Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
  • B29C67/24—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 characterised by the choice of material
  • B29C67/242—Moulding mineral aggregates bonded with resin, e.g. resin concrete
  • B29C67/243—Moulding mineral aggregates bonded with resin, e.g. resin concrete for making articles of definite length
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/003—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor characterised by the choice of material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/02—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising combinations of reinforcements, e.g. non-specified reinforcements, fibrous reinforcing inserts and fillers, e.g. particulate fillers, incorporated in matrix material, forming one or more layers and with or without non-reinforced or non-filled layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/02—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising combinations of reinforcements, e.g. non-specified reinforcements, fibrous reinforcing inserts and fillers, e.g. particulate fillers, incorporated in matrix material, forming one or more layers and with or without non-reinforced or non-filled layers
  • B29C70/021—Combinations of fibrous reinforcement and non-fibrous material
  • B29C70/025—Combinations of fibrous reinforcement and non-fibrous material with particular filler
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K13/00—Use of mixtures of ingredients not covered by one single of the preceding main groups, each of these compounds being essential
  • C08K13/04—Ingredients characterised by their shape and organic or inorganic ingredients
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2063/00—Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2067/00—Use of polyesters or derivatives thereof, as moulding material
  • B29K2067/06—Unsaturated polyesters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
  • B29K2105/08—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns
  • B29K2105/0854—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns in the form of a non-woven mat
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
  • B29K2105/12—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of short lengths, e.g. chopped filaments, staple fibres or bristles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
  • B29K2105/16—Fillers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2309/00—Use of inorganic materials not provided for in groups B29K2303/00 - B29K2307/00, as reinforcement
  • B29K2309/08—Glass

Definitions

• the invention relates to a process for the production of moldings by mixing unsaturated polyester resin, inorganic fillers and magnesium oxide, thickening this mixture in the presence of glass fibers and pressing parts of the thickened mass at elevated temperature.
• molded parts which contain unsaturated polyester resin, mineral fillers and glass fibers, have long been known in the trade as 'dough molding compound' (DMC). These masses contain relatively large amounts of resin and fairly long, bundled glass fibers. Such compositions are less suitable for the production of thin-walled, arbitrarily shaped and / or strongly curved molded parts.
• the glass fibers orient themselves in certain directions during the pressing process, as a result of which the polymerisation shrinkage is not evenly absorbed, so that the reinforcement of the strength and elasticity is not homogeneous.
• the glass fiber bundles lying on the surface of the molded part act like capillaries, which has an adverse effect on the quality of the product in a moist environment. Because a lot of air is trapped in the mass, it is difficult to process into thin-walled, arbitrarily shaped parts.
• the high resin content makes the molded parts relatively expensive.
• SMC 'sheet molding compound'
• This mixture is allowed to thicken in the presence of a glass fiber layer between the polyethylene film. Then you fill a mold with the mass or with parts of it together with the glass fiber layer and the whole is pressed at elevated temperature. The processing of masses of this type is quite labor intensive. The required high glass fiber content and the resin also make the molded parts relatively expensive.
• a third mass called the 'bulk molding compound' (BMC)
• BMC 'bulk molding compound'
• the object of the present invention is now to produce molded parts from a mixture of the composition mentioned at the outset, which is easier to process, is cheaper and has an equally good or even better modulus of elasticity than the mixtures mentioned.
• the mixture comprises 80 to 95% by weight of inorganic fillers with a grain size mainly between 0 and 500 microns, 1 to 5% by weight of glass fibers , based on the entire mixture, of which at least 3/4 have a length of less than 15 mm and are mainly present as random threads and contains 0.5 to 5% by weight of magnesium oxide, based on the unsaturated polyester resin, which mixture is thickened until it is compact and almost air-free.
• the invention is based on the knowledge that it is possible to produce a molding compound with a very high filler content, which can be pressed very well into thin-walled molded parts of any shape and good quality.
• the prerequisite for this is that the glass fibers are available in a well-specified form and quantity.
• the low content of resin and glass fibers makes the cost price of the molded parts to be lower than when using the known mixtures.
• Another prerequisite for the method according to the invention is that the mass is compact and almost air-free before it is pressed.
• glass fibers are necessary to catch the polymerization shrinkage. In order to be able to distribute this shrinkage well, the glass fibers must be randomly distributed as threads in the molding compound. In order to keep the arbitrary distribution of the fibers during pressing, it is still necessary that they be relatively short. It has also been found that the mixture is difficult to process before thickening if the glass fiber content is higher than stated above. Despite the small amount of glass fiber, the molded parts have a sufficiently high modulus of elasticity. A glass fiber content of not more than 1 to 2.5% by weight gives very good results. Because the fibers are absorbed in the form of threads, they do not act capillary, so that there is no exposure to moisture.
• a suitable length of the glass fibers is predominantly 6 to 12 mm, the average length preferably being approximately 9 mm.
• the fibers can be fed to the device in which the mass is mixed in a bundled manner, stirring being carried out so long that the glass fibers are finally randomly distributed as threads in the mixture.
• the arbitrarily oriented glass fibers continue to ensure that the polymerisation shrinkage is well distributed even in strongly bent places and that the modulus of elasticity of the molded part is the same in all directions.
• any inorganic, preferably mineral, filler is suitable as filler, such as calcium magnesium carbonate (domomite), calcium carbonate, quartz powder, talc, various types of clay and the like.
• filler such as calcium magnesium carbonate (domomite), calcium carbonate, quartz powder, talc, various types of clay and the like.
• a well compressible mass for not too thick-walled Shaped parts with a wall thickness of, for example, 5 to 10 mm are obtained when the grain size of the filler is mainly between 0 and 500 microns and preferably not more than 200 microns.
• the unsaturated polyester resin can be any suitable reaction product of polyhydric alcohols and polyhydric and saturated acids or acid-forming anhydrides.
• alcohols propylene glycol, ethylene glycol, pentanediol, butanediol, butylene glycol and dipropylene glycol can be mentioned.
• acids are maleic anhydride, phthalic anhydride, isophthalic anhydride, adipic acid and the like. Like. Common.
• the unsaturated polyester resin is usually cross-linked.
• Unsaturated compounds such as styrene, methyl methacrylate, vinyl acetate and diallyl phthalate are suitable for this purpose.
• the usual peroxides such as benzoyl peroxide or tertiary butyl perbenzoate can be used as a catalyst in this crosslinking.
• a product such as hydrogenated bisphenol A plus catalyst, known commercially as 'Synolite 373', is also useful for this purpose.
• the mixture of resin, fillers and glass fibers described above is viscous.
• the mixture is poured into a container or the like and allowed to thicken to a compact, almost air-free molding compound in 1 to 48 hours.
• a compact molding compound With a compact molding compound, a dense mass similar to window putty is indicated, which is so viscous that it almost does not lose a given shape and can be divided into parts by cutting.
• This thickening is based on the effect of the magnesium oxide, which is also mixed in.
• the required amount can be cut off from the thickened mass and placed in the press mold or die, after which the whole is pressed to the desired molded part at elevated temperature. It is of crucial importance that, in contrast to the known molding compounds, an air-free, compact molding compound is obtained.
• Temperature and pressure are not critical when pressing the mass and are among other things due to the wall thickness of the desired molded part in relation to the optimal pressing time and the catalyst. Usual temperatures are 100 to 250 ° C, usual pressures are between 3 and 20 MPa.
• the pressing time will normally be between t and 30 minutes and preferably about 1 t to 6 minutes.
• Molded parts produced using the method described above can be provided with a hard and / or decorative surface layer during or shortly after pressing.
• the molded part which is still hot and not yet fully cured, can be treated with a powdery resin, for example, shortly after pressing.
• Epoxy resins containing free hydroxyl groups, such as methylol or phenol groups, or unsaturated polyester resins and mixtures of an epoxy and a polyester resin are suitable for this purpose.
• the free hydroxyl groups of the not yet fully cured molded part can also bring about three-dimensional crosslinking in this way, as a result of which good adhesion between the surface layer and molded part is achieved.
• the molded part according to the invention has a high heat content thanks to its high content of inorganic fillers.
• Treatment with powdered resin can consist of spraying, electrostatic atomization, and dipping into a fluid bed of the powder. In general, 50 to 300 g of powder are applied per m 2 .
• the modified epoxy resin does not have to be monochromatic, it is also possible to use systematic or arbitrary shades of color
• Another method of applying a hard surface layer is to apply one or more pre-impregnated glass mat.
• one or more glass fleece impregnated with an epoxy or polyester or a mixture of these two resins is placed in the mold or die before the molding compound is poured into the mold or die. If a transparent or partially transparent layer is desired, this corresponds to Refractive index of the resin after curing preferably about the refractive index of the glass fleece.
• a decoration can be beautifully attached by placing it between two glass fleece. There are a number of possibilities for this decoration. You can e.g. Place finely divided inorganic or organic substances between the glass fleece. Examples are metal powder, colored minerals, polymer parts, etc.
• One of the two glass nonwovens can also be printed with a motif beforehand, preferably using a colored or pigmented resin. Combinations of both methods are possible.
• molded parts can also be provided with a decoration in the manner described in Dutch patent application 7305807.
• the surface can be structured using a press mold with structured walls.
• a glass fleece is preferably also applied to the other side of the molded part.
• a mixture is produced which, based on the total mass, contains 85% by weight calcium magnesium carbonate with a particle size of 0-200 microns and 1.5% by weight glass fibers with a length mainly between 6 and 9 mm contains.
• the viscous mixture was poured into a container. After 24 hours, the mixture has thickened to an almost air-free, compact and cuttable molding compound. A part cut from this mass is then pressed in a die 1 1 30 "at a temperature of 200 ° C and a pressure of 150 kg / cm 2 (15 MPa) to a plate with a thickness of about 8 mm.
• the E -Module of this material is approximately 150,000 kg / cm 2 (15 GN / m 2 ) compared to 115,000 kg / cm 2 (11.5 GN / m 2 ) or 110,000 kg / cm 2 (11 GN / M 2 ) for the Compressed BMC or SMC compounds commercially available in the same way.
• the same plate with an untreated surface is exposed to the weather conditions of a sea climate for a long time.
• the surface shows no visible changes.
• the same pressing test is carried out with 0.5 or 6% by weight of glass fibers.
• the plate In the first case the plate is very brittle; in the second case, the mixture cannot be poured out and cannot be converted into an air-free, compact molding compound.
• a molding compound as described above with the same weight ratios of the components, but with long glass fibers is less suitable for pressing into strongly curved, thin-walled molded parts than a molding compound with short, arbitrarily oriented glass fibers. In this case, it turns out that the strength at bent points is less good than when using short fibers. The risk of breakage on strongly curved stiffeners is too great to produce everyday objects from this mass.
• the invention also relates to molded parts whose bodies, based on the total body weight, are 80 to 95% by weight of inorganic fillers with a grain size mainly between 0 and 500 microns, and a maximum of 5% by weight, based on the total Body weight, made of glass fibers, from which at least 3/4 have a length of less than 15 mm and are mainly available as threads in an arbitrary distribution, and consists of hardened polyester resin containing magnesium oxide.
• the present invention is not only limited to relatively complicated molded parts, but also includes relatively simple molded parts such as tiles or wall panels.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Composite Materials (AREA)
• Health & Medical Sciences (AREA)
• Structural Engineering (AREA)
• Ceramic Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Reinforced Plastic Materials (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Moulding By Coating Moulds (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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• 1977
  • 1977-06-24 NL NLAANVRAGE7706997,A patent/NL186016C/nl not_active IP Right Cessation
• 1978
  • 1978-06-19 DE DE7878200045T patent/DE2862193D1/de not_active Expired
  • 1978-06-19 EP EP78200045A patent/EP0000223B1/de not_active Expired
  • 1978-06-23 IT IT50016/78A patent/IT1105043B/it active
  • 1978-06-23 JP JP7636678A patent/JPS5411174A/ja active Granted

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