DD214074A1 - PROCESS FOR PRODUCING COMPOSITE MATERIALS - Google Patents

Abstract

Preferably glass-reinforced ungasettigten polyester resins, in which a primer is used, which allows a high composite fuse. Object of the invention orzugsweise from glass fiber reinforced ungesettigten polyester resins, in which a bonding agent is used, which allows a high composite fuse. The aim of the invention is to overcome the disadvantages of the previously used methods and the adhesion promoter used in the process, such as versproing near-surface areas of the thermoplastics, high production-technical effort and Gesundheitsgefaehrdungen. According to the invention, the high composite security is made possible by the fact that a special adhesion promoter layer is applied and dried at room temperature on the untreated thermoplastic substrate, which retains its permanent elasticity even at temperatures <0 ° C. and the temperature stability of the adhesive bond even at temperatures of more than 100 ° C. gewaehrleistet. In order to increase this adhesive bond, the adhesion promoter may be admixed with solid additives which have a light-reflecting and scattering effect when the UV-curing process is used.

Description

Field of application of the invention

The invention relates to a process for producing composite materials from a thermoplastic, preferably from FVC and hardenable fiber-reinforced plastics, preferably from glass fiber-reinforced unsaturated polyester resins, in which a high bond strength is achieved by a special adhesion promoter.

The invention finds application primarily in the manufacture of composite containers and tubes.

Oaaraicteris ~ iic of the known 0ecn.n1scn.en solutions

In the known manufacturing methods of composite materials made of thermoplastics and thermosets of the adhesive bond between the two is 7 / off erkst components uiidmaterials achieved in a variety of species by using adhesion promoters, special intermediate layers, or by pretreatment of the ™ -r.

The most significant disadvantages of these solutions are the required pretreatment effort, the low bond strength and the low temperature resistance.

Thus, in the patent DD-PS 11801? a method is described in which a composite of the thermoplastic liner material is provided with a glass fiber reinforced reaction molding material characterized by the thermoplastic to be coated before or during mi mi

It is a fiber-reinforced, hardenable plastic

"-." Πι j λ η r>. r \ f \ A O ~

superficially solubilized by a solvent (eg acrylic monomer, styrene, etc.). By dissolving the surface of the thermoplastic over a sufficient period of time is to be achieved that the subsequently applied glass fibers penetrate the surface of the composite and so a Dauervsrbund comes about. This process has the disadvantage that the surface of the thermoplastic may be embrittled to near-surface areas of the liner material or to cause stress cracking, in addition to extensive air-handling measures for avoiding harmful effects on the environment.

In another invention (DD-PS 139929) is proposed to build as a bonding agent of the composite material, a special intermediate layer, which can be produced while avoiding hazardous work with little procedural effort. This intermediate layer is said to consist of a water-dispersible, compressible material of polyvinyl acetate, plasticizers, fillers and water applied to a surface roughened by grinding. This method has the disadvantage that the surface of the liner material to be coated has to be mechanically roughened, which results in considerable work-related expense.

In a further process for the production of composite structures (DD-FS 13294-Ό, the interlayer consisting of a material which is solid in the solid state at room temperature is formed to bond the thermoplastic liner material to a glass fiber reinforced reaction molding material The heat released in the exothermic curing process of the glass fiber reinforced reaction molding materials is used to transfer the intermediate layer into an adhesive state and thus to secure the bond, but this bond is partly negatively affected by the fact that the desired higher temperatures during the melting of the intermediate layer lead to a deformation r * ö G τ *; h ii -7rn f \ TN Ί ocri ο ρ '^ a τ - .!. ] γ * J2 -τ σ τ * ''' -) y? zi r ~ i ^: / ρ, η · Λθ ^

Adhesive at higher operating temperatures i-.ip'of c-iphcTi .70: jt sh T "P ⁿ 'C""ο · * ·

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Since the quality and thus the service life of the composites produced depends substantially on the adhesion shear strength between liner and reinforcing material, in pipes international adhesive catalogs and standards stipulate adhesive shear strengths which are associated with PVC / C-UP processes

T = 7 N / mm. However, this strength refers to normal operating temperatures and is achieved by relevant pipe manufacturers by applying a special adhesive resin. At higher operating temperatures, it may then come due to the reduction of adhesive shear strength to a detachment of the thermoplastic liner.

Object of the invention

The aim of the invention is the production of composite materials with a high adhesive bond while eliminating disadvantages of the previously known solutions. At the same time, with little effort in terms of production, and avoiding ^ θ ε and the same for the work, these are said to be and

Position of composites of a thermoplastic, preferably, from PVC and curable fiber reinforced resins, preferably before to develop from glass fiber reinforced unsaturated polyester resins, in which a primer is used, which allows a high composite fuse in a wide range of applications.

The task is served by the fact that a

f to be applied and dried.

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Subsequently, the fiber-reinforced plastic, preferably glass fiber reinforced unsaturated polyester resin, applied. With an expected heat accumulation, combined with high temperatures at the interfaces to the bonding agent and the PVC pipe as a result of fre ‡ ing reaction and radiant heat in the curing process and poor heat conduction of the materials, especially in thick plastic layers, a layer of this multilayer fiber-reinforced plastic is first applied and listened to. Subsequently, all other layers can be applied and heard or heard together.

As adhesion promoter, according to the invention, a coating is applied which consists of a hydroxyl-containing polyester-polyurethane which is dissolved in known organic solvents. The polyester-polyurethane is a prepolymer whose hydroxy! Polyester is preferably composed of adipic acid and 1,6-hexanediol and which, according to the known polyaddition process with diisocyanates, with the addition of 1,4-butanediol and 1,6-hexanediol Chain extender is reacted so that a Peaktionsorodukt with a molecular weight greater than 30. IC ¹ " ¹ and a proportion of 1-3 Y" free OH groups formed. As the diisocyanate, preference is given to using ^, 4-diphenylmethane diisocyanate.

To. Increasing the strength of the composite material, the adhesion promoter solid additives up to 50 % with a particle size <0.5 2 ^ are added.

When using the UV curing process, light-reflecting and scattering solid additives are added to the adhesion promoter.

By this method according to the invention substantial disadvantages of the previously used methods and thereby doing eings adhesion promoters are eliminated.

As advantages can be called:

no chemical or mechanical pretreatment of the surface of the thermoplastic base body

- Very good adhesive properties of the primer on the thermoplastic body - especially on PVC

- Temperature resistance of the adhesive bond according to the maximum operating temperature of the thermoplastic liner

- Ensuring a permanent elasticity even at temperatures below ⁰ ° C

Suitability of the adhesion promoter according to the invention for all known methods of curing unsaturated polyester resins

- Increasing the bond to the fiber-reinforced plastic by adding solid additives, creating a "doweling effect" arises.

Increasing the effectiveness of the / hardness method by providing a reflective surface of the primer.

Ausführungsbeisoiel

The applicability of the invention will be explained with reference to embodiments.

, pe ispje 1 Ί

Made ?? a composite pipe made of PVC hard and glass fiber reinforced unsaturated polyester resin. As an intermediate layer 7 / ird applied to the untreated Eohr a bonding agent, which consists of a solution of polyester-polyurethane and ganischem solvent.

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As the polyester-polyurethane, a prepolymer whose hydroxyl polyester consists of adipic acid and 1,6-hexanediol is used. This is reacted with 4,4-diphenylmethane diisocyanate with addition of 1,4-butanediol and 1,6-hexanediol as chain extender so that a reaction product having a molecular weight of greater 30. 1Cr and a proportion of 1 - 3 % free OH groups formed.

After drying this bonding agent, after at least 2 hours, but at the latest after 24 hours, the glass fiber reinforced unsaturated polyester resin is applied in several layers. The curing (crosslinking) of the polyester resin is carried out by catalytic cold curing, d. H. Cyclone xanone peroxide is added to the resin as activator and cobalt accelerator prior to processing, causing hardening within a certain period of time (approximately 20 to 30 minutes).

The pipes produced by this process are suitable for normal temperature loads (up to a maximum of 50 ^° C.) of the pipe both during the production process (heat of reaction) and for later use within a pipe system. The ITachhärtung of the composite tube at about 80 C is possible because the bonding agent takes no damage even at these temperatures.

The process described in this example can also be used in the manufacture of PVC / GUP composite containers.

Example 2

A composite pipe made of PVC-hard and glass-fiber reinforced unsaturated polyester resin is produced. As an intermediate layer, a primer with the same chemical constituents as on the unprepared pipe is produced. described in Example 1, applied. However, for the purpose of increasing the strength of the composite of materials, this adhesion promoter is 20 % solid aggregates in the form of G. flour with a particle size

of <100 jam mixed.

After drying this adhesion promoter, after at least 2 hours, but at the latest after 24 hours, the glass fiber reinforced unsaturated polyester resin is applied in several layers. The curing of the polyester resin is carried out catalytically, d. H. The resin is admixed with the catalysts mentioned in Example 1 which, within 20 to 30 minutes, bring about the curing of the laminate consisting of polyester UFAS 2333 and reinforcing material (eg roving fabric). With thick laminate layers, high temperatures are to be expected in the hardening process at the interfaces to the adhesion promoter and to the PVC pipe, therefore initially only one layer is applied and cured. Thereafter, all other layers can be applied one after another in one operation and cured.

The gradual structure of the laminate has the advantage that due to the lower temperature load during the manufacturing process deformations of the PVC pipe due to high ^; , Värmeeinv / ir-. be avoided. 7 / eerhin an excellent bond to the PVC-hard pipe is achieved in that by the adhesion promoter zügemischten solids, which are'auch on the surface of the laminate, a Verdübelungseff.ekt to laminate arises.

Due to the high bond strength, the composite tubes are suitable for high temperature loads up to SO ⁰ C. This in this case

The method described can also be used in the production of PVC / GUP composite containers.

Example 3

A composite pipe made of PVC hard and glass fiber reinforced unsaturated polyester resin is produced. As an intermediate layer, an adhesion promoter with the same basic chemical constituents as in Example 1 is applied to the unprepared tube, but this is used to increase the thermal expansion.

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strength as crosslinker 5 % polyisocyanates (B. B. crosslinkers consisting of several cores of diphenylmethane-4, 4-diisocyanate) are added to this adhesion promoter were to further increase the strength of 7 / erkst off composite 20 % solid aggregates, which light reflecting are πιπί mixed in the form of glass beads with a size of 0.3 to 0.5.

After drying this bonding agent, after at least 2 hours, but at the latest after 24 hours, the glass fiber reinforced unsaturated polyester resin is applied in several layers. Curing of the polyester resin is photochemical, i. The photoinitiators are admixed with the resin, which cause crosslinking and thus curing of the UP resin upon irradiation by UV light.

With thick laminate layers, high temperatures are to be expected at the interfaces to the adhesion promoter and to the PVC pipe. Therefore, initially only one laminate layer is applied and cured. Thereafter, all other layers can be applied one after another in one operation and cured. The stepwise structure of the laminate has the advantage that due to the low temperature load bsim manufacturing process an excellent bond to the PVC hard pipe is achieved. 7 / eerin caused by the adhesion promoter admixed glass beads, which are also on the surface, a Verdii.belungseffekt to the laminate.

The light-reflecting and scattering properties of this additive make it possible to achieve a rational application of the photochemical hardening process in a high degree. Due to the fact that in the processing of this adhesive no emission of harmful solvents, thus avoiding a health hazard and extensive procedural expenses during production are avoided.

Claims (4)

Srfindungsanspruch 1. A process for the production of composite materials from a thermoplastic, preferably made of PVC and hardenable fiber-reinforced plastics, preferably of glass fiber reinforced unsaturated polyester resin, characterized in that a coating is applied to the non-pretreated thermoplastic as a primer, which consists of a hydroxyl-containing polyester polyurethane, which is dissolved in known organic solvents, the polyester-polyurethane being a preneopolymer whose hydroxyl polyester is preferably composed of adipic acid and 1,6-hexanediol and which is prepared by the known polyaddition process with diisocyanates with the addition of 1,4-butanediol. and hexanediol-1,6 as Kettenverlengerer is reacted so that a heatration product having a molecular weight greater than 30. IC- ³ and a proportion of 1 - 3 % free OH groups formed and is preferably used as diisocyanate ^, 4-diphenylmethane diisocyanate. 2. Continue by applying the hardenable fiber-reinforced plastic, preferably glass-fiber-reinforced unsaturated polyester resin, to the adhesion promoter coating initially in one layer only and then buffing it. Subsequently, the other layers can be successively 'applied and cured together or be gehörtet. 3. The method according to item 1 and, or 2, characterized in that to increase the strength of the Verkstof! Composite solid aggregates up to 50 %, preferably 10 to 30 % with a particle size <0.5 mm admixed to the adhesion promoter: - / η y η Pt ή rl \ ^ ^ _ --1. ^ Lj- . 4. By way of example, the solid additives have a light-reflecting and scattering action.