Clay composition for modeling

Abstract

To provide a clay composition for modeling that exhibits superior shape retention, transparency, and formability.SOLUTION: A clay composition for modeling comprises a partially crosslinked styrene-butadiene copolymer rubber, an uncrosslinked styrene-butadiene copolymer rubber, and a plasticizer. The mass of the uncrosslinked styrene-butadiene copolymer rubber is 1 pt.mass or more and 50 pts.mass or less per 100 pts.mass of the total of the partially crosslinked styrene-butadiene copolymer rubber and the uncrosslinked styrene-butadiene copolymer rubber. Preferably, the mass of the plasticizer is 60 pts.mass or more and 100 pts.mass or less per 100 pts.mass of the total.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a modeling clay composition.

Background Art

[0002] Patent Document 1 discloses a silicone rubber clay composition. The silicone rubber clay composition contains an organopolysiloxane, an inorganic filler, and glass balloons.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the clay composition is used for modeling applications in fields such as toys and handicrafts, it is desirable that the clay composition has good shape retention. Also, when the clay composition is used in a wide range of applications such as accessories and miniature hoods, it is desirable that the clay composition has transparency. Further, it is desirable that the clay composition has good moldability.

[0005] In one aspect of the present disclosure, it is preferable to provide a modeling clay composition having good shape retention, transparency, and moldability.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a modeling clay composition including a partially crosslinked styrene-butadiene copolymer rubber, an uncrosslinked styrene-butadiene copolymer rubber, and a plasticizer. With respect to 100 parts by mass, which is the total mass of the partially crosslinked styrene-butadiene copolymer rubber and the uncrosslinked styrene-butadiene copolymer rubber, the mass of the uncrosslinked styrene-butadiene copolymer rubber is 1 part by mass or more and 50 parts by mass or less.

[0007] The modeling clay composition, which is one aspect of the present disclosure, has good shape retention, transparency, and moldability.

Mode for Carrying Out the Invention

[0008] Exemplary embodiments of the present disclosure will be described. 1. Configuration of the Modeling Clay Composition The modeling clay composition can be used, for example, in the fields of toys, handicrafts, accessories, miniature food, etc. The modeling clay composition includes a partially crosslinked styrene-butadiene copolymer rubber, an uncrosslinked styrene-butadiene copolymer rubber, and a plasticizer.

[0009] The partially crosslinked styrene-butadiene copolymer rubber and the uncrosslinked styrene-butadiene copolymer rubber are each one type of styrene-butadiene copolymer rubber. The total mass of the partially crosslinked styrene-butadiene copolymer rubber and the uncrosslinked styrene-butadiene copolymer rubber contained in the modeling clay composition is hereinafter referred to as the SBR mass. With respect to 100 parts by mass of the SBR mass, the mass of the uncrosslinked styrene-butadiene copolymer rubber contained in the modeling clay composition is 1 part by mass or more and 50 parts by mass or less.

[0010] When the mass of the uncrosslinked styrene-butadiene copolymer rubber is 1 part by mass or more with respect to 100 parts by mass of the SBR mass, the modeling clay composition has good moldability. Good moldability means that it is not overly hard and is easy to knead.

[0011] When the mass of the uncrosslinked styrene-butadiene copolymer rubber is 50 parts by mass or less with respect to 100 parts by mass of the SBR mass, the modeling clay composition has good shape retention. Good shape retention means that it is not overly soft and is easy to maintain a certain shape.

[0012] With respect to 100 parts by mass of the SBR mass, within the range of 1 part by mass or more and 50 parts by mass or less, the greater the mass of the uncrosslinked styrene-butadiene copolymer rubber, the better the transparency of the modeling clay composition.

[0013] Let the bound styrene content in the uncrosslinked styrene-butadiene copolymer rubber be SA (%). Let the bound styrene content in the partially crosslinked styrene-butadiene copolymer rubber be SB (%). The bound styrene content SA is preferably 21% or more and 26% or less.

[0014] SA / SB is preferably 0.8 or more and 1.2 or less. SA / SB is the value obtained by dividing SA by SB. When SA / SB is 0.8 or more and 1.2 or less, the compatibility between the partially crosslinked styrene-butadiene copolymer rubber and the uncrosslinked styrene-butadiene copolymer rubber is even better.

[0015] Examples of the product of the uncrosslinked styrene-butadiene copolymer rubber include those described in Table 1. Table 1 shows the bound styrene content and the Mooney viscosity at 100°C of each product.

[0016]

Table 1

[0017] With respect to 100 parts by mass of the SBR mass, the mass of the plasticizer contained in the clay composition for shaping is preferably 60 parts by mass or more and 100 parts by mass or less. When the mass of the plasticizer is 60 parts by mass or more with respect to 100 parts by mass of the SBR mass, the transparency of the clay composition for shaping is even better. When the mass of the plasticizer is 100 parts by mass or less with respect to 100 parts by mass of the SBR mass, the shape retention of the clay composition for shaping is even better.

[0018] With respect to 100 parts by mass of the SBR mass, the mass of the plasticizer contained in the clay composition for shaping may be less than 60 parts by mass. Also, with respect to 100 parts by mass of the SBR mass, the mass of the plasticizer contained in the clay composition for shaping may exceed 100 parts by mass.

[0019] Examples of plasticizers include paraffin oil, liquid paraffin, non-phthalate-based, phthalate-based, etc. Examples of plasticizer products include those listed in Table 2 below.

[0020] [Table 2]

[0021] The modeling clay composition may further contain, for example, pigments, fragrances, etc. Examples of pigments include Sumiplast Blue SR (trade name, manufactured by Sumitomo Chemical Tex Co., Ltd.), etc. Examples of fragrances include CITRAL-R (trade name, manufactured by Kuraray Co., Ltd.), etc. The forms of the pigments and fragrances are, for example, liquids. The modeling clay composition may further contain resin-based materials, fillers, etc. as long as the properties such as transparency and shape retention are not excessively reduced. Also, it may contain multiple types of uncrosslinked styrene-butadiene copolymer rubber.

[0022] 2. Effects Exhibited by the Modeling Clay Composition (1A) The modeling clay composition has good transparency, shape retention, and moldability. (1B) The mass of the plasticizer contained in the modeling clay composition is, for example, 60 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the SBR mass. In this case, the modeling clay composition has even better transparency and shape retention.

[0023] 3. Examples (3-1) Production of the Modeling Clay Composition The modeling clay compositions of Examples 1 to 13 and Comparative Examples 1 to 2 were produced by the following method. First, the raw materials were charged into an open kneader. The raw materials were the products shown in the rows of "Partially Crosslinked SBR", "Uncrosslinked SBR", and "Plasticizer" in Tables 3 to 5. The blending amounts of the raw materials were the numerical values described in the rows of "Partially Crosslinked SBR", "Uncrosslinked SBR", and "Plasticizer" in Tables 3 to 5. The unit of the blending amount was parts by mass.

[0024] Next, the raw materials were kneaded and defoamed using an open kneader to obtain a clay composition for shaping.

[0025] Next, the clay composition for shaping was put into the hopper of an extruder. The clay composition for shaping having a predetermined shape was extruded by a screw provided in the extruder. Next, the extruded clay composition for shaping was cut to a predetermined length. Through the above steps, the clay compositions for shaping of each example and each comparative example could be manufactured.

[0026] [Table 3]

[0027] [Table 4] [[ID=B21]]

[0028] [Table 5]

[0029] In Tables 3 to 5, "partially crosslinked SBR" is a partially crosslinked styrene-butadiene copolymer rubber. In Tables 3 to 5, "uncrosslinked SBR" is an uncrosslinked styrene-butadiene copolymer rubber.

[0030] In Tables 3 to 5, SBR1009OC is the trade name of a partially crosslinked styrene-butadiene copolymer rubber manufactured by LION ELASTOMERS. The bound styrene content of SBR1009OC is 22.5 to 24.5%.

[0031] In Tables 3 to 5, Tufdene 2100R is the trade name of an uncrosslinked styrene-butadiene copolymer rubber manufactured by Asahi Kasei Corporation. The Mooney viscosity of Tufdene 2100R at 100 °C is 45.0.

[0032] In Tables 3 to 5, Liquid Paraffin No. 40-S is the trade name of a plasticizer manufactured by Sanko Chemical Industries, Ltd. (3-2) Evaluation of the Modeling Clay Composition For the modeling clay compositions of each example and each comparative example, transparency, shape retention, and moldability were evaluated. The evaluation methods and criteria were as follows.

[0033] (i) Evaluation of Transparency By cutting the modeling clay composition, a plate-shaped sample was prepared. When viewed from the thickness direction of the plate, the shape of the sample was square. The size of the sample was 30 mm in length, 30 mm in width, and 10 mm in thickness.

[0034] The sample was placed on a piece of paper printed black. The thickness direction of the paper and the thickness direction of the sample were each the vertical direction. In that state, the sample was left standing at 23°C for one month. Then, the sample was visually observed from above. Transparency was evaluated according to the following criteria. The evaluation results of transparency are shown in Tables 3 to 5.

[0035] 1. The sample is whitish and hazy, and the turbidity affects the visibility of black. 2. The sample is whitish and hazy, but black can be visually recognized. 3. The sample is whitish and hazy, but black can be clearly visually recognized. 4. The sample is slightly whitish and hazy, but black can be seen almost clearly. 5. Black can be seen as clearly as when there is no sample.

[0036] (ii) Evaluation of Shape Retention Samples similar to those in (i) above were prepared. The samples were left standing at 40°C for two days. Then, the change in the external shape of the samples was visually observed. Shape retention was evaluated according to the following criteria. The evaluation results are shown in Tables 3 to 5.

[0037] 1. The corners and sides of the sample become rounded, and the thickness decreases. 2. The corners and sides of the sample become rounded, and the thickness slightly decreases. 3. The corners and sides of the sample become slightly rounded. 4. The corners of the sample become slightly rounded. 5. The change in the external appearance shape of the sample is hardly observable visually.

[0038] (iii) Evaluation of moldability Based on the ease of kneading when kneading the molding clay composition by hand, the moldability was evaluated according to the following criteria. The evaluation results are shown in Tables 3 to 5.

[0039] 1. The molding clay composition is too hard to knead. 3. The molding clay composition is slightly firm but can be kneaded. 5. The molding clay composition is easy to knead.

[0040] (iv) Evaluation results of each item In the molding clay compositions of the respective examples, transparency, shape retention, and moldability were good. In particular, in Examples 1 to 6 and 8 to 13 in which the mass of the plasticizer was 60 parts by mass or more with respect to 100 parts by mass of the SBR mass, the transparency was even better. Further, in Examples 1 to 12 in which the mass of the plasticizer was 100 parts by mass or less with respect to 100 parts by mass of the SBR mass, the shape retention was even better. On the other hand, in Comparative Example 1, the shape retention was poor. Also, in Comparative Example 2, the moldability was poor.

[0041] 4. Other embodiments As described above, the embodiments of the present disclosure have been described, but the present disclosure is not limited to the above-described embodiments and can be implemented with various modifications.

[0042] (1) When producing the molding clay composition, a kneader may be used instead of an extruder. (2) The function of one component in each of the above embodiments may be shared by a plurality of components, or the functions of a plurality of components may be exhibited by one component. Also, a part of the configuration of each of the above embodiments may be omitted. Further, at least a part of the configuration of each of the above embodiments may be added to, replaced with, etc., the configuration of other of the above embodiments.

[0043] (3) In addition to the above-described modeling clay composition, the present disclosure can also be realized in various forms such as a system including the modeling clay composition as a component and a method for manufacturing the modeling clay composition.

Claims

**Claim 1** A clay composition for modeling, a partially crosslinked styrene-butadiene copolymer rubber, an uncrosslinked styrene-butadiene copolymer rubber, a plasticizer, comprising, with respect to 100 parts by mass, which is the total mass of the partially crosslinked styrene-butadiene copolymer rubber and the uncrosslinked styrene-butadiene copolymer rubber, the mass of the uncrosslinked styrene-butadiene copolymer rubber is 1 part by mass or more and 50 parts by mass or less, a clay composition for modeling. **Claim 2** The clay composition for modeling according to Claim 1, with respect to 100 parts by mass, which is the total mass of the partially crosslinked styrene-butadiene copolymer rubber and the uncrosslinked styrene-butadiene copolymer rubber, the mass of the plasticizer is 60 parts by mass or more and 100 parts by mass or less, a clay composition for modeling.

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