MXPA98008437A - Adhesive based on lower organic solvent vola - Google Patents

Abstract

The present invention relates to: a solvent-based adhesive comprising a mixture of at least two organic solvents and a thermoplastic resin. Desirably, the adhesive has a flash point of at least 37.7 ° C (100 ° F) when restricted in accordance with ASTM D3828-87 and a lower VOC. In addition, this novel solvent based adhesive is easy to apply, cost effective and solidify within a reasonable time without the use of heat, ultraviolet light or other mechanical devices. In addition, the novel solvent-based adhesive has good storage stability in metal containers and not metal

Description

• i-S "VOLATILE LOWER ORGANIC SOLVENT-BASED ADHESIVE" DESCRIPTION OF THE INVENTION This invention relates to an adhesive-based solvent that is capable of bonding two thermoplastic materials together.In addition, the invention relates to a solvent-based adhesive that is preferably has a lower volatile organic content (VOC) and a solvent that volatilizes at a substantially reduced rate when compared # with those solvent-based adhesives solvents conventional for thermoplastic materials. Additionally, the invention relates to a solvent-based adhesive having a flash point substantially above 37.7 ° C (100 ° C) as determined by the test methods set forth in the ASTM. of 3828-87. Preferably, the invention comprises a solvent-based adhesive used to join two objects or articles made from chlorinated polyvinyl chloride (CPVC). A preferred useful solvent in a solvent-based adhesive of the invention is naphthalene which has one or more alkyl groups therein and a total of 11 to 14 carbon atoms and / or benzene having one or more alkyl groups therein and a total of 10 to 14 carbon atoms. Solvent-based adhesives are used to join thermoplastic tubes and accessories. Sometimes, the thermoplastic tube and the attached accessories use solvent-based adhesive that can be tested on the same day. Generally, solvent-based adhesives comprise a mixture of solvents as well as resins and other additives such as thixotropic agents. The solvent-based adhesive typically dissolves the surface layers of the thermoplastic material to which it is applied, causing volume increase. The resin in the adhesive accelerates the hardening of two materials to be joined, fill any gap and reduce internal stresses. The adhesive solidifies by evaporation. The primary solvents used in conventional solvent-based adhesives include tetrahydrofuran, methylethyl ketone and cyclohexanone. These solvents, when used in relatively large amounts, tended to be volatile and consequently adhesive, they tend to have VOC levels in the range of 750 to 850 g / 1 when calculated by South Coast Air Quality Management District (SCAQMD) 316A . In addition, prior to the application of these conventional solvent-based adhesives, the desirable thermoplastic material is prepared with any primer, such as tetrahydrofuran, or a cleaner such as acetone to minimize adhesive failure. In this cleaning process, even more voltaic organic compounds can be released into the atmosphere. Since these conventional # solvent based adhesives are largely formed by relatively volatile solvents, the adhesive tends to spread over a large area and drip during application to the thermoplastic materials, causing additional volatilization. The 5 conventional solvent based adhesives and / or adhesive primers also generally have lower inflation points. The lower flash points require special precaution in handling and packaging to avoid the combustion of these adhesives and / or primers. The The evaporation of solvents from solvent-based adhesives can contribute to air pollution. Various adhesives have been formulated which contain lower VOC levels than conventional solvent based systems. The VOC levels of adhesive systems based on conventional solvent were generally about 650 grams / liters when calculated by the South Coast Air Quality Management District 316A test method prior to 1994. For example, Australian Patent Application 86750/91 describes an adhesive that comprises more than 80% by weight of N-methyl-2-pyrrolidone, more than 0.25% by weight of a viscosity modifier and more than 10% by weight of a vinyl-based polymer. Similarly, U.S. Patent No. 4,675,354 discloses a gum solution which comprises a solution of a synthetic organic polymer insoluble in water in a solvent such as N-methyl-2-pyrrolidone. Also, U.S. Patent No. 4,687,798 discloses a cement solvent used to bond water insoluble polymers. The cement solvent comprises about 10-15% by weight of a water insoluble polymer and a solvent. This solvent comprises ethyl acetate and N-methyl-2-pyrrolidone. The ethyl acetate ranges from about 3% to 50% by weight of the solvent with the rest being N-methyl-2-pyrrolidone. In addition, European Patent Application 0 547 593 A1 discloses a lower VOC adhesive composition. The composition described in this European patent application comprises a mixture of approximately 5% by weight a about 60% by weight of at least one water insoluble polymer, from about 1% by weight to about 30% by weight of synthetic or inorganic resinous hollow microspheres and about 20% by weight to about 70% by weight of by weight less a liquid volatile organic which is a solvent for the water insoluble polymer. U.S. Patent No. 5,470,894 to Patel et. al., provides for an example of adding a lower VOC solvent based adhesive. The base adhesive of lower VOC solvent in this patent can be used to join CPVC tubes. The adhesive comprises a high vapor pressure solvent comprising from about 15 to about 35% by weight of tetrahydrofuran and 0 to about 30% by weight of methylethyl ketone; and a lower vapor pressure solvent comprising 20 to about 45% by weight. Cyclohexanone, 0 to about 30% by weight of N-methylpylorridone and 0 to 10% by weight of dibasic esters Patel, et al., states that the VOC level of its adhesive is below 450 grams / liters, while the adhesive meets or exceeds the required performance standards such as hydrostatic bursting force and hydrostatic maintained pressure tests. There are alternatives for adhesives based on solvents. These alternatives include mechanical, reactive, and / or thermal systems. Mechanical joining systems are generally expensive to use. Examples of mechanical joining systems include Acorn accessories from Hepworth Building Products; Polygrip accessories from Philmac Corporation and accessories Uncopper from Genova. Thermal systems can be unpredictable due to the difficulty in the consistency that properly produce pipe / fitting joints. Examples of thermal systems include heat melted gums available from Minnesota, Mining and Manufacturing Company. These thermal systems can be difficult to apply. and can perform less consistently than solvent-based adhesives. An example of a reactive system includes an epoxy. The epoxy is available from the Noble Corporation under the trade name Copper Bond. Other examples of an epoxy include General Purpose Urethane, High Shear Strength Urethane and All Purpose Epoxy, all available from Hardman Corporation. These reactive systems can be problematic because they have a longer solidification time and strength before poor cooking. Its effectiveness can also be temperature dependent. At lower temperatures the epoxy materials can have very long solidification time. Also, there they can be; byproducts of chemical reactions which may damage the strength of thermoplastic materials. _ There are benefits to continuing to use solvent-based adhesives to bond thermoplastic materials. First, solvent-based adhesives are easy to use, and many workers have years of experience using these types of adhesives. Second, there are typically lower production costs in the manufacture of solvent based adhesives and generally long term durability once the adhesives will be used to bond the two thermoplastic materials together. In addition, the solvent-based adhesive can be used in place to join the two thermoplastic materials together without * any additional equipment. Fourth, the solvent-based adhesive system usually solidifies quickly, allowing immediate testing. One technique can be used to apply the solvent system for all 5 pipe sizes. Generally, solvent-based adhesive can be applied for bonding at any temperature in the range of -17.7 to 48.8 ° C (0 to 120 ° F). Also the solvent-based adhesive usually does not depend # of a chemical reaction for its effectiveness. Therefore, in together solvent-based adhesives are generally practical and inexpensive. The present invention comprises a novel solvent-based adhesive comprising a mixture of two or more solvents and a resin. Optionally, the adhesive based on The novel solvent may contain a thixotropic agent such as silica. Preferably, the novel solvent-based adhesive comprises 5-15% by weight of thermoplastic resin; 38-75% by weight of substituted naphthalenes and / or benzenes substituted with one or more alkyl groups; about 20-20% by weight of dimethyl adipate and optionally 1.5-2% by weight of silica based on the weight of the solvent-based adhesive. Optionally, the solvent-based adhesive may contain N-methyl-2-pyrrolidone. All percentages by weight are based on the weight of the adhesive based on solvent, unless otherwise stated. More preferably, this novel solvent-based adhesive has an inflation point of about 37.7 ° C (100 ° F) when calculated in accordance with ASTMD 3828-87. Preferably, the solvent-based adhesive has a lower VOC (ie, no greater than 450 g / 1 when tested according to the test method SCAQMD 316A). More preferably, a novel solvent comprises 5-15% by weight of thermoplastic resin, 38-75% by "weight" of N-methyl-2-pylorridone and / or a substituted alkyl of naphthalene and / or substituted benzene with 10- 14 carbon atoms, 15-45% by weight of dimethyl adipate; optionally about 1.5-2% "by weight of silica and optionally about 5-10% by weight of a ketone having an inflation point greater than 21.1 ° C (70 ° F) and more desirably above 37.7 ° C (100 Preferably, the ketone is any 5-methyl-2-exanone (methyl iso-amyl ketone) or 4-methyl-2-pentanone (methyl isobutyl ketone), or combinations thereof. The solvent-based adhesive of the present invention preferably has a VOC level of less than 450 grams / liter when calculated by SCAQMD 316A. More preferably, the novel solvent-based adhesive has a VOC level of less than 350 grams / liter and preferably less than 250 grams / liter when calculated by SCAQMD 316A.

- The solvent-based adhesive of the present invention comprises a mixture of two or more volatile organic liquid solvents that are capable of vaporization at room temperature and a thermoplastic resin. Other 5 ingredients, including different ~ solvents, fillers, thixotropic agents or stabilizers can be added to adhesive solvents as desired. The solvent-based adhesives as described herein, in greater detail generally have the following characteristics: viscosity of 500-3000 centipoise; a resistance before firing of approximately 1-3 minutes; less than 20% by weight of solids in the adhesive, an indefinite shelf life in non-reactive containers and a relatively fast solidification time (i.e., less than one day). Time solidification can be varied by different end-use needs by minor adjustments of the percentages of solvent used. Preferably, the first, second and optional additional solvents are mixed in proportions (as teaches later in the specification) such that the total volatile organic content when calculated by the SCAQMD test method 316A is below 450 grams / liter (g / 1), more desirably less than 400 g / 1, even more desirably less than 350 g / 1 and more preferably less than 250 g / 1.

The substituted naphthalenes with alkyl and / or benzenes substituted with 1 or more alkyl groups as described below, being found to be an effective substitute for N-methyl-2-pyrrolidone (NMP) in these adhesives. The flash point of a material was used as one of the properties that is considered when determining the total flammability of a material. One method to determine a flash point of a material is ASTM D 382 -87, which is incorporated in the present in its entirety. If a material has a higher flash point, the packaging and its shipping requirements can not be as strict as those generally required for solvent cements and / or primers. The thermoplastic resin that can be used in the formulation of the solvent-based adhesive of the present invention includes polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), poly (acrylonitrile-butadine-styrene) (ABS), polystyrene, and any other amorphous thermoplastic resins which are soluble in the mixture of two or more volatile organic solvents. Generally, the resin used in the solvent-based adhesive of the present invention is the same as the resin used to form thermoplastic materials to be bonded. Preferably, the resin is either CPVC, PVC or ABS. Examples of ABS resin possible for use include the Cycolac ABS resins from GE Plastics and the ABS Lustran ABS resins from Monsanto. More preferably, the resin is CPVC. The amount of thermoplastic resin added to the solvent-based adhesive in the desirable ranges of 5 to 20% by weight "and more preferably 10 to 15% by weight.If the CPVC and / or PVC resin is used, it should have a inherent viscosity in the range of 0.6 to 0.96 Preferably, the chlorination levels for CPVC resins in the range of 58 to 72% by weight Preferably, the chlorination levels of the PVC resin should be less than 57% by weight of the resin. Generally, the CPVC resin used is the CPVC resin as defined in Class 23477 of ASTM D1784. Examples of CPVCs suitable for use in the present invention include TempRite 674x571 CPVC, a preferred compound and TempRite 677x670 CPVC, all available from The B.F Goodrich Company. (TempRite is a registered trademark of B.F. Goodrich Company). In addition to the thermoplastic resin, the solvent-based adhesive of the present invention includes a mixture of two or more volatile organic liquid solvents that are capable of vaporizing at room temperature. The first solvent or organic solvents that are used in the mixture is a lower vapor pressure solvent. Alkyl-substituted naphthalenes having one or more alkyl groups and a total of 11 to 14 carbon atoms and / or one or more substituted alkyl benzenes with one or more alkyl groups and a total of 10 to 14 carbon atoms, Vapor pressure solvents are most preferred. Preferred benzenes have 2 or more, 3 or more and 4 or more alkyl groups. NMP can also be included in the solvent. NMP is commercially available from Aldrich Chemical, Ashland, BASF, Chemoxy International and Janssen Chemical. Substituted substituted alkyl and benzene naphthalenes having 1 or more alkyl groups are available from distillation of petroleum as insulating fractions. Available from Koch Specialty Chemical Group, Corpus Christi, Texas, either under a chemical name for example methyl naphthalene or as a specific Sure Sol product (used primarily by benzenes substituted with alkyl). They are usually classified as specialty chemicals while benzene, xylene, toluene, eumeno and ethylbenzene are generally classified as useful chemicals. The first organic liquid solvent is generally found in the novel adhesive in the range of about 38 to 75% by weight, and more desirably from 38 to 65% by weight. Additional additional solvents other than NMP, alkyl substituted naphthalene and alkyl substituted benzene may be present in amounts of 5 to 47% by weight, more desirably 15 to 47% by weight based on the solvent-based adhesive. The "solvent addition may include a second and optionally a third or more solvents." The second organic liquid solvent in the solvent-based adhesive is chosen from the group comprising polycarboxylic acids desirably having 4 to 15 carbon atoms; its mono, di alkyl esters desirably having from 4 to 19 carbon atoms such as pimelic acid, monomethyl glutarate, monomethyl pimelate, monomethyl acelate, monomethyl sebacate, monoethyl adipate, dimethyl succinate, dimethyl glutarate, adipate of dimethyl, dimethyl pimelate, dimethyl subrate and dimethyl acelate, or chloride of polycarboxylic acids desirably have from 4 to 15 carbon atoms such as glutaryl chloride, adipoyl chloride, and pimeloimethyl chloride, and alkyl chloride of such polycarboxylic acids having from 4 to 17 carbon atoms such as methyl adipoyl chloride and methyl primeloyl chloride, etc.; mixtures thereof. For example, the mixture or "dimethyl glutarate, dimethyl adipate and dimethyl succinate can be used." A commercially available example of such mixtures is DBE-9 available from DuPont Chemical Company The second organic solvent is preferably dimethyl adipate (" DMA "). DMA is available from DuPont Chemical Company under the trade name DBE-6, DBE-6 is recognized to be a mixture comprising 98.7% DMA, <0.5% dimethyl glutarate and <0.1% succinate. It is desirably that the polycarboxylic acid esters and alkylilic alcohols and / or polycarboxylic acid chlorides are present in amounts of 10 to 35% by weight and more desirably of 25 to 35% percent by weight based on the weight of the In other embodiments, the second organic solvent is desirably found in the range of 20% to 45% by weight in the solvent mixture, In the most preferable embodiment, 27% by weight of the base adhesive mixture. of solvent is DMA. The solvent-based adhesive of the invention may also include other ingredients such as minor amounts of other solvents which, preferably do not raise the VOC levels of the adhesive above 450 grams / liter and which is miscible with the mixture of Two or more volatile liquid organic solvents. Examples of optional solvents which may be used include cyclic or linear cenotes, monocarboxylic acid esters and alkyl alcohols, allogenated solvents, ethers and other liquids such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). they can be used in the present invention as additional solvents include acetone, methyl ethyl ketone (MEK), methyl iso-amyl ketone, methyl iso-butyl ketone, isophorone, cycloexanone and other ketones having 3 to 15 carbon atoms. Desirably, these ketones are present in amounts of 15% by weight or less more desirably 5 to 10% by weight based on the solvent-based adhesive Desirably the addition of one or more solvents and especially all of the ketones have a point of inflammation above 21.1 ° C (70 ° F), or more preferably above 37.7 ° C (100 ° F) when calculated by ASTM D 3828-87. In a desirable embodiment, the entire addition of one or more solvents and especially the ketones which essentially consist of solvents having a flash point above 21.1 ° C (70 ° F) and preferably 37.7 ° C (100 ° F). All ketones when mixed as a ketone mixture desirably have a flash point above 21.1 ° C (70 ° F). Desirably the amount of solvents has a flash point below 10 ° C (50 ° F), is limited to less than 5% by weight. Examples of esters of monocarboxylic acids have from 2 to 15 carbon atoms and alkyl alcohols having from 1 to 15 carbon atoms which can be used in the present invention including methyl acetate, ethyl acetate (EA), formate ethyl, ethyl propionate and butyl acetate. The allogenated solvents which may be used include methylene chloride, ethylene dichloride and trichlorethylene. An ether derived from methyl cellulose is an example of an ether having from 3 to 15 carbon atoms that can be used as an additional solvent. The "fillers" which are known in the The technique and any other materials which can function as inert fillers can be used in the present invention. Examples of fillers which , ^. they may optionally be used in the present invention include hollow spheres, (glass or ceramic), polymers, glass spheres, magnesium silicate, magnesium oxide, fluorine coating, alumina, talcum, barium sulfate, calcium carbonate, and additional fine powder. These fillers are generally added to the composition in the amount of 0.05 to 20% by weight. The fillers Preferred include polymers and calcium carbonate. Jflr The solvent-based adhesive may also optionally include thixotropic agents. Examples of possible tisotropic agents used in the invention include fumed silica, precipitated silica, clay bentonite, soil quartz, mica, ethyl cellulose, hydrogenated castor oil, organic modified clay, other thickeners or viscosity adjusters. Preferably thixotropic agents that include fumed silica. Generally, the amount of thixotropic agent used, if is used in the total, it is in the range of 1 to 3% by weight, more desirably 1.5 to 2% by weight based on the weight of the solvent-based adhesive. Additional pigments, inks, dispersions or dyes can be added to the solvent-based adhesive. Examples of possible pigments which may be used include titanium dioxide, calcium carbonate, or carbon black. The amount of pigment used is generally in the range of 0.05% by weight to 5.0% by weight based on the weight of the solvent-based adhesive. The lower VOC solvent based adhesive may include other additives. These include any additives known to those in the art. Suitable additives include, for example, but not limited to, various antioxidant stabilizers, electrostatic dissipating agents, smoke retardants, moisture scavengers, and acid scavengers. As some additives can be combined in countless variations, the total amount of additive can vary from application to application. The optimization of the particular additive composition can easily be determined by one of ordinary skill in the art. Optionally, 0.5% to 1.0% by weight of additives are added based on the weight of the solvent-based adhesive. The ingredients for the solvent-based adhesive can be. combined in any way you convenient. For example, all the ingredients can be mixed together uniformly by a mixing means such as a mixer. Preferably, the two solvents are first mixed together. The special sequence or order is not necessary. The thermoplastic resin and the thixotropic agent are then added to the solvent mixture. No special order is required. A stirring mixer such as Grenier Mixer, Model 3002 with rapid stirring can * be used to dissolve the solids in a solvent quickly. The mixing can be set at 400-500 rpm for 10-15 minutes. The mixing can then be placed on a slow-moving roller mixed to mix the composition evenly. An example of a possible roller mixer which can be used is the Ball Mill by Paul O. Abbe. The mixture can "be placed in this Ball Mill for one hour at 160 rpm. ~ There are different uses of the solvent-based adhesives of the present invention For example, the solvent-based adhesive can be used to join tubes thermoplastics and accessories in various applications such as plumbing systems, hot and cold water distribution systems, sprinkler systems, spas, sprinkler fire extinguishing systems, drainage system, waste and ventilation. The following examples ns are limiting, further serve to illustrate the present invention. EXAMPLES In the following examples as represented in Tables 1-5, a solvent based NMP adhesive was formulated. The desired VOC level was determined by the selection of the two solvents. Using SCAQMD 316A, the VOC constant for each of the solvents used in the solvent-based adhesive was determined experimentally. The estimated VOC for the solvent-based adhesive was then determined using the following equation: (the VOC constant of the solvent 1 x% of solvent 1 based on the total amount of the solvent in the adhesive) + (the constant VOC of the solvent 2 x% of the solvent 2 in the adhesive based on the total amount of the solvents) + the similar calculations for addition solvents are = the estimated VOC level of the adhesive. Once this desired VOC constant was determined, the lower VOC solvent based adhesive was formulated and the VOC level verified using SCAQMD 316A. The viscosity of the solvent cement was optimized by the addition of thixotropic agents. The strength before firing and the solidification time was varied by adjusting the percentages of the solvent while maintaining a desired VOC level and viscosity.

** In the first examples (Examples 1-4), the amount of NMP and dimethyl adipate (DMA) used varied. The formulation in the first examples was fully tested by the VOC level, solidification time, resistance before firing and rapid bursting. The VOC level was calculated using the test in SCAQMD 316A. The rapid burst was measured using ASTM 1599 and the solidification time is calculated using Underwriters Laboratories UL 1821. 10"The resistance before firing was tested by a procedure so the tester checks separating by pulling or twisting the tube and attached fixture The procedure to carry out, the inner part of the thermoplastic fitting and the outer part of the tube thermoplastic (which is fixed in the accessory) where.-Each was coated with the same adhesive. At the end of a * Minute, the tester checks to separate pulling or twisting the two pieces. Generally, the attached tube and attached fitting were subjected to 6 foot-pounds of torque during the test. If the two pieces do not separate, then a "yes" is recorded and the experiment is repeated until a "no" is obtained. Each time the experiment was performed again, an additional minute was added to the previous time. The first time a "no" was reached, indicating the resistance before firing. The formulations as well as the results are set forth in Table 1. The tube used to generate the data in the tables, unless otherwise specified, was SDR-11 also known as CPVC pipe of% inch that has an outer diameter of 0.875-0.878 and a wall thickness of 0.080-0.100 inches. In the examples of commercial solvent cements with which the present invention was compared and contrasted includes Orange Lo V.O.C. Medium Booked included Cement CPVC (one stage); two stages of cement available from Oatey; and the Weld-On CPVC 2714MR Orange Heavy Booked Cement (one stage) and two stages of IPS cement. Generally, the commercial solvent cements stage has a VOC level of about 450 grams / liter, while the two stage cement has a VOC level greater than 650 grams / liter.

Examples 1 to 4 in Table 1 illustrate that solvent-based adhesive formulations have a DMA / NMP ratio of 0.31 to 1.125 that have a lower VOC level than standard solvent cement formulations. Examples 3 and 4 should be unacceptable for commercial use due to high viscosity even though they are effective as an adhesive. ro? 1 PF means the failure of the tube before the failure of the adhesive ro - Examples 5 to 24 in Table 2 illustrate that solvent-based adhesives have a DMA / NMP ratio of 0.3 to 1.3 and that they have either a third minor solvent or combination of solvents which provides a smaller portion. (<10% by weight) of the total formulation having a lower VOC level of 400 grams / liter and yield, as well as commercial solvent based adhesive systems, which have a VOC level of 450 grams / liter or higher 10 In these examples, the VOC levels are all less than 300 g / 1 and the bond strength passes all the listed criteria.The formulations 15, 16, 17 and 18 could be -acceptable commercially due to the high viscosity, although still they have effectiveness as an adhesive l \ 3 < T > Examples 25 to 32 in Table 3 illustrate that solvent based adhesives have a DMA / NMP radius of 0.3 and that they have a minor third solvent comprising < 10% by weight of the total formulation having a lower VOC level and the formulation yields also exist commercial solvent based adhesives. In addition, if a lower molecular weight of CPVC (eg Temprite 677x670) resins used in the formulation, the viscosity can be improved and the adhesive can present better than the existing solvent based adhesive.

Examples 33 to 43 illustrate that solvent based adhesives have a DMA / NMP radius of 0.54 to 0.97 and have an MEK (2-butanone) as a minor component at a level of less than 10% by weight of the minor formulation having a VOC level lower than the commercial solvent-based adhesive (with a VOC level of 450 grams / liter or greater) and these commercial solvent-based adhesives will also be executed. In addition, Example 38 illustrates that a solvent-based adhesive has a DMA / NMP radius of less than 0.55 and has MEK (2-butanone) as a minor component at a level of less than 8% by weight of the total formulation having a level VOC of 201 grams / liter and also running as conventional solvent based adhesives. The following examples in Table 5 illustrate how they substituted naphthalenes with 11 to 14 carbon atoms and / or substituted benzenes with 10 to 14 carbon atoms and could be used in place of NMP in the solvent-based adhesive and the result in the values Lower VOCs according to SCAQMD 316 A (for example as below 73g / l) and meets the physical property tests of a solvent-based adhesive. Examples with 8% by weight MEK have desirable flash points lower than the other examples using ketones with higher flashpoints. The addition of ketones tend to require a shorter time for "resistant" forces but they increase the VOC level.The particular ester of a dicarboxylic acid and methyl alcohol (DBE-6) must be replaced with other esters.The methyl naphthalene used in the experiment was >95% for "pure weight. The SS-150 was a Sure "Sol which is 98% by weight of C0 isomer of benzene and the SS-150 ND was similar to SS-150 but depleted naphthalene, both of SS-150 and 150 ND were available as distilled fractions. Oil from Koch Specialty Chemical Group in Corpus Christi, Texas.

VOC is a volatile organic compound as determined by SCAQMD 316A. . As determined by ASTM D3828-87. ASTM 493. See also ASTMD D1598--86 and D1599-88.

While all the previous examples of the invention did not individually pass all the tests, the examples as a total and suggestive teaching, as it has modified the poor performance to achieve the desired properties. Example 49, teaches that MIAK instead of MIBK in example 50 must achieve the desired property. Example 52 when compared to 53 teaches a similar change. Another slight change in the solvent mixture (MIAK and MIBK varies only by one carbon atom per molecule) are also anticipated to compensate for poor performance and thus the total yield can be optimized by routine experimentation. In summary, a novel and non-obvious solvent-based adhesive has been described. The desirable adhesive has a flash point above 34.7 ° C (100 ° F) as limited by ASTM D3828.87. Although the preferred embodiments and experiments have been described herein, it should be borne in mind that this has been provided by a form of explanation and illustration and the present invention is not limited hereby. The modifications are certainly within the ordinary skill of the art that is considered to be demonstrated within the scope of this invention, as defined by the following claims.

Claims (11)

1. A solvent-based adhesive, characterized in that it comprises: a) from 38 to 75 weight percent of a first solvent being at least one naphthalene substituted with alkyl, having one or more alkyl groups and from 11 to 14 carbon atoms , or at least one benzene substituted with alkyl having one or more alkyl groups and from 10 to 14 carbon atoms, or combinations thereof, wherein at least one naphthalene substituted with alkyl and / or at least one alkyl substituted benzene is present in an amount of at least 5 weight percent; b) from 5 to 20 weight percent of a thermoplastic resin; and c) from 5 to 47 weight percent of an addition of one or more solvents, wherein the weight percent values are based on the weight of the solvent-based adhesive.

2. A solvent-based adhesive according to claim 1, characterized in that the adhesive comprises a ketone.

3. A solvent-based adhesive according to claim 1 or 2, characterized in that the adhesive ß comprises acetone, cyclohexanone, methyl ethyl ketone, metho-iso-amyl ketone or combinations thereof.

4. A solvent-based adhesive according to claim 1, characterized in that the adhesive 5 comprises N-methyl-2-pyrrolidone.

5. A solvent-based adhesive according to claim 1, characterized in that the addition of f one or more solvents comprises from 10 to 35 percent in ^ weight 10 total of 4 to 15 carbon atoms, mono or dialkyl esters thereof having a total of 4 to 19 carbon atoms, alkyl chloride and polycarboxylic acids having a total of 4 to 17 carbon atoms, chlorides of such acids polycarboxylics having a total of 4 to 15 carbon atoms or combinations thereof.

6. A solvent-based adhesive, characterized in that it comprises: a) from 38 to 70 weight percent of at least one alkyl substituted naphthalene having from 11 to 15 atoms 20 carbon and / or benzene substituted with alkyl having at least one alkyl group and from 10 to 14 carbon atoms; b) from 5 to 20 weight percent of a chlorinated chlorinated polyvinyl chloride, and c) from 10 to 35 weight percent of one or more polycarboxylic aliphatic acids having a total of 4 to 15 carbon atoms, mono or dialkyl esters of them, who have a. total of 4 to 19 carbon atoms, alkyl chlorides of polycarboxylic acids having a total of 4 to 17 carbon atoms, chloride of polycarboxylic acids having a total of 4 to 15 carbon atoms or combinations thereof, wherein the weight percent value is based on the weight of the solvent-based adhesive.

7. A solvent-based adhesive, characterized in that it comprises: a) a first solvent being at least one benzene substituted with alkyl having one or more alkyl groups and from 10 to 14 carbon atoms in an amount of at least 5 percent by weight; b) polyvinylchlorinated chloride in an amount of at least 5 weight percent not more than 20 weight percent; and c) an addition of one or more solvents in an amount of at least 5 weight percent and not more than 47 weight percent, wherein the weight percent values are based on the weight of the adhesive based of solvent.

8. A solvent-based adhesive according to claim 7, characterized in that the addition of one or more solvents is selected from the group consisting of methyl iso-amyl ketone, dimethyladipate, and mixtures thereof.

9. A solvent-based adhesive according to claim 6, 7 or 1, characterized with the proviso that the total amount of any one of the additions of one or more solvents which have a flash point below 37.7 ° C (100 ° F) as restricted by ASTM D3828-87 is less than 10 weight percent where the volatile organic content by South Coast Air Quality Management District Test Method 316A is less than 350 g / 1.

10. A solvent-based adhesive according to claim 1, characterized in that the thermoplasresin comprises polyvinyl chloride, polyvinylchloridated chloride, ABS or polystyrene and wherein the first solvent is present in an amount of 38 to 65 weight percent.

11. A solvent-based adhesive according to claim 7, 8 or 1, characterized in that the volatile organic content by South Coast Air Quality Management District Test Method 316A is less than 250 g / 1.