JP3676605B2 - Golf ball paint and golf ball using the same - Google Patents

Description

【００５７】
【表２】

【００５８】
〔評価〕
表１及び表２からわかるように、塗料の種類が同じであれば、ボールの種類（１ピースまたは２ピース）に拘わらず、密着性、乾燥性については同じ結果を示した。
【００５９】
Ｎｏ．１，５，６，８，９の比較から、ウレタンポリオールの分子量が同じであっても、添加する触媒量を変えることによって、塗膜密着性、乾燥性が異なることがわかる。つまり、触媒量を増加することによって粘度上昇度が大きくなり、密着性が低下することがわかる（Ｎｏ．８参照）。逆に触媒量が少なく粘度上昇度が小さいと乾燥性が劣る（Ｎｏ．９参照）。
【００６０】
また、Ｎｏ．１〜４はポリオールとポリイソシアネートの混合比率を変えて触媒量を同じにした場合であり、触媒量が同じであっても、ポリオールとポリイソシアネートの混合比率が異なれば粘度上昇度が変わることがわかる。
【００６１】
よって、触媒量、主剤と硬化剤との混合比率、主剤の種類等をコントロールすることによって、粘度上昇度を一定範囲（０．５〜３秒）に設定することにより、塗料の種類に応じて乾燥性がよく、しかも１ピース（ゴム表面）、２ピース（アイオノマー表面）ボールのいずれに対しても優れた密着性を有する塗膜を形成することができる。
【００６２】
【発明の効果】
本発明のゴルフボール塗料は、乾燥性に優れ、しかも１ピースゴルフボール及び２ピースゴルフボールのいずれに対しても優れた密着性を示す。従って、本発明のゴルフボール用塗料を用いれば、生産性に優れ、且つバンカーショットや浸水した場合であっても、塗膜がはがれたりすることがない長寿命のゴルフボールを高生産性をもって提供できる。
【図面の簡単な説明】
【図１】ＪＩＳ Ｋ５２００のフォードカップ法に用いた装置の斜視図（図１（ａ））及びフォードカップ本体部の断面図（図１（ｂ））である。[0001]
BACKGROUND OF THE INVENTION
The present invention is a golf ball paint capable of forming a urethane coating film excellent in impact resistance and scratch resistance in a short drying time without impairing ball productivity without impairing adhesion to the ball body. And a golf ball formed by applying the paint.
[0002]
[Prior art]
The performance required for the paint for golf balls is as follows: (1) When the golf ball body (portion other than the paint film of the golf ball) is deformed by an external force applied upon impact, the paint film follows the deformation of the ball body. It has impact resistance (coating film peeling resistance) and (2) scratch resistance that hardly causes scratches and cracks in the coating film even when subjected to impact friction when hit by a metal head such as a short iron. That is, the golf ball is deformed by 30% or more due to impact upon hitting. Therefore, if the adhesion of the coating film to the ball body is insufficient or too hard and the elasticity is insufficient, the coating film peels without following the deformation of the ball body, while the coating film is too soft. And cause scratches. Furthermore, these characteristics are required not only when the golf ball is in a dry state but also in a wet state. That is, golf balls often get wet with water, and when wet, water bubbles form in the coating film or at the interface between the coating film and the golf ball main body, and the hardness of the coating film decreases, or the coating film and the ball main body. This is because the adhesiveness to the lowers.
[0003]
As a paint excellent in impact resistance and scratch resistance, there is a two-component urethane paint in which a polyol (main agent) and a polyisocyanate (curing agent) are combined. In this coating material, the main agent and the curing agent are mixed and applied, and then the curing reaction is usually promoted by baking or the like.
[0004]
Here, the golf ball main body generally includes a core portion and a cover portion, and generally uses an ionomer resin as a cover portion material. Since the ionomer resin has weak ionic bond strength at high temperatures, both the elasticity and hardness of the ionomer resin decrease when drying after coating is performed at high temperatures. Therefore, it is conceivable to lower the drying temperature, but the curing reaction becomes slow, and it takes time to dry, resulting in poor productivity. For example, JP-A-8-182775 discloses a urethane paint blended so that the hydroxyl group amount of polyol is excessive in molar ratio with respect to the isocyanate group amount of polyisocyanate as a paint having excellent adhesion to the cover. Although disclosed, this urethane paint takes 24 hours or more when dried at a temperature of 40 to 50 ° C., and the productivity is poor. Therefore, the development of urethane-based paints with good drying properties is underway.
[0005]
In recent years, as a urethane paint having a short drying time, a paint using a part of a polyol previously reacted with an isocyanate to form a prepolymer (hereinafter referred to as “urethane polyol”) has been developed.
[0006]
For example, JP-A-9-59566 proposes a paint for golf balls using a urethane polyol having a weight-average molecular weight of 10,000 to 50,000 having a urethane bond in the main chain and a hydroxyl group at both ends as a polyol. Yes. This paint has a rapid drying and excellent productivity because a part of hydroxyl groups in the polyol has already reacted with an isocyanate group in the state of the paint to be urethanized. However, paints using urethane polyol have fewer free hydroxyl groups and free isocyanate groups in the paint than ordinary urethane paints, so the reactivity with the base (the surface of the ball body) is reduced and adhesion is reduced. Sex is reduced. In particular, since this coating is a top coating to be applied to the surface of the cover part, there is a problem that the adhesion to the main body of a one-piece golf ball made of a single rubber core that does not have an ionomer cover is poor. . Even when applied to the rubber surface, if the drying temperature becomes high, the physical properties of the rubber are deteriorated. From this viewpoint, there is a demand for shortening the drying time while avoiding an increase in the drying temperature. Yes.
[0007]
On the other hand, JP-A-10-165886 discloses a surface treatment method for improving the adhesion between a ball body and a coating film regardless of the type of paint. This surface treatment method is a method in which the surface of the ball body is treated with a silane coupling agent represented by the general formula (RO) _a -Si- (X) _b before coating. It is intended to enhance the adhesion between the coating film. However, such surface treatment requires new equipment and increases the number of operations by one step. Furthermore, since the silane coupling agent represented by the above formula is generally poor in drying properties, the waiting time until coating becomes long, which hinders improvement in productivity.
[0008]
[Problems to be solved by the invention]
The present invention has been made in view of such circumstances, and the object of the present invention is that the drying time is short without raising the drying temperature so much, and it is excellent without performing a new pretreatment or the like. Another object of the present invention is to provide a golf ball paint capable of forming a urethane coating film capable of exhibiting excellent adhesion and a golf ball formed by applying the paint.
[0009]
[Means for Solving the Problems]
The paint for golf balls of the present invention is a paint for golf balls in which a polyol containing urethane polyol is a main component, polyisocyanate is a curing agent, and a catalyst is further added, and the molecular weight of the urethane polyol is 4370 or more and 9113 or less. And a hydroxyl value of 51 to 113 mgKOH / g, immediately after mixing the main agent , the curing agent and the catalyst , a Ford Cup No. JIS K5400. The flow-down time measured based on Method 4 was T ₁ second, and after 1 hour had elapsed after mixing of the main agent , the curing agent and the catalyst , the Ford Cup No. JIS K5400. The flow-up time measured based on the four methods is T ₂ seconds, and the degree of increase in viscosity represented by (T ₂ −T ₁ ) is 0.5 to 3 seconds.
[0010]
The golf ball paint of the present invention is a paint that is applied to the surface of a golf ball main body using an air spray gun or by an electrostatic coating method.
[0011]
It is preferable to blend so that the equivalent ratio (NCO / OH) of the isocyanate group of the curing agent to the hydroxyl group of the main agent is 0.9 to 1.5.
[0012]
The golf ball of the present invention is formed by coating the outer surface of the ball main body with the golf ball paint of the present invention.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The golf ball paint of the present invention is a two-pack type urethane paint comprising a main component mainly composed of urethane polyol, a curing agent mainly composed of polyisocyanate , and a catalyst, and is mixed for a certain time from the mixing of the main component, the curing agent and the catalyst. The degree of subsequent increase in viscosity is within a certain range.
[0014]
That is, the Ford Cup No. specified in JIS-K5400 immediately after mixing. When the flow-down time measured by Method 4 is T ₁ second and the flow-down time measured by the same method 1 hour after mixing is T ₂ seconds, the degree of increase in viscosity represented by (T ₂ −T ₁ ) is 0 Adjusted to 5 seconds or more and 3 seconds or less. The preferred lower limit is 0.7 seconds or more, more preferably 1.0 seconds or more, and the preferred upper limit is 2.9 seconds or less, more preferably 2.0 seconds or less. That (T ₂ -T ₁ ) is less than 0.5 seconds means that the viscosity increase is slow, and such a viscosity increase takes too much time for drying, which hinders productivity. is there. Conversely, if (T ₂ −T ₁ ) exceeds 3 seconds, it means that the viscosity rises rapidly. If the viscosity rise is too fast, the pot life becomes too short, and the workability deteriorates. This is because, as will be described later, the adhesion of the coating film also decreases.
[0015]
Here, Ford Cup No. stipulated in JIS-K5400. Method 4 is a method for measuring the flow-down viscosity of a sample (paint). When a certain amount of paint is filled in the Ford cup body as shown in FIG. Second). The measurement temperature is 20 ° C. The shorter the flow down time measured by the Ford Cup method, the smaller the viscosity of the paint. Therefore, by measuring the flow time (T ₁ ) immediately after mixing and the flow time (T ₂ ) 1 hour after mixing, know the speed of viscosity increase, in other words, the speed of curing reaction and drying property. Can do. In addition, the pot life refers to a time during which fluidity suitable for use is maintained without causing gelation or curing when the paint is mixed for use. A larger viscosity increase means a faster curing reaction and a shorter pot life.
[0016]
As described above, the golf ball paint of the present invention adjusts the degree of increase in viscosity after the start of the curing reaction to a certain range, thereby improving workability (pot life) and drying (sufficient curing time). To meet both requirements. Therefore, the main agent and the curing agent only need to satisfy the above conditions for increasing the viscosity, but from the viewpoint of improving the scratch resistance, impact resistance, and coating film adhesion of the formed urethane coating film, It is preferable to use a main agent and a curing agent such as
[0017]
First, the main agent will be described.
[0018]
The main component of the urethane paint of the present invention is mainly composed of urethane polyol.
[0019]
Urethane polyol is synthesized by a reaction between a polyisocyanate compound and a polyol. The polyisocyanate compound used for the synthesis is not particularly limited as long as it has two or more isocyanate groups. For example, hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H ₆ XDI), isophorone diisocyanate (IPDI), tetramethylxylylene diisocyanate (TMXDI), hydrogenated diphenylmethane diisocyanate (H ₁₂ MDI) and the like, and aliphatic, alicyclic, aromatic and araliphatic diisocyanate compounds. Of these, non-yellowing polyisocyanates (aliphatic and alicyclic polyisocyanates) are preferably used from the viewpoint of weather resistance.
[0020]
The polyol used for producing the urethane polyol may be any low molecular compound or high molecular compound as long as it has a plurality of hydroxyl groups. Examples of the low molecular weight polyol include diols such as ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and 1,6-hexanediol; glycerin , Triols such as trimethylolpropane and hexanetriol. As a high molecular polyol, a polyether polyol obtainable by reaction of an initiator having an active hydrogen source with an alkylene oxide; a condensation polyester obtained by dehydration condensation of a dibasic acid such as adipic acid and glycol or triol Polyols: Lactone polyester polyols obtained by ring-opening polymerization of lactams such as ε-caprolactam; polycarbonate diols synthesized using cyclic diols; polymer polyols such as acrylic polyols obtained by appropriately introducing hydroxyl groups into acrylic copolymers Is mentioned. Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples of the condensed polyester polyol include polyethylene adipate. Examples of the lactone polyester polyol include poly-ε-caprolactone. Can be mentioned.
[0021]
Among the above polyols, those having a weight average molecular weight of 50 to 2000, particularly about 100 to 1000 are preferably used. In addition, you may use these polyols 1 type or in mixture of 2 or more types.
[0022]
The urethane polyol is a polyol having a hydroxyl group at both ends by reacting the diisocyanate compound and the polyol to form a urethane bond. Here, the ratio of the urethane bond in the urethane polyol is preferably 0.1 to 5 mmol / g with respect to 1 g of the urethane polyol. This is because the urethane bond ratio is related to the rigidity of the coating film to be formed, and if it is less than 0.1 mmol / g, the urethane concentration in the coating film to be formed becomes small and the scratch resistance is poor. On the other hand, if it exceeds 5 mmol / g, the coating film becomes too hard and the followability to the deformation of the ball body is reduced, so that cracking is likely to occur.
[0023]
Moreover, it is preferable that the weight average molecular weight of urethane polyol is 4370 or more, More preferably, it is 5900 or more. The upper limit of the weight average molecular weight is 9113 or less . If the viscosity is less than 4370 , the original viscosity is too low, and even if the degree of increase in viscosity is controlled, it takes too much time to form a sufficient coating film, resulting in a decrease in productivity. On the other hand, when the urethane polyol having a high molecular weight exceeding 9113 is used, the OH value of the urethane polyol is relatively small, the reaction amount after coating is reduced, and the adhesion to the ground (the surface of the ball body) is lowered. Moreover, if the weight average molecular weight is 9113 or less, a dense coating film with little decrease in coating film adhesion can be formed even in a state where it is wet.
[0024]
The hydroxyl value of the urethane polyol is preferably 40 mgKOH / g or more, more preferably 50 mgKOH / g or more. Moreover, it is preferable that the upper limit of a hydroxyl value is 120 mgKOH / g or less, More preferably, it is 115 mgKOH / g or less. This is because if the amount is less than 40 mgKOH / g, the amount of reaction with the curing agent becomes too small, and the adhesion strength with the ball body cannot be obtained. On the other hand, if it exceeds 120 mgKOH / g, it takes a long time to react with the curing agent, and the drying time becomes longer, resulting in a decrease in productivity, and the modulus of the coating film becomes too large. This is because the adhesion strength is deteriorated.
[0025]
The urethane polyol as described above is synthesized by diluting the raw material polyol with a solvent and adding a reaction catalyst (for example, dibutyltin laurate) to form a urethane bond while gradually adding an isocyanate compound. The terminal is a hydroxyl group. The ratio of urethane bonds can be determined by adjusting the molecular weight of the polyol used as a raw material, the blending ratio of polyol and isocyanate, and the like.
[0026]
The main agent used in the coating material of the present invention is preferably the urethane polyol itself having the above-described configuration, that is, the main agent is substantially the specific urethane polyol described above, but satisfies the conditions for increasing the viscosity. If it is in the range, in addition to the urethane polyol, a polyol that is compatible with the urethane polyol and does not have a urethane bond may be contained.
[0027]
As a polyol that can be used in this case, a polyol that can be used for the synthesis of a urethane polyol, that is, a low-molecular diol, a triol, or a polymer polyol can be used. Specifically, low molecular weight diols such as ethylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol; Low molecular weight triols such as methylolpropane and hexanetriol; polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; condensed polyester polyols; lactone polyester polyols; polycarbonate diols;
[0028]
When the main agent contains a polyol having no urethane bond, the urethane polyol content in the main agent is preferably 50% by weight or more, and preferably 80% by weight or more. This is because when the polyol content is less than 50% by weight, the urethane polyol content is relatively low, and thus it takes time to dry and it is difficult to satisfy the requirement for increasing the viscosity.
[0029]
The curing agent used in the coating material of the present invention is a polyisocyanate compound, specifically hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H ₆ XDI), isophorone diisocyanate (IPDI). Aliphatic, alicyclic, aromatic, araliphatic diisocyanate compounds such as tetramethylxylylene diisocyanate (TMXDI) and hydrogenated diphenylmethane diisocyanate (H ₁₂ MDI), among which non-yellowing polyisocyanate compounds (Aliphatic and alicyclic isocyanates) are preferred. These polyisocyanate compounds may be used alone or in combination of two or more.
[0030]
The degree of increase in viscosity can be adjusted by appropriately selecting the type of main agent and curing agent used (for example, molecular weight of urethane polyol, hydroxyl value, mixing ratio of main agent and curing agent, etc.), but the same Even when a main agent or a curing agent of a kind is used, the degree of increase in viscosity can be changed by a catalyst. Since the type of the main agent and the curing agent, particularly the molecular weight of the urethane polyol, the hydroxyl value, the mixing ratio of the main agent and the curing agent are preferably selected from the above ranges in relation to scratch resistance and impact resistance. It is preferable to adjust the degree of increase in viscosity with a catalyst.
[0031]
Here, the catalyst used is preferably a catalyst that accelerates the reaction between the isocyanate group of the curing agent and the hydroxyl group of the main agent, and specifically, a tin-based catalyst such as dibutyltin laurate is preferably used, but is not limited thereto. . Such a catalyst can accelerate the reaction between the isocyanate group of the curing agent and the hydroxyl group of the main agent to shorten the drying time. In other words, it is possible to satisfy the drying property while securing the reactivity with the ball body and consequently the adhesion by using a urethane polyol having a smaller molecular weight than conventional one.
[0032]
The addition amount of the catalyst is appropriately selected according to the type of the catalyst, the main agent and the type of the curing agent. When a urethane polyol having a molecular weight of 4370 to 9113 and a hydroxyl value of 51 to 113 mgKOH / g is used as the main agent, It is preferable to add an amount of 0.01 to 0.05% by weight based on the coating film forming component. If the amount of the catalyst is excessive, the reaction between the main agent and the curing agent, that is, the reaction rate between the hydroxyl group and the isocyanate group becomes too fast, and the golf ball surface (carboxylic acid or its metal salt in the case of an ionomer cover) This is because the reaction hardly occurs and as a result, the adhesion strength of the coating film is deteriorated. Moreover, the pot life is shortened and workability is deteriorated. On the other hand, if the amount of the catalyst is too small, the curing reaction cannot be accelerated, so that the pot life is prolonged and the workability is improved. However, the ball becomes longer as the drying time becomes longer because the drying temperature cannot be increased. This is because the production time per piece becomes longer and the calorie cost for drying becomes higher.
[0033]
The catalyst may be added to and mixed with either the main agent or the curing agent, may be added and mixed in advance, or may be added immediately before mixing.
[0034]
The coating of the present invention, added as needed, silicon slick agents, leveling agents, viscosity modifiers, optical brighteners, anti-blocking agents, curing catalysts, coloring pigments, may be generally contained in a golf paint An agent may be contained. These additives may be contained in either the main agent or the curing agent.
[0035]
The golf ball paint having the above composition is used by mixing the main agent and the curing agent immediately before use. Here, the mixing ratio of the isocyanate group in the curing agent to the hydroxyl group in the main agent (isocyanate group / hydroxyl group) is 0.9 or more, preferably 1.0 or more, 1.5 or less, preferably 1.3 or less. It is.
[0036]
Such a paint can be used as a primer paint to be applied to the core surface as well as the cover surface of a multi-piece golf ball including a two-piece ball in which the core is covered with an ionomer cover, Furthermore, you may use as a clear coat apply | coated to a primer application surface. Further, even a golf ball having an ionomer cover may be either a wound golf ball whose core is a wound body or a solid golf ball having a rubber lump. Furthermore, it can also be used as a surface paint for a one-piece golf ball that comprises a ball body with a rubber core alone. The rubber composition constituting the one-piece golf ball is preferably a rubber composition containing a metal salt of an unsaturated fatty acid such as zinc acrylate, whereby the paint of the present invention is used for the rubber composition of the one-piece golf ball. When the coating is directly applied on the outer surface made of a material, the outer surface and the coating can be firmly adhered. This is considered that adhesion is improved by the reaction between the isocyanate group of the coating and the metal salt of the unsaturated fatty acid.
[0037]
The coating method is not particularly limited, and it has been conventionally applied as a coating method for two-component paints such as air spray guns and electrostatic coatings on golf balls that have been surface treated such as washing after mixing the main agent and curing agent. A known method can be used. When painting with a spray gun, the main agent and curing agent may be mixed in small amounts, or a two-component constant ratio pump may be used in the paint transport route just before the spray gun, such as a static mixer. Two liquids may be continuously mixed at a constant ratio through a line mixer, or an air spray system equipped with a mixing ratio control mechanism may be used.
[0038]
It is preferable to dry at a temperature of less than 50 ° C. after application. The paint for golf balls of the present invention can be dried and cured in about 0.5 to 2 hours even at a temperature of less than 50 ° C. by setting the degree of increase in viscosity within a certain range. This is because the rubber characteristics are hardly affected. Therefore, when the golf ball paint of the present invention is used, the productivity is not lowered, and the thermoplastic resin cover such as an ionomer is not intimately adhered to the ball body without causing plasticization. A urethane-based hard coating excellent in properties can be formed. Therefore, the golf ball of the present invention has a hard coating film excellent in impact resistance and scratch resistance without impairing the characteristics of the original ball constituting material, and is excellent in productivity.
[0039]
【Example】
〔Evaluation methods〕
First, the evaluation method used in the examples will be described.
[0040]
a) Cross cut test A sheet for a cross cut test having a thickness of 2 mm was prepared, a cross cut test of JIS K5400 was performed, and 0 to 10 points were evaluated according to the amount of the defect. Specific evaluation criteria are as follows.
10 points: The intersection of the cuts and the square cannot be separated at a glance 8 points: There is a slight peeling at the intersection of the cuts, the squares are not separated at a glance, and the area of the defect is within 5% of the total square area 6 Point: There is peeling between both sides of the cut and the intersection, and the area of the defect is 5 to 15% of the total square area
4 points: The width of the peeling due to the cut is wide, and the area of the defect is 15 to 35% of the total square area.
2 points: The width of the peeling due to the cut is wider than 4 points, and the area of the missing part is 35 to 65% of the total square area
0 point: The area of peeling is 65% or more of the total square area.
b) After drying the paint, set the driver on a swing machine manufactured by True Temper, and visually observe the ball after hitting the golf ball 100 times with this driver. According to the degree of peeling and cracking, ◎ (no cracking or peeling), ○ (total peeling area is 2 mm ² or more), Δ (total peeling area is ² to 5 mm ² ), × (total peeling area is 5 mm ² or more) It was evaluated with.
[0042]
c) The golf ball after wet coating was dried and immersed in water for 7 days, and then evaluated based on the peeled state after testing in the same manner as in the dry state. The evaluation criteria are the same as in the dry state.
[0043]
{Circle around (2)} Paint-drying When the coated balls were put in an oven at 50 ° C. and dried, the evaluation was made based on the time required to touch the coating film with a finger and no fingerprint was attached.
[0044]
◎ (Dry to a level where no fingerprints can be made within 30 minutes), ○ (Dry to a level where no fingerprints are attached within 30 minutes to 1 hour), △ (Fingerprints within 1 hour to 3 hours) Evaluation was made in 4 grades, that was, it was able to dry to a level not sticking) and x (it took more than 3 hours to dry until no fingerprints remained).
[0045]
(3) Viscosity increase degree Immediately after mixing the main agent and curing agent, and after 1 hour has elapsed after mixing, Ford Cup No. stipulated in JIS-K5400. The falling viscosity (second) was measured according to Method 4. The Ford cup used was a cup as shown in FIG. 1, and the flow time (seconds) was measured when it flowed down from the orifice immediately after mixing the main agent and the curing agent and after 1 hour from mixing. The temperature at the time of measurement was 20 ° C. The flow time immediately after mixing T _1, for 1 hour under a stream after the elapsed time as T _2, and a look which the increase in viscosity index (T ₂ -T _1).
[0046]
(4) Weight average molecular weight It was determined in terms of standard polystyrene by gel permeation chromatograph.
[0047]
[Preparation of paint]
(1) Preparation of main agent Polyols shown in Tables 1 and 2 were dissolved in a solvent (toluene and methyl ethyl ketone), and dibutyltin laurate as a curing catalyst was added to the resin content of the paint (coating film forming component) to 0.1%. It added so that it might become weight%. While maintaining this polyol solution at 80 ° C., isophorone diisocyanate was added dropwise and mixed in the amount shown in the table. After the dropping, stirring is continued until the isocyanate disappears, and then cooled at room temperature. Urethane polyol (solid content 60% by weight) was synthesized.
[0048]
The polyol used in the synthesis of the urethane polyol is PTMG650 (a product name of Hodogaya Chemical, a polytetramethylene glycol having a molecular weight of 650) as a dihydric polyol, and trimethylolpropane (manufactured by Koei Chemical Co., Ltd. with a molecular weight of 135) as a trivalent polyol. Used one). The weight-average molecular weight and OH value of each synthesized urethane polyol are as shown in the table.
[0049]
(2) Curing agent triphorone diisocyanate (manufactured by Sumitomo Bayer Urethane) was used.
[0050]
(3) Preparation of paint The above-prepared urethane polyol, fluorescent brightener, lubricant, ultraviolet light inhibitor, catalyst and solvent (toluene, methyl ethyl ketone) are blended to obtain a solid content of 35%. To the above polyol, an HDI-based isocyanate (N3500) was added with a curing agent so that the NCO / OH (equivalent ratio) was 1.2, followed by stirring for 2 minutes. It was set as the coating material of 1-9. The curing agent was added by filling the air gun in the above ratio. No. Nos. 1 to 6 correspond to examples of the present invention. 7 to 9 correspond to comparative examples.
[0051]
[Create golf ball]
A: One-piece golf ball 100 parts by weight of high-cis polybutadiene rubber “BR-11” (a butadiene rubber having a cis-1,4 bond content of 96%) manufactured by Nippon Synthetic Rubber Co., Ltd., 25 parts by weight of zinc methacrylate 1 part golf ball ball body with a diameter of 43 mm by mixing 20 parts by weight, barium sulfate 27 parts by weight, and 2 parts by weight dicumyl peroxide made by Ouchi Shinsei Chemical Co., Ltd. Produced.
[0052]
The paint (Nos. 1 to 9) prepared above was applied to the surface of the ball body. The coating was performed for 1 minute by moving the air gun up and down while rotating the ball body. The application amount is 150 mg.
[0053]
After application, adhesion and drying were evaluated according to the above evaluation methods. The evaluation results are shown in Table 1.
[0054]
B: 2 piece golf ball Nippon Synthetic Rubber Co., Ltd. high cis polybutadiene rubber (BR-11) 100 parts by weight, zinc acrylate 25 parts by weight, zinc oxide 22 parts by weight, dicumyl peroxide 1 part by weight, A core having a diameter of 38.4 mm was formed by compression vulcanization molding at 160 ° C. for 20 minutes. Next, 50 parts by weight of Himilan 1605 (sodium-neutralized ethylene-methacrylic acid copolymer ionomer) manufactured by Mitsui DuPont Chemical, 50 parts by weight of Himilan 1705 (zinc-neutralized ethylene-methacrylic acid copolymer ionomer), A ball body for a two-piece golf ball having a diameter of 43 mm was produced by encapsulating with a cover material containing 2 parts by weight of titanium oxide.
[0055]
On the surface of the cover of the ball body, the paint no. 1 to 9 were applied in the same manner as in the case of a one-piece golf ball, and after application, adhesion and drying were evaluated according to the above evaluation methods. The evaluation results are shown in Table 2.
[0056]
[Table 1]

[0057]
[Table 2]

[0058]
[Evaluation]
As can be seen from Tables 1 and 2, if the type of paint was the same, the same results were shown in terms of adhesion and drying, regardless of the type of ball (1 piece or 2 pieces).
[0059]
No. From the comparison of 1, 5, 6, 8, and 9, it can be seen that even when the molecular weight of the urethane polyol is the same, the coating film adhesion and drying properties differ by changing the amount of catalyst to be added. That is, it can be seen that increasing the amount of catalyst increases the degree of increase in viscosity and decreases adhesion (see No. 8). Conversely, if the amount of catalyst is small and the degree of increase in viscosity is small, the drying property is poor (see No. 9).
[0060]
No. 1-4 is the case where the mixing amount of polyol and polyisocyanate is changed to make the catalyst amount the same, and even if the catalyst amount is the same, the degree of increase in viscosity may change if the mixing ratio of polyol and polyisocyanate is different. Understand.
[0061]
Therefore, by controlling the amount of catalyst, the mixing ratio of the main agent and the curing agent, the type of the main agent, etc., by setting the degree of increase in viscosity within a certain range (0.5 to 3 seconds), depending on the type of paint It has good drying properties and can form a coating film having excellent adhesion to both 1-piece (rubber surface) and 2-piece (ionomer surface) balls.
[0062]
【The invention's effect】
The golf ball paint of the present invention is excellent in drying properties and exhibits excellent adhesion to both one-piece golf balls and two-piece golf balls. Therefore, by using the golf ball paint of the present invention, it is possible to provide a high-productivity golf ball with high productivity that is excellent in productivity and does not peel off even when bunker shot or water is immersed. it can.
[Brief description of the drawings]
FIG. 1 is a perspective view (FIG. 1 (a)) of a device used in the Ford Cup method of JIS K5200 and a cross-sectional view (FIG. 1 (b)) of a Ford cup body.

Claims (6)

A golf ball paint containing a polyol containing a urethane polyol as a main component, a polyisocyanate as a curing agent, and a catalyst added thereto,
The urethane polyol has a weight average molecular weight of 4370 or more and 9113 or less , and a hydroxyl value of 51 to 113 mgKOH / g,
Immediately after mixing the main agent , the curing agent and the catalyst , the Ford Cup No. JIS K5400. The flow time measured based on the four methods is T ₁ second
After 1 hour has passed since the mixing of the main agent , the curing agent and the catalyst , the Ford Cup No. JIS K5400. The flow time as T ₂ seconds measured according to 4 method,
A golf ball paint characterized in that the degree of increase in viscosity represented by (T ₂ -T ₁ ) is 0.5 to 3 seconds. Amount of pre-Symbol catalyst, golf ball paint according to claim 1, characterized in that 0.01 to 0.05% by weight of the coating film-forming components.   The golf ball paint according to claim 1, wherein the golf ball paint is applied to the surface of the golf ball main body using an air spray gun or by an electrostatic coating method.   The golf ball paint according to any one of claims 1 to 3, wherein the equivalent ratio (NCO / OH) of the isocyanate group of the curing agent to the hydroxyl group of the main agent is 0.9 to 1.5. .   The golf ball paint according to claim 1, wherein the golf ball is a one-piece golf ball.   A golf ball obtained by coating the outer surface of the ball body with the golf ball paint according to claim 1.

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