JPH0534992B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to a bowling ball, and more particularly, the present invention relates to a bowling ball that has a polyurethane resin layer mixed with whiskers as at least the surface layer, has extremely high rigidity, and has high impact resistance, abrasion resistance, and oil resistance. , relates to a bowling ball with excellent heat resistance, rebound resilience, etc. [Prior Art] Conventional bowling balls are made of a single molded material such as ebonite, polyurethane resin, or polyester resin, or have a core layer made of ebonite or polyester resin with a covering layer made of polyurethane resin or the like. In addition, the core layer as described above has two layers with different compositions.
A three-layer structure including an intermediate layer made of a polyurethane resin and a surface coating layer has been proposed. [Problems to be Solved by the Invention] The conventional bowling balls described above, for example those made of a single molded material such as ebonite or polyester resin, are easily damaged or worn out due to collisions or contact with pins or lanes. That is, the impact resistance and abrasion resistance were poor. In addition, products made of a single polyurethane resin material or multi-layered products with a surface coating layer made of polyurethane resin have better impact resistance and abrasion resistance than those made of ebonite or polyester resin as mentioned above. Although it is better than
It has poor oil resistance and heat resistance, and has the disadvantage that it absorbs the oil components applied to the lane and may swell and deform, or it may soften and deform when the temperature exceeds 40°C during transportation in the summer. Therefore, it is an object of the present invention to provide a bowling ball that overcomes the drawbacks of conventional bowling balls as described above and has excellent impact resistance, abrasion resistance, oil resistance, heat resistance, rebound resilience, etc. With the goal. [Means for Solving the Problem] The bowling ball of the present invention is characterized in that it has a polyurethane resin layer mixed with whiskers as at least the surface layer. The bowling ball of the present invention includes both a molded product made of a single material of polyurethane resin mixed with whiskers and a multilayer molded product having a surface coating layer of polyurethane resin mixed with whiskers, It also includes balls that have any internal components necessary for a bowling ball, such as a balancer. The polyurethane resin used in the present invention may be any resin as long as it can obtain the desired physical properties.
Balls used in conventional bowling balls can be suitably used. Although so-called two-component room-temperature curable or thermosetting materials or thermoplastic materials may be used, two-component thermosetting materials are preferred from the viewpoint of moldability and heat resistance. The polyol component, which is one component of the polyurethane resin, is generally a polyester polyol manufactured from a polybasic acid and a hydroxyl compound,
Although polyether polyols such as alkylene oxide polymers or other polyols may be used, polyether polyols are preferred in the present invention. Examples of polyether polyols include polyoxypropylene glycol, polyoxypropylene polyoxyethylene glycol, polyoxybutylene glycol, polyoxytetramethylene glycol, polyoxypropylene triol, polyoxypropylene polyoxyethylene triol, polyoxypropylene polyoxy Examples include ethylene polyoxypropylene triol. At least difunctional compounds such as ethylene glycol, alkylene glycols such as 1,4-butanediol, amines such as ethylene diamine and aromatic diamines can also be used as chain extenders. Examples of the polyisocyanate component, which is another component of the polyurethane resin, include methylene diisocyanate, hexamethylene diisocyanate, xylylene isocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, etc. However, in the present invention, aromatic polyisocyanates are preferred. Needless to say, the blending ratio of the polyol component and polyisocyanate component constituting the polyurethane resin used in the present invention is preferably such that the corresponding number of reactive groups of each component is present in a stoichiometric amount, and the weight ratio is Although it depends on the molecular weight and number of functional groups of each component, it is generally 60 to 65 parts by weight of the isocyanate component per 100 parts by weight of the polyol component. The whiskers used in the present invention include:
Potassium titanate fibers having an average length of 10 to 30 μm, an average diameter of 0.2 to 0.5 μm, and an aspect ratio of 10 to 100 can be preferably used. The amount of the whiskers added is 3 to 3 parts by weight per 100 parts by weight of the polyol component constituting the polyurethane resin.
The amount is 20 parts by weight, more preferably 3 to 10 parts by weight.
If the amount is less than this range, it is difficult to obtain the effect of whisker addition, and if it is more than this, the physical properties of the polyurethane resin become unsuitable for use in bowling balls. In the bowling ball of the present invention, the above whiskers are mixed with the polyurethane resin used, so that the spaces in the crosslinked structure of the polyurethane resin are filled with minute whiskers and crosslinked, resulting in excellent rebound resilience. , not only impact resistance and abrasion resistance are obtained, but also oil resistance and heat resistance are improved. The whisker-containing polyurethane resin layer of the bowling ball of the present invention may further contain arbitrary additives. Examples of optional additives include water absorbing agents, catalysts, defoamers, anti-aging agents, anti-tarnishing agents, colorants, stabilizers and the like. The bowling ball of the present invention can be manufactured by a method known per se. That is, the resin is manufactured by blending the resin before curing and optionally performing defoaming treatment, etc., then injecting or injecting the resin into a mold with a balancer fixed therein, heating and curing it, and then removing the mold. After demolding, a process such as surface treatment can be optionally added. When manufacturing a bowling ball consisting of multiple layers, molds as many as the desired number of layers may be used and the layers may be sequentially molded. That is, the steps of starting from molding the core layer, fixing the molded material at the center of the next molding die, injecting or injecting the resin material of the covering layer around the periphery, and curing it may be repeated. In this case, it is convenient to integrally mold the support body and balancer portion for subsequent fixation in the mold at the time of molding the first core layer. Whiskers can be added to and mixed with the resin before curing. When using a two-component polyurethane resin, prepare a mixture of the desired amount of whiskers with the polyol component in advance, and add the isocyanate component to the resin before casting or injection. Mix with. In this case, the desired additives as well as the whiskers are mixed with the polyol component. When whiskers are mixed into the polyol component, the viscosity of the polyol component may increase and molding may become difficult, so it is preferable to subject the whiskers to anti-thickening treatment. When the bowling ball of the present invention is manufactured as having multiple layers, the material, thickness, and diameter of the core layer and intermediate layer, or the thickness of the whisker-containing polyurethane resin surface layer, It can be arbitrarily selected depending on the desired impact resilience, weight, etc. in fact,
The thickness of the surface layer of the whisker-containing polyurethane resin is preferably about 15 to 40 mm for a ball with an official standard diameter of 215.9 to 218.31 mm. [Example] Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 Glycerin+ with an OH value of 220 to 240 mgKOH/g as a polyol component constituting a polyurethane resin
Polyether polyol of propylene oxide, NCO% is 27-30 as isocyanate component
% modified methylene diisocyanate, with an average diameter of 0.2-0.5 μm and an average length as whiskers.
A bowling ball of the present invention was manufactured using potassium titanate fiber whiskers having a diameter of 10 to 30 μm and an aspect ratio of 50. First, an uncrosslinked polyester resin was filled and mixed and injected into a mold for the core layer, and heated at 55°C for about 50 minutes to harden and form a core layer with a diameter of 138 mm.
In this molding, a support part and a balancer part for fixation in the mold used for later molding of the intermediate layer and coating layer were integrally molded. Next, the above-mentioned molded product was fixed in the center of the coating layer mold, and the composition was as follows: Polyether polyol 100 Water absorbing agent 5 Catalyst (tin-based metal catalyst) 0.1 Pigment 10 Defoaming agent 1.0 Potassium titanate whisker 5.5 Aromatic Prepare a mixture of 65 (parts by weight) of whisker-containing polyurethane resin layer materials other than the aromatic isocyanate, keep the temperature of the mixture and the aromatic isocyanate at around 20°C, and immediately bring them together. Mixed and injected. It was cured by heating at 65°C for 30 minutes. Thereafter, the mold was removed, burrs were removed, and the surface was treated with a polisher to obtain a bowling ball according to the present invention. The whisker-containing polyurethane resin surface layer of the resulting bowling ball had a thickness of 40 mm. Example 2 The following tests were conducted to examine the physical properties of the whisker-containing polyurethane resin surface layer of the bowling ball of the present invention. Surface hardness The whisker content was adjusted to 0, 3, 5, and 10% by weight, and the composition was otherwise the same as that used in Example 1. The whisker-containing polyurethane resin was cured at a mold temperature of 70°C for 15 minutes. A plate-like sample with a thickness of 6 mm was prepared. Adjust the temperature of each sample to 10, 20, 30, 40℃,
Type hardness tester (ASTM.D2240D, JIS.K7215D
The hardness (degree) at three points on the surface of each sample was measured and recorded using a DUROMETER HARDNESS. The reading of the measured value was the maximum value indicated by the needle. The results are shown in Table 1 below.

[Table] Also, the polyurethane resin surface layer (40 mm thick portion) of a bowling ball manufactured in the same manner as in Example 1 except that the whisker content was 0 and 3% by weight.
The surface hardness was investigated in the same manner as above. The results are shown in Table 2 below.

[Table] Oil resistance The whisker content was adjusted to 0, 3, 5, and 10% by weight, and the composition was otherwise the same as that used in Example 1. It was cured for 15 minutes at a mold temperature of 70°C, and the whisker content was adjusted to 0, 3, 5, and 10% by weight. A 3 mm thick plate sample of the polyurethane resin was prepared. Each sample was cut to 100 x 50 x 3 mm, immersed in lane oil, and the change in weight (g) over time was measured. The results are shown in Table 3 below.

[Table] Flexural Modulus Using the same sample as used in the oil resistance test above, the flexural modulus was measured. The results are shown in Table 4 below.

[Table] Abrasion resistance The whisker content was adjusted to 0, 3, 5, and 10% by weight, and the composition was otherwise the same as that used in Example 1, and was cured for 15 minutes at a mold temperature of 70°C. A 3 mm thick plate sample of whisker-containing polyurethane resin was prepared. A traverse abrasion tester was used to test the normal cotton canvas 10
Depending on the number, the speed of the friction cloth is 30 reciprocations/min, the stroke
The surface of each sample was rubbed 5000 times at 100 mm. The surface condition of each sample was judged according to the following grades: Grade Surface Condition 5: Slight change in gloss 4: Significant change in gloss 3: Significant change in gloss 2: Severe wear and steps 1: Significant wear and cracks observed In addition, the amount of wear was measured using the William wear test for the same sample. The results are shown in Table 5 below.

【table】

Claims (1)

[Claims] 1. Average length 10 to 30 μm, average diameter 0.2 to 0.5 μm,
A bowling ball having at least a surface layer of a polyurethane resin layer mixed with potassium titanate fiber whiskers having an aspect ratio of 50. 2 The content of whiskers is 3 to 100 parts by weight of the polyol component constituting the polyurethane resin.
20 parts by weight of the bowling ball according to claim 1.