US3220731A - Deterioration and impact - resistant wooden surfaces and bowling pins - Google Patents

Description

INQ

ETAL 3,220,731 ACT-RESISTANCE WOODEN LING PINS M IMP Nov. 30, 19

- GE AND DETERIQ CES AN ow FIG. 2

' NmRs No lNo ND J MOSHY FELIX SEPH RAYMO RICHAR BY Md [W ATTORNEY.

United States Patent 3,220,731 DETERIORATION AND IMPACT-RESISTANT WOODEN SURFACES AND BOWLING PINS Felix .l. Germino, Peekskill, and Joseph R. Infantino,

Chappaqua, N.Y., Raymond J. Moshy, Westport, (Iona,

and Richard A. Smith, Cornwall on the Hudson, N.Y.,

assignors to American Machine & Foundry Company,

a corporation of New Jersey Filed Apr. 5, 1961, Ser. No. 100,885 14 Claims. (Cl. 27382) This invention relates to wooden surfaces and wooden articles imparted with resistance against deterioration and damage from impact. In a more specific application this invention relates to bowling pins.

It is generally recognized that wood surfaces have a tendency to splinter, dent, chip, check, pit and have grain separation weaknesses in use. The defects become particularly apparent when the wooden surface or article is subjected to impact or rough usage as for example with bowling pins or bats. Dehydration of the internal composition of the wood also results in the deterioration of the wooden article. This also considerably shortens the useful life of wood articles.

The invention and its advantages is applicable generally to wooden surfaces. It is attractive especially in connection with wooden articles subject to severe usage, as for example: tool handles; propellers; fan blades; boat hulls; and sport equipment including baseball bats, hockey sticks, polo and croquet mallets, toboggans, skis and the like. It has especial application in the protection of, and extension of the useful life of, bowling pins which are subject to severe battering in play. The invention accordingly will be discussed in conjunction with coating wooden bowling pin cores although it will be apparent that the system of the invention may be applied in coating wood surfaces generally.

The manufacture of bowling pins by first preforming a bowling pin core or body from a suitable hardwood and then applying thereto any of various coating materials comprising a plastic cover is known. While it has been possible in the past to produce bowling pins which are attractive in appearance and have substantial resistance to destruction from the rigors of play for a period of time, the procedure used in producing these pins has been expensive and time consuming. Also the coating materials have been costly and difiicult to apply. Moreover, the useful life of pins produced by the prior art methods has always been far shorter than is desirable.

We have discovered that excellent protection may be imparted to wood surfaces by applying thereto a film of certain hydrophilic compounds such as amylose. When applied to wood bowling pin cores, prior to application of the relatively thick plastic protective coating, such films are found to extend the useful life thereof very markedly. We have found that such films provide very tenacious prime coating which is compatible with the wood constitution, and with the subsequently applied protective organic plastic layer. The film-forming substances contemplated are all derivable from natural occurring materials and include polysaccharides such as amylose and derivatives thereof; high amylose starches and chemically modified starches; hydrophilic film-forming natural gums, and protein.

It is an object of the invention to provide a novel tenaciously adhering coating system for wooden surfaces which imparts improved impact and deterioration resistance to surfaces of this type. It is a further object of the invention to provide an expensive coating for wood which is applied from an aqueous medium. It is a more specific object of the invention to provide a novel method of pro- 'ice tectively coating wooden bowling pin bodies. It is a further object of the invention to provide a novel primerimpregnant for wooden surfaces. Additional objects and advantages of the invention will become apparent from the more detailed description of the invention provided hereinbelow.

By conducting life tests with bowling pins constructed in many different ways, we have found that the relatively short useful life of pins made from hardwood bodies by the methods of the prior art is due to a large extent to the failure of the bond between the respective protective coatings applied to the hardwood body. It is due also, very substantially, to failure of the wood itself, as by crushing of the wood fiber. In the ball-impact area of the pin, the pin body is repeatedly subjected during play to very severe concussive forces. The crushing of the fibrous structure of the wood is most severe at, and adjacent to, the surface of the ball-irnpact area. The rate of deterioration of the wood core depends on the various factors in addition to impact, such as moisture loss. The consequences of wood failure are rupture of the core and loss of the surface coating or coatings carried thereby. Once the fibrous orientation of the wood structure begins to fail, the pin is rapidly rendered unattractive and unusable. Damage may be of various kinds such as: cracks in the coating or coatings; separation, splitting and loss of coating material; change in diameter of the pin in the ball-impact area due to dehydration and compression; deterioration of pin rebound characteristics; and the like.

We have discovered that the life of Wood substrates is very substantially upgraded by applying, from a dilute aqueous dispersion, a deposit which fills the interstices of the wood, penetrates significantly into the pore of the wood and intimately and tenaciously adheres thereto. The treatment further provides a bulking or stabilizing effect for the composition of the wood. When dried, the film deposit comprises a layer of resin which has penetrated into the wood body to a substantial depth, has intimately bonded the fibrous structure of the wood, and provides a continuous layer on the surface of the wooden body.

In order that the manner in which these and other objects are attained in accordance with the invention can be understood in detail, reference is made to the accompanying drawing wherein:

FIG. 1 is a view, partly in section of a bowling pin produced in accordance with the invention.

FIG. 2 is a fragmentary sectional view, enlarged in scale, illustrating the various layers of a four-layer coating system for a wooden surface.

FIG. 3 is another fragmentary view illustrating a twolayer coating system.

The invention can be best understood by describing the coating procedure generally with reference to the drawing.

FIG. 1 illustrates one form of pin which can be made in accordance with the invention and which comprises a pin body 10 of maple or other hardwood, the body being coated with a synthetic resinous material, as indicated at 11, to reinforce and protect the wood. The layers of the plastic coating, as more clearly shown in FIG. 2, comprise a first layer of the water-dispersible material 13 of the invention deposited upon the wooden substrate 12. Subsequent coatings comprise an optional sealer coat 14, a relatively thick gel lacquer coat 15 and a topcoat 16. In the embodiment of FIG. 3, the pin body has a prime or first layer as described in FIG. 2 but contains a single subsequent outer layer 17, in lieu of the multiple layer system 14, 15 and 16 illustrated in FIG. 2.

The penetration of the prime coating anchors the film to the texture of the wood and substantially aids in pre- Patented Nov. 30, 1965 venting separation of the resin coating from the wood base, as generally occurs with organic solvent-soluble films which present a sharply defined or distinct separation between coatings. The nature of the prime coats is such that it provides a cushioning effect to resist the severe blows on the pin by distributing the shock over a larger area of the pin body.

In accordance with the invention, a hydrophilic film comprising a material of the group consisting of polysaccharides or protein when applied to the wood surface prior to coating with organic coatings, produces very definite advantages. The hydrophilic film on the food substrate behaves as a buffering zone between the wood, which has a tendency to give up water, and the organic plastic protective shell, which comprises the protective cover and is incompatible with water. In the absence of this buffering film or barrier, of the character provided by the present invention, water evaporated from the wood contacts the organic layer and results in heaving, or separation of the coating from the wood core in a relatively early stage in the life of the plastic-coated wood article. When the film of hydrophilic material is present as a barrier between the wood surface and the relatively hydrophobic organic coating, water evaporated from the wood is absorbed by the film and in effect smooths out the tendency of the wood core to change in dimension from loss of water. The chemical composition of the hydrophilic film is such that it is completely compatible with the cellulose composition of the wood; it penetrates the surface of the wood; and it provides reinforcement.

Upon the surface of the pin containing the prime layer, may optionally be applied a conventional coating which comprises a relatively thin, substantially vapor-impervious sealing film or coat 14. For this purpose, nitrocellulose or other composition which is firmly adherent to the prime layer 13 on the wood pin body 12 may be used.

Continuously overlying the sealing coat 14 and uniformly bonded thereto is a relatively thicker protective gel coat 15. This protective coat may in turn be coated by a relatively thin dirt-repellent topcoat 16.

Penetration of the primer-impregnant hydrophilic film into the wood interstices may vary to depths of from about 1 to about 250 mils depending on the viscosity and means of application. The continuous layer or deposit over the wood surface may vary from about 0.1 mil to about 50 mils and depends also on variable factors such as the composition and concentration of the aqueous dispersion. The sealing coat 14, when employed, is generally of the order of 2-12 mils although a thicker film may be employed. The subsequent protective coat 15 is of more substantial depth having a thickness of the order of 25-75 mils although thicknesses up to 250 mils may be employed. The finish topcoat 16 is of conventional thickness, generally varying from about 0.5 mil to 12 mils but may be as thick as 40 mils or more where practical and desirable. It will be understood that the invention in essence resides in the use of a hydrophilic primerimpregnant surface layer on wood and the bond thereof with the fibrous composition of the wood. Also, of importance is the bond of the primer-impregnant with subsequent organic protective layers. The invention is not limited by the application or composition of the protective or finish coatings which overlie the primerimpregnant layer and which are described herein for the purpose of providing a fuller understanding of the invention and its environment. Accordingly, as shown in FIG. 3, a single coating may be applied over the primer-impregnant layer of the invention in lieu of the three- coat system 14, 15 and 16 of FIG. 2. For this purpose, a cured polyurethane resin such as that available commercially as Adiprene may be used, for example.

Having thus generally described the nature and mannor of applying coatings to wood surfaces, a more detailed procedure is provided herein below in which bowling pins are manufactured in accordance with the invention.

PRIME COAT COMPOSITION The primer-impregnant contemplated for treatment of wood surface according to the invention comprises hydrophilic film-forming polysaccharide compounds, including modified polysaccharides and protein.

The water-soluble hydrophilic film-forming polymers contemplated within the invention are those which effectively treat the exterior nature of the wood by reinforcing and physically sealing the porous structure. The advantages of the hydrophilic film on the wood is due to the intermolecular linkages of the hydrophilic composition with the cellulose of the wood through such forces as hydrogen bonding and Van der Waals forces. These forces or bonds are distinguishable from the true chemical or co-valent linkages. In essence, the nature of these polymers is such that they are of a type that are nonchemically reactive with hydroxyl groups. Materials contemplated as useful in forming hydrophilic films in accordance with the invention are carbohydrates and more specifically polysaccharides and derivatives of polysaccharides such as amylose, derivatives of amylose such as the esters of amylose, the ethers of amylose and the oxidized amyloses; hydrophilic water-dispersible gums such guar, locust bean gum, tragacanth, the oxyalkyl celluloses, e.g., hydroxyethyl cellulose, carboxymethyl cellulose; and proteins, including animal and seed proteins such as casein, blood albumin, soy, cottonseed, rape seed and tung. Each of these hydrophilic materials are soluble or dispersible in water or capable of solubilization in aqueous media which includes slightly alkaline aqueous medium. Significantly these film-forming materials are characterized by being substantially insoluble in all common organic solvents and consequently do not interfere in standard coating procedures utilizing organic solvent soluble resinous systems which are applied over the hydrophilic layer of the invention.

In addition to amylose, which is preferred primerimpregnant, water dispersible derivatives of amylose such as hydroxyethyl amylose, methyl amylose, carboxymethyl amylose, hydroxypropyl amylose, ethyl hydroxyethyl amylose, ethyl amylose, amylose acetate, carbamylethyl amylose and the like may be used. Derivatives of amylose or amylose containing film-forming materials having an excess of 50% amylose content as determined by conventional idiometric analysis are preferred. As such for example, fractions of starch, derived from various sources such as corn, wheat, potato, tapioca, and high amylose corn starch, sodium salts of ungelatinized low substituted starch acid esters and the like may be employed.

In general, concentrations in the aqueous medium of from about 1% to 40% of the film-forming material and preferably from about 2% to 30% of solids may be employed. With high viscosity materials such as guar, locust bean gum, or agar-agar below about 10% and preferably below about 5% may be adequate. While with proteins and some low viscosity derivatives of amylose and cellulose up to 30% or greater concentration (parts of film-forming material per parts of water) may be used with high amylose starch from about 1% to about 18% and preferably from about 3% to about 10% is employed.

Wood primed by applying films of the foregoing from aqueous solutions have very definite advantages in economy, coating periods and facility in processing times and procedure. The pins are fully coated after 15 minutes residence time. The variation in core weight is less than with known organic solvent soluble resin prime coats or with Water based emulsions of the vinyl acetate or copolymer type. Within about three hours after the pins are coated, they are normally sufliciently prepared by air drying to be subsequently coated with organic solvent film forming compositions. By applying heat to the coated substrates, drying periods as low as 15 minutes may be adequate. The primer-impregnant layer functions as a barrier between the water and the organic-soluble resin thereby moderating changes in the moisture content of the wood. It also prevents penetration into the wood, of water incompatible organic resin and solvent, during the later coating steps. The increased durability of pins coated with the hydrophilic impregnant layer of the invention over commercial wood pins, wherein organic impregnants are employed, is believed due to the formation of secondary bonding forces between the Wood and the hydrophilic impregnant. The impregnants such as amylose, for example, generally have chemical compositions similar to cellulose of the wood and have a strong afiinity therefor. The effect of the impregnant on the wood can be further strengthened by derivatizing the film on the wood substrate as by dipping the film-coated wood article into a suitable reaction mixture. With amylose films, for example, a reaction mixture containing acetic anhydride and catalytic amounts of sulfuric acid may be used. Cross-linking of the film, such as by treatment with formaldehyde or glyoxal, may also be effected in a like manner.

The film-forming composition used as impregnant may contain various additives of the type conventionally utilized in the art to effect various results such as gel inhibiting or retarding agents, e.g., formaldehyde, NaOI-I; plasticizers, e.g., glycerine, sorbital; flexibilizing agents, and the like. The term aqueous dispersible as employed herein is contemplated as inclusive of and generally used interchangeably, where applicable, with soluble. Further, as used herein, aqueous dispersible means soluble in water to the extent of at least 0.2% by weight and includes colloidal aqueous media.

The following examples, in which the parts recited are parts by weight, are provided in order that the invention may be better understood. The examples are illustrative only and should not be interpreted as indicative of limitations on compositions or conditions stated.

In protectively coating wooden bowling pin cores, the following general procedure may be employed. The details relating to applying protective and finish coatings over the prime coat are presented only as an aid in providing a more complete description and not as a limitation of the invention presented.

Wood cores of proper weight and dimensions are first conveniently supported to facilitate handling such as by inserting dowels in the head of the pins. The doweled cores are then placed in racks and secured in place. The arrangement is such that preferably throughout the coating process the cores remain on these racks. These racks are preferably fed, in a continuous manner, through the primer-soak units in which the cores are impregnated with the primer solution. The impregnating period varies as desired or as necessitated by conditions or compositions used. The primer-coated pins are then dried. Room temperature drying with forced air is relatively rapid and is preferred although drying times may be accelerated at elevated temperatures.

In a multiple coat system of sealer coat, gel coat and topcoat over the primer, the sealer material is next applied to the primed cores. Any suitable means of applying the sealer may be used. In so treating the pins, racks of primed, dried cores are fed to the sealer operation where the sealer solution is applied over the primed core surfaces. If more than one coat of sealer is applied, each sealer coat is preferably given an interim drying period. Optionally, the sealer coat may be omitted and preferably it is replaced with a second application of the hydrophilic primer-impregnant film-forming compositions as taught by the invention. The second application may be either of the same or different composition. For example, an amylose prime coat may be topped with a guar gum before the organic solvent protective coating is applied.

After proper drying, the sealed cores are readied for application of the gel protective lacquer. For this purpose, ethyl cellulose is preferred. A dipping operation is preferably employed. At predetermined timed intervals, the prepared articles are dipped into protective compositions, generally comprising a gel-lacquer, at a constant temperature and Viscosity, and a uniform coating of desired thickness is achieved. One or more dip applications of the pins in the lacquer may be employed. At least some drying is preferably conducted after each protective coating dip or application to aid in preventing sagging and minimize total drying times.

After the relatively thick gel coating has dried sufficiently, a thin clear lacquer coating is preferably, although optionally, applied by suitable means. Subsequent drying is preferably conducted at moderate temperatures, e.g. from about 70l50 F. for a minimum period of from 15 minutes to 5 or 6 hours or more.

At this point, the coating operation is complete and various conventional finishing operations may be performed on the coated pins: e.g. dowel removal, bottom facing, striping, insignia or decal application, weighing, grading and the like. An aging period to effect thorough chemical cure of the plurality of layers comprising the plastic shell may be advisable depending on the treatment used before the pins are applied to lane use.

In the examples which follow, unless otherwise provided, the primer-impregnant described in the examples was followed by coating at room temperature, first with a sealer coat (about 3-12 mils) of nitrocellulose 8% solids; next with a titanium dioxide pigmented gel lacquer coating of ethyl cellulose (about 25-60 mils) obtained by three dips in the gel lacquer and then a finish coat (about 2-l2 mils) of 10.5% solids nitrocellulose.

Example 1 Twenty-four preformed hard maple bowling pin cores are soaked for 15 minutes in a 13.4% solution of amylose. The amylose immersing solution is prepared as follows: 18 parts by weight of amylose commercially obtained as Superlose from Stein, Hall & Co., Inc. is slurried in parts of Water and heated at 160 C. in an autoclave until the amylose is solubilized. The solution is stabilized with formaldehyde (7% based on amylose solution) and diluted to the above (13.4%) concentration. The pins are removed and dried overnight at room temperature. Thereafter the pins are further coated using the procedure described above with 3 sealer coats of nitrocellulose (total about 5 mils thick) 3 gel coats of ethyl cellulose (about 70 mils) and one topcoat of nitrocellulose lacquer about (2 mils thick). The bowling pins prepared above are subjected to actual play and compared with commercial plastic coated pins. After 2000 lines of play none of the amylose primed pins show any evidence of cracks or failure in the coating system. The commercial control pins have definite signs of deterioration; after 1500 lines substantial cracking and chipping of these control pins had occurred, particularly at the ball-line.

Example 2 The procedure of Example 1 is repeated with the exception that a 14% aqueous solution of hydroxyethyl amylose is employed instead of the amylose of Example l. The pin cores are retained in this solution for a residence time of 12 minutes. The hydroxyethyl amylose solution is prepared by dispersing 14 parts of hydroxyethyl amylose available as Superlose HAA-l 1-HV, from Stein, Hall Co., Inc. by stirring while heating to C. for about 10 minutes into 86 parts of water until the solution is clear. The pins are air dried at room temperaure overnight and finished as in Example 1 with 3 sealer coats, 3 gel coats and 1 topcoat.

Example 3 The procedure of Example 1 is substantially repeated with the exception that a 2% agar-agar gel dispersion prepared by stirring 2 parts of agar in 98 parts of water on a bath of boiling Water. The agar solution is maintained above about 40 C. while the pins are immersed in order to prevent gelation of the solution. The pins are thereafter finished with the sealer coats, gel coats and topcoat as in Example 1. These pins also have characteristics superior to organic solvent primer compositions.

Example 4 The procedure of Example 1 is substantially repeated with the exception that a 15% solution of low viscosity sodium alginate is employed instead of the amylose solution of Example 1. After drying at room temperature overnight, the pins are finished by applying the subsequent coats as in Example 1.

Example 5 The procedure of Example 1 is substantially repeated employing in place of the amylose solution a solution of parts of carboxymethyl amylose in 85 parts of hot water 85 C. with constant agitation. The residence time of the pins in the dispersion is minutes. The pins are thereafter coated as in Example 1 with the sealer coats, gel coats and topcoat.

Example 6 Forty hard maple bowling pin cores are primed with amylose in the manner described in Example 1 and dried. Thereafter in lieu of the sealer coat, gel coat, and topcoat, a single coating comprising polyurethane is applied by dipping the pins in the liquid composition. The polyurethane liquid composition is prepared by mixing 100 parts by weight of urethane prepolymer obtainable as Adiprene L-100 from E. I. du Pont de Nemours & Co. Inc., and mixed with 6 parts by Weight of 4,4 methylene bis(2 chloroaniline) as catalyst. The amylose prime pins are then immersed 3 times in this liquid organic composition until a coating having a thickness of about 50 mils is deposited. Preferably after each dip, the pins are dried for about 30 minutes at a temperature of 50 C. and thereafter cure is completed by 3 hours bake at 212 F.

Two randomly selected bowling pins from each batch prepared according to Examples 1 to 6 were subjected to repeated impacts on a laboratory impact testing apparatus, the tests being continued until the pins had been subjected to 6000 impacts directed at the ball-line on the impact tester, representing approximately 2500 lines of actual bowling alley service. Each of the test pins were then substantially free of hair-line cracks in the composite coating, had excellent surface appearance, exhibited little loss of coating material and little change in ball-line diameter. Each of six pairs of commercial pins used as control in the same test Were visibly more deteriorated. Each of the control pins had very substantial cracks and chips in the coating.

Example 7 Ten parts of sodium casein is dissolved in 90 parts of water at 35 C. while stirring. The water contains 0.5% of thymol as preservative. Twenty-four wood pins are dipped in the solution and held for a residence time of 30 minutes. The pins are then primed and further coated in the manner described in Example 1.

Example 8 Thirteen parts of amylose containing 0.1 part of sodium meta bisulfite is mixed into hot water (90 C.) and then heated to 160 C. in an autoclave to insure complete solution. The temperature of amylose solution is maintained above 70 C. to retard gelation. Twentyfour pins are primed in the manner described in Example 1. At this point the pins are air dried and then passed into a bath containing acetic anhydride and catalytic amounts of H 80 Residence time is 15 minutes. The

pins are dried by hot air at 60 C. and further coated as in Example 1.

Example 9 A 3% solution of guar (available as Jaguar Industrial Gum from Stein, Hall & Co., Inc) solution containing 0.5% formaldehyde as a preservative is prepared and then poured over twenty-four bowling pins which have been preheated in a vacuum system. The pins are dried in .a hot air oven at a temperature of 50 C. for 90 minutes. The pins are then further coated with layers of nitrocellulose and ethyl cellulose in a manner similar to that described in Example 1.

Example 10 750 parts of water containing 0.5 preservative thymol is heated to 55 C. under constant agitation. Then 200 parts of low viscosity soy protein (obtainable as ADPRO 410 from Archer Daniels Midland Co.) is added to the solution. The temperature is adjusted to 55 C. and the blend is stirred for ten minutes after adding the protein. Then 5.5 parts of NaOH is dissolved in 45 parts of water and added to the protein slurry The stirring is continued for 20 minutes at 55 C. until all protein is dispersed. Twenty-four pins are dipped in a solution for 5 minutes, dried, sealed and coated in the manner described in Example 1.

Example 11 The procedure of Example 10 is employed except that the wet pins lifted from the soy solution are then dipped into a second bath containing 2% formaldehyde solution for two minutes prior to further coating. The pins are then dried in a hot air oven at 35 C. for 4 hours and further coated as in Example 1.

In this example, treatment of the deposited film with the formaldehyde solution results in substantial crosslinking of the film.

Example 12 The procedure followed in Example 10 is repeated with the exception that a 20% protein solution prepared from soy protein, available ADPRO 112 from Archer Daniels Midland Co. is used, containing 3% sodium hydroxide based on protein content dissolved in the primer dispersion. Subsequent coatings are applied as in Example 1.

Example 13 Five parts of carboxymethylcellulose, medium viscosity grade Hercules Powder Co., is introduced into and mixed under constant agitation in 95 parts of water at C. and mixed until very smooth. Twenty-four maple pin cores are dipped into and retained in this solution for 30 minutes, air dried for 1.5 hours and thereafter further coated in the manner of Example 1.

Example 14 Ten parts of hydroxyethylcellulose is sifted slowly into 90 parts of water while rapidly stirring and stirred vigorously until completely dissolved. Twenty-four wood pin cores are then prime coated and further coated in the manner described in Example 1.

Example 15 Fifteen parts of carboxymethylcellulose (low viscosity grade, from Hercules Powder Co.) is stirred with agitation into parts of water. After complete solution of the gum, twenty-four maple bowling pins are soaked for 15 minutes, dried at room temperature for 3 hours and coated in a manner similar to Example 1.

Example 16 Two parts of ethyl hydroxy ethyl cellulose is dispersed into 98 parts of cold water (25-30" C.) under constant agitation until completely dissolved. The resulting gum solution is deaerated by centrifugation. Twenty-four maple bowling pins are then dipped into this solution for a residence time of minutes; dried and further coated in the manner described in Example 1.

Example 17 Two parts of locust bean gum is stirred into 98 parts of water at 25 C. and allowed to hydrate for 2 hours. The mixture is then further stirred for 2 minutes. Twenty-four maple pins are dipped in this solution for a residence time of 30 minutes and coated in the manner described in Example 1.

Example 18 Example 19 A mixture is prepared comprising 3 parts of hydroxyethyl amylose prepared according to the procedure of Example 2 and one part of the hydroxyethylcellulose dispersion as prepared in Example 14. Twenty-four pins were soaked for minutes in this combined blend. After air drying, the pins were further coated with polyurethane in the manner described in Example 6.

SEALING COMPOSITION In general, any conventional lacquer which upon drying produces an adhering substantially impermeable film can be employed to provide the optional sealing coating 5, see FIG. 2, over the primer-impregnant hydrophilic layer of the invention. The sealer composition must be of such nature that it provides a uniform and continuous relatively thin film over the entire primed surface of the bowling pin body, the film being capable not only of adhering securely to the primer but also should aid in assuring that gases which are entrapped in the wood of the bowling pin bodywill not pass into contact with the protective organic layer either during application or curing of the protective coating 15 or during the useful life of the wood article. Although the primer of the invention may be employed in conjunction with an auxiliary sealer, it is of itself in appropriate thickness an advantageous sealant or barrier.

Various'cellulose esters may be suitably utilized as auxiliary vapor barriers. The following formulation is illustrative for cellulose ester lacquer sealing coat compositions which may be adapted for use in accordance with the invention.

Ingredient: Parts by weight Nitrocellulose 7.0 Ethyl acetate 45. Toluene 30.0 Ethanol 15.0 Dibutyl phthalate 2.2 Alkyd plasticizer 0.2

PROTECTIVE COAT COMPOSITION The protective coat 6 is of substantial thickness and generally comprises a plurality of layers of any one of various compositions known for this purpose. Preferably a composition providing a relatively thick coating with each application is used. Various formulations are available commercially for this purpose. Application of these compositions to the substrates may be effected by any convenient procedure such as by hot dip or flow coat techniques. In hot dipping, coatings varying from about 3 mils to about 30 mils for each dip are obtainable. Examples of suitable protective coatings include various gel lacquers e.g. ethyl cellulose, cellulose acetate butyrate, polyurethane compositions, generally containing suitable pigmentation, such as titanium dioxide, and plasticizer, such as dioctylphthalate, dibutylphthalate, etc. Ethyl cellulose gel lacquers are particularly advantageous. A protective coat comprising multiple applications of nitrocellulose lacquer solutions may also be employed for this purpose. The following is typical of gel lacquers that are useful and can be applied over the substrate prepared in accordance with the invention.

Ingredient: Parts by weight Ethyl cellulose 316.0 Xylene 610.0 Ethylene glycol monoethyl ether 278.0 Petroleum naphtha 222.0 Titanium dioxide pigment 7.0 Alkyd plasticizer 7.0

1 cps., medium ethoxy.

2 (;See note 2 for sealing composition.)

This composition is applied to the impregnated bowling pin body by dipping the body in the lacquer composition while maintaining the lacquer composition at approximately 200 F., the bowling pin body then being withdrawn at a controlled rate over a 5 minute cycle, although this cycle is not critical. The dipping operation is repeated three times (although more or less dips may be suitable). Preferably the multiple layers should provide a coating of at least 25 mil thickness. The pins are dried for 2 hours at F. after each of the first two dips, and for 1 /2 hours at 180 F. after the third dip.

The particular solvent composition employed in this example is so prepared as to provide for slight dissolution or swelling of the nitrocellulose of the sealing film 14, so that the protective coat 15 is more securely adhered to the sealing film.

TOP COAT COMPOSITIONS Any conventional lacquer suitable for providing an attractive, glossy, dirt-repellent topcoat can be employed for coat 16. As such for example, compositions comprising polyurethane, polycarbonates, acrylics, vinyls, shellac, polystyrene and the like may be employed and modified where desired with suitable solvents, plasticizers etc. Advantageously, a composition containing a conventional nitrocellulose base is used. Compositions such as the following provide excellent top coats.

1 1A, see. viscosity.

9 5-6 see. viscosity.

Such compositions are applied by flow coating followed by drying at suitable temperatures and for appropriate times, e.g. about 30 minutes at approximately 100 F. Dip or spray coating techniques and/or air drying of the coated pin may also be employed.

In lieu of the three subsequent coatings applied to the primed wood, a single coating of resinous composition may be employed as described in connection with FIG. 3. For this purpose, for example, a polyurethane, resin available commercially as Adiprene from E. I. du Pont de Nemours & Co., Inc., as described in Example 6 may be used.

A plurality of layers of such compositions are generally employed with preferably at least partial drying between each layer or dip. In coating bowling pin cores, satisfactory results are obtainable, also by placing the undersized core treated with the primer-impregnant of the invention in a mold and casting a plastic shell over the pin body.

It will be apparent to those skilled in the art that the present method can be modified in various ways without departing from the scope of the invention. For example, where it is desirable to accomplish extensive penetration of the prime coat composition or to accelerate the application thereof, the wood bowling pin bodies can be heated prior to being immersed in the impregnating liquid, the resulting cooling of the pin bodies producing a vacuum elfect by reason of condensation of vapors in the pores of the wood, so that impregnation is enhanced. Other types of vacuum impregnating procedures can be employed with similar efiect. Conversely, impregnation can be accomplished under elevated pressures, so that deeper short-time penetration of the prime coat composition so obtained relative to results obtained from the case of simple soaking.

Various changes will be apparent to those skilled in the art in the practice of the invention. It is therefore understood that the enumeration of certain details, for the purpose of illustrating the invention, should not be considered as a limitation on the inventive concept provided herein nor restrictions on the scope of the invention except as provided in the appended claims.

We claim:

1. A wood article wherein the wood is impregnated with an amylose solution and coated with a resinous composition selected from the group consisting of ethyl cellulose and polyurethane.

2. A wood article wherein the wood is impregnated with an amylose solution and coated with a first coat of nitrocellulose and a second coat of ethyl cellulose.

3. Wood impregnated with a primer consisting essentially of a polysaccharide material selected from the group consisting of amylose, an ester of amylose, an ether of amylose, an oxidized amylose and an oxyalkyl cellulose.

4. Wood impregnated with a primer consisting essentially of amylose.

5. Wood impregnated with a primer sentially of an ester of amylose.

6. Wood impregnated with a primer consisting essentially of an ether of amylose.

7. Wood impregnated with a primer sentially of an oxidized amylose.

8. Wood impregnated with a primer sentially of an oxyalkyl cellulose.

9. A synthetic plastic coated wood bowling pin whose wood core is impregnated with a primer consisting essentially of a polysaccharide material selected from the group consisting of amylose, an ester of amylose, an ether of amylose, an oxidized amylose and an oxyalkyl cellulose.

10. A synthetic plastic coated wood bowling pin whose wood core is impregnated with a primer consisting essentially of amylose.

11. A synthetic plastic coated wood bowling pin whose wood core is impregnated with a primer consisting essentially of an ester of amylose.

12. A synthetic plastic coated wood bowling pin whose wood core is impregnated with a primer consisting essentially of an ether of amylose.

13. A synthetic plastic coated wood bowling pin whose wood core is impregnated with a primer consisting essentially of an oxidized amylose.

14. A synthetic plastic coated wood bowling pin whose wood core is impregnated with a primer consisting essentially of an oxyalkyl cellulose.

References Cited by the Examiner consisting esconsisting esconsisting es- UNITED STATES PATENTS 1,297,491 3/1919 Powell 117147 1,732,419 10/1929 Rice 117-148 1,785,571 12/1930 Allen 117-148 1,918,691 7/1933 Fawkes et al 117-147 X 2,128,962 9/1938 Patterson 117-147 2,716,612 8/1955 Marks et al 117-84 2,804,399 8/1957 Kelly et al. 117-85 2,804,400 8/1957 Kelly et at. 117-148 X 2,901,467 8/1959 Croco 117-148 2,988,455 6/1961 Rosenberg 106-197 X 3,018,106 1/1962 Satchell 27382 3,046,272 7/1962 Stratling 106-294 3,054,755 9/ 1962 Windemuth et al. 117-48 X 3,080,257 3/1963 Berry 117-148 X OTHER REFERENCES Senti: Research to Utilize Amylose, Chemurgic Digest, May, 1958.

WILLIAM D. MARTIN, Primary Examiner.

RICHARD D. NEVIUS, Examiner.

Claims (1)

1. A WOOD ARTICLE WHEREIN THE WOOD IS IMPREGNATED WITH AN AMYLOSE SOLUTION AND COATED WITH A RESINOUS COMPOSITION SELECTED FROM THE GROUP CONSISTING OF ETHYL CELLULOSE AND POLYURETHANE.

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