JP2008515761A - Water repellent glass fiber binder containing a fluorinated polymer - Google Patents

Abstract

  A glass fiber binder composition comprising a polycarboxy polymer, a polyol and a fluorinated polymer is provided. The binder also includes a catalyst that is preferably an alkali metal salt of a phosphorus-containing organic acid. The resulting binder provides a glass fiber product that exhibits minimal processing difficulty and minimal water absorption.

Description

  The present invention relates to polycarboxy polymer binding resins having improved water repellency properties. More particularly, the present invention relates to a thermosetting acrylic binder resin that is cured by crosslinking with a multifunctional, hydroxyl group reactive curing agent, the binder comprising a resin that exhibits minimal water absorption. Containing binder. Such a binder is useful as a substitute for a formaldehyde-based binder for nonwoven glass fiber products.

  Glass fiber binder is used to apply the binder to woven or non-woven glass fiber sheet products and cure to give the hardness to produce a more rigid product; to apply binder resin to sheets or bulky fibrous products After being dried, it has a variety of applications ranging from thermoforming applications, optionally B-stages, from which curable intermediates are formed; to fully cured systems such as building insulation.

  In general, fibrous glass insulation products include matted glass fibers bonded together by a cured thermoset polymeric material. The molten stream of glass is drawn into random length fibers, which are blown into a forming chamber and randomly deposited as a mat on a running conveyor. While moving through the molding chamber, the fibers are sprayed with an aqueous binder while still hot for the drawing operation. Phenol formaldehyde binders have been used throughout the fibrous glass insulation industry. Residual heat from the glass fibers and the air flow through the fibrous mat during the molding operation is generally sufficient to volatilize most of all the water from the binder, thereby making the remaining components of the binder viscous. Or on the fiber as a semi-viscous high solids liquid. The coated fibrous mat is moved to a curing oven where, for example, heated air is blown through the mat to cure the binder and firmly bond the glass fibers together.

  The glass fiber binder used in the sense of the present invention should not be confused with a matrix resin, which is a completely different and dissimilar technical field. Sometimes referred to as a “binder”, the matrix resin serves to fill all interstitial spaces between the fibers, resulting in a dense fiber reinforced product, where the matrix must convert the fiber strength properties into a composite. I must. On the other hand, in this specification, the “binder resin” does not fill a space but only covers a fiber, particularly a joint point of the fiber. Also, glass fiber binders cannot be equated with paper or wood product “binders” whose adhesive properties are adapted to the chemistry of the cellulosic substrate. Many such resins are not suitable for use as glass fiber binders. Those skilled in the art of glass fiber binders do not rely on cellulosic binders to solve any known problems with glass fiber binders.

  Binders useful in glass fiber insulation products generally have low viscosity in the uncured state and require properties that when cured will form a rigid thermoset polymer mat for the glass fibers. A low binder viscosity in the uncured state is necessary to make the mat accurately to a predetermined size. Also, viscous binders tend to be sticky or sticky and therefore these binders cause fiber buildup on the molding chamber walls. This accumulated fiber will later fall on the mat, causing problems in dense places and products. The final glass fiber thermal insulation product, when compressed for packaging and shipping, is rigid when cured to restore the vertical dimensions of the fabricated state when installed in a building. A binder that forms the matrix is required.

  Among many thermosetting polymers, there are a number of candidates for a suitable thermosetting glass fiber binder resin. However, binder-coated glass fiber products are often commodity products, and therefore price is a driving factor and generally excludes resins such as thermosetting polyurethanes, epoxies, and others. Due to its excellent price / performance ratio, the resin chosen in the past was a phenol / formaldehyde resin. Phenol / formaldehyde resins can be produced economically and can be augmented with urea before being used as a binder in many applications. Such urea-enhanced phenol / formaldehyde binders, for example, have long been the mainstay of the glass fiber insulation industry.

  However, over the past few decades, due to industry and federal regulations that want to provide a cleaner environment, extensive investigations to minimize volatile organic compound emissions (VOC) have resulted from current formaldehyde-based binders. It has been done not only to reduce emissions, but also to candidate alternative binders. For example, in the preparation of a basic phenol / formaldehyde resol resin, a slight change in the ratio of phenol to formaldehyde, a change in catalyst, and the addition of a different complex formaldehyde scavenger has previously been observed in the release from a phenol / formaldehyde binder. There was a considerable improvement compared to the binder used. However, due to increasingly stringent federal regulations, more attention has been paid to alternative binder systems that do not formaldehyde.

  One such candidate binder system uses a polymer of acrylic acid as the first component and a polyol such as glycerin or moderately oxyalkylated glycerin as the curing or “crosslinking” component. The preparation and properties of such poly (acrylic acid) -based binders, including information on VOC release, and a comparison of binder properties and urea-formaldehyde binders can be found in "Formaldehyde-Free Crosslinking Binders For Non-Wovens", Charles T . Arkins et al., TAPPI JOURNAL, Vol. 78, no. 11, 161-168, November 1995. It is believed that the binder disclosed by Arkins article is capable of B-stage and can provide physical properties similar to those of urea / formaldehyde resins.

  US Pat. No. 5,340,868 discloses a glass fiber insulation product that is cured with a combination of a polycarboxy polymer, a hydroxyalkylamide, and at least one trifunctional monomeric carboxylic acid such as citric acid. The particular polycarboxy polymer disclosed is a poly (acrylic acid) polymer. See also US Pat. No. 5,143,582.

  US Pat. No. 5,318,990 discloses a fibrous glass binder comprising a catalyst comprising a polycarboxy polymer, a monomeric trihydric alcohol and an alkali metal salt of a phosphorus-containing organic acid.

  The published European patent application EP 0 583 086 A1 appears to provide details on polyacrylic acid binders whose curing is catalyzed by a phosphorus-containing catalyst system, as discussed in the Arkins article cited above. is there. High molecular weight poly (acrylic acid) is described which provides a polymer that exhibits more complete cure. See also U.S. Patent Nos. 5,661,213; 5,427,587; 6,136,916; and 6,221,973.

Some polycarboxy polymers have been found useful for making glass fiber insulation products. Provides a finished product that exhibits the necessary recovery and stiffness to provide a glass fiber insulation product problem, as well as the problem of glass fiber agglomerating or sticking inside the molding chamber during processing To do has already been overcome. See, for example, US Pat. No. 6,331,350. However, thermosetting acrylic resins have been found to be more hydrophilic than traditional phenolic binders. This hydrophilicity can result in a glass fiber insulation that is more likely to absorb liquid water, possibly jeopardizing the integrity of the product. It has also been found that the thermosetting acrylic resins to be used as glass fiber binders do not react effectively with the types of silane coupling agents traditionally used by this industry. The addition of silicone as a hydrophobizing agent creates problems due to incineration when a cutting device is used. Also, the presence of silicone during the manufacturing process can interfere with the adhesion of certain upholstery substrates to the final glass fiber material. Overcoming these problems helps to better utilize polycarboxy polymers in glass fiber binders.
“Formaldehyde-Free Crosslinking Binders For Non-Womens”, Charles T. Arkins et al., TAPPI JOURNAL, Vol. 78, no. 11, 161-168, November 1995 US Pat. No. 5,340,868 US Pat. No. 5,143,582 US Pat. No. 5,318,990 European patent application EP0 583 086A1 US Pat. No. 5,661,213 US Pat. No. 5,427,587 US Pat. No. 6,136,916 US Pat. No. 6,221,973 US Pat. No. 6,331,350 U.S. Pat. No. 4,076,917

Accordingly, it is an object of the present invention to provide a novel non-phenol / formaldehyde binder.
Still another object of the present invention is to provide a binder that is more water-repellent and that makes it possible to prepare a glass fiber insulation product that is difficult to absorb liquid water.

Yet another object of the present invention is to provide a glass fiber insulation product that exhibits good recovery and stiffness, is free of formaldehyde, and is further waterproof.
These and other objects of the present invention will become apparent to those of ordinary skill in the art upon review of the following description and the claims appended hereto.

  In accordance with the foregoing objects, the present invention provides a novel glass fiber binder. The binder composition of the present invention comprises a polycarboxy polymer, a polyol, and a fluorinated polymer. The binder preferably contains a catalyst such as an alkali metal salt of a phosphorus-containing organic acid.

  An important aspect of the binder of the present invention is that the binder composition comprises a fluorinated polymer in addition to the polycarboxy polymer and the polyol. The presence of the fluorinated polymer in the binder is believed to make the binder, and thus the glass fiber mat to which the binder is applied, essentially waterproof. As a result, the glass fiber insulation made with the binder of the present invention was found to be exposed to water because the binder of the present invention repels water and maintains the bond between the glass fiber and the binder. Avoid potential problems that may come off.

  In particular, by including a fluorinated polymer in a formaldehyde-free binder for glass fibers, especially polycarboxy / polyol binders, the water repellency to the prepared glass fiber mats will not adversely affect performance or processing To be realized. Glass fiber mats can be used as thermal or acoustic insulation, as well as air or liquid filtration media.

  In the context of the present invention, the binder of interest is a formaldehyde-free binder that is useful for glass fibers. Of particular interest are polycarboxy polymer and polyol binder composition compounds. Such binder compositions are described, for example, in US Pat. No. 6,331,350, which is expressly incorporated herein in its entirety by reference.

  The polycarboxy polymers used in the preferred binders of the present invention comprise organic polymers or oligomers containing more than one pendant carboxy group. The polycarboxy polymer is not necessarily limited, but includes acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, maleic acid, cinnamic acid, 2-methylmaleic acid, itaconic acid, 2-methylitaconic acid, methyleneglutaric acid, and the like. It may be a homopolymer or copolymer prepared from an unsaturated carboxylic acid containing. Alternatively, polycarboxy polymers can be prepared from unsaturated anhydrides including, but not necessarily limited to, maleic anhydride, methacrylic anhydride, and the like, as well as mixtures thereof. Methods for polymerizing these acids and anhydrides are well known in the chemical field.

  The polycarboxy polymer of the present invention further includes, but is not necessarily limited to, one or more of the aforementioned unsaturated carboxylic acids or anhydrides, such as styrene, methylstyrene, acrylonitrile, methacrylonitrile, methyl acrylate, ethyl acrylate, n -Copolymers with one or more vinyl compounds including butyl acrylate, isobutyl acrylate, methyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, glycidyl methacrylate, vinyl methyl ether, vinyl acetate and the like may be included. Methods for preparing these copolymers are well known in the art.

  Preferred polycarboxy polymers include homopolymers and copolymers of polyacrylic acid. It is particularly preferred that the molecular weight of the polycarboxy polymer, especially the polyacrylic acid polymer, is less than 10,000, more preferably less than 5000, and most preferably about 3000 or less. The low molecular weight polycarboxy polymer results in a final product that exhibits excellent recovery and stiffness.

  The formaldehyde-free curable aqueous binder composition of the present invention also includes a polyol containing at least two hydroxyl groups. The polyol must be sufficiently non-volatile so that it remains substantially during heating and curing operations and is available for reaction with the polyacid in the composition. The polyol may be a compound having a molecular weight of less than about 1000 carrying at least two hydroxyl groups, examples of which are ethylene glycol, glycerol, pentaerythritol, trimethylolpropane, sorbitol, sucrose, glucose, resorcinol, catechol, Pyrogallol, glycolated urea, 1,4-cyclohexanediol, diethanolamine, triethanolamine, and certain reactive polyols such as hydroxyalkylamides such as bis [N, N-di (hydroxyethyl)] adipamide, This reactive polyol can be prepared in accordance with the teachings of US Pat. No. 4,076,917, which is hereby incorporated by reference herein in its entirety, or a polyol such as polyvinyl Alcohol, partially hydrolyzed polyvinyl acetate, and hydroxyethyl (meth) acrylate, such as homopolymers or copolymers of hydroxypropyl (meth) acrylate may be an addition polymer containing at least two hydroxyl groups. The most preferred polyol for the purposes of the present invention is triethanolamine (TEA).

  The ratio of the number of equivalents of polyacid carboxy, anhydride, or salt thereof to the number of equivalents of hydroxyl in the polyol is from about 1 / 0.01 to about 1/3. However, it is preferred that the carboxy, anhydride or salt equivalent of the polyacid is in excess relative to the equivalent of hydroxyl in the polyol, and thus the equivalent number of polyacid carboxy, anhydride or salt thereof versus the polyol. A more preferred ratio of the number of equivalents of hydroxyl therein is about 1 / 0.2 to about 1 / 0.95, more preferably 1 / 0.6 to 1 / 0.8, and most preferably 1 / 0.65. ~ 1 / 0.75. A low ratio close to 1 / 0.7 has been found to be particularly advantageous, especially when combined with a low molecular weight polycarboxy polymer, as described above, and also preferably with a low pH binder.

  It is also most preferred that the binder of the present invention has a low pH, i.e., 4.5 or more, preferably less than 3.5, because the combination of low molecular weight polycarboxy polymer and low pH is treated. Because it has been found to provide a binder that minimizes the difficulty of and a final product with excellent recovery and stiffness. Maintaining the pH in the range of 3.5-4.5 allows us to avoid the serious problems associated with corrosion of the device while further recognizing the benefits of low pH. However, lower pH, such as less than 3.5, can also be used, and lower pH is actually preferred for advantageous results if care is taken with proper handling.

  An important aspect of the present invention is that the binder of the present invention also includes a fluorinated polymer as an additive. The presence of the fluorinated polymer has been found to make the polycarboxy / polyol binders of the present invention more difficult to absorb water, while in addition, excellent products and good processing of those products such as heat And enables acoustic insulation products and filtration media in filtering air or liquid. As a result, its presence can well maintain the integrity of the bond between the binder and the glass fibers and thus the integrity of the entire mat product when exposed to liquid water. The binder bond, and thus the entire product, becomes even more waterproof.

  Preferred fluorinated polymers are copolymers prepared from fluorine-containing acrylate monomers and styrene, or other commonly used acrylate comonomers. Such fluorinated polymers are available, for example, under the trademark ParaChem RD-F25 ™. In general, any suitable fluorine-containing polymer in which hydrogen is replaced with fluorine in an organic polymer can be used. This includes vinyl fluoride polymers and tetrafluoroethylene polymers. Among the tetrafluoroethylene polymers, tetrafluoroethylene homopolymers and their copolymers with hexafluoropropylene, perfluorovinyl ether and ethylene can also be used to make the polycarboxy / polyol binder of the present invention hydrophobic. Can be given.

  The fluorinated polymer used is generally added to the polycarboxy / polyol binder as a dispersion or emulsion and can be added directly to the binder composition, which is then used in the formation of glass fiber products. used. Alternatively, the fluorinated polymer can be sprayed onto the glass fiber product itself after it has been formed and cured. Combinations of these two things can also be used. However, it is preferred to add the fluorinated polymer directly to the binder composition used during the formation of the glass fiber product.

  The amount of fluorinated polymer used is generally such that the final glass fiber product contains 0.005 to 0.5 weight percent fluorine-containing polymer. More preferably, the amount of fluorine-containing polymer in the final product is generally in the range of about 0.01 to about 0.3 wt%, more preferably about 0.04 to 0.1 wt%, and most preferably about It exists in the range of 0.05-0.09 weight%. It has been found that the use of fluorine-containing polymers can be at a much lower level than silicone materials to achieve similar water repellency, while also overcoming the inherent problems that are common when using silicone hydrophobizing agents. A further preferred range, for example 0.05 to 0.09% by weight of the fluorine-containing polymer, provides excellent water repellency while using small amounts of this additive, thus also making this use economical.

  The curable aqueous binder composition of the present invention containing no formaldehyde preferably also contains a catalyst. Most preferably, the catalyst is a phosphorus-containing cure accelerator, which is a compound having a molecular weight of less than about 1000, such as alkali metal polyphosphate, alkali metal dihydrogen phosphate, polyphosphoric acid, and alkylphosphinic acid. Or may be an oligomer or polymer bearing a phosphorus-containing group, for example an acrylic acid and / or maleic acid addition polymer, phosphite chain transfer agent or termination formed in the presence of sodium hypophosphite Addition polymers prepared from ethylenically unsaturated monomers in the presence of an agent, and addition polymers containing acid functional monomer residues, such as copolymerized phosphoethyl methacrylate, and similar phosphonic acid esters, and copolymerized Vinyl sulfonic acid monomers, and salts thereof; The phosphorus-containing cure accelerator can be used at a level of about 1% to about 40% by weight, based on the combined weight of the polyacid and polyol. A level of phosphorus-containing cure accelerator of about 2.5% to about 10% by weight based on the combined weight of the polyacid and polyol is preferred.

  Formaldehyde-free curable aqueous binder compositions can further include, for example, emulsifiers, pigments, fillers, migration inhibitors, curing agents, coalescence agents, wetting agents, biocides, plasticizers, organosilanes, antifoaming agents, colorings. Conventional processing ingredients such as agents, waxes, and antioxidants can be included.

  A formaldehyde-free curable aqueous binder composition can be prepared by mixing the polyacids, polyols, and phosphorus-containing cure accelerators of the present invention using conventional mixing techniques. In other embodiments, carboxyl- or anhydride-containing addition polymers and polyols can be present in similar addition polymers, the addition polymer comprising carboxyl, anhydride or their salt functionality, and hydroxyl functionality. It will include both sex. In other embodiments, the salt of the carboxy group is a salt of a functional alkanolamine having at least two hydroxyl groups such as, for example, diethanolamine, triethanolamine, dipropanolamine, and diisopropanolamine. In additional embodiments, polyols and phosphorus-containing cure accelerators can be present in similar addition polymers, which can be mixed with the modified polyacids of the present invention. In yet other embodiments, carboxyl- or anhydride-containing addition polymers, polyols and phosphorus-containing cure accelerators can be present in similar addition polymers. Other embodiments will be apparent to those skilled in the art. As disclosed herein above, neutralizing the carboxyl group of the polyacid to a degree of less than about 35% with a base defined before, after, or during mixing to provide an aqueous composition Can do. Neutralization can be performed in part during the formation of the polyacid.

  Once the polyacid, polyol and fluorinated polymer composition is prepared, in a preferred embodiment, other additives can then be mixed with the composition to form the final composition to be sprayed onto the glass fibers. it can. A glass melt stream is drawn into random length fibers and blown into a forming chamber. In this molding chamber, the fibers are randomly deposited as a mat on a traveling conveyor and the fibers are sprayed with the aqueous binder composition of the present invention containing the modified polyacid while moving in the molding chamber.

More particularly in the preparation of glass fiber insulation products, the products can be prepared using conventional techniques. As is well known, glass fiber porous mats can be produced by fiberizing molten glass and immediately forming a fibrous glass mat on a traveling conveyor. Next, the spread mat is transported to and passed through a curing furnace where heated air is passed through the mat to cure the resin. The mat is slightly compressed to give the final product a predetermined thickness and surface finish. Generally, the curing furnace is operated at a temperature of about 150 ° C to about 325 ° C. Preferably the temperature ranges from about 180 ° C to about 225 ° C. Generally, the mat stays in the furnace for a period of about 1/2 minute to about 3 minutes. For typical production of thermal or acoustic insulation products, the time ranges from about _^3/4 minutes to about 1 _^1/2 minutes. The cured glass fiber with the rigid binder matrix exits the furnace in the form of a bat and can be compressed for packing and shipping and then its vertical dimensions when unpacked. Virtually recover.

  Formaldehyde-free curable aqueous compositions may also be applied to nonwovens already formed by conventional techniques such as air, airless spray, padding, impregnation, roll coating, curtain coating, beater deposition, agglomeration, etc. Can do.

  The aqueous formaldehyde-free composition of the present invention is heated to dry and cure after application to the nonwoven. The time and temperature of heating affects the drying rate, processability and handleability, and the outcome of the properties of the treated substrate. A heat treatment at about 120 ° C. to about 400 ° C. can be carried out for a period of about 3 seconds to about 15 minutes, with a treatment at about 150 ° C. to about 250 ° C. being preferred. If desired, the drying and curing functions can be performed in two or more separate steps. For example, the composition is first heated at a temperature and time that is sufficient to substantially dry the composition but does not substantially cure, and then secondly heated at a higher temperature and / or longer time. Thus, curing can be performed. Such a procedure, referred to as “B-staging”, can be used, for example, to provide a binder treated nonwoven in the form of a roll, which can be formed or molded into a specific shape at a later stage? Can be cured at the same time as the curing process.

Heat-resistant non-woven fabrics, for example, as insulating plates (batts) or rolls, as reinforced mats for roofing or flooring applications, as rovings, as micro glass substrates or battery separators for printed circuit boards, as filter materials, as tape materials Can be used as tape board for office petitions, in duct liners or duct boards, and as reinforced scrims for cemented and non-cemented coatings for masonry . Most preferably, the product is useful as a thermal or acoustic insulation. Nonwoven fabrics can also be used as filtration media for air and liquids.
The invention is further illustrated by the following examples, which are not meant to limit the scope in any way.

An emulsion copolymer of styrene and a fluorine-containing acrylate monomer, available under the trademark ParaChem RD-F25 ™, was added to the polyacrylic acid / polyol binder in the glass fiber building product manufacturing process. Here, the final insulation product contained a binder amount of about 5% by weight. Fluorine-containing polymers were added to the binder at several levels to produce samples of R19 insulation containing various levels of fluorine-containing polymer additives. In addition, a test was conducted in which a silicone hydrophobizing agent was added so that the final product contained 0.09% by weight of the silicone additive. All of the samples were tested for water repellency by measuring the amount of water impregnation by weight. This was accomplished by taking a 6 inch × 6 inch square of glass fiber product and placing it in a water bath for 5 minutes. After that time, the glass fiber was removed and suspended from one corner for 30 seconds to allow water to flow down. The glass fiber sample was then weighed after 30 seconds. Weight gain was recorded as a percentage of the original weight. The results are shown below:

  The foregoing results for Samples 1, 2, and 3 show that the fluorinated additive of the present invention is repellent even at low levels compared to the silicone level compared to Control and Sample 4 (without additives). It shows that it can be water-based.

  Although the present invention has been described in terms of preferred embodiments, it should be understood that variations and modifications will be apparent to those skilled in the art. Such variations and modifications are to be considered within the scope and scope of the claims appended hereto.

Claims (19)

  A glass fiber binder comprising an aqueous solution of a polycarboxy polymer, a polyol and a fluorinated polymer.   The glass fiber binder of claim 1, wherein the polycarboxy polymer has a molecular weight of less than 5000.   The glass fiber binder of claim 1, wherein the polycarboxy polymer has a molecular weight of less than 3000.   The glass fiber binder of claim 1, wherein the binder further comprises a catalyst comprising an alkali metal salt of a phosphorus-containing organic acid.   The glass fiber binder according to claim 4, wherein the catalyst is sodium hydrogen phosphite, sodium phosphite, or a mixture thereof.   The glass fiber binder according to claim 1, wherein the polyol is triethanolamine.   The glass fiber binder of claim 1, wherein the polycarboxy polymer comprises a homopolymer and / or copolymer of polyacrylic acid.   The glass fiber of claim 1, wherein the amount of polycarboxy polymer and polyol in the binder is such that the ratio of carboxy group equivalent to hydroxyl group equivalent is in the range of about 1 / 0.65 to 1 / 0.75. binder.   The glass fiber binder of claim 1 wherein the fluorinated polymer is a fluorinated acrylate copolymer.   A glass fiber binder comprising an aqueous solution of a homopolymer and / or copolymer of polyacrylic acid, wherein the polyacrylic acid polymer has a molecular weight of 5000 or less, triethanolamine and a fluorinated polymer.   The glass fiber binder of claim 10, wherein the binder further comprises a catalyst comprising an alkali metal salt of a phosphorus-containing organic acid.   11. The amount of polyacrylic acid polymer and triethanolamine in the binder is such that the ratio of carboxy group equivalent to hydroxyl group equivalent is in the range of about 1 / 0.65 to 1 / 0.75. Glass fiber binder.   A glass fiber product comprising a glass fiber mat comprising the binder of claim 1.   The glass fiber product according to claim 13, wherein the product is a building insulation.   The glass fiber product according to claim 13, wherein the product is a reinforced mat for roofing or flooring.   14. The glass fiber product according to claim 13, wherein the product is a fine glass-based substrate useful for printed circuit boards or battery separators, filter materials, tape materials or reinforced scrims.   The glass fiber product according to claim 13, wherein the product is a filter material.   A glass fiber product prepared by using a binder comprising a polycarboxy polymer and a polyol and spraying the product with a fluorinated polymer.   19. A glass fiber product according to claim 18, which is a heat or acoustic insulation, or a filtration medium for air or liquid.