MXPA96000262A - Cristali polyesters - Google Patents

Abstract

This development provides crystalline unsaturated polyesters, which have an unreacted, olefinically unsaturated monomer trapped within their crystal grid. This crystalline polyester can be used in high performance sheet molding structural composite products, or as a glue or binder for glass fiber reinforcement or mats.

Description

CRYSTAL POLYESTERS TECHNICAL FIELD This development refers to crystal polyesters. It also relates to the use of compositions for glass fiber coatings or for the molding of compounds. PREVIOUS TECHNIQUE Crystalline polyesters have found increasing use as coatings for glass fibers. The industry also uses them as sheet molding compounds (C H). The crystalline polyesters function as binders for glass cords forming a mat, wet process mats, continuous cord mats and the like. They also function as a matrix resin for the molding of automobiles. An advantage of the thermosetting formation of the solid polyesters with the reactive monomers is the reduction of the styrene emission. In addition, solid styrenated polyester has an extremely fast cure for molding. EXPOSITION OF THE INVENTION We have developed crystalline unsaturated polyesters with monomers, olefinically unsaturated, trapped. This meltable, solid, thermoset polyester has application as a binder of glass fibers or a matrix resin. Because styrene (or other monomers) lock in the crystalline grid, a significantly reduced evolution of the monomer relative to conventional liquid polyesters is possible. The solid nature of the material easily leads, by itself, to a powder coating. The key to producing the entrapped unsaturated monomer is to carefully follow the synthesis of the solid styrene polyester. THE BEST WAY TO CARRY OUT THE INVENTION Our process produces a crystalline unsaturated polymer, which contains unreacted, olefinically unsaturated monomers, but trapped within the polymer's crystalline grid. The polymer can be, for example, a polyester, polyethylene terephthalate, a poly-acrylate, or other thermoset polymers. The monomer may be, for example, styrene, divinyl-benzene, alpha-methyl-styrene, vinyl-toluene or acrylic acid. The composition is produced by heating the crystalline unsaturated polymer to form a viscous liquid, which is added to the monomer, while maintaining the temperature below 80 ° C. The composition is then cooled to form a solid and then ground to a powder. Typically, the molten polyester, from the polyester condensation reaction, is fed into the unsaturated monomer. The molten polyester is at a temperature of 150 ° C. This molten polyester (at 150 ° C) is embedded in the styrene slowly, at such a rate that it does not allow the temperature to exceed 80 ° C. However, the polyester is maintained above the melting temperature of the polyester during the addition. The polyester inside the reactor melts and is brought above the melting temperature. That is, it is a potential crystalline entity by nature, but above the temperature at which crystallinity will not be observed. When this molten polymer is placed in contact with a diluent and allowed to cool, the polyester chains begin to associate and eventually crystallize, with this diluent becoming "trapped" within the crystal grid. molding, not sticky, that emits a significantly reduced amount of monomers In principle, any diluent will be present, which include monomers of all kinds, polymers, mold release agents, adhesion promoters and anti-separation additives. crystallines, which contain an ethylenic unsaturation, which can react with the ethylenic unsaturation of the monomers, and the processes for their preparation, are well known.For example, the crystalline polyester can be prepared by polyesterifying an aliphatic diol with fumaric acid or esters of lower alkyls of fumaric acid, maleic anhydride or maleic acid or steres of lower alkyl of maleic acid, mixtures of fumaric acid or its esters can also be used with maleic anhydride or maleic acid or its esters. Part of the ethylenically unsaturated acid can be replaced with unsaturated dicarboxylic acids, such as adipic, sebacic, isophthalic or terephthalic acids. Diols are diols such as propylene glycol or dipropylene glycol. Specific examples of crystalline polyesters for use in the present invention include the polyfumarates of: 1,6-hexanediol, neopentyl glycol; bis- (hydroxyethyl) -resorcinol,; ethylene glycol; 1,4-butanediol; 1,4-cyclohexanediol; or bis- (hydroxyethyl) -hydroquinone. Examples of monomers which may be used are styrene, substituted styrenes in the ring, such as vinyltoluene, divinylbenzene, t-butyl styrene and chlorostyrenes, diallyl phthalate and methyl methacrylate. As will be discussed more fully below, the resins of the present invention can be conveniently prepared from a crystalline polyester powder or other forms with small particle size of the polyester. The unsaturated polyester comprises the reaction product of the polycondensation of one or more dihydric alcohols and one or more ethylenically unsaturated polycarboxylic acids. Polycarboxylic acids are generally understood to be polycarboxylic or dicarboxylic acids or anhydrides, polycarboxylic or dicarboxylic acid halides and polycarboxylic or dicarboxylic esters. Suitable unsaturated polycarboxylic acids and the corresponding anhydrides and acid halides, which contain polymerizable carbon-to-carbon double bonds, may include maleic anhydride, maleic acid and fumaric acid. A minor proportion of the unsaturated acid, up to 40 mole percent, can be replaced by the dicarboxylic or polycarboxylic acid which does not contain a polymerizable carbon-to-carbon bond. Examples of which include 0-phthalic, isophthalic, terephthalic, succinic, adipic, sebacic, methyl-succinic acids, and the like. Dihydric alcohols which are useful in preparing the polyesters include 1,2-propane diol (hereinafter referred to as propylene glycol), dipropylene glycol, diethylene glycol, 1,3-butanediol, ethylene glycol, glycerol. and similar. The monomer component of the resinous system comprises materials that copolymerize with the unsaturated polyester. The ethylenically unsaturated monomer that is copolymerizable with the unsaturated polyester is more generally styrene; however, methyl styrene is also useful, such as acrylates and methacrylates, such as methyl acrylates, ethyl acrylate, methyl methacrylate, ethyl methacrylate, etc. The low profile additive component of the resinous system comprises the thermoplastic polymers, which cause phase separation and porosity during the curing reaction. Low profile additives are materials that, when mixed in an unsaturated polyester and cured, result in a multi-phase system. Some polymers that are useful as low profile additives include the homopolymers and copolymers of the esters of acrylic and methacrylic acids, cellulose acetate butyrate, vinyl acetate homopolymers and copolymers, polyurethanes prepared from polyisocyanates, preferably diisocyanates, and polyether glycols, numerous saturated polyesters, polycaprolactone, styrene-butadiene copolymers, some modified celluloses and certain alkyl oxide polymers. The above list of low-profile additives does not attempt to list all low profile additives, but rather show examples of materials that have been used to cause the presence of multi-phase morphology in low profile resins. The number of acid to which the polymerizable unsaturated polyesters are condensed, generally ranges from 10 to 60. Preferably, the acid number ranges from 15 to 30. The weight average molecular weight of the unsaturated polyester ranges from 750 to 10,000 g / mol. Preferably, the weight average molecular weight ranges from 1,000 to 7,500 g / mol. The sheet molding compound of this invention may also include other conventional materials, for example, conventional chemical thickeners may be physically mixed in the resin. These chemical thickeners generally include the oxides, hydroxides and alkoxides of metals of Group II, III or IV of the Periodic Table. The calcium oxide and the magnesium oxide or the respective hydroxides are used more often. In the preferred modalities, the thickener is present in amounts ranging from about 0.5 to 6 parts, by weight. Catalysts can also be incorporated in small amounts into polyester, thermoset, crystalline resins. These catalysts are well known and can similarly be used in this invention to aid in the cure of the unsaturated polyester and monomer mixed with the low profile thermoplastic polymer. Typical catalysts include, for example, organic peroxide and peracids, such as tertiary butyl benzoate, tertiary butyl peroctoate, benzoyl peroxide, and the like. The amounts of the catalysts can vary with the molding process and vary similarly with the level and type of the inhibitors used, in a manner well known in the art. In preferred embodiments, the catalyst is present in amounts ranging from about 0.5 to 2.5 parts by weight, based on one hundred parts of the system. The curing of the composition is carried out under heat and pressure typically, in closed molds, preferably of the positive pressure type. Mold release agents can be added to the compositions to perform their normal function, as is well understood in the art. In the preferred embodiments, the mold release agents are present in amounts ranging from about 0.5 to 6.0 parts, by weight, based on one hundred parts of the four-component resin system. The fibers, fillers and pigments, normally added to the resin compositions, can be formulated similarly in the sheet molding composition of this invention. Reinforcing fibers or fibrous reinforcements indicate glass fibers, in one form or another, such as glass fabrics, cut glass cords, glass fiber mats of cut or continuous cords.; however, the terms also include reinforcing agents that can be used, if desired, for example, asbestos, cotton, synthetic organic fibers and metals. The fillers, usually inert, and the inorganic material, useful with the composition, include, for example, talc of clay, calcium carbonate, silica, calcium silicate and the like. In preferred embodiments, the fillers are present in amounts ranging from about 165 to 250 parts by weight, based on one hundred parts of the system. Examples of pigments include carbon black, iron oxide, titanium dioxide and the like, as well as organic pigments. In preferred embodiments, the pigments are present in amounts ranging from about 0 to 4 parts by weight, based on one hundred parts of the four component resinous system. In one aspect of the present invention, the preparation of the sheet molding composition is generally carried out by mixing together a first portion, comprising the unsaturated polyester, the low profile additive, the monomer and such additives as a catalyst, a mold release agent, and fillers. This is generally known in the industry as the side A formulation. The second portion (generally known as the side B formulation), comprises the thickener and its carrier resin, and such additives as pigments and mold release agents. . In another aspect of the invention, an additional or secondary monomer may be added to the side B formulation, in which the thickener is suspended. This additional monomer comprises vinyl toluene or styrene and is present in amounts ranging from about 1 to 8 parts by weight, based on one hundred parts of the four-component resinous system. The sheet molding composition of the present invention can be prepared by mixing the components in a suitable apparatus, at temperatures which are conventional and known to those skilled in the art. Once the sheet molding composition is formulated, this composition can be molded into thermoset articles, having a desired configuration. The actual molding cycle, of course, will depend on the exact composition to be molded. In the preferred embodiments, suitable molding cycles are conducted at temperatures ranging from about 121 to 177 seconds, for periods of time ranging from about 1/3 to about 5 minutes. The crystalline polymers can also be used with any glass fiber, conventionally used for the reinforcement of polymeric resins. The term "glass fibers", as used herein, means filaments formed by attenuation of one or more streams of molten glass and the strands formed when the filaments of glass fibers are joined together in formation. The terms also mean threads and cords formed by applying and / or twisting a multiplicity of cords to each other, and woven and non-woven fabrics, which are formed of such cords, threads or cords of glass fibers. Preferably, the coating formulation of the present invention can be used with the available fibers. When our polyester functions as a fiber coating, the invention comprises an aqueous coating composition, which includes, approximately, a weight percent basis: Weight percent crystalline thermoplastic polyester 5-50 surface active agent 0-2 polymer that forms the film 0-5 a thickener 0-0.1 water rest The final solids content varies from 2 to 50 percent by weight. The coating composition is applied in order to deposit a dry coating on the fibers. The surface active agent used in the aqueous coating composition can be a conventional polyether polyol, such as, for example, an alkyl and aryl polyester alcohol, sold under the tradename TRITON X 100®, available from Rohm & amp; amp;; Haas Co.

The dispersible or emulsifiable film forming polymer used in the aqueous coating composition may be a conventional elastomeric polyurethane polymer, such as, for example, RUCO 2010 L, available from RUCO Polymer Corp. The gel or thickening agent, used in the aqueous coating composition, it can be selected from a wide range of conventional thickening agents. The Drewfloc 270, a polyamide from Drew Chemical Co., has been found to be particularly useful in this application. The amount of water in the aqueous coating composition is that amount necessary to give a total (non-aqueous) solids content of the aqueous coating composition sufficient to coat the fibers. It is preferred to have the total solids content in the range of 2 to 50 weight percent, more preferably 15 to 30 weight percent, in approximate form. The following formulations are provided to illustrate examples of the compositions of the present invention. INDUSTRIAL APPLICABILITY Example I A crystalline polyester with trapped styrene was prepared according to the following synthesis of solid styrenated polyester: Ingredients Amount (g) Propylene glycol (PG) 166 g Neopentyl glycol (NPG) 1611.2 g Maleic anhydride (MAN) 1725.0 g toluhydroquinone, inhibitor 0.30 g reaction Piperidine, catalyst 2.0 mi Procedure: To a 4 liter reactor, adjusted for the condensation of the polyester, the maleic anhydride was added and then the PG, IPA, THQ and NPG. The reactor was then heated to 1902C, with nitrogen spraying at 2360 10 ~ 4 m3 / second. When the evolution of the distillate decreased (after about 220-225 ml), piperidine was added. Then the reactor temperature was increased to 2052C and baked to the following endpoints: AV = 25-28 mg KOH / g ICI resin (175QC) = 35 poises (3.5 Pa.sec.) Viscosity of the bubbles with the time (60/40 resin / styrene) = 30-34 1/100 minutes. Mixing with Styrene: The molten polyester (at 1502C) was slowly embedded in the styrene, at such a rate so as not to allow the temperature to exceed 80SC.

Ingredients Amount (g) Styrene 1,210 g Parabenzoquinone (PBQ) 0.056 g MTBHQ 0.25 g BHT 0.25 g The temperature of the mixture was also carefully maintained above the crystallization temperature of the polyester. When the mixture was completed, it was cooled to form a solid and then this solid was ground to a powder. Example II The crystalline unsaturated polyesters were prepared with the trapped styrene of Example I, in the CMH formulations, as follows. Ingredient Weight (a) Comments Resin 2,799 Unsaturated polyester of the Example. I LPA 943 Poly (ethylene glycol-co-propylene glycol-co-adipic acid) styrene CBA-60 (6%) 218 Additive against separation from Witco Para-benzoquinone (PBQ) butyl peroxybenzoate 77 1 Initiator tertiary free radical (TBPB) Calcium stearate 206 Mold releasing agent Calwhite II 318 Calcium carbonate filler P-710 151 Polypropylene oxide, low profile additive E-4600 604 Magnesium oxide pigment, side "B" The resin was formulated in a sheet molding composition (CMH) and let mature for several days. The typical viscosity of the resin at the time of molding was 6-20 MM cps (6,000-20,000 Pa-sec.) Vs typically 20-40 MM cps (20,000-40,000 Pa-sec.). The CMH was molded to 37.2-376.3 metric tons (instead of 98 standard metric tons, and an excellent piece was obtained with good surface of a 305 x mold 457 mm. The surface analysis revealed a Loria value in the range of 40 to 60. A very acceptable Loria value for auto-parts is less than 80 (lower values mean a smoother surface). Example III The crystalline powder polyester could be coated on glass fibers as follows. % in weigh Crystalline thermoplastic powder of Example I 25 alkyl aryl polyether alcohol surfactant, TRITON X 100, from Rohm & Haas 0.89 Polyurethane latex polymer, film-forming, RUCO 2010, from RUCO Polymer Corp. 2.0 Polyacrylamide thickener, 0.048 Drewfloc 270 from Drew Chemical Co. Water remaining The final solids content was about 27 weight percent. The coating composition was applied on conventional glass fibers from Owens-Corning Fiberglas Corporation, so that a dry coating was deposited on the fibers, which corresponds to about 26 weight percent of the fiber (LOI). The heating of the coated fibers to about 150 caused the adhered crystalline polyester powder to flow and melt, thus producing a fiber-reinforced product. The fiber-reinforced, cured, coated product, when wound on a cable, supplied a cable with the necessary flexibility and a proper degree of rigidity for the subsequent process.

Claims (12)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as property: CLAIMS 1. A composition, comprising: a crystalline unsaturated polyester, having a lattice of crystals, which includes a polycondensation product of one or more polyhydric alcohols and one or more ethylenically unsaturated polycarboxylic acids; and an unreacted, olefinically unsaturated monomer trapped within the polyester crystal grid.
2. 2. A composition, comprising: a crystalline unsaturated polyester, having a grid of crystals, which includes a polycondensation product of propylene glycol, neopentyl glycol and maleic anhydride; and an unreacted styrene, trapped inside the polyester crystal grid.
3. 3. The sheet molding compound, which includes the composition according to claim 1.
4. 4. The sheet molding compound, which includes the composition according to claim 2.
5. 5. The composition according to claim 3, which includes one or more low profile thermoplastic additives.
6. 6. The composition according to claim 4, which includes one or more low profile thermoplastic additives.
7. 7. An aqueous coating or binder composition, comprising, on a basis in percent by weight: Percent by weight The thermoplastic polyester 5-50 crystalline of claim 1 surfactant 0-2 film-forming polymer 0-5 a thickener agent 0-0.1 water residue
8. 8. An aqueous coating or binder composition, comprising, on a base in weight percent: Percent by weight The thermoplastic polyester 5-50 crystalline of claim 2 surfactant 0-2.0 film-forming polymer 0-5 a thickener 0-0.1 water rest.
9. 9. A plurality of flexible filaments, at least a portion of the surface of the filaments is coated with a residue produced by the evaporation of the water of the aqueous coating composition according to claim 7.
10. 10. A filament, according to the claim in which the filament is made of glass.
11. 11. A plurality of flexible filaments, at least a portion of the surface of the filaments is coated with a residue produced by evaporating the water from the aqueous coating composition according to claim 8.
12. 12. A filament, according to the claim 11, in which this filament is made of glass.