CA1219696A - Water-based non-flammable cement for new and retread tires - Google Patents
Water-based non-flammable cement for new and retread tiresInfo
- Publication number
- CA1219696A CA1219696A CA000453326A CA453326A CA1219696A CA 1219696 A CA1219696 A CA 1219696A CA 000453326 A CA000453326 A CA 000453326A CA 453326 A CA453326 A CA 453326A CA 1219696 A CA1219696 A CA 1219696A
- Authority
- CA
- Canada
- Prior art keywords
- cement
- tread
- water
- tire
- rubber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Adhesives Or Adhesive Processes (AREA)
- Tires In General (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Tyre Moulding (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A non-flammable water-in-oil cement emulsion for new and retread tires comprising:
A non-flammable water-in-oil cement emulsion for new and retread tires comprising:
Description
12~ 9696 I NTRODUCT ION
This invention relates to the development of an adhesive having a very low level of volatile hydrocarbon. It has particular utility for bonding a tire tread to the carcass or casing.
The key requirements for tread adhesive in the tire industry are: good green tack, good cured adhesion and fast drying time. Tread adhesives, also referred to as tread cements in the industry, are employed in the tire-building stage to bind green tread to green tire carcass or, in case of retread tires, to tire casing. There are two types of tread adhesives, namely tread bottom (or "under tread") and tread end (or "splice") adhesives, These adhesives are applied to the tread while the tread stocks are being made, as follows: as a strip of tread is being extruded (at a temperature between 200-250 I the tread bottom adhesive is continuously applied to the bottom part of the hot tread, generally by a roller or a brush. After the adhesive solvents evaporate, the tread is passed through water tanks for cooling. Afterwards, the tread is dried, skied (meaning cut on an angle into small pieces), coated with a tread end adhesive, and stored in a tread tray. The time required for the tread to travel from the exit end of the extrude to the water tanks is called scorch time, usually less than a minute. Therefore t any adhesive should dry sufficiently within this scorch time to the extent that the adhesive will not wash off the extruded tread in the cooling tanks.
Another application for tread adhesives is the retreading of tires. A retreading comprises replacing the tread portion of a tire with a new tread to allow reuse of the tire.
l l 3L2~L~369~
There are basically 5 generalized methods for retreading tines.
Tile most prevalent is hot capping. For a generalized description of the various retreading methods, referrals may be hold to the brochure, Retreadillg Methods, Their Advantages and Disadvantages, published by Bandage [incorporated, Bandage Center, ~luscatine, Iowa.
The hot capping method referred to above is described in the Retreading Methods brochure as follows:
"The 'hot capping' method of retreading has been around the longest and still accounts for the largest share of the retreading market.
"'hot capping' or conventional retreading includes all those systems which apply uncured tread rubber to a buffed casing and then place the tread and the casing into a rigid mold which cures the tread rubber and forms a tread design in the tire at the same time. Ye uncured (or 'hot cap') rubber may be tread rubber reshaped by the supplier Cole back), strip rubber or rubber stock which is milled right at the retreader's location.
"The tires are cured in either a full circle mold and matrix with a curing tube and rim in the tire, a segmented mold and matrix with a curing tube and rim in the tire, one of thinner rimless, bugles press setups, or one of the band systems. Whether they are heated by steam or electricity, they cure the rubber on the casing at a temperature of 295F. or higher and usually at a pressure of 150 psi or more."
It is common practice to use a recapping adhesive to more firmly bond the new tread to the tire carcass 3 ?
EYE;
To INVENT_ A tire tread/retread cement ColDpriSing a water-in-oil emulsion havillg as its oil phase an organic solvent solutioll of a vulcanizable rubber compound.
The invention specifically comprises a tire tread and recapping cement having the following general formula:
General Formula Ingredients it. % Range Vulcanizable rubber compound 1 - 5 Tackifier O - 8 Organic Solvent with high Flash Point 18 - 40 Surfactant 0 2 - 1.5 I. The Organic Solvent of the Vulcanizable Rubber Compounds A. The Vulcanizable Rubber Compound The vulcanizable rubber compound includes an unvulcanized natural or synthetic rubber (e.g., Bun, SIR, etc.) combined with a cross-linking system and other compounding ingredients. Preferred is a tread stock rubber compound, since there can be no question that it will be compatible with the tread rubber of the tire. There are many equivalents. The amount present in the emulsion will vary between 0.5 to 15 and, preferably, 1 to 10% by weight.
B. The Organic Solvents The invention utilizes as the organic solvent an organic hydra-carbon liquid which has a Flash point at least 100 F. Such solvents may be selected from a wide variety of materials. One such material may I
be designated as a low odor powerful solvent, LOPS. This solvent has the :EoLIowing characteristics:
Specific Gravity 60F. 0.780 - 0.806 Color, Sublet 30 min.
Appcarcmce, visual Bright and Clear Aniline Point, F., ASTM D-611 160 min.
Distillation, OF, ASSAY D-86 IMP 365 min.
FOP 505 max.
Flash Point, OF., TOO 140 min.
Sulfur, ppm, ~licrocoulometer 15 max.
In addition to using these paraffin-type solvents which are preferred, it is understood that other solvents such as high boiling kerosene, nuthouse, lubricating stocks, mineral spirits, and the like may be used.
II. Ratio of Organic Solvent to Water To make satisfactory emulsion, it is desirable that the ratio of organic solvent to water be within the Tango of 1:5 to 4:1. In most instances, good products are afforded when the ratio is 1:1 to 1: 3.5. Again, the ratios must be adjusted to suit the use to which the particular products are employed.
II. The Surfactant - Water~in~Oil Emulsifier Emulsifiers may be classified by using the Atlas HUB System.
This system is described in the publication entitled, The Atlas HUB System, Thea Printing, Atlas Chemical Industries, Inc., Wilmington, Delaware 1963.
Generally, oil-soluble emulsifiers produce water-in-oil emulsions, whereas water-soluble emulsifiers produce oil-in-water emulsions.
lZ19696 Also, as a general rule, the HUB number of the oil-soluble emulsifier will range between 4 - 9, whereas the LO
number of the water-soluble surfactant or emulsifier will have a value of approximately 8 - 40. In certain cases, a single surfactant may be capable of producing either a water-in-oil or oil-in-water emulsion.
One of the surprising features of the invention is that the emulsions used in the invention are rendered stable by utilizing a surfactant which has an HUB within the range of 8-18 and preferably ~-14.
Surfactants within the HUB range of 8 - 18 are normally considered as oil-in-water emulsifiers, yet they act as water-in-oil emulsifiers for the emulsions used in the practice of this invention. A preferred surfactant is the material known as Pol~tergent B-150,* which is a nonylphenoxy polyethoxyethanol having an HUB of 8.8. It is further characterized as dispersible, but not soluble in water. Another useful material is Briton X-114,*which is octylphenol reacted with about nine moles of ethylene oxide. It has an HUB of 12.5.
Other water-dispersible or -soluble surfactants falling within the above parameters may be used.
While surfactants of the above type are preferred, it is understood that low HUB surfactants may be used to stabilize the emulsions.
IV. Additional Ingredients A. Tackifier~
It is common to employ in the formulas of the invention tackifiers which aid in developing the tackiness of the vulcanizable rubber compound. Materials of this type are * Trade Mark 12'1 9696 well-known to the art. A typical material of this type is sold under the trademark AKROCHEM P-90. This material is an alkylphenol formaldehyde resin. The tackifiers may be used in the formulation in amounts ranging between 1-10% by weight with a preferred range being 2-5% by weight. Another method of calculating tackifier dosage is to use an amount ranging between the weight ratios of 0:1 to 8:1 based on the vulcanizable rubber compound. From these ratios is apparent the tackifier is an optional ingredient.
V. Breaking the Emulsions Another surprising feature of the invention is that the emulsions break under conditions of use. Specifically, they break when they come in contact with uncured rubber, either natural or synthetic. This deposits the adhesive on the surface treated with the emulsion. The high boiling organic solvent may partly or wholly be absorbed into the rubber, thereby increasing its tackiness. This improves the adhesive characteristics of tile total assemblage treated with the adhesive.
Compositions of the type described above omit the use of plasticizers often used in conventional tire tread adhesive compositions. The reason for this is that they tend to increase drying time, thereby rendering the total compositions less satisfactory in commercial applications.
Typical compositions useful in the practice of the invention are listed below as Cement A and Cement B.
~LZ~9696 Cement A '.
Ingredient Wt. %
Natural rubber-based vulcanizable rubber compound 1.05 Akrochem P-90 resin 4.21 LOPS 20.00 Polytergent B-150* 0.26 HO 74.48 100.00 Cement B
Ingredient Wt. %
Natural rubber-based rubber compound 1.65 Akrochem P-90* 6.61 LOPS 23.14 Santisizer 97* 8.26 Polytergent B-150* 0.34 HO 60.00 '100. 00 The drying time of Cement A is fast enough fox use as a.
new tire cement (4 mix coating on a green tread at about 2000F.
dried in less than 45 seconds). The performance properties (cured adhesion and green tack) of Cements A and B by laboratory tests are summarized in Table I. They are compared to a commercial water-based tire cement containing volatile Component.
¦ * Trade Mark o o ox I o O a I` I C
N Al 8 e U Us I c c c us x ,~~ o a ED x Jo a) I
_ b = ,=
En v I
En U C C
I¦ i G
a a I to I I C C G Jo no -'a . ~1 Lo a S
o o arc I o a e a ` I n I C a C
Lo C Jo I
e c I a E O I LO
u I a ¢ ,~, 3 O
Al Lo U C En to Q\ e --I
a a) O O
~Z1~696 The weight ratio of the volatile solvent (LOPS to the cement active (rubber compound plus tackifier) for Cement B is 23.14/8.26=2.8. For Cement A, this ratio is 20/5.26=3.8. For cement coatings based on cement active, Cement B is less polluting than Cement A. The drying time of Cement B at 4 mix coating on hot (200F.) green rubber was between 1.5 to 2 minutes. The cured adhesion of Cement B is comparable to that of Cement A. however, a short-term (4 his.) green tack of Cement B
was lower because the cement was not completely dry. For the green tack test, no additional drying devices were used to dry coated cements. Cements were brush coated on unheated green rubber and aged at ambient temperature before testing.
The type of emulsion, water-in-oil rather than oil-in-water, is a critical part of this invention. Because the cement emulsion is water-in-oil rather than oil-in-water, when the cement is coated on substrates (rubber or buffed casing), the chance of water being trapped between cement active (oil-soluble) and substrates can be avoided or minimized. When water is trapped, it can cause tire failure. Trapped water is also more difficult to remove by drying
This invention relates to the development of an adhesive having a very low level of volatile hydrocarbon. It has particular utility for bonding a tire tread to the carcass or casing.
The key requirements for tread adhesive in the tire industry are: good green tack, good cured adhesion and fast drying time. Tread adhesives, also referred to as tread cements in the industry, are employed in the tire-building stage to bind green tread to green tire carcass or, in case of retread tires, to tire casing. There are two types of tread adhesives, namely tread bottom (or "under tread") and tread end (or "splice") adhesives, These adhesives are applied to the tread while the tread stocks are being made, as follows: as a strip of tread is being extruded (at a temperature between 200-250 I the tread bottom adhesive is continuously applied to the bottom part of the hot tread, generally by a roller or a brush. After the adhesive solvents evaporate, the tread is passed through water tanks for cooling. Afterwards, the tread is dried, skied (meaning cut on an angle into small pieces), coated with a tread end adhesive, and stored in a tread tray. The time required for the tread to travel from the exit end of the extrude to the water tanks is called scorch time, usually less than a minute. Therefore t any adhesive should dry sufficiently within this scorch time to the extent that the adhesive will not wash off the extruded tread in the cooling tanks.
Another application for tread adhesives is the retreading of tires. A retreading comprises replacing the tread portion of a tire with a new tread to allow reuse of the tire.
l l 3L2~L~369~
There are basically 5 generalized methods for retreading tines.
Tile most prevalent is hot capping. For a generalized description of the various retreading methods, referrals may be hold to the brochure, Retreadillg Methods, Their Advantages and Disadvantages, published by Bandage [incorporated, Bandage Center, ~luscatine, Iowa.
The hot capping method referred to above is described in the Retreading Methods brochure as follows:
"The 'hot capping' method of retreading has been around the longest and still accounts for the largest share of the retreading market.
"'hot capping' or conventional retreading includes all those systems which apply uncured tread rubber to a buffed casing and then place the tread and the casing into a rigid mold which cures the tread rubber and forms a tread design in the tire at the same time. Ye uncured (or 'hot cap') rubber may be tread rubber reshaped by the supplier Cole back), strip rubber or rubber stock which is milled right at the retreader's location.
"The tires are cured in either a full circle mold and matrix with a curing tube and rim in the tire, a segmented mold and matrix with a curing tube and rim in the tire, one of thinner rimless, bugles press setups, or one of the band systems. Whether they are heated by steam or electricity, they cure the rubber on the casing at a temperature of 295F. or higher and usually at a pressure of 150 psi or more."
It is common practice to use a recapping adhesive to more firmly bond the new tread to the tire carcass 3 ?
EYE;
To INVENT_ A tire tread/retread cement ColDpriSing a water-in-oil emulsion havillg as its oil phase an organic solvent solutioll of a vulcanizable rubber compound.
The invention specifically comprises a tire tread and recapping cement having the following general formula:
General Formula Ingredients it. % Range Vulcanizable rubber compound 1 - 5 Tackifier O - 8 Organic Solvent with high Flash Point 18 - 40 Surfactant 0 2 - 1.5 I. The Organic Solvent of the Vulcanizable Rubber Compounds A. The Vulcanizable Rubber Compound The vulcanizable rubber compound includes an unvulcanized natural or synthetic rubber (e.g., Bun, SIR, etc.) combined with a cross-linking system and other compounding ingredients. Preferred is a tread stock rubber compound, since there can be no question that it will be compatible with the tread rubber of the tire. There are many equivalents. The amount present in the emulsion will vary between 0.5 to 15 and, preferably, 1 to 10% by weight.
B. The Organic Solvents The invention utilizes as the organic solvent an organic hydra-carbon liquid which has a Flash point at least 100 F. Such solvents may be selected from a wide variety of materials. One such material may I
be designated as a low odor powerful solvent, LOPS. This solvent has the :EoLIowing characteristics:
Specific Gravity 60F. 0.780 - 0.806 Color, Sublet 30 min.
Appcarcmce, visual Bright and Clear Aniline Point, F., ASTM D-611 160 min.
Distillation, OF, ASSAY D-86 IMP 365 min.
FOP 505 max.
Flash Point, OF., TOO 140 min.
Sulfur, ppm, ~licrocoulometer 15 max.
In addition to using these paraffin-type solvents which are preferred, it is understood that other solvents such as high boiling kerosene, nuthouse, lubricating stocks, mineral spirits, and the like may be used.
II. Ratio of Organic Solvent to Water To make satisfactory emulsion, it is desirable that the ratio of organic solvent to water be within the Tango of 1:5 to 4:1. In most instances, good products are afforded when the ratio is 1:1 to 1: 3.5. Again, the ratios must be adjusted to suit the use to which the particular products are employed.
II. The Surfactant - Water~in~Oil Emulsifier Emulsifiers may be classified by using the Atlas HUB System.
This system is described in the publication entitled, The Atlas HUB System, Thea Printing, Atlas Chemical Industries, Inc., Wilmington, Delaware 1963.
Generally, oil-soluble emulsifiers produce water-in-oil emulsions, whereas water-soluble emulsifiers produce oil-in-water emulsions.
lZ19696 Also, as a general rule, the HUB number of the oil-soluble emulsifier will range between 4 - 9, whereas the LO
number of the water-soluble surfactant or emulsifier will have a value of approximately 8 - 40. In certain cases, a single surfactant may be capable of producing either a water-in-oil or oil-in-water emulsion.
One of the surprising features of the invention is that the emulsions used in the invention are rendered stable by utilizing a surfactant which has an HUB within the range of 8-18 and preferably ~-14.
Surfactants within the HUB range of 8 - 18 are normally considered as oil-in-water emulsifiers, yet they act as water-in-oil emulsifiers for the emulsions used in the practice of this invention. A preferred surfactant is the material known as Pol~tergent B-150,* which is a nonylphenoxy polyethoxyethanol having an HUB of 8.8. It is further characterized as dispersible, but not soluble in water. Another useful material is Briton X-114,*which is octylphenol reacted with about nine moles of ethylene oxide. It has an HUB of 12.5.
Other water-dispersible or -soluble surfactants falling within the above parameters may be used.
While surfactants of the above type are preferred, it is understood that low HUB surfactants may be used to stabilize the emulsions.
IV. Additional Ingredients A. Tackifier~
It is common to employ in the formulas of the invention tackifiers which aid in developing the tackiness of the vulcanizable rubber compound. Materials of this type are * Trade Mark 12'1 9696 well-known to the art. A typical material of this type is sold under the trademark AKROCHEM P-90. This material is an alkylphenol formaldehyde resin. The tackifiers may be used in the formulation in amounts ranging between 1-10% by weight with a preferred range being 2-5% by weight. Another method of calculating tackifier dosage is to use an amount ranging between the weight ratios of 0:1 to 8:1 based on the vulcanizable rubber compound. From these ratios is apparent the tackifier is an optional ingredient.
V. Breaking the Emulsions Another surprising feature of the invention is that the emulsions break under conditions of use. Specifically, they break when they come in contact with uncured rubber, either natural or synthetic. This deposits the adhesive on the surface treated with the emulsion. The high boiling organic solvent may partly or wholly be absorbed into the rubber, thereby increasing its tackiness. This improves the adhesive characteristics of tile total assemblage treated with the adhesive.
Compositions of the type described above omit the use of plasticizers often used in conventional tire tread adhesive compositions. The reason for this is that they tend to increase drying time, thereby rendering the total compositions less satisfactory in commercial applications.
Typical compositions useful in the practice of the invention are listed below as Cement A and Cement B.
~LZ~9696 Cement A '.
Ingredient Wt. %
Natural rubber-based vulcanizable rubber compound 1.05 Akrochem P-90 resin 4.21 LOPS 20.00 Polytergent B-150* 0.26 HO 74.48 100.00 Cement B
Ingredient Wt. %
Natural rubber-based rubber compound 1.65 Akrochem P-90* 6.61 LOPS 23.14 Santisizer 97* 8.26 Polytergent B-150* 0.34 HO 60.00 '100. 00 The drying time of Cement A is fast enough fox use as a.
new tire cement (4 mix coating on a green tread at about 2000F.
dried in less than 45 seconds). The performance properties (cured adhesion and green tack) of Cements A and B by laboratory tests are summarized in Table I. They are compared to a commercial water-based tire cement containing volatile Component.
¦ * Trade Mark o o ox I o O a I` I C
N Al 8 e U Us I c c c us x ,~~ o a ED x Jo a) I
_ b = ,=
En v I
En U C C
I¦ i G
a a I to I I C C G Jo no -'a . ~1 Lo a S
o o arc I o a e a ` I n I C a C
Lo C Jo I
e c I a E O I LO
u I a ¢ ,~, 3 O
Al Lo U C En to Q\ e --I
a a) O O
~Z1~696 The weight ratio of the volatile solvent (LOPS to the cement active (rubber compound plus tackifier) for Cement B is 23.14/8.26=2.8. For Cement A, this ratio is 20/5.26=3.8. For cement coatings based on cement active, Cement B is less polluting than Cement A. The drying time of Cement B at 4 mix coating on hot (200F.) green rubber was between 1.5 to 2 minutes. The cured adhesion of Cement B is comparable to that of Cement A. however, a short-term (4 his.) green tack of Cement B
was lower because the cement was not completely dry. For the green tack test, no additional drying devices were used to dry coated cements. Cements were brush coated on unheated green rubber and aged at ambient temperature before testing.
The type of emulsion, water-in-oil rather than oil-in-water, is a critical part of this invention. Because the cement emulsion is water-in-oil rather than oil-in-water, when the cement is coated on substrates (rubber or buffed casing), the chance of water being trapped between cement active (oil-soluble) and substrates can be avoided or minimized. When water is trapped, it can cause tire failure. Trapped water is also more difficult to remove by drying
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A non-flammable water-in-oil cement emulsion for new and retread tires comprising:
2. An emulsion according to claim 1 wherein the surfactant has an HLB rating of from about 8 to about 18.
3. An emulsion according to claim 1 wherein the surfactant has an HLB rating of from about 8 to about 14.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US51080583A | 1983-07-05 | 1983-07-05 | |
| US510,805 | 1990-04-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1219696A true CA1219696A (en) | 1987-03-24 |
Family
ID=24032271
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000453326A Expired CA1219696A (en) | 1983-07-05 | 1984-05-02 | Water-based non-flammable cement for new and retread tires |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS6036580A (en) |
| CA (1) | CA1219696A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130097886A1 (en) * | 2010-03-16 | 2013-04-25 | Bridgestone Corporation | Method of drying water-based rubber mixes for producing tyres |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5230838A (en) * | 1975-04-28 | 1977-03-08 | Konishi Kk | Water-in-oil type contact adhesive |
| JPS51143040A (en) * | 1975-06-04 | 1976-12-09 | Denki Kagaku Kogyo Kk | An adhesive composition |
-
1983
- 1983-10-25 JP JP58198436A patent/JPS6036580A/en active Pending
-
1984
- 1984-05-02 CA CA000453326A patent/CA1219696A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130097886A1 (en) * | 2010-03-16 | 2013-04-25 | Bridgestone Corporation | Method of drying water-based rubber mixes for producing tyres |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6036580A (en) | 1985-02-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |