DE3121382A1 - ADHESIVE COATING SIZE AND COVERED FIBERGLASS - Google Patents

Description

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This invention relates to an adhesive coating composition and glass fibers coated therewith.

Fibrous materials are already on a large scale for reinforcing rubber objects such as pneumatic tires, drive belts, assembly lines and High pressure hoses.

For this purpose both natural and synthetic fibers in the form of single threads, groups of threads such as filaments, ropes, cords, rovings and fabrics. Examples of used natural Fibers are cotton, silk and ramie and examples of synthetic fibers are rayon, polyamide fibers, Polyester fibers and glass fibers.

Glass fibers are an excellent fibrous material for reinforcing rubber and are the natural ones and superior to the other synthetic organic fibrous materials since the glass fibers are below Stress cannot be stretched or deformed to the same extent as other fibrous materials. The difference compared to other fibrous materials are special combinations of glass fibers with encapsulating Coatings are made that give reinforced rubber products that give greater strength

as glass fibers or the coating material alone. While fibrous materials other than glass fibers are an essential Elongation when subjected to tension and essentially affects tensile strength of fiber are limited even when coated, coated glass fibers give higher strength than the fiber alone. For example, the low modulus of elasticity of glass can be used to to give reinforced rubber tires that have better driving performance if a suitable covering of the Glass fibers are present to transfer the stresses to all fibers in the glass fiber cord, so that the load is substantially uniform. This phenomenon is illustrated by observing a typical non-coated fiberglass cord (G75.5 / 0, filaments 2000, i.e. 2000 filaments of G fiber about 9.14 microns in diameter, 15120 m / kg, 5 filaments per cord), which has a tensile strength of 156 to 178 newtons on ASTM test G178-52, but after coating, for example with a resorcinol-formaldehyde latex, a tensile strength of about 220 to 311 newtons has.

The previously characterized coated fiberglass cord, GT-75.5 / 0, is used especially for reinforcement of rubber in drive belts and in tires reinforced with fiberglass. In such coated fiberglass

cords is a latex of a resorcinol-formaldehyde conversion product as an adhesive system for the transmission of mechanical loads and for the better Adhesion is used between the glass fibers and the rubber. Typically the resorcinol formaldehyde resin or also a resorcinol-phenol-aldehyde resin for the improvement of the adhesion between glass fibers and rubber by a process produced, at which a basic pH of, for example, 8 to 10 prevails. The resorcinol aldehyde resin usually has a resorcinol content in the range from 0.4 to 0.8 per 1 mol of the base. Such a thing Resin is characterized by a low degree of condensation and a minimum molecular weight. A particularly suitable resorcinol-aldehyde condensate contains formaldehyde and resorcinol in a ratio of 0.6: 1. This product is commercially available under the name "Penacolite ^ R-2200 "available.

There are various processes for the production of resorcinol-aldehyde condensates that are used as adhesive systems should be known. As early as 1947, US Pat. No. 2,385,372 proposed a permanent Manufacture fusible resin from resorcinol and an aldehyde in two stages, with no catalyst during of the two stages of implementation was in place. It was believed that by the presence of the Catalyst in the first stages of the reaction

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too thick resin would be formed for the removal of the water produced in the reaction. This problem was solved by using a two-stage reaction in which resorcinol is reacted with the aldehyde with heating and reflux cooling without the presence of a catalyst until a major part of the reaction has ended. Then, however, either an alkaline or an acidic catalyst is added in order to react the last residues of the aldehyde with the resorcinol.

From US-PS 40 25 454 the production of a phenol aldehyde condensate is known by a precondensate from formaldehyde, resorcinol and para-substituted phenol and a precondensate made from resorcinol and Formaldehyde used. In a first stage, resorcinol and a para-substituted phenol with two active methylene groups condensed in the presence of an acidic catalyst. In the second stage will Formaldehyde condenses with the product of the first stage in an alkaline medium. In a third stage will the product of the second stage dissolved in water with a resorcinol precondensate to form a phenoplast system form, which is a mixture of phenol aldehyde condensate. Then there is a condensation with an elastomer Latex was made to make an adhesive for textile fibers.

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In US-PS 39 56 205 the production of a resol is described in two stages. The first stage of the Reaction is carried out under conditions of formation of novolak resins, using an acidic catalyst used to give a pK less than 5. In the first stage, one mole of phenol is 0.05 to 0.30 mol of formaldehyde converted under conditions that favors the formation of a diene and its formation is suppressed by higher oligomers. In the second stage, the reaction is carried out in the presence of a basic catalyst, which has a pK value greater than 9, with the addition of 1.75 to 3.5 mol of formaldehyde per mol of the original phenol for the resole reaction. At the end of the reaction the catalyst is through Addition of acid is reduced to a pH of 6 to 8.9, with the formation of the resole resin.

The known phenol or resorcinol aldehyde resins, such as

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the commercial product "Penacolite ^" and also those which are produced by the aforementioned multi-step processes are in their application as an adhesive system not completely satisfactory for composite bodies made of glass fibers and rubber. It therefore exists the desire to improve these resins in order to give the coated glass fibers greater flexibility and to give better resistance to breakage due to compression fatigue, thereby making durable reinforced Rubber products would arise.

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One of many reinforced rubber products made by using coated glass fibers of higher quality Flexibility and better resistance to pressure fatigue would have a big advantage, would be that pneumatic tires. A coated fiberglass tire with greater flexibility and durability against pressure fatigue would have better performance properties and a longer running distance.

The object of the invention is therefore to provide an improved adhesive coating composition for glass fibers to make the glass fibers more flexible and more resistant to compression fatigue.

According to the invention, this object is achieved by a Adhesive coating composition containing a flexible and tough resorcinol-aldehyde resin, which is characterized is that this resin is a thermoplastic, water-soluble resorcinol-aldehyde resin that is a mixture of oligomers and a larger amount of trimer and only a smaller amount of dimer and higher oligomer, which have arisen through slight crosslinking, contains and was obtained by

a) Reacting up to less than 100% of resorcinol with an aldehyde in amounts corresponding to a molar ratio of 0.8 to 1.5, at a pH of 3.5 to 5.5, whereby the formation of resorcinol alcohols is avoided for a period of time, which is a period of time

from 3 to 10 hours at a temperature of 13 to 32 ° C is equivalent, so that a resinous Mixture arises that contains a greater amount of trimer and a smaller amount of dimer and a smaller amount of the higher oligomers and unreacted starting materials resorcinol and aldehyde contains,

b) Continuing the reaction at a pH of 7 to 7.5 at a temperature of 13 to 32 ° C for one Period of 0.75 to 10 hours, making a thermoplastic, water-soluble resorcinol-aldehyde resin arises, which mainly contains the trimer, a low level of crosslinking and improved flexibility and has improved toughness.

The resinous mixture contained in the coating compound is a thermoplastic, water-soluble resorcinol-aldehyde resin, which is ideally suited for use in an adhesive system such as the "RFL" system and is very useful for coating fiberglass. This gives glass fibers that are attached to the to be reinforced Rubber adhere better and produce reinforced rubber articles of very good quality.

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The resole and the aldehyde can be implemented with or without the addition of any acidic or basic catalysts , so that the intended pH values are maintained during the reaction.

The resorcinol aldehyde resin, which through careful control is manufactured in a two-step process, is a flexible and tough resin that is coated in an adhesive system for coating glass fibers Glass fibers result that are more flexible and more break-resistant. Through the pH control in both process stages and because the starting materials are not fully implemented in the first stage and also due to the relation of the temperature and time conditions in both stages, a trap arises in predominant amounts in the Condensate. While other oligomers are formed, the weight of the dimer and higher is the same Oligomers much lower than that of the trimer. The trimer can be represented by the following formula will:

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OH

Formula I.

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In this formula, R is a hydroxyl radical, but R can also be hydrogen if it is used as starting materials phenol is also used for resorcinol. Also can the trimer also contain other groups, such as methylol groups. The resorcinol aldehyde resin is consequently a mixture of oligomers in which the trimer forms the predominant amount, with the resin also has a low degree of cross-linking between the chains.

To increase the adhesive properties, the resorcinol aldehyde resin is combined with an elastomer latex, see above that the resin in an amount of 5 to 50 parts by weight per 100 parts by weight of the solids of the elastomer Latex is present. As further components, the coating mass can contain the usual additives, such as wax, antioxidants, Agents to increase adhesion, such as resorcinol, and agents to retard crosslinking, such as concentrated ammonia, contain. The aqueous coating composition contains such amounts of water that the entire solids content is about 20 to about 40 wt%. This adhesive system is ideal for coating fiberglass materials, how. individual glass threads, groups of glass threads in the form of filaments, ropes, cords, rovings or fabrics.

The resorcinol aldehyde resin used in the coating has a specific composition and is produced by a carefully controlled multi-stage process. In the first stage, the starting materials not converted to 100% and an acidic pH of 3.5 to 5.5 is maintained. In the in the second stage the reaction is continued at a pH of 7 to 7.5.

Without limiting the invention, it is assumed that the choice of starting materials and the process conditions have the following effects: Phenolic compounds have a strong ortho-, para-directing effect because of their hydroxyl group. Since resorcinol is the is the predominant phenolic compound, the 2, 4 and 6 positions are activated twice. If that The ratio of aldehyde to phenol compound is about 1, a resin is obtained in the acidic medium which is permanent is meltable and soluble. There is either no or at most only a slight crosslinking and the resin consists mainly of chains in which the phenol nuclei are linked by methylene bridges. In an acid medium the 2 and 6 positions of the phenol nuclei are preferred in the condensation reaction. The speed for resin formation, the hydrogen ion concentration is directly proportional. By setting a acidic pH value in the first stage and by controlling the temperature and the residence time within the specified There are no limits to the implementation of the starting materials

Completely. It follows that the resin produced in the first stage has not yet reacted aldehyde and possibly contains unreacted resol. Since the resin formation in the first stage is incomplete even then if the ratio of aldehyde to phenol compound is greater than 1 or even 1.5, that is obtained Resin permanently meltable and soluble. The average molecular weight of the resin from the first stage is usually less than 1000. The resinous product of the first stage contains a predominant amount of the polymer,, but is a resinous mixture containing lesser amounts of the dimer and lesser amounts of the higher oligomers such as tetramers and pentamers. It is desirable to increase the proportion of the higher oligomers to be kept to a minimum as these higher oligomers are not water soluble. This resin mixture possesses good flexibility, which is also transferred to substrates coated therewith.

The pH of the reaction mixture from the first stage is adjusted to about 7 to about 7.5. The addition corresponding to the amounts of basic catalysts is sufficient to have an effect on the reaction to have. The first stage resinous materials continue to react with the unreacted aldehyde and Any unreacted phenolic compound present, with the formation of methylol groups, which continue with aging condense and form a slightly networked, but essentially

still result in linear thermoplastic resin, in which the trimer predominates in the mixture of oligomers.

Since a basic pH is only used in the second stage, the formation of phenolic alcohols is in the second Stage mostly limited to the formation of monomethylol compounds instead of dialcohols or trialcohols. This will further the growth of the resin towards a substantially linear, thermoplastic Resin promoted. The formation of methylol groups in the second process stage leads to a little crosslinking of the linear chain of the resinous material from the first stage and imparts to the resin a higher toughness, but the flexibility and the linear character are essentially retained. The reaction in the second stage is continued for about two to about ten hours, at which point the desired Resin of good flexibility with low crosslinking and high toughness is obtained. the Crosslinking and / or branching is not so high that the resin becomes infusible.

Resorcinol is preferably used as the phenol compound in the invention. However, mixtures can also be used used by resorcinol with other phenolic compounds in which the pheno! compound is, however, weight

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is massively in excess. As such mixtures come mixtures of resorcinol and phenol are particularly suitable. Other phenols that are mixed with resorcinol Resoles, xylenols, phloroglucinol, orcinol, cresorcinol and m-xylorcinol can be used. The others Phenols as resorcinol are usually used in small amounts at most.

Suitable aldehydes are those which form methylene groups and are soluble in the reaction medium. A be -..-. ■ The preferred aldehyde is formaldehyde, which is usually used as a 37% aqueous solution (formalin). Further can use various polymers of formaldehyde, such as paraformaldehyde, hexamethylenetetraamine, acetaldehyde and furfural can be used. The formaldehyde is preferably used as formalin.

The invention will now be made with reference to resorcinol and formaldehyde are described in more detail, but can also be used in the context of the findings already made other connections can be used.

Formaldehyde and resorcinol are used in the range of the molar ratios from 0.6 to 1.5, preferably 0.8 to 1.5. An example of such a ratio is 1 mole of formaldehyde to 1.5 moles of resorcinol, accordingly a molar ratio of formaldehyde to resorcinol of about 0.65.

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If too little resorcinol or too much formaldehyde is used, an infusible cross-linked resin is created. If too much resorcinol and too little formaldehyde is used, the resin will not be flexible enough to because the proportion of the trimer in the oligomeric mixture is not very large. Examples of catalysts that Can be used in the first acidic stage are sulfuric acid, oxalic acid, hydrochloric acid, sulfamic acid, Benzenesulfonic acid, toluenesulfonic acid or trifluoroacetic acid. The concentration of the acid catalyst can range from 0.001 to 0.002 molar equivalents per mole Resorcinol, but any acid that gives the desired pH can be used. The preferred one The pH of the first reaction stage is the acidic pH obtained by combining resorcinol and formaldehyde in the form of formalin. Most preferably, this pH is achieved that the starting materials have a pH in the range by autocatalysis from 3.5 to 5.5 result. An acidic pH higher than 5.5 can be achieved by autocatalysis by small amounts of a basic catalyst are added. If the pH is above 5.5, resorcinol alcohols can be used with methylol groups that lead to crosslinking To give reason.

In the first stage, resorcinol and formaldehyde are added to the reaction vessel in the desired molar ratio

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brought in. If a monohydric phenol, such as phenol, is also used, the reaction conditions should be tightened because monohydric phenols react more slowly than resorcinol or other polyhydric phenols. In general, the reaction between the resorcinol and the formaldehyde in a first stage Temperature between 13 and 32 ° C and carried out for a period of 3 to 10 hours, the temperature and time are inversely related. Equivalent reaction times and temperatures can also be used can be used to achieve the same degree of implementation. As a result, when the temperature is increased, the implementation time is shortened. If the temperature is increased above 32 ° C, the reaction time will be shortened to less than 3 hours and if the temperature is lowered below 11 ° C, the implementation time is increased over 10 hours.

At the end of the first stage of the reaction, a resinous polymeric mixture is produced which comprises a predominant Share of trimers and a smaller amount of dimers and higher oligomers of resorcinol and also still Contains unreacted formaldehyde and resorcinol. The majority of the trimer is at least 40% of the converted material of the polymeric mixture, the dimer and the higher oligomers each in lesser amount are available.

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The resinous mixture of the first stage is then adjusted to a pH of above 7 to 7.5. Man achieves this by adding a basic catalyst. Suitable basic catalysts are sodium hydroxide, Potassium hydroxide and other alkali hydroxides as well as alkali carbonates and alkaline earth hydroxides. These Catalysts can be used as solids, but their aqueous solutions are preferred. The concentration of the basic catalyst is generally from about 0.01 to about 0.06 moles of catalyst per Mole of resin.

After the pH of the resinous mixture has been adjusted, the reaction between unreacted Formaldehyde continued with the resin and the unreacted resorcinol. The implementation takes place in generally at a temperature in the range from 13 to 32 ° C when the reaction time in the range from about 2 to about 10 hours. If the temperature is increased or decreased, the conversion time is set accordingly. All temperatures and conversion times can be used that allow a degree of conversion which is equivalent to the stated temperature and time conditions. If the pH is above 7.5, too many methylol groups are created and the resin is too strongly crosslinked. If the pH is below 7, runs the reaction continues in the sense of the acidic implementation

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the first stage and the linear polymer does not receive the desired low level of crosslinking to form a tough flexible resin.

The two-stage process can be discontinuous, semi-continuous or continuous in one vessel with be carried out in several stages or in several vessels, with the starting materials and the products of one vessel into the other. Known equipment for the manufacture of resins can be used will. Vessels for reactions at ambient temperatures are preferably used, but vessels can also be used with heating or cooling equipment to be applied when temperatures are too low in winter or too in summer are high.

The resorcinol-formaldehyde condensate used in the invention is mixed with an aqueous elastomeric latex combined. Usual elastomeric latices, especially those known for adhesive systems, related. Examples of suitable elastomeric latexes are latexes of vinylpyridine-styrene-butadiene terpolymers (Commercial products GEN-TAC, GOODRITE or PYRATEX). Also dispersions of polybutadiene, styrene-butadiene copolymers, Reclaimed rubber, butyl rubber, and ethylene propylene butadiene terpolymers can be used will. It is also possible to use natural rubber latex in both its raw and treated form.

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To use delter form, the treatment being a breakdown or oxidation or both. The latices can contain accelerators, vulcanization auxiliaries, Contain stabilizers, dispersants or other common additives. The type of elastomer used Latex depends to a certain extent on the type and type of rubber or rubber that is used is to be reinforced by the fibrous material, in particular by glass fibers. Mixtures can also be used of the elastomeric latices or dispersions mentioned are used.

The combination of the resorcinol aldehyde resin with an elastomeric latex forms an adhesive system respectively a system to improve adhesion. In this system the ratio of resin to elastomeric latex is in the Typically 5 to 50 parts by weight of resin per 100 parts by weight of the solids of the elastomeric latex. The mixture Resorcinol-formaldehyde resin can also contain additives, like wax to protect the elastomer against attack by ultraviolet light. More possible Additives are zinc oxide, magnesium oxide, black lead or red lead oxide, which can serve to improve the crosslinking of the elastomeric latex and to increase the resistance of the mixture to aging, heat and light. Antioxidants, treated dietary earths, are also used as additives and other known additives for adhesive systems.

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The aqueous adhesive system should have a pH value between 7 and 10. The pH value can be adjusted by adding aqueous Alkali hydroxide solutions such as sodium hydroxide or ammonium hydroxide can be adjusted. This can also Any formaldehyde that may still be present can be bound. When the composition is a latex of a vinyl pyridine polymer contains, which usually has a pH of 10.2, a further adjustment of the pH value is usually not mandatory. The adhesive system produced in this way should as soon as possible, expediently at least within one week for coating fiber materials, especially glass fibers. It can be on the fibrous materials can be applied by conventional methods such as dipping, spraying or brushing.

Glass fibers are primarily considered as the fibrous material, but others are also natural and synthetic fibers such as cellulose fibers, polyamide fibers and polyester fibers are suitable. The ones for making Glass fibers used by glass fiber cord are obtained by pulling the fibers out of a nozzle, sizing with a conventional aqueous sizing composition, combining into a spun thread and winding into one Winding. The manufacture of the glass fibers is described in more detail in US Pat. Nos. 34 37 517, 34 59 585 and 38 87 389. The windings of the filaments are then dried and mounted on a frame, unwound, coated with the adhesive system and dried.

In the first stage, the conversion takes place from less than 100% with a molar ratio of formaldehyde to resorcinol from 0.8 to 1.5.

With the preferred ratio of formaldehyde and resorcinol, the pH at the first stage is in the range of 3j5 to 5.5. If the starting materials are resorcinol and formaldehyde used in the form of formalin is usually the addition of an acidic catalyst for adjustment this pH range is not necessary. In an alternative embodiment with different Starting materials, it may be necessary to add an acidic catalyst to adjust the pH range mentioned. The reaction between resorcinol and formaldehyde is carried out in the first stage at ambient temperature, preferably one Temperature between about 20 and 32 ° C, carried out for a period of 3 to 10 hours, preferably 3 to 4 hours. The resinous product obtained contains a major proportion of trimer from the condensation of resorcinol and formaldehyde and small amounts of dimers and higher oligomers of resorcinol and formaldehyde in admixture with unreacted formaldehyde and a smaller amount of unreacted resorcinol.

In the second stage of the reaction, the pH of this mixture becomes adjusted to a range of 7 to 7.5 by preferably adding 0.01 to 0.06 mol of an aqueous solution of

Potassium hydroxide can be added per mole of resin. The reaction of the resorcinol-formaldehyde resin, the unreacted resorcinol and the unreacted formaldehyde is then carried out at this pH and a preferred temperature in the range from about 20 to about 32 ^° C. for a period in the range from about 2.5 to about 10 hours, preferably about 5 hours, continued. The resin-like product that is formed in the second stage is a flexible but tough resorcinol-formaldehyde condensate, which is thermoplastic and is a mixture of reaction products with different degrees of condensation, but the main component is a trimer, which has little and less crosslinking contains more than 20% unreacted formaldehyde due to incomplete conversion. The unreacted formaldehyde is available for reaction with the resorcinol-formaldehyde condensate when this is combined with an elastomer latex to create an adhesive system.

In the preferred embodiment, the preferred resorcinol-formaldehyde resin prepared as described above is combined with a polybutadiene latex such as "LPM 6290" from Goodyear and a vinylpyridine styrene butadiene terpolymer latex such as ^"11 LVP 5622" from Goodyear.

In this preferred embodiment, the two Latices in the range from 70 to 90 parts by weight, in particular 70 parts by weight, of the first-mentioned latex and 10 to 30 parts by weight, particularly 30 parts by weight, of the terpolymer latex is used. The ratio of the Resorcinol-formaldehyde condensate to the rubber latex should be between 5 to 50 parts by weight of this resin per 100 parts by weight of latex solids. Other known latexes of elastomers can also be used such as styrene butadiene latices. When the amount of Resin is less than 5 parts by weight, the adhesion is insufficient, while resin amounts of greater than 50 parts by weight per 100 parts of latex are uneconomical. It is desirable to make the adhesive system from the resin and to add to the latex a phenol-type antioxidant such as the commercial product "Bostex 294" from US Pat Akron Dispersion, Akron, Ohio, USA. The amount of antioxidant added is usually in the range of one part by weight to 100 parts by weight of the dry rubber. This increases the flexibility of the coating increased within a wide temperature range. Another suitable antioxidant is the commercial product "Paracure A09", which is preferably used in an amount of about 0.5 parts by weight per 100 parts by weight of rubber will. An aliphatic wax, preferably in an amount of about 5%, can also be added to the adhesive system Parts by weight per 100 parts by weight of rubber are added

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will. A suitable such wax is the "Mobilcer Q" commercial product from Mobile Company. After manufacture the adhesive system is allowed to age at ambient temperature for at least 10 hours. Because of this aging a further condensation of the formaldehyde condensate with the formaldehyde in the presence of the elastomer Latex possible. Long-chain, slightly crosslinked thermoplastic resins are obtained in a mixture with the latex. After aging, a small amount of a nitrogenous base, such as ammonia or an amine, is mixed with a medium boiling point, e.g. diethanolamine, but preferably a small amount of concentrated ammonia (28% solution) added to bind any unreacted formaldehyde that is still present, so that no further networking occurs. The amount of ammonia or amine is usually less than 1 part by weight to 100 parts by weight of rubber. By adding ammonia, the adhesive system is stabilized and its useful life is extended.

It was also found that adding about 1 part by weight of ammonia to 100 parts by weight of the Rubber, the adhesion of the adhesion system can be increased by adding the Ammonia solution adds about one part by weight of resorcinol to 100 parts by weight of the rubber of the system. The added resorcinol increases the adhesiveness and the polarity of the adhesive system and leads to a

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their rotation, the glass silk filaments the coating mass to. The coated and impregnated filaments are then combined into a bundle. By lowering the Tension of the combined bundle creates gaps between the fibers and the filaments, causing the impregnation of the bundle is increased. As a rule, the aqueous immersion bath has a share of 20 up to 40% by weight of solids, the amount of solids in the bath depending on the desired solids content in individual cases depends on the bundle. Depending on the use of the treated glass fibers, it is desirable that they 15 to 40% by weight, based on the weight of the glass fibers, of the solids in the adhesive system. Is preferred a range from 20 to 30 wt%.

After the glass fiber bundle has been brought into contact with the coating composition for a sufficient period of time is to completely impregnate the bundle with water and the solids it contains, the bundle becomes passed through a dielectric heater or drying oven. The drying oven is designed in this way and operates to rapidly remove water from within and from the surface of the bundle without causing any substantial migration of the solids from the interior to the surface of the bundle and more blistering occurs.

The dried glass bundle is then heated to partially vulcanize the rubber of the coating. It it is preferable to only partially vulcanize the coating and vulcanize it at this point to be finished only when the coated glass fiber is embedded in the rubber matrix and the rubber vulcanized into the finished reinforced rubber article. A second suitable method of manufacture of glass fiber bundles is described in US Pat. No. 3,718,448.

The adhesive system according to the invention can contain natural or synthetic rubber as the rubber component. Examples of suitable synthetic rubber are polymerized isoprene, polymerized butadiene, halogen-substituted polybutadienes, such as polymers of halogen-2-butadiene-1,3, especially polymers of Chlorine-2-butadiene-1,3.

The invention is explained in more detail in the examples. Unless expressly stated otherwise, all information on quantities or percentages is given by weight is detected.

example 1

A thermoplastic resorcinol-formaldehyde resin is produced by adding 70 to 75 % of the total water at 20 to 25 ^° C. to a premixing vessel. Then 26 kg of resorcinol are dissolved in this water with stirring. Then 27.8 kg of formaldehyde are introduced into this vessel. The resorcinol and the formaldehyde are reacted in the aqueous solution at a temperature of 25.6 to 26.7 ° C and a pH of 5.0-0.5 for 4 hours. A solution of potassium hydroxide in water is prepared by adding 0.82 kg of potassium hydroxide to 10.39 kg of water and dissolving it therein. At the end of the period of 4 hours, the aqueous solution of potassium hydroxide is slowly added to the premixing vessel with the reacted resorcinol and formaldehyde. After the addition, the temperature is maintained at 24-27 ° C with a pH of 7.5 and the reaction is continued for a period of 5 hours. The resorcinol-formaldehyde resin obtained after 5 hours is thermoplastic, water-soluble and contains a predominant amount of slightly crosslinked trimer, a minor amount of uncrosslinked trimer and dimers and higher oligomers which can be slightly crosslinked. The reaction product also contains a small amount of unreacted formaldehyde.

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Example 2

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41.6 liters of deionized water at a temperature of 43.3 ° C was placed in a vessel, and then 8.71 kg of resorcinol was dissolved therein with stirring. 9.25 kg of formaldehyde were added to this aqueous resorcinol solution and the temperature was adjusted to 26-27 ° C. with a pH of 5.0-0.5. This temperature was maintained for a period of 4 hours. In the meantime, an aqueous solution of 0.27 kg of potassium hydroxide in 3.63 kg of deionized water was prepared. At the end of the 4 hour period, the potassium hydroxide solution was slowly added to the vessel containing the resorcinol-formaldehyde reaction mixture. After the addition of the potassium hydroxide solution, a temperature of 24 to 27 ^° C. and a pH of 7.5 were maintained for a period of 5 hours. After the 5 hours, a thermoplastic water-soluble resorcinol-formaldehyde resin according to the invention was obtained.

Example 3

There were submitted to 45.4 liters of deionized water at a temperature of 43.3 ⁰ C in a vessel and it was dissolved therein 9.4 kg resorcinol. To the resorcinol

10.3 kg of formaldehyde were added to the solution. The formaldehyde and resorcinol were reacted in aqueous solution at a temperature of 26 to 27 ^° C. and a pH of 5.0-0.5 for a period of 4 hours. In the meantime, 0.27 kg of potassium hydroxide was dissolved in 7.6 liters of deionized water. At the end of the 4 hours, the potassium hydroxide solution was slowly added to the resorcinol-formaldehyde reaction mixture. After adding the aqueous potassium hydroxide, the reaction mixture was kept at 24 to 27 ° C. while maintaining the pH for a period of 5 hours. A thermoplastic, water-soluble resorcinol-formaldehyde resin according to the invention was obtained.

Example 4

653 kg of polybutadiene latex were placed in a main mixing vessel (Goodyear 6290) and 490 kg of a latex of a butadiene vinyl pyridine copolymer (Goodyear 5622). to to this mixture were added 503.5 liters of deionized water and 9.8 kg of an antioxidant (Boxtex 294). 174 liters were placed in a separate mixing vessel added deionized water and 4.9 kg of an antioxidant (Paracure A-09). To this mixture were 49 kg of wax (Mobilcer Q) are given. The solution was then mixed for 10 minutes and was then incorporated into the latex

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added to the main mixing vessel. In this mixing vessel Then a resorcinol-formaldehyde resin prepared as in Example 1, which had been aged for 9 hours, was also used was introduced slowly. The resulting mixture was aged for 10 hours. Care was taken that the resorcinol-formaldehyde resin had a pH of 7.5 or higher to avoid coagulation of the latex. If the pH of the resin is lower than 7.5, it can be adjusted by adding potassium hydroxide will. A mixture of aqueous ammonium hydroxide is then prepared by adding 3.3 kg of commercially available Ammonium hydroxide can be diluted with 34 liters of deionized water. After mixing the resin and the latex has been aged, the ammonium hydroxide is added to this mixture. The mix will then stirred and an adhesive system is obtained which contains 27 0.5% solids, a pH of 8.5-0.3 and has a diving duration of 50 hours. This system of detention is suitable for improving the adhesion between glass fibers and rubber substrates.

Example 5

241 kg of polybutadiene latex (Goodyear 2374) and 181.4 kg of a latex of a styrene are placed in a mixing vessel. butadiene vinyl pyridine copolymers. Besides that

132 liters of deionized water and 3.6 kg of an antioxidant (Bostex 294) are added. 37.9 liters of deionized water and 1.8 kg of an antioxidant (Paracure A-09) and 18 kg of wax (Mobilcer Q) are placed in a separate vessel. These materials are mixed for 10 minutes and the mixture is then added to the mixture of latices. The long-chain, thermoplastic, water-soluble resorcinol-formaldehyde condensate according to Example 3, which has been aged for 9 hours, is then slowly introduced into this mixture. The mixture is then aged for 10 hours. An aqueous solution of ammonium hydroxide is prepared by diluting 1.1 kg of commercially available ammonium hydroxide with 15 liters of deionized water. This aqueous ammonium hydroxide solution is slowly added to the mixture of the resin with the latex with stirring and stirred for about 10 minutes. An aqueous resorcinol solution is prepared by dissolving 1.8 kg of resorcinol in 15 liters of deionized water with stirring. The resorcinol solution is then added very slowly to the resin-latex mixture over a period of 15 minutes. The mixture obtained is stirred for 25 minutes and then automatically stirred for one minute at intervals of half an hour. The coating composition obtained had a solids content of 27-0.5%, a pH of 8.5-0.3 and an immersion time of 50 hours.

The resorcinol solution was added to the resin latex mixture, to increase the adhesion of the adhesive system, which is probably due to the fact that the This increases the wetting and impregnation of the glass fibers.

Example 6

91 liters of deionized water at 43.4 ° C. are placed in a premixing vessel. In this water will be under Stirring 43.5 kg of resorcinol dissolved. 25.8 kg of formaldehyde are added to the resorcinol solution. The resorcinol and the formaldehyde are in the aqueous solution at 26 to 27 ° C and at a pH of 5.0 ΐ 0.5 for a Implemented for a period of 5 hours. An aqueous potassium hydroxide solution is prepared by adding 0.73 kg of potassium hydroxide be dissolved in 18 kg of deionized water. At the end of the four hour reaction under acidic conditions the potassium hydroxide solution is slowly added to the reaction mixture. The implementation is then at a pH of about 7.5 and a temperature of 26-27 ° C for 5 hours. At the end of that period a long-chain, thermoplastic, water-soluble resorcinol-formaldehyde resin is obtained.

414 kg of a latex of a styrene-butadiene copolymer (Firestone SR6642) are added to a main mixing vessel and 181.4 kg of a latex of a carboxylated polybutadiene (GenFlow 8020) and 327 kg of a polybutadiene-styrene latex (Firestone S-272) given. 75.7 liters are deionized in a separate vessel Water, 3.6 kg of an antioxidant (Paracure A-09) and 36.3 kg of wax (Mobilcer Q) mixed for 10 minutes and then placed in the mixing vessel containing the latices. The long-chain, thermoplastic, water-soluble resorcinol-formaldehyde resin was added after it had been aged for 9 hours. The mixture is then aged for 6 hours and there are 127 kg of a latex of a rubber based on chlorobutadiene (Neoprene 735-A) slowly admitted. An aqueous solution of ammonium hydroxide is prepared by adding 4.8 commercially available ammonium hydroxide is diluted with 23 liters of deionized water. This aqueous solution of ammonium hydroxide is added to the reaction mixture after it has aged about minutes after the addition of the latter latex has been. The addition is very slow and after that the mixture is aged for 15 minutes and afterwards one hour it is stirred for one minute at intervals of half an hour. The system of adhesion obtained has a solids content of 28.0 - 0.5%, a pH of 8.5 - 0.3 and an immersion time of 60 hours.

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Example 7

Glass fibers were used which had been produced in a known manner, in that molten glass was drawn out of a nozzle, the glass threads were treated with an aqueous size and combined to form spun threads, and the spun threads were wound up and then dried. The dried windings were mounted on a frame, unwound and coated with the adhesive system according to the invention. Glass silk filaments of the types G-75.5 / 0 or G-75/10/0 or G-75.15 / 0 were used, with a diameter of 9.6 χ 10 ⁶ m to 9.1 χ 10 "^ m and having a thread count of 2000 in a cord, the cord consisting of 5 spun threads each with 400 individual threads. K fibers were also used, such as K-15 spun threads, which are typically 100 single threads, the single threads having a diameter of 13.34 - 0.63 micrometers. 1 to 3 such spun threads are used for a cord, which have also been coated with the adhesive system according to the invention. 5 spinning threads are used for G cord and 10 to 15 spinning threads per cord for cords for radial tires.

The cord of 10 to 15 filaments allows a higher packing of the cord per unit area, thereby creating the tire carcass gets a higher strength. This strength is required to achieve the desired properties

to have a belted tire. G fibers were treated with a size which predominantly contained a polypropylene emulsion with 25% by weight of polypropylene and 6 % of emulsifier and also small amounts of polyvinyl alcohol, amidimidazoline and methacryloxypropyltrimethoxysilane. This size was applied to the fibers during their formation and the spun thread formed was dried and / or hardened according to US Pat. No. 3,655,353.

The adhesive systems of Examples 4 and 5 were used to cover glass fiber cord. The fiberglass cord was produced by treating 15 sized filaments with the coating composition of Examples 4 and 5. This cord was incorporated into rubber samples and also to reinforce the belt of pneumatic ones Used tires.

The level of adhesion of the adhesive system in various rubber materials was investigated. The success The adhesion between rubber and tire cord is determined by various tests, including the Strip adhesion is one of them. The strip adhesion for rubber-coated glass cord is determined by the following method: A cylindrical drum is covered with a 10.2 26.7 cm 0.1 cm strip a rubber sample covered. The rubber sample occupies essentially the entire surface of the cylindrical

4 ft - * *

PM # ft φ. 0 *

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Drum a. The treated glass fiber is wound around the rubber sample on the drum in a cylindrical manner, so that a continuous layer of glass fiber is created over the rubber sample. Then the rubber-glass fiber sample detached from the drum and 7.6 25.4 cm samples are cut. It will be a streak of 7.6 χ 25.4 cm rubber placed in a 7.6 χ 25.4 cm mold and on this strip the rubber strip covered with the fiberglass thread is placed so that the fiberglass side faces away from the first rubber strip. A number of 27.62 χ 2.54 cm strips "Holland" cloths are placed at opposite ends of the fiberglass side of the rubber strip. It then add another 7.62 χ 25.4 cm strip of rubber placed on the "Holland" cloth and finally a 7.62 χ 25.4 cm rubber strip with the treated Glass fibers thereon which have been brought into contact with the last-mentioned rubber strip. Form is closed and the rubber cord laminate is cured at 4780 Pa for 30 minutes at 149 ° C. Then it will be removed the laminate from the mold and allowed to cool overnight.

The laminate is then cut into 14 χ 2.54 cm strips and heated to 121 ° C for 30 minutes. Then the "Holland" cloth is removed. After hiring a "Instronw" test device to a test length of 1.27 up to 1.9 cm and calibrating the unit for one speed

At a rate of 5.1 cm per minute, the bottom layer of the heated rubber and the exposed cord in pinched the top clamp and the top layer of heated rubber in the bottom clamp. The test device is operated until a separation of 5.1 cm has been achieved and the reading is recorded. It Then the top layer is clamped in the upper clamp and the cord in the lower clamp with a test length from 1.27 "to 1.9 cm. The tester is operated again until a separation of 5.1 cm has been achieved is. The test is repeated for opposite ends of the specimen and performed on multiple specimens. The mean values of the results are given as the adhesion of the cord to the rubber.

The "in-rubber tensile" is determined by vulcanizing or curing a rubber sample with the cord embedded therein. The glass fiber reinforced rubber sample is then tested in an "Instronv ^Rr " device with a test length of 17.8 to 19 cm and a head speed of 5.1 cm per minute. The grips are removed from each other and the force required to tear the sample is determined. The results of these tests are summarized in Table I.

3121332

TABLE I.

Cord Strip adhesion 2 3 In rubber 91 Type B ^Z Type C ^J tensile strenght different types of rubber kg / load kg / load kg 95 evaluation evaluation Type a 21.3 / 15.4 / 104 kg / load 4.5 4.8 Coating compound rating * 20.4 / 20.0 / from example 4 9.5 / 5.0 5.0 Coating compound 1.3 22.2 / 21.3 / from example 5 18.6 / similar over 4.7 tensile mass like 16.3 / Example 5, but others Latices (Firestone SR 6642 and SR 272)

* Evaluation: 1-5, whereby the limit value 1 is an adhesion

fail and 5 mean cohesive failure.

1. Commercially available rubber from McCreary Tire & Rubber Co.

2. Commercial rubber from B.F.Goodrich Co.

3. Commercial rubber from Firestone Tire & Rubber Co,

Tests were also carried out with coated fiberglass cord according to the invention in pneumatic tires. One of these tests is the "Gristmill" test, which measures the resistance of the cord to compression fatigue. A large part of the stress is applied to the outside shoulder of the tire where the cord is most likely to break is. The cord breaks are recorded for each radial tire tested and for comparison to the number of Fractions per meter of belt length converted.

The "Gristmill" test has the following stages:

a. Inflate the tires to a pressure of 1.69 kg / cm at 24 ⁰ C.

b. Mounting a tire on the right front wheel of a standard vehicle with 100% T and RA load

at 1.65 kg / cm. The tire pressure is measured at this point and no change is made.

c. Driving the vehicle at a speed of 24.1 km / h for 800 laps in a counter-clockwise direction. the The temperature and pressure of the tire are measured at the end of the test.

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d. X-ray examination of the inflated tire to determine the condition of the cord.

The cold "Gristmill" test has the following stages:

a. Inflate the tires to a pressure of 1.69 kg / at 21 ⁰ C.

b. Cool the tires to -40 ° C for 4 hours, then remove a tire from the cold chamber and mount it on the right front wheel. Before the test begins, warming up to -32 ⁰ C allowed. The pressure at this point was measured without making any change.

c. Driving the vehicle at a speed of 24.1 km / h for 10 laps in a counter-clockwise direction. This represents a cold cycle. After that, the Temperatures and the pressure of the tire measured.

d. The tire is placed back in the temperature chamber at -40 ⁰ C for 4 hours.

e. Steps b, c and d are repeated for the specified number of cycles.

f. the examined ^; Tire is subjected to an X-ray examination to determine any cord breaks that may be present. The test conditions for the tests at ambient temperatures or the cold test provide for a circle with a diameter of 24.4 m in which the laps are driven at a speed of 15.1 km. The load is a "T&RA" standard load for a tire pressure of 1.69 kg / ^

Table II shows the results of the "Gristmill" test for rubber tires in which fiberglass yarn with the adhesive systems of Examples 4, 5 and 6 is used for reinforcement became. For comparison, a radial tire with a commercially available glass cord is shown.

TABLE II

Radial tire cord "Gristmill" test

Cord cover

Ambient temperature 1600 laps: Fractions / m *

cold

7 cycles:

Fractions / m

Example 4 Adhesion System

Example 5 Adhesion System

Example 6 Adhesion System

commercial cord

5 3 15th 100 10 4th

* B / M is the average number of breaks per meter of tire belt.

For the determination in Table III compiled values for the Kaltradtest in a closed space with a 5 - slip angle, the tire is cooled to -290 ⁰ C and mounted on a wheel loaded and run one hour. This is a cycle. This process is then repeated for a total of 4 cycles.

get. The tire is removed and the belt becomes rated. The quality of the tire is rated with numbers from 1 to 7. The number 7 means the cord has no errors and the number 7 indicates that there were many breaks in the cord.

TABLE III

Rating of cord in radial tires

Cold bike test: 5 ° glide angle

Cord cover

number

the

Cycles

Strap egg rating

upper lower belt belt

Example 4 Adhesion System

Example 5 Adhesion System

commercial cord

4.5

5.5

5.5

6.8

6.9

6.5

Claims (20)

Patent Attorneys (1370) H / W Dr. Michael Hann Dr. H.-G * Sternagel Marburger Strasse 38 6300 Giessen PPG Industries, Inc., Pittsburgh, Pennsylvania, USA ADHESIVE COATING COMPOUNDS AND GLASS FIBERS COATED WITH IT Priority: June 26, 1980 / USA / Ser. No. 163 355 claims: 1. Adhesive coating compound containing a flexible and tough resorcinol aldehyde resin, characterized in that this resin is a thermoplastic, water-soluble resorcinol-aldehyde resin, the one Mixture of oligomers and a larger amount of trimers and only a smaller amount of dimers and higher oligomers, which are formed by slight crosslinking, contains and was obtained by a) Converting up to less than 100% of resorcinol with an aldehyde in amounts corresponding to a molar ratio of 0.8 to 1.5, at pH from 3.5 to 5.5, avoiding the formation of resorcinol alcohol, for a period of time that is equivalent to a period of 3 to 10 hours at a temperature of 13 to 32 ° C is, so that a resinous mixture is formed, which contains a larger amount of the trimer and a smaller amount of the dimer and a smaller amount of the higher oligomers and unreacted Contains raw materials resorcinol and aldehyde, b) Continuing the reaction at a pH of 7 to 7.5 at a temperature of 13 to 32 ° C for a period of 0.75 to 10 hours, so that a thermoplastic, water-soluble resorcinol-aldehyde resin arises, which contains predominantly the trimer, a low crosslinking and an improved flexibility and an improved toughness owns. 2. Coating composition according to claim 1, characterized in that instead of resorcinol a mixture of resorcinol and Phenol is used. 3. Coating composition according to claim 1 or 2, characterized in that that the aldehyde is formaldehyde. 4. coating composition according to claim 3, characterized in that the formaldehyde is used in the form of formalin will. 5. Coating composition according to claim 4, characterized in that that the thermoplastic, water-soluble resorcinol aldehyde resin has up to 20% unreacted aldehyde contains. 6. coating composition according to claim 1, characterized in that that an acid catalyst used to adjust a pH of about 3.5 to about 5.5 became. 7. Coating composition according to one of claims 1 to 6, characterized in that it additionally contains one or more elastomeric latices in an amount of 100 parts by weight of latex solids per 5 to 50% by weight of resin. 8. coating composition according to claim 7, characterized in that the mixture of the elastomeric latex 70 to 90 parts by weight of polybutadiene and 10 to 30 parts by weight of a rubber made from a vinylpyridine tyrolbutadiene terpolymer contains. 9. Coating compound according to claim 7, characterized in that the coating compound additionally has 25 weight parts contains wax. 10. Coating composition according to claim 7 or 8, characterized in that it is about one part of resorcinol per 100 parts of the resorcinol resin. 11. Coating composition according to claim 7 or 8, characterized in that that it contains 0.1 to 1 part by weight of diatomaceous earth treated calcium or magnesium. 12. Coating composition according to claim 1, characterized in that in the preparation of the resorcinol aldehyde ^{resin after the treatment at 13 to 32 0} C, the resin mixture contains less than 20% by weight of unreacted aldehyde and this mixture with one or more elastomeric latices in the Amount ratio is combined that for 100 parts by weight of latex solids 5 to 50 parts by weight of the resorcinol aldehyde resin are present, the resulting combination is allowed to age for at least 10 hours at ambient temperature so that part of the unreacted aldehyde reacts with the resin and the aged mixture a little Amount of ammonia or amine added to bind unreacted aldehyde. 13. Coating composition according to claim 12, characterized in that that the elastomer latex consists of 70 to 90 weight share polybutadiene polymer and 10 to 30 weight share a rubbery terpolymer made up of vinyl pyridine styrene and butadiene. 14. Coating composition according to claim 12 or 13, characterized in that after the addition of the nitrogenous base further phenolic compound is added. 15. Coating composition according to claim 14, characterized in that the phenolic compound resorcinol or a
Mixture of resorcinol and phenol is. 16. Coating composition according to claim 12 or 13, characterized in that they additionally and optionally antioxidants, Contains accelerators, vulcanizing agents, stabilizers, dispersants and adhesives. 17. Coated glass fibers, characterized in that they are treated with a dried residue of the Coating composition according to one of Claims 1 to 3, which are coated. 18. coated glass fibers, characterized in that they are in the form of a fiber cord and 15 to 40% by weight of the dried residue of the coating composition, based on the weight of the fibrous Materials included. 19. Coated glass fibers according to claim 17, characterized in that that they are in the form of fiberglass filaments. 20. Gunrai materials reinforced with glass fibers according to one of claims 16 to 19.