethyl thermosetting composition according to claim 1 or 2, wherein the solvent is water or an organic solvent when used. A thermosetting composite prepared using the low temperature curable liquid hydroxymethyl thermosetting composition according to any one of claims 1 to 5.