JPH0867724A - Unsaturated-polyester resin composition for pregelation, pregelation method, and pregelation product - Google Patents

Abstract

PURPOSE: To obtain an unsaturated polyester resin composition whose pregelationcan easily be controlled and which gives a pregelation product having satisfactory storage stability by compounding an unsaturated polyester resin with an organic peroxide and ascorbic acid. CONSTITUTION: This resin composition comprises an unsaturated polyester resin, an organic peroxide (e.g. t-butyl hydroperoxide or t-butyl peroxybenzoate), and ascorbic acid. The composition is heated at 40-100 deg.C and then cooled to 20 deg.C or lower to cause the polyester resin to undergo pregelation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pregelling composition, a pregelling method and a pregelled product from an unsaturated polyester resin. More specifically, the present invention relates to a pregelling composition of an unsaturated polyester resin, a pregelling method, and a pregelation product, in which the pregelation can be easily controlled and the storage stability of the pregelation product is good.

[0002]

2. Description of the Related Art In recent years, molding materials in which unsaturated polyester resin is mixed with glass fiber and various additives are widely used as molding materials for bathtubs, septic tanks, vehicle parts, electric parts, buttons, artificial marble and the like. These molding materials are easy to handle, and in order to improve moldability, they are used as a pudding-like or dough-like non-adhesive pregelled product by chemically reacting an unsaturated polyester resin to increase the viscosity. As typical examples of the pregelled product, there are a sheet molding compound (hereinafter abbreviated as SMC) and a bulk molding compound (hereinafter abbreviated as BMC), and many pregelling methods have been proposed.

Typical methods are listed as follows: (a) a pregelation method using an alkaline earth metal oxide such as magnesium or calcium or a hydroxide thereof (US Pat. No. 2,568,331), (b) trifluoride. Pregelling method using boron or its complex (US Pat. No. 9209)
No. 01), (c) a pregelling method using a metal alkoxide such as aluminum and titanium (British Patent No. 920902), and many other proposals have been made.

In the field of molding buttons, a curing agent that decomposes at a low temperature when mixing an unsaturated polyester resin, a filler, a colorant, etc., and a redox curing system in which cobalt naphthenate and ketone peroxide are used in combination are combined. As a result, a sheet-shaped or tubular pregelled product is used which is heated and cured in a rotating drum or a metal pipe.

In addition, when the unsaturated polyester resin is cured, a chain transfer agent may be used together to reduce the maximum temperature reached by the accumulation of heat of curing or to stop the curing reaction on the way. For example, a method using 2,4-diphenyl 4-methyl 1-pentene (Nippon Yushi Co., Ltd., trade name: NOFMER MSD) represented by Structural Formula 1 (JP-A-59-81322) and There is a method of using terpinolene (manufactured by NOF Corporation, trade name: NOFMER TP) represented by the structural formula 2 (JP-A-3-79616).

On the other hand, it is known that unsaturated polyester resins can be cured at room temperature by using various alkyl esters of ascorbic acid and isoascorbic acid as promoters and using methyl ethyl ketone peroxide and benzoyl peroxide together (Japanese Patent Publication No. 36-15393). Gazette).

[0007]

However, SMC and B
MC basically has to be heat-aged (aged) at a temperature of around 40 ° C. for 2 to 3 days to increase its viscosity to make it non-tacky. This aging for 2 to 3 days is indispensable, and therefore a molding material cannot be obtained in a short time. Further, a pregelled product using an alkaline earth metal oxide as a thickener has poor water resistance. Further, in the pre-gelling of button molding, it is difficult to adjust the degree of pre-gelling because it uses a redox curing system such as cobalt naphthenate and ketone peroxide, which are hardeners that decompose at low temperature, and the pre-gel state Was difficult to keep stable.

Further, in the method of producing a pregelled product disclosed in JP-A-59-81322 and JP-A-3-79616, the rate of pregelation is slow due to the action of the chain transfer agent, and the degree of pregelation is low. Is difficult to adjust. On the other hand, in the curing method disclosed in Japanese Patent Publication No. 36-15393, the stability of the pregel state is poor because the curing and crosslinking reaction proceeds at room temperature due to the action of the alkyl ester of ascorbic acid, etc. There has been a strong demand for a simple method for producing a pregelled product that can be retained for a long time.

The present invention has been made by paying attention to the above-mentioned conventional technique. The purpose thereof is to allow pregelation to be carried out quickly, stability in pregel state is good, and pregelling composition of unsaturated polyester resin capable of adjusting the degree of pregelation, pregelling method and pregelling. To provide a compound.

[0010]

In order to achieve the above object, the inventors of the present invention in accordance with the invention of a pregelled composition of an unsaturated polyester resin as set forth in claim 1 (1): It is composed of (2) an organic peroxide and (3) ascorbic acid. In the invention of the pregelling method according to claim 2, after heating the pregelling composition comprising (1) unsaturated polyester resin, (2) organic peroxide and (3) ascorbic acid at 40 to 100 ° C., 2
It is cooled to 0 ° C. or lower. In the invention of the pregelled product according to claim 3, (1) an unsaturated polyester resin,
After heating the pregelled composition comprising (2) organic peroxide and (3) ascorbic acid at 40 to 100 ° C, 20 ° C
It is cooled below.

The unsaturated polyester resin pregelling composition according to claim 4 is (1) unsaturated polyester resin, (2) organic peroxide, (3) ascorbic acid and (4) chain transfer agent. It consists of In addition, in the invention described in claim 5, in the invention described in claim 4, the chain transfer agent is the compound represented by the structural formula 1. In the invention described in claim 6, in the invention described in claim 4, the chain transfer agent is the compound represented by the structural formula 2.

In the invention of the pregelling method according to claim 7, the pregelling composition of the unsaturated polyester resin according to claim 4 is heated at a temperature of 100 ° C. or lower. In the invention of the pregelled product of the unsaturated polyester resin described in claim 8, it is obtained by heating the pregelled composition of the unsaturated polyester resin described in claim 4 at a temperature of 100 ° C. or lower.

The present invention will be described in detail below. First, regarding the pregelled composition of the unsaturated polyester resin in the present invention, as the unsaturated polyester resin, an unsaturated dibasic acid, a saturated dibasic acid and a polyunsaturated alcohol obtained by dehydration condensation at a specific ratio A mixture of an alkyd resin and a copolymerizable monomer is used. This copolymerizable monomer is bonded between the unsaturated groups of the unsaturated alkyd resin to form a crosslinked structure.

Here, examples of the unsaturated dibasic acid include maleic anhydride, maleic acid and fumaric acid. Examples of the saturated dibasic acid include phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, succinic acid and sebacic acid. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hydrogenated bisphenol A, ethylene oxide and propylene oxide.
As the copolymerizable monomer, styrene, vinyltoluene,
Examples thereof include methyl methacrylate and diallyl phthalate. The mixing amount of the copolymerizable monomer is usually 20 to 60.
%, Most commonly 20 to 50% by weight.

Next, the organic peroxide which functions as a curing catalyst for the unsaturated polyester resin will be described. When the pregelled composition in this invention comprises (1) unsaturated polyester resin, (2) organic peroxide, (3) ascorbic acid and (4) chain transfer agent, the organic peroxide is unsaturated polyester. To cure the resin,
Almost all organic peroxides are used. This is because ascorbic acid acts as a strong pregelling agent, and a desired pregelled product can be obtained at room temperature in a short time. Therefore, examples of the organic peroxide that can be used in the present invention include tertiary butyl hydroperoxide, cumene hydroperoxide and other hydroperoxides, methyl ethyl ketone peroxide and other ketone peroxides, tertiary butyl peroxybenzoate and tertiary butyl peroxyisopropyl. Peroxyesters such as carbonates, diacyl peroxides such as benzoyl peroxide, dialkyl peroxydicarbonates such as para-tertiary butyl cyclohexyl peroxydicarbonate, dicumyl peroxide and 2,5-dimethyl 2,5
Almost all organic peroxides such as dialkyl peroxides such as tert-butyl peroxyhexane. These organic peroxides are used alone or in combination of two or more.

When the pregelled composition comprises (1) unsaturated polyester resin, (2) organic peroxide and (3) ascorbic acid, the following organic peroxides give suitable pregelled products. It is preferably used for. That is, as the organic peroxide, hydroperoxides such as tertiary butyl hydroperoxide and cumene hydroperoxide, peroxyesters such as tertiary butylperoxybenzoate and tertiary butylperoxyisopropyl carbonate, 1,1-bis (Tertiary butylperoxy) 3,3,5-trimethylcyclohexane and other peroxyketals and dicumyl peroxide, 2,5-
Dialkyl peroxides such as dimethyl-2,5-ditertiary butylperoxyhexane and the like can be mentioned. These organic peroxides are used alone or in combination of two or more.

Here, ascorbic acid acts as a strong pregelling agent when used in combination with a specific organic peroxide. Examples of such organic peroxides include diacyl peroxides such as benzoyl peroxide, dialkyl peroxydicarbonates such as para-tertiary butylcyclohexyl peroxydicarbonate, and ketone peroxides such as methyl ethyl ketone peroxide. When using these organic peroxides, the usual blending amount with respect to the unsaturated polyester resin,
That is, when 1% by weight is added, the unsaturated polyester resin tends to be completely cured at room temperature. Therefore, it is not preferable to use these organic peroxides alone as a curing agent for pregelation.

However, the above-mentioned organic peroxides such as hydroperoxides, peroxyesters, peroxyketals and dialkylperoxides may be used in combination with diacylperoxides, dialkylperoxydicarbonates and ketone peroxides. You can In this case, the latter organic peroxide is preferably added in an amount of 50% by weight or less based on the total amount of the curing agent used, and if it exceeds 50% by weight, the degree of curing of the unsaturated polyester resin becomes too high.

The blending amount of these organic peroxides depends on the pregelling conditions and the desired pregel state, but for example, it is 0.1 to 5 parts by weight, preferably 0 per 100 parts by weight of the unsaturated polyester resin. Within the usual range of use of 0.5 to 3 parts by weight. If the compounding amount of the curing agent is too large, it is economically disadvantageous, and if it is too small, the unsaturated polyester resin tends to be in an incompletely cured state.

The ascorbic acid used in the present invention is usually L-ascorbic acid represented by the following general formula 3, but it may be D-ascorbic acid or a mixture thereof. Good. L-ascorbic acid is a compound contained in natural fruit juice and the like and generally called vitamin C. Ascorbic acid that is industrially mass-produced can be used. This ascorbic acid is considered to have a function of pregelling the unsaturated polyester resin in a short time.

[0021]

[Chemical 3]

Such ascorbic acid is usually acicular crystals and can be blended in a crystalline state or as an organic solvent solution, but an organic solvent solution is preferable from the viewpoint of handling.
Examples of usable organic solvents include various organic esters such as ketones, phthalic acid esters and phosphoric acid esters, various solvents such as alcohols, alkylene glycols and various aliphatic hydrocarbons, and further used as an aqueous solution. It is possible. A particularly preferable organic solvent is a phosphoric acid ester such as triethyl phosphate having a high solubility in ascorbic acid. The concentration of ascorbic acid in this organic solvent is in the usual concentration range, for example, about 5 to 20% by weight.

The ascorbic acid content is as follows:
It is determined by the pregelation conditions and the desired pregelation state. For example, when the pregelled composition is composed of (1) unsaturated polyester resin, (2) organic peroxide and (3) ascorbic acid, the unsaturated polyester resin is
0.001 to 100 parts by weight of ascorbic acid
0.5 parts by weight, particularly preferably 0.01 to 0.2
Within the range of parts by weight.

On the other hand, when the pregelling composition comprises (1) unsaturated polyester resin, (2) organic peroxide, (3) ascorbic acid and (4) chain transfer agent, 100 of unsaturated polyester resin is used. The amount of ascorbic acid is 0.001 to 1.0 part by weight, and particularly preferably 0.01 to 0.5 part by weight. If the blending amount is too small, the pregelling time becomes long, and conversely, if it is too large, it shifts from the pregel state to complete curing, which is not preferable.

Next, the chain transfer agent in the present invention is a compound generally used for radical polymerization of styrene and the like, and is 2,4-diphenyl-4- represented by the above-mentioned structural formula 1.
Methyl 1-pentene (for example, NOFMER MSD, manufactured by NOF CORPORATION) or terpinolene represented by the above structural formula 2 (for example, NOFMER Co., Ltd., trade name:
Nofmer TP). These chain transfer agents are used alone or in combination. It is considered that this chain transfer agent has a function of maintaining the pregelled substance stably for a long time.

The content of these chain transfer agents is usually 0.01 to 1 per 100 parts by weight of the unsaturated polyester resin.
It is in the range of 0 parts by weight, preferably 0.1 to 3 parts by weight. If the blending amount is too large, the time for pregelation becomes long, so it is necessary to take measures such as performing pregelation for a long time or raising the heating temperature, and conversely, if it is too small, transition from pregel state to complete curing. It is not desirable. These chain transfer agents can be used alone or in combination.
When the copolymerizable monomer used for curing the unsaturated polyester resin described later is styrene, the chain transfer agent represented by the structural formula 1 is preferable, and the copolymerizable monomer is methyl methacrylate. In the case of such an acrylic type, the one represented by the structural formula 2 is preferable.

Next, the pregelling method of the present invention will be described. This pregelling method, that is, the curing temperature in the method of curing the pregelled composition of the unsaturated polyester resin, is the amount of ascorbic acid used, the type and amount of the organic peroxide used, and the type and the amount of chain transfer agent used. It is determined by the amount and the degree of cure of the pregelled material required. The curing temperature is such that the pregelled composition is (1) unsaturated polyester resin, (2) organic peroxide and (3).
When it is composed of ascorbic acid, it is usually 40 to 100 ° C.
And is preferably in the range of 50 to 95 ° C. At a high temperature of 100 ° C. or higher, the pre-gel state is completely cured, which is not preferable. On the other hand, pregelling is possible even at a temperature of 40 ° C. or lower, but it is unsuitable from the viewpoint of stability of the obtained pregelled product.

On the other hand, when the pregelled composition comprises (1) unsaturated polyester resin, (2) organic peroxide, (3) ascorbic acid and (4) chain transfer agent, it is usually at 0 to 100 ° C. And the range of 10 to 95 ° C. is preferable.
In this curing method, the pregelling reaction between ascorbic acid and the organic peroxide is rapidly carried out even at a very low temperature, and for example, it sufficiently proceeds even at around 0 ° C. However, at a high temperature of 100 ° C. or higher, the pre-gel state is completely cured, which is not preferable.

Similarly, the heat setting time for pregelation cannot be specified because it is governed by the environmental conditions, but from the industrial and economical viewpoint, it is 5 minutes to 1 minute.
It is within the range of 0 hours.

Next, the pregelled product of the present invention will be described. Pre-gelling is a state in which a certain degree of cure has been reached, and the degree of cure is determined according to the purpose of use. Here, the degree of cure is expressed as the degree of crosslinking with respect to the initial blending amount of the copolymerizable monomer as shown in the following formula 1.

[0031]

[Equation 1]

The pregelled product of the present invention has a curing degree of 5
It means about 70%. Since there is a preferable range of the curing degree depending on the purpose of use, the range of the curing degree cannot be unconditionally determined, but, for example, in the field of button molding, the curing degree is about 5 to 20%, and the thin film state is used for multiple purposes The curing degree when it is applied is about 70%. Since it is in the middle for other uses, the range of the degree of curing of the pregelled product of the present invention is preferably 5 to 70%.

Here, the pregelled composition comprises (1) unsaturated polyester resin, (2) organic peroxide and (3).
In the case of ascorbic acid, the degree of pregelation is largely controlled by environmental conditions such as the type and amount of ascorbic acid or organic peroxide, the reactivity of unsaturated polyester resin with ascorbic acid, and the pregelling temperature and heating time. To be done.
In addition, the degree of pregelation varies depending on the size and shape of the pregelation product or the pregelation method, for example, in the air bath, the water bath or the oil bath.

For example, when pregelation is carried out in a large block state in an air bath, the maximum exothermic temperature reached due to the accumulation of curing exotherm becomes high, and there is a tendency for complete curing without stopping in the pregelation state. . Therefore, in this case, a method of absorbing a heat generated by pregelation in a water bath or an oil bath in a thin film state with a thickness of about 10 mm or less or preferably with a radius of 30 mm or less, preferably 20 mm or less is desirable. Furthermore, in order to maintain the desired degree of cure, the pregelled product that has reached the prescribed degree of cure is kept at 20 ° C.
Hereinafter, it is desirably cooled to 10 ° C. or less. In this case, it is desirable to cool immediately after curing in order to set the curing degree of the pregelled product to a predetermined value.

In the present invention, a polymerization inhibitor can be used especially for the purpose of controlling the pregelling rate, the maximum exothermic temperature and the like. Examples of the inhibitor include quinones, pyrogallols, catechols and the like which are generally commonly used, and the compounding amount thereof is appropriately selected as necessary,
0 to 1 per 100 parts by weight of unsaturated polyester resin
Parts by weight are preferred.

It is also possible to use cobalt naphthenate, N, N-dimethylaniline or the like as an accelerator for room temperature curing of the unsaturated polyester resin. In particular, cobalt naphthenate accelerates the pregelation rate with a very small amount, so the amount of addition is 0.001 to 6% cobalt naphthenate per 100 weight of unsaturated polyester resin.
0.1 part by weight is preferable, and if the amount added is more than that, the degree of curing becomes too high to obtain a preferable pregelled product.

In the pregelling method of the present invention, a reinforcing agent such as roving cloth, chopped strand or chopped strand mat, glass fiber or carbon fiber, calcium carbonate, clay, etc. for the purpose of improving the strength of the molded article. A filler such as aluminum hydroxide and the like, and if necessary, a toner or a pigment as a colorant can be used. Further, a thermoplastic resin, a low shrinkage additive, and a release agent such as zinc stearate may be used depending on the purpose.

In the present invention, it is presumed that ascorbic acid can pre-gelate the unsaturated polyester resin in a short time as described above, and at the same time, the chain transfer agent can maintain the pre-gelled product stably for a long time. Therefore, the pregelling of the unsaturated polyester resin can be performed quickly, the stability of the pregelled product is good, and the degree of pregelation can be controlled by adjusting the compounding amounts of ascorbic acid and the chain transfer agent relatively. It can be easily adjusted.

[0039]

EXAMPLES Next, the present invention will be described more specifically by way of Examples and Comparative Examples. In each example, the number of parts means part by weight.

In the examples and comparative examples of the present invention, three types of commercially available unsaturated polyester resins (A, B, C) were used. The copolymerizable monomer in these three types of unsaturated polyester resins is a styrene monomer. Resin A is an orthophthalic acid type unsaturated polyester resin (Nippon Shokubai Co., Ltd.)
Made by trade name: Epolak G-110AL), and the styrene content is 30.1%. Resin B is an orthophthalic acid type unsaturated polyester resin (Dainippon Ink and Chemicals, Inc.)
Manufactured by M-311) with a styrene content of 42.
0%, and the resin C is an isophthalic acid unsaturated polyester resin (manufactured by Hitachi Chemical Co., Ltd., trade name: PS-3).
715), the styrene content is 43.9%.

The degree of cure in the present invention is expressed as the degree of copolymerization with respect to the initial blending amount of styrene monomer as described above, and the amount of this styrene monomer was measured by gas chromatography.

Ascorbic acid (L-ascorbic acid) was used as a 10% solution in triethyl phosphate, which is abbreviated as A-10, and a 20% aqueous solution of ascorbic acid is abbreviated as A-20.

The curing catalyst is abbreviated as follows. CHP 80% cumene hydroperoxide (Nippon Yushi Co., Ltd., trade name Parkmill H) MEKP 55% dimethyl phthalate solution of methyl ethyl ketone peroxide (Nippon Yushi Co., Ltd., trade name Permek N) TCP di (tertiary butyl) Cyclohexyl) Peroxydicarbonate (Nippon Yushi Co., Ltd., trade name Perloyl TCP) BPO Dibenzoyl peroxide 50% dicyclohexyl phthalate diluted product (Nippon Yushi Co., Ltd., trade name Niper FF) TBPO Tertiary Butyl Peroxy Ethyl hexanoate (Nippon Oil & Fats Co., Ltd., trade name Perbutyl O) TBPB tertiary butyl peroxybenzoate (Nippon Oil & Fats Co., Ltd., trade name Perbutyl Z) TBIN tertiary butyl peroxy 3,5,5-trimethyl Hexanoate (NOF Co., Ltd., trade name Perbutyl 355) DCP dicumyl peroxide (Nippon Yushi Co., Ltd.,
Trade name Park Mill D) Furthermore, 2,4-phenyl 4-methyl 1-pentene (manufactured by NOF CORPORATION, trade name: NOFMER MSD) as a chain transfer agent and terpinolene (manufactured by NOF CORPORATION), trade name: Nofmer TP) was used and is abbreviated as MSD and TP respectively. (Example 1) An unsaturated polyester prepared by mixing 100 g of an orthophthalic acid-based unsaturated polyester resin (A), 1.0 part of TBIN, 0.2 part of A-10 and 0.5 part of MSD in a 200 ml beaker. A pregelled composition of the resin was obtained. Then, according to JIS-K-6901, φ1
A pregelled product was obtained by heating in an 8 mm test tube in an oil bath at 50 ° C. for 30 minutes. When the pregelled product was cooled and the cured product was measured, it was 24%, and it was a flexible pregelled product that could be depressed when pressed. (Example 2) A pregelled composition of an unsaturated polyester resin was produced in the same manner as in Example 1 except that 2 parts of MSD was blended, and then a pregelled product was obtained. The degree of cure of this pregelled product was 12%, and it was a sticky pregelled product.

The pregelled product obtained here was wrapped in cellophane paper, left at room temperature of about 20 ° C. for 3 days and then heated again in an oil bath at 120 ° C., and the maximum exothermic temperature reached 131 ° C. after about 3 minutes. The hardness of the cured product obtained was 97%. It was found that the reheating causes the curing reaction to occur again and the unsaturated polyester resin can be completely cured. (Example 3) 1 part of TBPO, A-1 instead of TBIN
A pregelled composition was produced according to Example 1 except that 1 part of 0 and 0.5 part of MSD were blended, and then a pregelled product was obtained. The degree of cure of this pregelled product was 48%. Further, this pregelled product was wrapped in cellophane paper and left in an air bath at 20 ° C. for 1 week. The degree of cure after one week was 52%, and it was found that there was little change in the degree of cure over time. (Example 4) 1 part of TBPO, 3 parts of A-20 and M
A pregelled composition and a pregelled product of an unsaturated polyester resin were obtained in the same manner as in Example 1 except that 0.5 part of SD was blended. The degree of cure of this pregelled product was 64%. Further, according to Example 3, this pregelled product was added to 2
The curing degree after standing for 1 week at 0 ° C. was 69%. (Comparative Example 1) 1 part of TBPO, 1 part of A-10 and M
A pregelled composition and a pregelled product of an unsaturated polyester resin were obtained in the same manner as in Example 1 except that SD was not added. The degree of cure of this pregelled product was 70%.
This pregelled product was left at 20 ° C. according to Example 3. The degree of cure after one week was 82%, and it was found that the change in the degree of cure with time was large when the chain transfer agent was not added. Example 5 In a 200 ml beaker, 100 g of an orthophthalic acid-based unsaturated polyester resin (B) and 1.
0 part, 1.25 parts of A-20 and 0.5 part of MSD were blended to obtain a pregelled composition. Then, JIS-K
A pregelled product was obtained by heating in an oil bath at 80 ° C for 60 minutes according to -6901. When the pregelled product was cooled and the curing degree was measured, it was 53%, and it was a flexible pregelled product. (Comparative Example 2) A pregelled composition and a pregelled product of an unsaturated polyester resin were obtained in the same manner as in Example 5 except that MSD was not added. Curing degree of pre-gelated product is 75%
It was a cured product with almost no flexibility. (Comparative Example 3) A pregelled composition was obtained in the same manner as in Example 5 except that A-20 was not added. Then 3 at 80 ℃
It was heated for hours but remained liquid. It has been found that DCP is a high temperature curing catalyst and cannot cure an unsaturated polyester resin at 80 ° C. in the absence of A-20. Comparative Example 4 The pregelled composition of unsaturated polyester resin according to Example 5 was heated in an oil bath at 110 ° C. for 20 minutes according to JIS-K-6901 to obtain a pregelled product. The degree of cure of this pregelled product was 93%, and it was a cured product in which curing was almost completely completed. Example 6 A pregelled composition was obtained in the same manner as in Example 5 except that 1 part of CHP, 0.5 part of A-10 and 0.3 part of TP were added instead of MSD. Then 25 ℃
It was left for 90 minutes to obtain a pregelled product. The pregelled product was a soft cured product having a little tackiness and the curing degree was 19%. (Example 7) A pregelled composition was obtained in the same manner as in Example 6 except that 0.3 part of 6% cobalt naphthenate was added.
Then, it was heated at 25 ° C. for 60 minutes to obtain a pregelled product.
The degree of cure of this pregelled product was 97%. It was found that the addition of 6% cobalt naphthenate resulted in a very high degree of cure. (Example 8) A pregelled composition was obtained in the same manner as in Example 6 except that 5 parts of TP was blended. Then, it was left at 25 ° C. for 6 hours to obtain a pregelled product. The degree of cure of this pregelled product was 8%. (Comparative Example 5) A pregelled composition was obtained according to Example 6 except that TP was not added. Then, it was left at 25 ° C. for 60 minutes to obtain a pregelled product. The degree of cure of this pregelled product was 63%. Further, the degree of cure after leaving at 20 ° C. for 3 days was 83%, and it was found that the degree of cure increased slightly with the passage of time. (Example 9) 1.5 parts of MEKP, 0.5 of A-20
Parts, 0.05 parts of MSD and 0.45 parts of TP were blended to obtain a pregelled composition according to Example 5.
Then, it was left at 25 ° C. for 3 hours to obtain a pregelled product.
The degree of cure of this pregelled product was 7%. Example 10 0.45 parts of MSD and 0.0 of TP
A pregelled composition was obtained in the same manner as in Example 9 except that 5 parts were blended. Then, it was left at 25 ° C. for 3 hours to obtain a pregelled product. The degree of cure of this pregelled product was 10%. (Example 11) Isophthalic acid-based unsaturated polyester resin (C), 0.3 part of TCP, and T in a 200 ml beaker
1 part of BPB, 0.2 part of A-10 and 1 part of MSD were blended to obtain a pregelled composition of an unsaturated polyester resin. Then, a copper wire having a diameter of about 0.5 mm was injected as a spacer into a sheet having a thickness of about 0.4 mm in the two glass plates. This was heated at 90 ° C. for 10 minutes to obtain a pregelled product. The curing degree of this pregelled product is 52%, and it is 30 ° C.
The curing degree after 1 week was 56%. (Example 12) Example 1 except that 2 parts of MSD were blended.
According to 2, a pregelled composition of unsaturated polyester resin was obtained. Then, it was heated at 90 ° C. for 10 minutes to obtain a pregelled product. The curing degree of this pregelled product was 45%, and the curing degree after 1 week at 30 ° C. was 48%. (Example 13) 0.3 part of BPO, 0.7 part of DCP,
A pregelled composition of an unsaturated polyester resin was obtained in the same manner as in Example 11 except that 0.2 part of A-10 and 0.5 part of MSD were blended. Then, it was heated at 80 ° C. for 30 minutes to obtain a pregelled product. The degree of cure of this pregelled product was 65%. (Comparative Example 6) An unsaturated polyester resin composition was obtained in the same manner as in Example 13 except that A-10 was not added. Then 80
It was heated at 0 ° C. for 30 minutes, but remained in a liquid state.

Next, in Examples 14 to 27 and Comparative Example 11 shown below, three types of commercially available unsaturated polyester resins (A, C, D) were used. The copolymerizable monomer in these three types of unsaturated polyester resins is a styrene monomer. Resin C is an isophthalic acid-based unsaturated polyester resin (Hitachi Chemical Co., Ltd., trade name: PS-3715),
The styrene content was 43.9%. Resin A is an orthophthalic acid type unsaturated polyester resin (manufactured by Nippon Shokubai Co., Ltd.,
Product name: Epolak G-110AL), and the styrene content is 30.1%. Resin D is an isophthalic acid type unsaturated polyester resin (manufactured by Nippon Yupica Co., Ltd., trade name: Yupica 7500), and the styrene content is 40.8%. Example 14 In a 200 ml beaker, 100 g of isophthalic acid-based unsaturated polyester resin (C), 1.0 part of TBPB as a curing catalyst and A-1 as a pregelling agent.
0.2 part of 0 was blended to obtain a pregelled composition of unsaturated polyester resin. Then, it was heated in a φ18 mm glass test tube in an oil bath at 60 ° C. for 30 minutes to obtain a pregelled product. When this pregelled product was cooled to 20 ° C. and the curing degree was measured, it was 48%, and it was a flexible pregelled product that could be depressed when pressed. (Example 15) TB as a curing catalyst instead of TBPB
A pregelled composition was obtained in the same manner as in Example 14 except that 1 part of IN was blended, and then a pregelled product was obtained. The degree of cure of this pregelled product was 37%. (Comparative Example 7) A pregelled composition and its pregelled product were obtained in the same manner as in Example 15, except that the pregelling condition was heating at 110 ° C for 5 minutes. The degree of cure of this pregelled product was 98%. Since the pregelling condition was a high temperature of 110 ° C., it is considered that complete curing did not occur without stopping in the pregelled state. (Comparative Example 8) Heat treatment was carried out in the same manner as in Example 14 except that the curing catalyst TBPB and the pregelling agent A-10 were not added and the mixture was heated at 110 ° C for 30 minutes. The resin in the test tube did not gel and remained in a liquid state. (Example 16) The pregelled composition of Example 14 was injected into two glass plates into a sheet of about 0.4 mm thickness using a copper wire having a diameter of about 0.5 mm as a spacer. 30 at 60 ℃
After heating for a minute, it was cooled to 20 ° C. or lower to obtain a pregelled product.
This pregelled product had a curing degree of 45% and was in the form of a soft film. Example 17 A pregelled composition and its pregelled product were obtained in the same manner as in Example 16 except that 0.8 part of TBPB and 0.2 part of TCP were blended as a curing catalyst. This pregelled product had a curing degree of 57% and was flexible. It was found that the degree of cure after storing this pregelled product at 20 ° C. for 2 weeks was 61%, and the change with time of the degree of cure was slight. (Examples 18 to 20) A pregelling composition was prepared according to Example 14 except that 1.0 part of TBPO and 0.2 part of A-10 as a pregelling agent were added instead of TBPB as a curing catalyst. Obtained. This composition was formed into a film according to Example 16, and the heating conditions were changed to obtain a pregelled product.
Table 1 below shows the relationship between the heating conditions for pregelation and the degree of curing.

[0046]

[Table 1]

As shown in Table 1, Examples 18 and 1
The pregelled product of Example 9 was flexible, while the pregelled product of Example 20 was a slightly hard pregelled product that was broken when bent. It was found that TBPO is a curing catalyst that decomposes at a slightly low temperature, and the curing degree becomes too high under the heating condition of 70 ° C. for 30 minutes. Therefore, it is understood that the degree of curing of the pregelled product is preferably 70% or less. (Example 21) Except that 1.0 part of DCP and 1.0 part of A-10 as a pregelling agent were compounded as a curing catalyst.
According to Example 16, a pregelled composition was obtained. This composition was heated at 90 ° C. for 10 minutes and then cooled to obtain a pregelled product. The degree of cure of the pregelled product after cooling was 66%.
The degree of cure after leaving this pregelled product at 20 ° C. for 2 weeks was 70%, and only a slight increase in the degree of cure was observed. (Comparative Example 9) A pregelled composition was obtained in the same manner as in Example 21 except that 0.2 part of the pregelator A-10 was blended. This composition was heated at 110 ° C. for 5 minutes and then cooled to obtain a cured product. The degree of cure of this cured product was 96%. In this comparative example, since the pregelling condition was a high temperature of 110 ° C., it is considered that complete curing was achieved without stopping in the pregel state. (Comparative Example 10) An unsaturated polyester resin composition was obtained in the same manner as in Example 21, except that the pregelator A-10 was not added. The composition was heated at 80 ° C. for 3 hours,
It remained liquid. It has been found that DCP is a high temperature curing catalyst and cannot cure an unsaturated polyester resin at 80 ° C. in the absence of A-10. (Comparative Example 11) An unsaturated polyester resin composition was obtained in the same manner as in Example 21 except that DCP as a curing catalyst was not added. The composition was heated at 80 ° C. for 3 hours,
As in Comparative Example 10, it remained in a liquid state. It has been found that unsaturated polyester resins cannot be pregelled and cured in the absence of a curing catalyst. Example 22 In a 200 ml beaker, 100 g of an orthophthalic acid-based unsaturated polyester resin (A), 0.8 part of DCP and 0.4 part of BPO as a curing catalyst, and 0.2 of A-10 as a pregelling agent. Parts were blended to obtain a pregelled composition. Then, according to Example 16, heating was performed at 80 ° C. for 20 minutes to obtain a film-form pregelled product having a thickness of about 0.4 mm. The degree of cure of the cooled pregelled product was 64%. (Example 23) 0.8 part of DCP and ME as a curing catalyst
0.2 part of KP and 0.2 of pregelling agent A-10
A pregelled composition and a pregelled product were obtained in the same manner as in Example 22 except that the parts were mixed. The degree of cure of this pregelled product was 59%. (Example 24) 0.7 part of CHP and TB as a curing catalyst
0.3 part of PO and 0.2 of A-10 of pregelling agent
Parts were blended to obtain a pregelled composition. According to Example 22, this composition was heated at 40 ° C. for 1 hour and then cooled to obtain a pregelled product. The degree of cure of this pregelled product was 30%. (Examples 25 to 27) In a 200 ml beaker, 100 g of an isophthalic acid-based unsaturated polyester resin (D), 1.0 part of CHP as a curing catalyst, and a pregelling composition in which the kind and blending amount of the pregelling agent were changed. Obtained. Then φ1
A pregelled product was obtained by heating in an 8 mm glass test tube at 50 ° C. for 30 minutes. Table 2 shows the composition of the pregelled composition and the curing degree of the cooled pregelled product.

[0048]

[Table 2]

As shown in Table 2, the pregelled product of each example has an appropriate degree of curing. Comparative Example 12 A pregelled composition was obtained according to Example 25 except that 1.0 part of CHP and 1.5 parts of pregelling agent A-20 were used as the curing catalyst. 3 of this composition
After heating at 0 ° C for 1 hour and cooling to 20 ° C, a pregelled product was obtained. The degree of cure of this pregelled product was 23%. Furthermore, after the pregelled product was stored at 20 ° C. for 2 weeks, the curing degree was measured and found to be 72%. In this comparative example, 3
Since it was necessary to pregelate at a temperature as low as 0 ° C., it is considered that the storage stability at 20 ° C. deteriorated as a result of increasing the amount of the pregelling agent compounded.

The technical ideas other than the claims understood from the above embodiment will be described below together with their effects. (1) The pregelled composition of unsaturated polyester resin according to claim 1, wherein the organic peroxide is hydroperoxides, peroxyesters, peroxyketals or dialkylperoxides. With this configuration, the pregelled composition can be cured to easily and quickly obtain a pregelled product having a desired degree of curing. (2) The organic peroxide comprises 50% by weight or more of hydroperoxides, peroxyesters, peroxyketals or dialkylperoxides and 50% by weight or less of diacyl peroxides, dialkylperoxydicarbonates or ketone peroxides. The pregelled composition of the unsaturated polyester resin according to claim 1, which is used in combination. With this configuration, the curing rate of the pregelled composition can be adjusted to obtain a pregelled product having a desired degree of curing. (3) The pregelling composition of an unsaturated polyester resin according to claim 1 or 4, wherein the ascorbic acid is an organic solvent solution or an aqueous solution. According to this structure, pregelation can be performed smoothly and promptly. (4) The pregelled composition of an unsaturated polyester resin according to claim 4, wherein the compounding amount of ascorbic acid is 0.001 to 1.0 part by weight based on 100 parts by weight of the unsaturated polyester resin. With this configuration, pregelling of the unsaturated polyester resin can be promoted. (5) Unsaturated polyester resin 1 containing a chain transfer agent
The pregelled composition of the unsaturated polyester resin according to claim 4, which is 0.01 to 10 parts by weight with respect to 00 parts by weight. With this configuration, the pregelled product can be stably retained for a long period of time.

[0051]

As described above in detail, according to the invention of the pregelled composition of unsaturated polyester resin described in claims 1 and 4 to 6, pregelation can be easily and quickly performed. At the same time, a stable pregelled product can be obtained.

According to the invention of the pregelling method described in claims 2 and 7, the unsaturated polyester resin can be rapidly pregelled at a low temperature of 100 ° C. or lower, and the degree of pregelling can be controlled. It can be easily adjusted.

Furthermore, according to the invention of the pregelled product according to claims 3 and 8, the pregelled product of the unsaturated polyester resin is excellent in storage stability in the pregelled state.

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Claims (8)

[Claims] 1. (1) Unsaturated polyester resin, (2)
A pregelled composition of an unsaturated polyester resin comprising an organic peroxide and (3) ascorbic acid. 2. (1) Unsaturated polyester resin, (2)
A method for pregelling an unsaturated polyester resin, which comprises heating a pregelling composition comprising an organic peroxide and (3) ascorbic acid at 40 to 100 ° C and then cooling it to 20 ° C or lower. 3. (1) Unsaturated polyester resin, (2)
A pregelled product of an unsaturated polyester resin obtained by heating a pregelled composition comprising an organic peroxide and (3) ascorbic acid at 40 to 100 ° C and then cooled to 20 ° C or lower. 4. (1) Unsaturated polyester resin, (2)
A pregelled composition of an unsaturated polyester resin comprising an organic peroxide, (3) ascorbic acid and (4) chain transfer agent. 5. The pregelled composition of an unsaturated polyester resin according to claim 4, wherein the chain transfer agent is a compound represented by the following structural formula 1. Embedded image 6. The unsaturated polyester resin pregel composition according to claim 4, wherein the chain transfer agent is a compound represented by the following structural formula 2. Embedded image 7. A pregelling method in which the pregelled composition of the unsaturated polyester resin according to claim 4 is heated at a temperature of 100 ° C. or lower. 8. A pregelled product of an unsaturated polyester resin obtained by heating the pregelled composition of the unsaturated polyester resin according to claim 4 at a temperature of 100 ° C. or lower.