JP2010508417A - Polyurethane urea system - Google Patents

Abstract

  In one embodiment, a polyurethaneurea system comprising part A and part B reaction components for polyurethaneurea is disclosed; an exemplary embodiment is 55-75% by weight oligomeric polyol, 3-7% by weight aromatic Part A is provided comprising a diamine chain extender and 0.1-1.5 wt.% Reactive catalyst; Part B is 1-15 wt.% Short chain aromatic diisocyanate, and 5-35 wt.% Short chain fragrance. An aromatic diisocyanate prepolymer which is a reaction product of an aromatic diisocyanate and a diol. The polyurethaneurea system further comprises an elastomeric surfactant comprising a second short chain aromatic diisocyanate and a second aromatic diisocyanate prepolymer, wherein at least one of the second diisocyanates is at least one of the diisocyanates of Part B. It can be the same as one.

Description

  The present invention relates generally to polyurethaneurea systems, and more particularly to polyurethaneurea systems useful for bonding and filling elastomers, particularly elastomers including crosslinked rubber.

Various adhesive products such as polyurethane adhesive products can be used as sealants or patched polymeric elastomeric materials such as natural rubber, synthetic rubber, plasticized polyvinyl chloride, polychloroprene, etc. However, it is commercially available.
Polyurethanes are typically synthesized from polyisocyanates, polyglycols and chain extenders. The chain extender is typically selected from low molecular weight diols, diamines, amino alcohols or water. When the chain extender is a diol, the polyurethane formed consists entirely of urethane bonds. However, for example, when the chain extender is water, amino alcohol or diamine, both urethane and urea linkages are present and the resulting composition is a so-called polyurethane urea or PUU. Accordingly, a polyurethane type composition having both urethane and urea bonds may be referred to as polyurethaneurea.

Certain embodiments of the present invention include polyurethaneurea systems that are useful for bonding and / or repairing elastomers. The system includes a reaction component that reacts to form polyurethaneurea, which includes part A and part B. These parts comprise a mixture such as the following, with a mass fraction of each of the reaction components based on the total mass of Part A and Part B reaction components: Part A comprises about 55 to about 75% by weight of about 1000 A mixture comprising an oligomeric polyol having a higher average molecular weight (primary polyol in some embodiments), about 3 to 7% by weight aromatic diamine chain extender, and about 0.1 to about 1.5% reactive catalyst. Yes; Part B contains about 1 to about 15% by weight of a short chain aromatic diisocyanate and about 5 to about 35% by weight of an aromatic diisocyanate prepolymer that is the reaction product of a short chain aromatic diisocyanate and a diol. It is a mixture containing. In certain embodiments of the polyurethaneurea system, the ratio of the isocyanate functionality to the total number of amine and hydroxyl functionality in the mixture of Part A and Part B is from about 0.8 to about 2. Also, in certain embodiments, the ratio is conditional on being between about 1 and about 1.07.
The polyurethaneurea system may further comprise an elastomeric surface activator comprising a second short chain aromatic diisocyanate and a second aromatic diisocyanate prepolymer, wherein at least one of the second diisocyanates is a part B diisocyanate. It can be the same as at least one.

  Certain embodiments of the present invention further provide a method comprising the step of reacting each reaction component of the polyurethaneurea system described above. The method may further comprise the steps of applying the polyurethaneurea to the surface of a crosslinked rubber article; and bonding the surface of the crosslinked rubber article to a substrate. Particular embodiments of the method may further comprise the step of applying an elastomeric surfactant to the surface of the crosslinked rubber article, the elastomeric surfactant comprising a second short chain aromatic diisocyanate and a second Contains aromatic diisocyanate prepolymers. If necessary, the method further includes a step of priming the surface of the crosslinked rubber article with a trichloroisocyanuric acid solution in a solvent.

Certain embodiments of the present invention further include an article comprising a component bonded to the article by the polyurethaneurea system described above.
Certain embodiments of the present invention include the step of applying the elastomeric surfactant to the tread band binding surface; applying the polyurethane urea material to the tread band binding surface; and the polyurethane urea material. There is provided a method for forming a tread of a tire, comprising a step of attaching a binding surface of the tread band having a surface on a binding surface to an external binding surface of a tire carcass.
Certain embodiments of the present invention further comprise the step of coating a damaged surface of an elastomeric article with the elastomeric surface activator (wherein the damaged surface is a hole, tear, groove, tear, cut or cut in the article or And a method for repairing an elastomeric article comprising the step of filling holes, tears, grooves, tears, cuts, or tears in the article with the polyurethaneurea.
The above and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments of the invention, as illustrated in the accompanying drawings, in which like reference numerals designate like parts of the invention. It will be clear from the general explanation.

2 is a graph plotting the elongation and modulus of various rubber compositions and a typical polyurethaneurea material according to the present invention. 2 is a graph plotting strain and true stress for various rubber compositions and a typical polyurethaneurea material according to the present invention. 2 is a graph plotting the elongation and hysteresis of various rubber compositions and a typical polyurethaneurea material according to the present invention. 2 is a graph plotting the fracture stress and strain of several rubber compositions bonded by a typical polyurethaneurea system according to the present invention.

The present invention includes a polyurethaneurea system, a method for its production, and a method for its use. The polyurethaneurea system is useful as an adhesive and / or as a repair material for various articles, such as elastomeric articles, and also elastomeric articles including cross-linked (cured) rubber compounds. The polyurethaneurea system causes damage to the original material, such as an elastomeric material, and is a repair material for filling holes, tears, grooves, tears, cuts, lacerations and / or other damage that should be repaired Useful as. The present invention further includes an article containing the polyurethaneurea as an adhesive and / or repair material.
The polyurethaneurea system of certain embodiments provides a polyurethaneurea product resulting from the reaction of Part A and Part B reaction components. Part A can include a mixture of reaction components including an oligomeric polyol and an aromatic diamine chain extender; while Part B can include a mixture of reaction components including a short chain aromatic diisocyanate and an aromatic diisocyanate prepolymer; The prepolymer is a reaction product of a short-chain aromatic diisocyanate and a diol. Advantageously, certain embodiments do not include solvents and / or fillers in the Part A and Part B mixtures.
The mixture of Part A and Part B reaction components may be characterized in some embodiments as having a ratio of isocyanate functionality to total number of amine and hydroxyl functionality in the mixture of from about 0.9 to about 2. Other embodiments have such a ratio of about 1 to about 1.7, while other embodiments have a ratio of about 1 to about 1.07 or about 1 to about 1.03.

The Part A mixture used to prepare the polyurethaneurea system of certain embodiments comprises an oligomeric polyol and an aromatic diamine chain extender. The oligomeric polyol reacts to form a urethane bond in the polyurethaneurea composition. Certain embodiments include oligomeric polyols having an average molecular weight higher than about 1000 or about 1000 to 4000, and other embodiments are polyols having an average molecular weight of about 1500 to 4000 or about 2000 to about 4000. including. Unless otherwise specified, molecular weight is expressed as mass average molecular weight throughout.
Certain embodiments of the oligomeric polyol reactant may be characterized as free of oligomeric polyols having a molecular weight of less than about 1000, or less than about 900, or less than about 800. Also, in certain embodiments, the oligomeric polyol is not more than about 5% by weight or not more than about 10%, 15% or about 25% by weight, less than about 1000, less than about 900, or about An oligomeric polyol having a molecular weight of less than 800 may be included.

The oligomeric polyol reaction component of certain embodiments may be further characterized as being primarily primary oligomeric polyol. For example, an embodiment may include an oligomeric polyol such that 100% by weight is a primary oligomeric polyol or at least 95% by weight is a primary oligomeric polyol or at least 75% by weight is a primary oligomeric polyol. Particular embodiments include an oligomeric polyol reaction component having an OH functionality of about 2.
Non-limiting examples of suitable primary oligomeric polyols include polyether polyols, amine-terminated polyols, polyester polyols, polyester ether polyols, polycyclic polyols and polycarbonate polyols. An example of the polyether polyol is polytetramethylene ether glycol (PTMEG). Amine-terminated polyols are based on polyether glycols having terminal hydroxyl groups substituted with primary or secondary amino functional groups. Polyester polyols can include, for example, polyethylene adipate, polyethylene glycol adipate, polycaprolactone diol, and polycaprolactone-polyadipate copolymer diol.

In embodiments that include oligomeric polyols that are not only primary, for example, secondary polyols may be included as reaction components in certain embodiments. Such secondary oligomeric polyols can include, for example, polybutylene oxide glycol (PBO), polypropylene oxide glycol (PPO), and castor oil.
If desired, the oligomeric polyol reaction component may comprise a mixture of oligomeric polyols selected from the oligomeric polyols described above and / or from other oligomeric polyols as are known to those skilled in the art.
Particular embodiments include an oligomeric polyol reaction component in an amount such as from about 50% to about 80% or about 55% to about 75% or about 60% to about 72% by weight of the total weight (part (Expressed as mass% of the total mass of the reactant components of A and Part B).

Another reaction component that can be included in the Part A mixture is an aromatic diamine chain extender. The aromatic diamine chain extender reacts to form urea bonds in the polyurethaneurea reaction product. The aromatic diamine chain extender can be, for example, a primary and / or secondary aromatic diamine. Particular embodiments include only primary aromatic diamines, or the aromatic diamine reaction component may include, for example, at least 75 wt% or at least 95 wt% primary aromatic diamines.
Non-limiting examples of aromatic diamine chain extender reaction components include 2,4 and 2,6 isomers of DETDA (diethyltoluenediamine), methylenebis (N, N-dibutyldianiline), IPDA (isophoronediamine) Or isomers of 3,5-dimethylthio-2,4-toluenediamine, 3,5-dimethylthio-2,6-toluenediamine, or a mixture thereof. Other examples include methylenedianiline (MDA), 4,4'-methylene-bis-3- (chloro-2,6-diethylbenzenamine) (MCDEA); 4,4'-methylene-bis- (2- Ethyl-6-methylaniline) (MMEA); 4,4'-bis- (2,6-diethylaniline) (MDEA); 4,4'-methylene-bis- (2-isopropyl-6-methylaniline) ( 4,4'-bis (sec-butylamino) diphenylmethane; phenylenediamine; methylene-bis-orthochloroaniline (MBOCA); 4,4'-methylene-bis- (2-methylaniline) (MMA); 4,4'-methylene-bis- (2-chloro-6-ethylaniline) (MCEA); 1,2-bis (2-amino-phenylthio) ethane; N, N'-di-alkyl-p-phenylenediamine 4,4'-methylene-bis- (2,6-diisopropylaniline) (MDIPA); dimethylthiotoluenediamine (DMTDA) or mixtures thereof.

Optionally, the aromatic diamine chain extender reactant is an aromatic diamine selected from the aromatic diamine chain extenders described above and / or other aromatic diamine chain extenders as known to those skilled in the art. It may contain a mixture of chain extenders.
Certain embodiments include an aromatic diamine chain extender in an amount such that it is about 0% to about 10% or about 5% to about 7% or about 3.5% to about 5% by weight of the total weight. Reacting components (expressed as mass% of the total mass of the reactant components of Part A and Part B).

The Part B mixture used to prepare the polyurethaneurea system of certain embodiments comprises a short chain aromatic diisocyanate and a prepolymer. Prepolymers can be prepared from short chain aromatic diisocyanates and diols. Short chain aromatic diisocyanates are typically unpolymerized components.
The short chain aromatic diisocyanate reaction component included in certain embodiments may be characterized as a low viscosity liquid at room temperature for ease of handling; for example, the short chain aromatic diisocyanate is about 25 ° C. It has a viscosity of 20 to about 30 cps. The short-chain aromatic diisocyanate reaction component typically has a molecular weight that is less than about 500, and certain embodiments have a molecular weight of 160-150 or 160-300. In certain embodiments, the short chain aromatic diisocyanate reaction component may have an isocyanate functionality of 2 or about 1.8 to 2.2 or about 1.9 to about 2.1.

Non-limiting examples of suitable short chain aromatic diisocyanates include, for example, phenylene diisocyanate, p- and m-phenylene diisocyanate; toluene diisocyanate, xylene diisocyanate, 2,4 and / or 2,6 toluene diisocyanate (TDI), 1,5-naphthalene diisocyanate; carbodiimide-modified methylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI) and optionally higher homologues (polymer MDI), modified MDI compounds, naphthalene diisocyanate (NDI), individual There are isomer mixtures of aromatic diisocyanates, or combinations thereof. An example of a modified MDI that is useful as a short-chain aromatic diisocyanate is polycarbodiimide modified diphenylmethane diisocyanate such as that available from Dow Chemical Company as ISONATE 143L.
Particular embodiments include short chain aromatic diisocyanate reactions in amounts such as from about 0% to about 25% or from about 1% to about 15% or from about 1% to about 13% by weight of the total weight. Ingredients (expressed as mass% of total mass of reactant components of Part A and Part B)

The aromatic diisocyanate prepolymer reaction component of the polyurethaneurea-based Part B mixture may be characterized as a reaction product of a short-chain aromatic diisocyanate and a diol as described above in certain embodiments. The aromatic diisocyanate prepolymer may be further characterized as having an isocyanate functionality of 2 or about 1.8 to 2.2 or about 1.9 to about 2.1.
In a particular embodiment, the diol that is reacted to prepare the aromatic diisocyanate prepolymer is a primary diol. In certain embodiments, the diol used to prepare the prepolymer can be 100% by weight primary diol, more than about 95% by weight can be primary diol, and about 75% by weight. More than% can be a primary diol, or more than about 50% by weight can be a primary diol. Particular embodiments include diols having a molecular weight of about 250 to about 3000 or about 400 to about 2000.
Typically, suitable prepolymers may have a molecular weight that is greater than 500 or from about 500 to about 4000. Other embodiments include prepolymers having a molecular weight that is from about 800 to about 3000 or from about 850 to about 1500.

A useful prepolymer as a reaction component in certain embodiments can be the reaction product of a short-chain aromatic diisocyanate and a polyether or polyester-based primary diol. An example of a useful polyether-based aromatic diisocyanate prepolymer is a polyether-based diphenylmethane diisocyanate-terminated prepolymer such as that available from Chemtura as VIBRATHANE B836. This polymer is the reaction product of a polyether and diphenylmethane diisocyanate (MDI).
Certain embodiments include an aromatic diisocyanate prepolymer reaction in an amount such as from about 0% to about 50% or from about 5% to about 45% or from about 10% to about 35% by weight of the total weight. Ingredients (expressed as mass% of total mass of reactant components of Part A and Part B)

The pot life or expiration date of the polyurethaneurea adhesive / repair material before it becomes too viscous to diffuse is about 1.5 at 40 ° C. after mixing each reaction component (Part A and Part B) together. It can be ~ 4 minutes. Accordingly, certain embodiments of the polyurethaneurea system may include as a reaction component a reactive catalyst that is useful for adjusting pot life as is known to those skilled in the art. A typical reactive catalyst is an alicyclic tertiary amine such as triethylenediamine.
The reactive catalyst may typically be added to the reaction components at about 0.1 to about 1.5 weight percent of the total reaction components (Part A and Part B). In other embodiments, the reactive catalyst may be added to the reaction components at about 0 to about 15 weight percent, about 0.05 to about 9 weight percent, or about 0.4 to about 1 weight percent.
In certain embodiments, omitting the catalyst results in only a polyurethaneurea material that is much harder and completely opaque when compared to the other embodiment materials produced when the catalyst is added. There was found. Certain embodiments comprising the reactive catalyst advantageously are polyurethane ureas that are typically equivalent in physical properties, such as stiffness, elongation at break and hysteresis, to the rubber elastic material to be bonded and / or repaired. Provide material.

  A protective agent can also be added to the reaction component to provide protection against environmental disasters. Such protective agents include, for example, antioxidants, UV absorbers, light stabilizers, and combinations thereof. A reactive polymer colorant can also be added as a reaction component to color the polyurethaneurea material. For example, when repairing a tire, a black colorant can be used to ensure that the repair material matches the color of the tire.

Certain embodiments of the polyurethaneurea system further include an elastomeric surfactant that is used to coat the surface of the material to be bonded and / or repaired prior to applying the Part A and Part B mixture. obtain. The material to be bonded and / or repaired by the polyurethaneurea system of certain embodiments can be an elastomeric material and / or a crosslinked rubber material. The use of an elastomeric surface activator, in certain embodiments, provides improved binding to the polyurethaneurea bonded or repaired surface formed from the Part A and Part B mixtures.
Certain embodiments of the elastomer surface activator may include short chain aromatic diisocyanates (as described above) and prepolymers. The prepolymer can be, for example, a reaction product of a short-chain aromatic diisocyanate and a diol as described above. In certain embodiments, the short chain aromatic diisocyanate of the elastomeric surfactant may be the same as the short chain aromatic diisocyanate selected as the reaction component of the Part B mixture; The chain aromatic diisocyanate may be different from the short chain aromatic diisocyanate selected as the reaction component of the Part B mixture. Certain embodiments include elastomeric surfactants that include only short-chain aromatic diisocyanates and prepolymers and no solvents, while other embodiments include solvents.
In embodiments that include a solvent in the elastomeric surfactant, the solvent content is typically about 35 to about 65% by weight based on the total weight of the elastomeric surfactant. Suitable solvents include, for example, toluene, ethyl acetate, methyl ethyl ketone (MEK) or mixtures thereof. Particular embodiments of the elastomeric surfactant are in an amount of about 0 to about 90%, or about 0 to about 80%, or about 5 to about 80% by weight, based on the total weight of diisocyanate in the elastomeric surfactant. Of the short chain aromatic diisocyanate, the remainder being a prepolymer. Certain embodiments include, for example, an about 50:50 weight percent mixture of short chain aromatic diisocyanate to aromatic diisocyanate prepolymer in the activator, or of short chain aromatic diisocyanate to aromatic diisocyanate prepolymer. It has a ratio of about 5: 95% by weight.

Certain embodiments of the present invention also include a method of making a polyurethaneurea adhesive / repair material. One particular embodiment includes reacting the Part A mixture with the Part B mixture. In one embodiment, the following amounts (expressed as mass% of the total mass of reactant components) are reacted:
Part A
a) about 55 to about 75% of an oligomeric polyol having an average molecular weight higher than 1000;
b) about 3 to about 7% aromatic diamine chain extender; and
c) 0.1-1.5% reactive catalyst.
Part B
d) about 1 to about 15% short chain aromatic diisocyanate; and
e) About 5 to about 35% of the prepolymer.
It can be noted that the stiffness of the polyurethaneurea material can be adjusted by changing the ratio of aromatic diamine chain extender to polyol in the Part A mixture. By increasing the amount of aromatic amine, stiffness is typically increased in the resulting polyurethaneurea material.
If desired, about 0 to about 5% by weight of a protective agent and / or colorant may be added to the reaction mixture. Particular embodiments contain about 0.5 to about 2% by weight of these substances. Typically, these materials can be added to the Part A mixture of reactant components. In certain embodiments, some or all of these components may be added to Part B of the reactant components.

Particular embodiments of the process for producing the polyurethaneurea composition include dispensing the two-part reaction mixture with an adhesive dispenser, and also with a dispenser that can have a static mixer. Static mixers are typically disposable and ensure that the Part A and Part B mixtures are well mixed during the dispensing process. The adhesive dispenser can be operated manually, pneumatically or electrically. The adhesive dispenser can be used as an alternative device to manually distribute and mix the Part A and Part B mixtures.
Such dispensers and their use are well known to those skilled in the art and are available, for example, under the trade name MIXPAC Systems from ConProTec, which has offices in New Hampshire. The cartridge volume ratio of the adhesive dispenser must be compatible with the adhesive preparation. For example, MIXPAC Systems is available in models that provide mixed adhesives with a two-component mixing ratio of 1: 1, 2: 1, 4: 1, or 10: 1.

Bonding and / or repairing elastomeric surfaces using certain embodiments of the polyurethaneurea system includes treatment of the surfaces to be bonded and / or repaired with the elastomeric surface activator. In certain embodiments of the above method, at least one surface to be bonded and / or repaired comprises an elastomeric surface, some of which may comprise an elastomer comprising a crosslinked rubber composition. If necessary (but not essential), the elastomeric surface should be cleaned and primed to bind and / or repair the surface before applying the elastomeric surface activator and / or polyurethaneurea reactant. Can improve the adhesion and wettability. Treatment with such a primer typically excludes contaminating layers or poorly adhering layers. A typical primer is, for example, a solution of trichloroisocyanuric acid (TIC) in a solvent, for example 2-6% TIC in ethyl acetate.
If a primer is used, it can be brushed on the elastomeric surface and left on the surface for about 15 minutes. The surface can then be washed with a solvent such as ethyl acetate to remove possible excess TIC. These steps can be repeated until the surface is clean and trimmed against the elastomeric surfactant and / or polyurethaneurea reactant.

The elastomeric surface activator may be applied using a brush, spatula, spray or other means known to those skilled in the art on the surface to be bonded and / or repaired. One or more layers of elastomeric surfactant can be applied to obtain the desired thickness. Particular embodiments include applying an elastomer surface activator up to about 0.5 mm or from about 0.05 to about 0.25 mm thick. The adhesion of the polyurethaneurea material is typically improved by the use of an elastomeric surfactant before applying the two-part polyurethaneurea reactive component.
Certain embodiments of repairing articles and / or bonding surfaces with the polyurethaneurea system may advantageously be performed at ambient temperature, ie, from about 20 ° C to about 40 ° C. When bonding relative surfaces together, for example, a pressure of about 0.03 bar to about 5 bar can be applied to the bonded piece, with the application time typically being proportionally longer at lower pressures.
The aging time of the polyurethaneurea system used in the present invention can be used when bonding and / or repairing materials. This aging time can typically be about 48 hours at ambient temperature or several hours at a temperature of 60 ° C to 100 ° C. Advantageously, a polyurethaneurea system prepared primarily from primary diols as described above maintains its binding / repair state even when subjected to a temperature of at least 130 ° C., this temperature being A typical cure temperature in the tire re-treading process using a cushion rubber material to bond the tire to the tire carcass.

Advantageously, certain embodiments of the polyurethaneurea system provide materials having stiffness and hysteresis properties that are perfectly compatible with the stiffness and hysteresis of various crosslinked rubber elastomers used in tires. This property of the polyurethaneurea material makes it extremely useful as an adhesive and / or repair material for tires.
Particular embodiments of the present invention include articles having binding surfaces and / or repair points using the polyurethaneurea systems disclosed herein. For example, an article according to certain embodiments of the present invention includes portions that are bonded together by a polyurethaneurea system disclosed in a relative plane, and at least one of the relative surfaces includes a crosslinked rubber composition. After mixing the polyurethaneurea reaction components, the polyurethaneurea reaction components are typically applied to the relative surfaces of each part using, for example, a spray gun, brush or two-part adhesive gun. In certain embodiments, the elastomeric surfactant is applied to both surfaces of the relative surface prior to applying the mixed polyurethaneurea reactant.

Particular embodiments of the present invention include tires having elastomer patches joined by the polyurethaneurea system disclosed herein. The elastomeric patch includes radio frequency identification (RFID) technology, which can be bonded to the interior or exterior surface of the tire.
Other embodiments include an article for bonding to the surface of another article, such as a tire. Such articles that can be bonded to the surface of another article such as a tire include, for example, elastomeric material or metal or fiber letters. The other article can be an electronic component or device that can be directly bonded to the surface of another article such as a tire (without mounting or encapsulating the electronic component or device in a patch). Non-limiting examples of such devices can be, for example, RFID chips, surface acoustic wave (SAW) sensors, pressure and / or temperature sensors. Such a device may be mounted on the inner surface of the tire or on the outer surface of the tire. Such embodiments may include any or all of the following steps: cleaning the surface of an article such as a tire; applying a primer (such as a TIC solution in a solvent) to the surface (described above) Applying elastomeric surface activator to the surface (as described above); placing the electronic component or device on the tire surface; mixing part A and part B reactive components into the electronic component or device; Applying directly on at least a part, thereby coupling the electronic component or device directly to the surface. As described above, in embodiments that include the step of bonding the article to the tire surface, the article (such as an electronic component or device) may be bonded to the outer or inner surface of the tire.
If desired, components such as, for example, RFID devices or SAW sensors can be applied using transfer films as is known to those skilled in the art. The transfer film can be a flexible plastic sheet. The device can be placed on a transfer film and then at least partially coated with the polyurethaneurea component (part A and part B mixture). The film with the above tag is then placed in the desired location, eg, on the surface of the tire; the film faces outward. The film is then peeled away, leaving the components bonded to the surface.

A tire or other article that includes an elastomeric surface can be repaired by filling holes, cuts, tears, grooves or other openings in the article with the polyurethaneurea system disclosed herein. Passenger car tires, truck tires, motorcycle tires, off-road tires and other types of tires may be repaired or patched using the polyurethaneurea system of the present invention. Such materials are particularly useful for repairing tears, holes or grooves in tire sidewalls. In certain embodiments, the article is repaired by applying an elastomeric surfactant and then a Part A and Part B mixture.
Accordingly, certain embodiments of the present invention include tires or other articles having an elastomeric surface to be bonded and / or repaired by the polyurethaneurea system. In the case of tires with cuts, cracks, holes or grooves, the area to be repaired is trimmed by removing loose surface material and cleaning the surface in or around the damaged area. Preparation may include buffing with any conventional equipment or treatment of the surface in the groove, cut or crack.

If the cord in the tire is damaged, the damaged cord can be removed and a reinforcing patch applied to the inner surface of the tire as known to those skilled in the art. Such cords can be made from polyester, nylon, steel, rayon, and the like. The reinforcing patch may be bonded to the inner surface of the tire using the polyurethaneurea system disclosed herein. Similarly, if the damage results in a hole through the sidewall, the patch can be applied as a repair part to the inner surface of the tire as well.
The inner surface of the grooves, cracks and / or holes can then be coated with an elastomer surface activator as described above, if desired. The damaged area is then filled with the polyurethaneurea material by mixing part A and part B materials and applying the mixture into the cracks or grooves. The material is then cured at ambient temperature, i.e., about 20 ° C to 40 ° C. The material can be placed in an autoclave as is known to those skilled in the art when other repairs to the tire require curing under heat and pressure.
Since the curing of the polyurethaneurea material occurs at ambient temperature, the polyurethaneurea system of the present invention is particularly useful in field repairs of large items such as off-road tires, conveyor belts and the like. The polyurethaneurea system can be used in the field without the need for special autoclaves, steam chambers or vulcanizable tire repair equipment.

Certain embodiments of the present invention further include the step of bonding the tread band to the tire carcass; the tire carcass is new or used. The joining of the tread band to the used tire carcass is known as tire tread formation. Embodiments of the present invention further include a tire having a tread bonded by the polyurethaneurea system of the present invention.
The re-tread forming method of the present invention includes a step of removing an old tread from a tire carcass, treating a tire carcass with an elastomer surface activator, treating a tread band with an elastomer surface activator, or both using an elastomer surface activator. Processing step. The method further includes applying a mixed polyurethaneurea reactant to the exposed surface of the tread band and / or tire carcass; and then placing the tread band on the surface of the tire carcass.

Certain embodiments of the present invention include the step of bonding or repairing an article having an elastomeric surface, particularly an article having at least one surface comprising a crosslinked rubber composition. Certain embodiments have at least one surface comprising a crosslinked rubber composition primarily comprising at least one diene elastomer.
The term “diene elastomer” means an elastomer (ie, a homopolymer or copolymer) derived from at least one part of a diene monomer (a monomer bearing two conjugated or nonconjugated carbon-carbon double bonds), in particular: To:
Any homopolymer obtained by polymerization of conjugated diene monomers containing 4 to 12 carbon atoms;
Any copolymer obtained by copolymerization of one or more conjugated dienes with each other or with one or more vinyl aromatic compounds containing from 8 to 20 carbon atoms;
Ternary copolymers obtained by copolymerization of ethylene or alpha-olefins containing 3 to 6 carbon atoms with non-conjugated diene monomers containing 6 to 12 carbon atoms, such as ethylene or propylene and the above types Elastomers obtained from non-conjugated diene monomers, especially 1,4-hexadiene, ethylidenenorbomene or dicyclopentadiene; or
Copolymers of isobutene and isoprene (butyl rubber or IIR), and also the halogen, especially chloro or bromo forms of this type of copolymer.
Particularly preferred diene elastomers are from the group consisting of polybutadiene (BR); polyisoprene (IR) or natural rubber (NR); styrene-butadiene copolymer (SBR); terpolymer of ethylene, propylene and diene (EPDM), butyl rubber and chloroprene. To be elected.

In a further embodiment of the invention, one of the part surfaces for joining together by the polyurethaneurea adhesive to obtain the article comprises a crosslinked rubber composition, while the other surface is steel. Including steel materials or ferrous alloys.
According to a further embodiment of the invention, one of the surfaces comprises a crosslinked rubber composition, while the other surface comprises a synthetic fiber such as a two-way stretch knitted type fabric, registered trademark “LYCRA”. A film having a shape containing fibers sold as is formed.
According to a further aspect of the invention, one of the surfaces includes a crosslinked rubber composition, while the other surface includes a hard plastic such as a thermoset polyurethane (eg, decorative application to a tire cover). .
The present invention is more specifically described by the following examples, which should be regarded as merely illustrative and not limiting the present invention in any way.

Multiple batches of polyurethaneurea systems were prepared using the reactant components shown in Table 1 below. A two-part adhesive / repair material was prepared by mixing the Part A component with the Part B component. These polyurethaneurea materials were then used to bond the two elastomer pieces together by filling the gap between the two elastomeric pieces with the polyurethaneurea system. Thereafter, the obtained bond strength was measured.

Table 1: Polyurethaneurea reaction components

  ETHACURE 300 is a short chain aromatic diamine chain extender available from Albemarle Corporation. This product is primarily the aromatic diamine 3,5-dimethylthio-2,4 (and 2,6) -toluenediamine (DMTDA). TERATHANE 2900 is an oligomeric polyol available from DuPont. This product is polytetramethylene ether glycol (PTMEG) having an average molecular weight of 2900. REACTINT BLACK X95AB is a polyol bond colorant available from Milliken Chemical Company. TINUVIN B75 is a protective system available from Ciba Specialty Chemicals. ISONATE 143L is a polycarbodiimide-based aromatic diisocyanate available from Dow Chemical. This modified MDI product is polycarbodiimide modified diphenylmethane diisocyanate. VIBRATHANE B836 is a polyether aromatic diisocyanate available from Chemtura. This product is an MDI-terminated polyether (PTMEG backbone) diisocyanate. DABCO 33-LV is a reactive catalyst, triethylenediamine, available from Air Products.

Part A materials were mixed together, Part B materials were mixed together, and then each was taken into each cartridge of a two-part adhesive dispenser gun. Each cartridge was inserted into a two-part cartridge adhesive dispenser gun. The ratio at which the gun dispenser delivered Part A and Part B to the static mixer was 4: 1; that is, the dispenser delivered part A in A1 and A2 that was about four times as large as Part B. Sent and 2: 1 in A3. Mixed by adhesive dispenser with a disposable static mixer fitted with the reaction components of Part A and Part B.
An elastomer surface activator was also prepared. The elastomer surface activator was prepared by mixing the amount of diisocyanate shown in Table 1 with a solvent. The mass% of each diisocyanate shown in Table 1 is based on the total mass of the diisocyanate. Each diisocyanate was mixed in a solvent to prepare an elastomer surfactant composed of 50% by weight (based on the total weight of the solution) ethyl acetate or toluene and 50% by weight diisocyanate.

Three different rubber elastomer materials were made using methods well known to those skilled in the art. The three materials are sidewall type (SW) rubber composition containing natural rubber and cis-polybutadiene rubber, inner liner type (IL) rubber containing butyl rubber, and tread type (T) rubber containing natural rubber. there were. These materials further included vulcanizing agents and the like as are well known to those skilled in the art.
Each composition was calendered to a thickness of 2.5 mm and cut into 15 × 15 cm squares. These square pieces were cured in a 15 × 15 cm mold. An approximately 1.25 cm strip was cut from each cured square piece so that each of the remaining portions of each square piece was separated by approximately 1.25 cm. The volume between the two parts resulting from the stripping was then filled with the polyurethaneurea material prepared in Example 1. Some of the surfaces were treated with the elastomeric surfactant prepared in Example 1. It should be noted that the Part A component was heated to 40 ° C. to improve its flow characteristics. After heating to 40 ° C., even if the material is cooled to room temperature, good flow properties will be retained for several hours (4-8 hours) thereafter.
After the polyurethaneurea material filled the gap between the two halves, each sample was cured in the mold. The upper part of the mold applied a pressure of about 1.5 bar on the sample as it cured. Curing occurred in the mold using the following procedure: After setting the top in place, the mold was heated for 20 minutes to raise the temperature from room temperature to 130 ° C; Kept for 100 minutes. After cooling, the square pieces were removed and each cut into 6 strips to make 6 samples for testing.

The test piece prepared in Example 2 was tested and its elongation property at break was measured. Elongation properties were measured as elongation at break (%) according to ASTM Standard D412 as measured on an ASTM C test piece at 23 ° C. Both elongation at break (%) and strain at break (MPa) were recorded. The results are shown in Table 2 below for specimens containing the sidewall rubber (SW) composition, in Table 3 below for specimens containing the inner liner (IL) composition, and the tread (T) composition. The specimens to be included are shown in Table 4 below.
Specimen No. 1 shown in each of the following three tables was a rubber witness test. The test results for the rubber witness test show the physical properties of elongation at break of the rubber composition itself which is not bonded by the polyurethaneurea system of the present invention.
As shown in Tables 2, 3 and 4, some of the test specimen binding surfaces were primed using a trichloroisocyanuric acid (TIC) solution in a solvent. Each table shows which specimen was primed, the solvent used, and the number of hours the solution was applied. For example, test piece No. 3 shown in Table 2 was primed by three coatings (brush coating) of 5% by mass of TIC in an ethyl acetate solution. The sample was dried at room temperature for 30 minutes after the primer treatment, and washed with ethyl acetate after drying.
Similarly, each table shows which specimens were treated with an elastomeric surface activator containing the ingredients shown in Table 1 of Example 1. The tables also show how long the elastomeric surfactant solution as well as the test pieces were dried before the PUU preparation was added to the surface.

Table 2: Test results for sidewall rubber (SW) composition

Table 3: Test results for internal liner (IL) composition

表２〜５に示す結果を図４にプロットしている。図４における選択サークル領域は、各種ゴム組成物の各々における最適接着条件を明確にしている。 Table 4: Test results for tread rubber (T) composition

The results shown in Tables 2-5 are plotted in FIG. The selected circle region in FIG. 4 clarifies the optimum bonding conditions for each of the various rubber compositions.

A sample of A2 material was made and cured as a sheet. ASTM C specimens of each of the rubber compositions (T, SW, IL) produced in Example 2 and A2 material were prepared.
The tensile modulus was then measured in each specimen according to ASTM D412 (1998) with ASTM C specimens at a temperature of 26 ° C. at 10%, 50%, 100%, 200% and 300%. These are the true secant modulus at MPa, ie, the secant modulus calculated by subtracting from the actual cross section of the specimen at a given elongation. Hysteresis was also measured on each specimen. The test procedure was performed on an INSTRON, Model 5500R test apparatus.
The results of these tests are shown in FIGS. As can be seen from these drawings, the A2 polyurethaneurea material is in good agreement with the stiffness and elasticity measurements of various rubber compositions. Figures 1 and 2 illustrate that the A2 material is more rigid at low deformation. FIG. 3 illustrates the low hysteresis of the material at low deformation. Although not clearly shown in FIG. 2, above high deformation, eg, 300% strain, the A2 material is shown to be softer than the T and SW materials.

  The terms “comprising”, “including” and “having” as used in the claims and specification indicate a group of disclosures that may include other elements not explicitly stated. Should be considered. As used in the claims and specification, the term “consisting essentially of” means that unless otherwise stated, the fundamental and novel features of the claimed invention are not substantially altered. It should be considered as a partial disclosure group that may include other elements not explicitly shown. The terms “a”, “an” and the singular are to be interpreted as including the same word in the plural and that these terms indicate something more than one. The terms “at least one” and “one or more” are used interchangeably. The term “one” or “single” should be used to indicate that one or only one is intended. Similarly, other specific integer values such as “2” are used when a specific number of things are intended. The terms “optional”, “can” and similar terms are used to indicate that the item, condition or process referred to is an optional (non-essential) feature of the invention. A range expressed as being between two points such as X to y includes x and y in the range.

  From the foregoing description, it should be understood that various modifications and changes can be made in the preferred embodiment of the present invention without departing from the true spirit of the invention. The above description is presented for purposes of illustration only and should not be construed in a limiting sense. The scope of the present invention should be limited only by the terms of the claims.

Claims (42)

A polyurethaneurea system in which reactive components react to form polyurethaneurea, wherein the reactive component comprises:
Part A (Part A is about 55 to about 75% by weight oligomeric polyol having an average molecular weight higher than about 1000, about 3 to 7% by weight aromatic diamine chain extender, and about 0.1 to about 1.5% by weight A mixture comprising a reactive catalyst); and
Part B (Part B is an aromatic diisocyanate prepolymer that is the reaction product of about 1 to about 15% by weight of short chain aromatic diisocyanate and about 5 to about 35% by weight of short chain aromatic diisocyanate and diol. A mixture containing
(The mass fraction of each of the reaction components is based on the total mass of Part A and Part B reaction components).   The polyurethaneurea system according to claim 1, wherein the oligomeric polyol comprises greater than 50% by weight primary oligomeric polyol.   The polyurethaneurea system of claim 1, wherein the oligomeric polyol comprises greater than about 95% by weight primary oligomeric polyol.   The polyurethaneurea system of claim 1 further comprising an elastomeric surface activator comprising a second short chain aromatic diisocyanate and a second aromatic diisocyanate prepolymer.   The polyurethaneurea system of claim 4, wherein at least one of the second diisocyanates of claim 2 is the same as at least one of the diisocyanates of claim 1.   The polyurethaneurea system according to claim 4, wherein the elastomer surface activator further comprises a solvent.   The elastomeric surfactant comprises 0-90% by weight of the short-chain aromatic diisocyanate; the mass fraction based on the total mass of diisocyanate in the elastomeric surfactant. Polyurethane urea system.   8. The polyurethaneurea system according to claim 7, wherein the elastomer surface activator comprises 5 to 80% by weight of the short chain aromatic diisocyanate.   The polyurethaneurea system according to claim 1, further comprising up to 2% by weight of a protective agent selected from antioxidants, UV absorbers, light stabilizers or combinations thereof.   The polyurethaneurea system of claim 1 further comprising a reactive polymeric colorant.   The polyurethaneurea system according to claim 1, wherein the short-chain aromatic diisocyanate is polycarbodiimide-modified diphenylmethane diisocyanate.   The short chain aromatic diisocyanate is 2,4 and / or 2,6 toluene diisocyanate (TDI), 4,4′-diphenyl-methane diisocyanate (MDI), polymeric MDI, modified MDI compound, naphthalene diisocyanate (NDI) or 2. The polyurethaneurea system according to claim 1 selected from these combinations.   The polyurethaneurea system according to claim 1, wherein the aromatic diisocyanate prepolymer is MDI-terminated polyether diisocyanate.   The polyurethane urea system according to claim 1, wherein the aromatic diisocyanate prepolymer is a reaction product of a diol selected from a polyether diol, a polyester diol, or a combination thereof.   The polyurethaneurea system of claim 1, wherein the oligomeric polyol is polytetramethylene glycol having an average molecular weight of about 1500 to about 4000.   The polyurethaneurea system of claim 1, wherein the aromatic diamine chain extender is a mixture of 2,4 and 2,6 isomers of dimethylthiotoluenediamine.   The polyurethaneurea system of claim 1 wherein the ratio of isocyanate functionality to total number of amine and hydroxyl functionality in the mixture of Part A and Part B is 0.8-2.   18. The polyurethaneurea system of claim 17, wherein the ratio of the isocyanate functionality to the total number of amine and hydroxyl functionality in the mixture of Part A and Part B is 1.0 to 1.07. A process comprising preparing a polyurethaneurea repair material by reacting the following reaction components in a mass fraction relative to the total mass of the reactants:
Part A (Part A is a mixture comprising 55-75% by weight oligomeric polyol having an average molecular weight higher than 1000, 3-7% by weight aromatic diamine chain extender, and 0.1-1.5% by weight reactive catalyst. And); and
Part B (Part B is a mixture comprising 1 to 15% by weight of a short chain aromatic diisocyanate and 5 to 35% by weight of an aromatic diisocyanate prepolymer which is the reaction product of a short chain aromatic diisocyanate and a diol. is there). The method of claim 19 further comprising the following steps:
Applying the polyurethaneurea to the surface of a crosslinked rubber article; and
Bonding the surface of the crosslinked rubber article to a substrate.   The method further comprises: applying an elastomeric surfactant to the surface of the crosslinked rubber article; wherein the elastomeric surfactant comprises a second short chain aromatic diisocyanate and a second aromatic diisocyanate prepolymer. 19. The method according to 19.   The method of claim 21, further comprising priming the surface of the crosslinked rubber article with a trichloroisocyanuric acid solution in a solvent.   The method of claim 19, wherein the substrate is a surface of a crosslinked rubber article.   An article comprising components joined by the polyurethaneurea system of claim 4.   25. The article of claim 24, wherein the bonding surface between the component and the article comprises a crosslinked rubber composition.   26. The article of claim 25, wherein the article is a tire.   27. The article of claim 26, wherein the component is a tread band.   27. The article of claim 26, wherein the component is a patch.   27. The article of claim 26, wherein at least one of the bonding surfaces between the component and the article is a crosslinked rubber composition.   30. The article of claim 29, wherein the surface of the component comprises a synthetic fiber, a thermosetting polymer, a steel material, a ferrous alloy, or combinations thereof.   30. The article of claim 29, wherein the surface of the article comprises synthetic fibers, thermosetting polymers, steel materials, iron-based alloys, or combinations thereof.   27. The article of claim 26, wherein the component is an electronic device.   The article of claim 32, wherein the component comprises an RFID chip.   35. The article of claim 32, wherein the article comprises a SAW sensor. A method for forming a tread for a tire, comprising the following steps:
Applying the elastomeric surfactant according to claim 2 to the tread band binding surface;
Applying the polyurethaneurea material of claim 1 to the binding surface of the tread band;
Attaching the tread band binding surface having the polyurethaneurea material on the binding surface onto the tire carcass external binding surface; 36. The method of claim 35, further comprising the following steps:
A step of applying the elastomer surface activator according to claim 2 to an external binding surface of the tire carcass.
A step of applying the polyurethaneurea material according to claim 1 to an outer bonding surface of the tire carcass. A method for repairing an elastomeric article comprising the following steps:
Coating a damaged surface of an elastomeric article with an elastomeric surface activator according to claim 2, wherein the damaged surface is an exposed surface of holes, tears, grooves, tears, cuts or tears in the article. is there;
The step of filling the holes, tears, grooves, tears, cuts or lacerations with the polyurethaneurea according to claim 1.   38. The method of claim 37, wherein the article is a tire.   38. The method of claim 37, wherein the hole, tear, groove, tear, cut or tear is present in a tire sidewall.   38. The method of claim 37, wherein the hole, tear, groove, tear, cut or tear is present on the inner surface of the tire.   38. An article repaired by the method of claim 37.   42. The article of claim 41, wherein the article is a tire.

Images