JPS61255815A - Preparation of molded article made of vinyl chloride resin - Google Patents

Abstract

PURPOSE:To eliminate not only the mutual blocking of surfaces but also surface sticky feeling, by scattering fine particles to the surface of a molded article in a semi-gel state such that a sol of a vinyl chloride resin has yet stickiness to form unevenness due to fine particles to the single surface thereof. CONSTITUTION:A hand mold is immersed in a vinyl chloride paste bath under heating to bring the plastisol adhered to the surface of the hand mold to a semi-gel state such that the surface of said plastisol has yet stickiness and fine particles 4 are uniformly scattered to said surface. As the material of the fine particles 4, a vinyl chloride resin or a copolymer with other monomer based on vinyl chloride is pref. The hand mold is introduced into a heating apparatus to be heated again and the plastisol is gelled and molted. In this obtained glove made of the vinyl chloride resin, because a large number of uneven parts due to fine particles 4 are present on the surface of one film layer 7 formed of the vinyl chloride paste, if said surface 8 is used in the inner surface side of a glove, the mutual blocking of the inner surfaces of the glove and the sticky feeling of the inner surfaces are eliminated and smooth wearing and taking-off of the glove can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Technical Field) The present invention relates to a method for producing a molded article made of vinyl chloride resin. More specifically, it relates to a method for manufacturing vinyl chloride resin moldings that eliminates the blocking phenomenon that occurs between the surfaces of vinyl chloride resin moldings and the sticky feeling on the surface, and is suitable for medical, household, and industrial use. This is a method for manufacturing a vinyl chloride resin molded product that is useful as a method for manufacturing soft vinyl chloride resin gloves that can be easily put on and taken off.

(Prior art) Molding processing using vinyl chloride paste does not require expensive and large-scale molding machines, has little thermal history, and does not apply external stress during melting, resulting in products without internal distortion. It has the characteristics that there are almost no restrictions on type or quantity, and it provides products in a wide range of fields using processing methods such as dip molding, slush molding, rotation molding, and spread painting. Among them, soft vinyl chloride resin gloves are a typical example, and are particularly useful because they are easily manufactured by dip molding of vinyl chloride paste, have constant quality, and are inexpensive.

By the way, molded products made of soft vinyl chloride resin generally have problems such as a blocking phenomenon between the surfaces of the molded product and a sticky feeling on the surface due to the plasticizer contained in the soft vinyl chloride resin composition. In the case of gloves made of soft vinyl chloride resin, it is extremely difficult to put on and take off the gloves because of a blocking phenomenon between the inner surfaces and a sticky feeling on the inner surfaces. Conventionally, in order to prevent the inner surfaces of soft vinyl chloride resin gloves from blocking each other and the sticky feeling on the inner surface, and to make it easier to put on and take off the gloves, fine particles such as talc or mica were applied to the inner surfaces of the gloves. Treatments such as spraying or embossing the inner surface are used, but in the method of scattering fine powder, the fine powder will come off from the inner surface after long-term use, making it virtually unnecessary. Furthermore, since the gloves are released from the mold by turning them inside out, even if you try to emboss them on the mold surface, only the outer surface of the glove will be exposed, and for the above purpose, it is impossible to emboss the inner surface. For this reason, the effects of preventing the blocking phenomenon and sticky feeling and making it easier to put on and take off the gloves could not be expected. In addition, a method has been devised in which particles such as vinyl chloride resin with a large particle size are dispersed in a sol and molded to create an embossed effect, but molding using only the dispersed sol results in weak product strength and The embossing will not be sufficiently developed, and on the other hand, there is a method in which after molding with a normal sol that does not contain such large particles, the molded product is immersed in the dispersion sol again (Japanese Unexamined Patent Application Publication No. 1986-1999). 110,272
(No.) had the drawbacks of being complicated to operate and increasing manufacturing costs.

(Problems to be Solved by the Invention) Therefore, the present invention aims to eliminate the blocking phenomenon and sticky feeling of soft vinyl chloride resin moldings produced by vinyl chloride paste processing.

That is, an object of the present invention is to provide a novel method for producing a molded article made of vinyl chloride resin.

Another object of the present invention is to provide a method for manufacturing a vinyl chloride resin molded product using vinyl chloride paste that can eliminate the blocking phenomenon and sticky feeling in the molded product. The object of the present invention is to provide a method for producing a molded product made of vinyl chloride resin, which can eliminate the blocking phenomenon and sticky feeling in the molded product, does not cause deterioration of the physical properties of the molded product, and has a simple manufacturing process and is suitable for mass production. purpose. A further object of the present invention is to provide a method for producing a vinyl chloride resin molded product suitable for producing gloves, sheets, etc. used for household, medical, industrial, and other uses.

Structure of the Invention (Means for Solving Problems) As a result of intensive research to achieve the above-mentioned objectives, the present inventors discovered that after adhering ordinary vinyl chloride paste to the mold surface. When heated, and when the surface is still in a semi-gel state with adhesive properties, fine particles made of vinyl chloride resin or a copolymer containing vinyl chloride as a main component with other hexamers having a particle size of 10 to 250 μm are added. After uniformly scattering on the surface of the paste in a semi-gel state, the paste is roughly heated to gel and melt the paste, so that fine irregularities are well formed by the fine particles on the surface of the molded product obtained. It has been found that this eliminates blocking between the surfaces and the sticky feeling of the surfaces. Furthermore, the mechanical strength of the molded product is comparable to that of conventional molded products, and the manufacturing process is relatively simple, which is why the present invention has been achieved.

That is, in the present invention, a sol of vinyl chloride resin is attached to the surface of a mold, heated, and while the surface is still in a sticky semi-gel state, fine particles are uniformly scattered on the surface.
This is a method for producing a molded product made of vinyl chloride resin, which is characterized in that the molded product is then further heated and melted to form irregularities made of fine particles on one side.

In this specification, the term "paste" or "sol" is used in a broad sense to collectively refer to all of plastisol, organosol, plastigel, and organogel.

(Example) The present invention will be described in more detail below based on a method for manufacturing vinyl chloride resin gloves as one embodiment.

Figures 1a-f sequentially show the manufacturing process of a vinyl chloride resin glove according to an embodiment of the present invention.

First, a PVC paste bath 1 containing plastisol kept at 30 to 45°C as shown in Fig. 1a is added.
As shown in the figure, the half mold 2 is soaked at a dipping speed of 10 to 35c, for example.
m/min, preferably 15 to 30 cm/min, and immerse for, for example, 3 to 20 seconds, preferably 5 to 10 seconds, to uniformly adhere the plastisol to the surface of the hand 2. This plastisol is a paste resin (particle size 0.2-2μm)
, a plasticizer, a stabilizer, a pigment, etc., and are the same as those conventionally used in the production of vinyl chloride resin gloves. In this example, plastisol is used as the vinyl chloride sol, but organosol, plastigel, or organogel can be used as desired depending on the type of molded product. The adhesion of the sol to the surface is not limited to immersion, and other spreading methods such as sludge molding, knife painting, roll painting, curtain 70-painting, and air knife painting can also be used.

After the mold half 2 is immersed in the vinyl chloride paste bath 1 in this way, the mold half 2 is chlorinated at a constant pulling rate, for example 3 to 25 cm/min, preferably 5 to 15 cm/min, as shown in FIG. 1C. After removing the plastic paste from the bath 1 and cutting off the sauce, it is heated using a heating device 3 such as an infrared lamp or hot air dryer, as shown in Fig. 1d, to remove the plastisol attached to the surface of the plastic paste 2. It is in a semi-gel state with the surface still sticky. The heating conditions for turning a vinyl chloride resin sol into a semi-gel cannot be generalized because they vary depending on the particle size of the paste resin used, the amount of plasticizer, etc., or even the type of sol, but In manufacturing the gloves of this example using
It is heated at 0 to 250°C, preferably 110 to 220°C, for 1 to 7 minutes, preferably 2 to 6 minutes to form a semi-gelled sol. Note that under this condition, the heating temperature ('COX heating time (minutes)) is required to be in the range of 200 to 1750, more preferably 300 to 1200. In this heating operation, the heating time is too short or
If the heating temperature is too low and the sol has not reached the desired semi-gelled state, as described below, even if fine particles are dispersed, the fine particles may sneak into the sol layer and the desired unevenness may not be developed. On the other hand, if the heating time is too long or the heating temperature is too high, the gelation and melting of the sol will progress, reducing the stickiness of the surface, and even if fine particles are sprayed, the surface will not stick to the surface. It will not be fixed and will peel off from the molded product.

Next, as shown in FIG. 1e, fine particles are uniformly sprinkled onto the surface of the plastisol, which is still sticky and semi-gelled, on the second side.

The fine particles to be sprinkled on the surface of the semi-gelled sol can be made of various materials, but from the viewpoint of wettability or compatibility at the interface with the vinyl chloride paste, vinyl chloride resin or vinyl chloride as the main component may be used. It is a copolymer with monomers such as vinylidene chloride, ethylene, propylene, vinyl acetate, vinyl fluoride, styrene, vinyltoluene, vinylpyridine, alkyl acrylate, alkyl methacrylate, urethane, etc. It is preferable. Furthermore, these resins are not limited to general ones; they may be cross-linked, foamed, or made into fine particles of a compound mixed with a certain amount of plasticizer. . However, the average particle diameter of these fine particles is 10 to 250 μm, preferably 30 to 15 μm, although it also depends on the wall thickness of the molded product.
It is preferable that the particle size is 0 μm, and more preferably the ratio of the average particle diameter to the wall thickness of the molded product is 1:3 to 1:10. In other words, if the average particle size of these fine particles is extremely small and is not much different from the paste resin used for the vinyl chloride paste, not only will sufficient unevenness not be formed, but the vinyl chloride paste will not be as smooth after being sprayed. During gelation and melting, there is a risk that the fine particles will fuse into the paste and no unevenness will be formed.1. In addition, if the average particle size is extremely large, the surface of the molded product may feel like a foreign body.
For example, if it is formed on the inner surface of a glove, it may cause discomfort such as pain in the half of the glove, and may reduce the physical properties such as mechanical strength and elongation of the molded product.

In order to uniformly scatter such fine particles on the surface of the semi-gelled sol, for example, as shown in Fig. 4, the fine particles 4 are placed in a tank having a porous plate 5 at the bottom, and compressed air 6 is fed from below the bottom. There is a method of scattering the suspended fine particles 4 onto the flat mold 2 (fluidized dipping method), or a method of simply rotating the flat mold and allowing the fine particles to fall freely through a sieve or feeding them with a fan. In this case, a small amount of antistatic agent may be mixed in to prevent fine particles from adhering to each other due to static electricity. A device that uses a fan to send fine particles together with static-eliminating ions while roughly rotating a flat mold (Shishide static electricity).
This can be carried out by any method such as a method in which fine particles are dispersed using Eliminostat (manufactured by Co., Ltd.) to prevent adhesion of fine particles to each other.

The amount of fine particles dispersed on the surface of the semi-gelled sol in this way varies depending on the type, size, wall thickness, etc. of the molded product, but it is necessary to It is desirable to adjust the number of unevenness to be 10 to 300/mm2, preferably 30 to 150/mm2.

After scattering fine particles on the surface of the plastisol, which is kept in a semi-gelled state on the 2 sides of the flat mold, the flat mold 2 is placed in a heating device 3 similar to that in Figure 1d, as shown in Figure 1f, and heated again to transform the plastisol. Gel and melt. The heating conditions for final gelling and melting of the vinyl chloride resin sol cannot be generalized, as they vary depending on the particle size of the paste resin used, the amount of plasticizer, etc., and the format of the sol. but,
In manufacturing the gloves of this example using plastisol, the temperature is, for example, 150 to 250°C, preferably 180 to 220°C.
C. for 7 to 15 minutes, preferably 9 to 11 minutes to gel and melt the plastisol to obtain a product. Even if the fine particles attached to the surface of the semi-gelled sol in this step are uncrosslinked vinyl chloride resin particles containing a certain amount of plasticizer, they will only slightly melt at the interface with the vinyl chloride paste. It maintains its shape and forms minute irregularities on the surface of the molded product.

The vinyl chloride resin gloves obtained as described above are
As shown in FIG. 2, there are many irregularities caused by the fine particles 4 on one surface 8 of the film layer 7 formed from the vinyl chloride paste, so if this surface 8 is used as the inner surface of the glove, there will be no blocking between the inner surfaces of the glove. Also, since there is no sticky feeling on the inner surface, it can be put on and taken off smoothly, and even if your hands are wet due to sweating from wearing it for a long time, you can easily put it on and take it off. Further, although the fine particles 4 are fused to the membrane layer 7, they are hardly buried inside the membrane layer 7, so that the physical properties such as the strength and elongation rate of the membrane layer 7 hardly deteriorate, and the fine particles 4 does not peel off, resulting in extremely excellent vinyl chloride resin gloves.

Next, the present invention will be specifically explained using examples.

EXAMPLE A flat mold preheated to 50'C was immersed at a dipping speed of 24 cm/min into a bath containing plastisol prepared according to the formulation shown in Table 1 and maintained at 35C. After being immersed for 6 seconds, the sample was pulled up at a rate of 12 cm/min to remove any sauce, and then heated at 140° C. for 5 minutes. After this, the average particle size was 40 μm.
Fine particles of vinyl chloride resin were sprayed using a fluidized dipping method. Thereafter, the mixture was heated again at 200° C. for 10 minutes to gel and melt the semi-gelled plastisol to obtain a product.

The wall thickness of the gloves obtained was 220 μm, and the ratio of the average particle diameter of the fine particles to the wall thickness was 1:5.5, and the dispersed vinyl chloride resin fine particles were located on the surface in the state shown in Figure 2. ,
It was easy to put on and take off, and the inner surfaces did not block each other or the inside felt sticky, giving a good feeling of wearing. The physical properties of this glove are a tensile strength of 100k (1/cm2) and an elongation rate of 390%.The physical properties of vinyl chloride paste gloves obtained using the same method except that fine particles were not sprayed are as follows: tensile strength of 108 kMccm2 and elongation rate of 390%. Even when compared with the ratio of 410%, no practical difference was observed.

Table 1 Resin for vinyl chloride paste 100 parts by weight (average particle size 0.8 μm) Diethylhexyl phthalate 90 parts by weight Epoxidized soybean oil 5 parts by weight Polyester plasticizer 10 parts by weight Calcium-zinc stabilizer 3 parts by weight Pigment
Small Comparative Example Gloves were made in the same manner as in the example except that vinyl chloride resin fine particles having an average particle size of 100 μm were used.

The wall thickness of the obtained glove was 220 μm, and the ratio of the average particle diameter of the fine particles to the wall thickness was 1:2°2. Although this glove did not show any blocking between the inner surfaces or a feeling of stickiness inside, when actually worn, the fine particles gave a feeling of a foreign body and pressed the half part, and when worn for a long time, it caused discomfort such as pain. . In addition, the physical properties of this glove are a tensile strength of 95 kg.
/Cm2, and the elongation rate was 270%, and compared to the one without fine particles on the surface, there was no practical difference in tensile strength, but the elongation was significantly lower.

Effects of the Invention As described above, the present invention is capable of attaching a sol of vinyl chloride resin to the surface of a mold, heating it, and then applying fine particles to the surface while the surface is still in a sticky semi-gel state. This is a manufacturing method for molded polyvinyl chloride resin, which is characterized by uniformly dispersing the resin, then heating and melting it roughly, and forming unevenness with fine particles on one side. By simply making changes, it is possible to provide a molded product with excellent characteristics such as no blocking or sticky feeling on the surface and almost no deterioration in physical properties compared to conventional products, and it is easy to mass-produce industrially. This is a method for producing molded products made of vinyl chloride resin, which is excellent in price and quality stability. Furthermore, the vinyl chloride resin gloves that can be manufactured by this manufacturing method have no blocking between their inner surfaces and no stickiness inside, and can be put on and taken off very easily.

[Brief explanation of the drawing]

Figures 1a to 1f are process diagrams of a method for manufacturing vinyl chloride resin gloves, which is an embodiment of the manufacturing method of the present invention.
The figure is a drawing schematically showing the fine structure of a molded product made of vinyl chloride resin produced by the manufacturing method of the present invention. 1... Vinyl chloride paste bath, 2... Flat type, 3
... Heating device, 4... Fine particles, 5... Porous plate, 6... Compressed air, 7... Membrane layer, 8...
surface. Patent applicant New Materials Research Institute Co., Ltd. Figure 1 (a) (c)

Claims (9)

[Claims] (1) A vinyl chloride resin sol is attached to the surface of the mold and then heated, and when the surface is still in a sticky semi-gel state, fine particles are uniformly scattered over the surface, and then further heated. A method for producing a molded product made of vinyl chloride resin, which is characterized by melting and forming irregularities made of fine particles on one side. (2) The manufacturing method according to claim 1, wherein the fine particles have an average particle size of 10 to 250 μm. (3) The ratio of the average particle diameter of the fine particles to the wall thickness of the molded product is 1:3
The manufacturing method according to claim 2, wherein the ratio is 1:10. (4) The manufacturing method according to claim 2 or 3, wherein the fine particles are vinyl chloride resin. (5) The manufacturing method according to claim 2 or 3, wherein the fine particles are a copolymer containing vinyl chloride as a main component with another monomer. (6) Heating temperature before spraying fine particles is 100-250
The manufacturing method according to claim 4 or 5, wherein the heating temperature (°C) x heating time (minutes) is 200 to 1750. (7) Heating temperature after spraying fine particles is 150-250
The manufacturing method according to any one of claims 4 to 6, wherein the temperature is .degree. (8) The manufacturing method according to any one of claims 1 to 7, wherein the vinyl chloride resin sol is attached to the mold surface by dipping. (9) The manufacturing method according to any one of claims 1 to 8, wherein the molded product is a vinyl chloride resin glove.