JPH08104722A - Resin concrete composition - Google Patents

Abstract

PURPOSE: To provide a resin concrete composition excellent in dispersion stability and reduced in shrinkable in ordinary temperature molding. CONSTITUTION: This composition comprises an unsaturated polyester, an ethylenically unsaturated monomer copolymerizable therewith, a shrinkable lowering agent, a curing agent and a filler. The shrinkable lowering agent contains 3-18 pts.wt., in total, per 100 pts.wt. in total of the polyester and the unsaturated monomer, A-B type block copolymer composed of a polymer block A comprising vinyl acetate and a polymer block B comprising styrene and polystyrene. The proportion of polymer block A in the A-B block copolymer is 2-50wt.%, and that of polymer block B is 98-5wt.%. The rate of the polymer block made from vinyl acetate is 0.01-0.19wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin concrete composition, and more particularly to a resin concrete composition excellent in dispersion stability and low shrinkage at room temperature molding.

[0002]

2. Description of the Related Art Instead of Portland cement, a curable resin such as unsaturated polyester resin is used as a binder,
Resin concrete, which is mixed with an inorganic filler such as calcium carbonate or an aggregate whose main component is sand or gravel, is more water resistant, acid resistant, chemical resistant, electrical insulating and harder than cement concrete. It is widely used as a civil engineering / construction material such as manholes and road signs because of its excellent properties, light weight and high strength. In addition, recently, it is also used as a material for forming an intermediate layer of sewage / agricultural water pipes and cable protection pipes, and the required characteristics are increasing more and more.

However, the unsaturated polyester resin, which is a binder for resin concrete, generally has a viscosity of 6 to 10 when cured.
%, There is a problem that cracks and distortions occur in the molded product and the dimensional accuracy is lacking.

For the purpose of improving these problems, a method has been proposed in which various thermoplastic resins are blended with unsaturated polyester resins as a low-shrinking agent. Of the thermoplastic resins, polystyrene is the most commonly used because it is cheap, but its compatibility with unsaturated polyester resins is low,
Since there is a protrusion to the surface during the curing process, there is a problem that tackiness occurs on the surface of the molded product, mold stains occur, and workability related to this deteriorates.

Therefore, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 60-991.
In JP-A-15, in order to improve the compatibility of polystyrene with an unsaturated polyester resin, from polystyrene, a polymer portion having vinyl acetate as a dispersion stabilizer as a dispersion stabilizer and a polymer portion having styrene as a constitutional unit are used. We have proposed a method of using block copolymers. Further, in JP-A-57-80413, a block copolymer composed of a polymer portion having vinyl acetate as a constituent unit and a polymer portion having styrene as a constituent unit, which has excellent compatibility with an unsaturated polyester resin. We proposed a method of blending coalesced as a low shrinkage agent.

However, these block copolymers have an excessively high compatibility with the low-reactivity unsaturated polyester resin generally used in room-temperature molding of resin concrete compositions and the low-shrinking agent, and when they are cured. Since it did not cause phase separation, it had no effect as a low-shrinking agent.

Furthermore, the inventors of the present invention have disclosed, as low-shrinking agents for room-temperature molding, Japanese Patent Publication Nos. 63-30956 and 63-63.
No. 40447, Japanese Patent Publication No. 4-7390 and Japanese Patent Publication No. 4-7391, a polymer portion having an alkyl ester of acrylic acid or methacrylic acid as a constitutional unit and a polymer portion having styrene as a constitutional unit. We proposed a block copolymer consisting of In addition, JP-A-4-3
In Japanese Patent No. 11761, a block copolymer composed of a polymer portion having a non-conjugated ethylenically unsaturated carboxylic acid such as vinyl acetate and crotonic acid as a constitutional unit and a polymer portion having styrene as a constitutional unit was proposed. .

However, the former low-shrinking agent, like polystyrene, has a low compatibility with the unsaturated polyester resin and has various problems related thereto. The latter low-shrinking agent has a too low proportion of the polymer portion having vinyl acetate as a structural unit in the low-shrinking agent. It did not work effectively with unsaturated polyester resins.

[0009]

As described above, the low-reactivity unsaturated polyester resin generally used in the conventional room temperature molding of resin concrete compositions has the following problems.
There are no low-shrinking agents that are excellent in both compatibility and low shrinkage. Therefore, it is difficult to obtain resin concrete having satisfactory dimensional accuracy and surface property.

The present invention has been made by paying attention to such problems of the prior art. The purpose is to
An object of the present invention is to provide a resin concrete composition which is excellent in dispersion stability and low shrinkage at room temperature molding.

[0011]

The present inventors have completed the present invention as a result of intensive studies to achieve the above object.
That is, the resin concrete composition of the present invention comprises, as a low-shrinking agent, a polymer portion A containing vinyl acetate as a constituent unit.
And a polymer portion B having styrene as a constituent unit
-A B-type block copolymer and polystyrene are included in a total amount of 3 to 18 parts by weight based on 100 parts by weight of the total weight of the unsaturated polyester and the ethylenically unsaturated monomer, and the A-
The ratio of the polymer portion A in the B-type block copolymer is 2 to 5
0% by weight, the proportion of the polymer portion B is 98 to 50% by weight, and the proportion of the polymer portion having vinyl acetate as a constituent unit in the low-shrinking agent is 0.01 to 0.19% by weight. Is. The resin concrete composition in the present invention includes a resin mortar composition.

The present invention will be described in detail below.
The unsaturated polyester in the present invention is obtained by polycondensation by a conventional method using a mixture of an α, β-unsaturated dibasic acid or its anhydride and a saturated dibasic acid or its anhydride, and a polyhydric alcohol. Unsaturated polyester. The composition ratio of each component is not particularly limited, and any of low-reactivity unsaturated polyester to high-reactivity unsaturated polyester can be used, but in room-temperature molding of a resin concrete composition, α, β- A low-reactivity unsaturated polyester produced from a mixture of unsaturated dibasic acid or its anhydride (15 to 50 mol%) and saturated dibasic acid or its anhydride (85 to 50 mol%) and a polyhydric alcohol is preferable. used.

Examples of the α, β-unsaturated dibasic acid or its anhydride include maleic acid or its anhydride, fumaric acid, mesaconic acid, tetraconic acid, itaconic acid or alkyl esters thereof. As the saturated dibasic acid or its anhydride, for example, phthalic anhydride, orthophthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, halogenated phthalic anhydride,
Examples thereof include adipic acid, sebacic acid, het acid, succinic acid, and alkyl esters thereof. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol,
Butylene glycol, neopentyl glycol, 1,3
-Butanediol, 1,4-butanediol, 1,6-
Hexanediol, cyclohexanedimethanol and other diols, hydrogenated bisphenol A, bisphenol A
In addition to glycols such as propylene oxide added to
Examples include triols such as trimethylolpropane.

The ethylenically unsaturated monomer copolymerizable with the unsaturated polyester in the present invention includes styrene derivatives such as styrene, vinyltoluene, α-methylstyrene, t-butylstyrene and chlorostyrene, acrylic acid or Examples thereof include alkyl esters of methacrylic acid, vinyl acetate and the like, which are selected from one kind or two or more kinds of these groups, and styrene is particularly preferable.

The preferred ratio of the unsaturated polyester to the ethylenically unsaturated monomer used is 30/70 to 70/3.
0% by weight. When the unsaturated polyester content is less than 30% by weight and the ethylenically unsaturated monomer content exceeds 70% by weight, the strength of the resin concrete obtained from this tends to decrease, and the unsaturated polyester content is less than 70% by weight. If the amount exceeds the above range and the amount of the ethylenically unsaturated monomer is less than 30% by weight, the viscosity of the resin concrete composition obtained from this tends to be high and the workability tends to deteriorate.

The low-shrinking agent in the present invention is polystyrene, and an AB type block copolymer comprising a polymer portion A having vinyl acetate as a constitutional unit and a polymer portion B having styrene as a constitutional unit. The proportion of the polymer portion having vinyl acetate as a constituent unit in the low-shrinking agent is 0.01 to
The essential requirement is 0.19% by weight. When the proportion of the polymer portion having vinyl acetate as a constitutional unit in the low-shrinking agent is less than 0.01% by weight, the low-shrinking agent and the unsaturated polyester resin have low compatibility and the low-shrinking agent is cured. Since it floats to the surface in the process, tackiness is generated on the surface of the molded product, and workability tends to deteriorate.
If it exceeds 0.19% by weight, the compatibility of the low-reactivity unsaturated polyester resin generally used in room-temperature molding of the resin concrete composition with the low-shrinking agent becomes too high, resulting in phase separation during curing. It does not function as a low-shrinking agent because it does not occur.

The combined ratio of the A-B type block copolymer consisting of the polymer portion A having vinyl acetate as a constitutional unit and the polymer portion B having styrene as a constitutional unit and polystyrene is in the low shrinkage agent. The proportion of the polymer portion having vinyl acetate as a constitutional unit in the above is determined to be within the above range.

As the polystyrene, any of commercial products such as general-purpose grade, high-fluidity grade and impact-resistant grade can be used, but the average molecular weight thereof is preferably
Number average molecular weight in terms of polystyrene by gel permeation chromatography 10,000 to 300,
000, and more preferably 30,000 to 20
It is 0000. When it is less than 10,000, the molding shrinkage of the resin concrete composition obtained from this is large, and cracks are likely to occur. 300,0
If it exceeds 00, the viscosity of the resin concrete composition obtained from this tends to be high, and the workability tends to deteriorate.

Further, in the AB type block copolymer consisting of the polymer portion A having vinyl acetate as a constitutional unit and the polymer portion B having styrene as a constitutional unit, the polymer portion A is
Is 2 to 50% by weight, preferably 5 to 30% by weight, and the proportion of the polymer portion B is 98 to 50% by weight, preferably 95 to 70% by weight. The proportion of polymer part A is 2
If the amount is less than 10% by weight, the ratio of the polymer portion A having vinyl acetate as a constitutional unit in the AB block copolymer is extremely small, so that the effect as a dispersion stabilizer of the block copolymer is obtained. As a result, the compatibility of the low-shrinking agent and the unsaturated polyester resin is low, and the low-shrinking agent floats out on the surface during the curing process, which causes tackiness on the surface of the molded product,
Workability tends to deteriorate.

When the proportion of the polymer portion A exceeds 50% by weight, the proportion of the polymer portion having vinyl acetate as a constitutional unit in the low shrinkage agent is 0.01 to 0.19% by weight. The amount of the AB block copolymer to be blended is extremely small, resulting in low compatibility between the low-shrinking agent and the unsaturated polyester resin, and the low-shrinking agent is transferred to the surface during the curing process. Since it floats, tackiness is generated on the surface of the molded product, and workability tends to deteriorate.

In the present invention, the proportion of the polymer portion having vinyl acetate as a constituent unit in the low-shrinking agent may be set within the above-mentioned predetermined range. Therefore, the proportion of the polymer portion A in the AB block copolymer may be reduced, the proportion of the block copolymer in the low-shrinking agent may be increased, and the proportion of polystyrene may be relatively reduced.

The A-B type block copolymer is prepared by using a polymeric peroxide (Japanese Patent Laid-Open No. 53-1 / 1993) as a polymerization initiator.
In accordance with a known production process (described in JP-B No. 49918) (described in JP-B-60-3327), it can be easily produced by any polymerization method such as bulk polymerization method, suspension polymerization method or emulsion polymerization method. From the industrial viewpoint, the suspension polymerization method is most preferable. At this time, the polymer having a peroxy bond in the molecule generated by the first stage polymerization reaction of vinyl acetate may be taken out from the reaction system as an intermediate and used as a raw material for the next block copolymerization, or may be taken out from the reaction system. It is also possible to carry out block copolymerization successively without the use.

Examples of the polymeric peroxide include those represented by the following chemical formulas (1) and (2), and one or more selected from these groups are used.

[0024]

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[0025]

Embedded image

The amount of the polymeric peroxide used is preferably 0.1 to 10 parts by weight based on 100 parts by weight of vinyl acetate. The polymerization temperature is 40 to 80 ° C. for the first stage polymerization reaction and 60 for the second stage polymerization reaction.
It is preferable that the polymerization temperature is -100 ° C and the polymerization temperature in the second-stage polymerization reaction is higher than the polymerization temperature in the first-stage polymerization reaction. The polymerization time is preferably 1 to 3 hours in the first stage polymerization reaction and 3 to 10 hours in the second stage polymerization reaction.

By the way, a homopolymer of vinyl acetate and styrene is produced as a by-product during the production of the A-B type block copolymer. According to the above production method, the net A content in the total polymer is obtained.
Since the ratio of the -B type block copolymer, that is, the block ratio is as high as 80% or more, when it is used as a low shrinkage agent for the unsaturated polyester resin in the present invention, it can be used as it is without any particular purification. Therefore, in the AB block copolymer of the present invention, the polymer portion A having vinyl acetate as a constitutional unit is a vinyl acetate homopolymer and the polymer portion B having styrene as a constitutional unit is a styrene homopolymer. It shall include each combination.

The compounding amount of the low-shrinking agent is 3 to 18 parts by weight, preferably 6 to 14 parts by weight, based on 100 parts by weight of the total weight of the unsaturated polyester and the ethylenically unsaturated monomer. . When the amount is less than 3 parts by weight, the molding shrinkage of the resin concrete composition obtained from this becomes large,
Cracks are likely to occur. If it exceeds 18 parts by weight, the viscosity of the resin concrete composition obtained from this tends to be high and the workability tends to deteriorate.

Examples of the curing agent in the present invention include ketone peroxide, diacyl peroxide, peroxy ester, peroxy ketal, hydroperoxide,
Examples thereof include known curing catalysts used for curing unsaturated polyester resins such as dialkyl peroxide.
Depending on the desired molding temperature and molding time, it is selected from one or two or more of these groups. Particularly in room temperature molding, organometals such as cobalt naphthenate and cobalt octenoate, aromatic or aliphatic amines such as N, N-dimethylaniline, N-ethylmetatoluidine and triethanolamine, and β-such as acetylacetone. It is general to use a curing accelerator such as a diketone together with the curing agent.
Examples of the most common combination of a curing agent and a curing accelerator include methyl ethyl ketone peroxide / cobalt naphthenate and benzoyl peroxide / N, N-dimethylaniline.

Therefore, the curing agent of the present invention also includes a curing accelerator. The compounding amount of the curing agent other than the curing accelerator is not particularly limited, but preferably 0.5 to 3 parts by weight based on 100 parts by weight of the total weight of the unsaturated polyester, the ethylenically unsaturated monomer and the low shrinkage agent. Is. If the amount is less than 0.5 part by weight, the curing rate of the resin concrete composition obtained from this will be slow and the productivity will be poor. If it exceeds 3 parts by weight, the curing agent will be wasted and the economy will be lost. Further, the curing accelerator is appropriately used in combination depending on the molding conditions, but especially in the case of room temperature molding, the compounding amount thereof is preferably the total weight of the unsaturated polyester, the ethylenically unsaturated monomer and the low-shrinking agent. 0.05 to 100 parts by weight
~ 1 part by weight. If the amount is less than 0.05 parts by weight, no hardening accelerating effect is observed, so that the hardening rate of the resin concrete composition obtained from this is slow and productivity is deteriorated. If the amount exceeds 1 part by weight, the curing accelerator is wasted and the economy is lost.

Examples of the filler in the present invention include inorganic fine powders such as calcium carbonate, glass powder, aluminum hydroxide, talc, clay, kaolin, stone powder and wood powder, and inorganic substances such as sand, gravel, crushed stone, silica stone and cold water stone. Granules can be mentioned, and they are selected from one or more of these groups. The compounding amount of the filler is not particularly limited, but is preferably 30 to 1000 parts by weight, more preferably 50 to 800 parts by weight based on 100 parts by weight of the total weight of the unsaturated polyester, the ethylenically unsaturated monomer and the low-shrinking agent. Parts by weight. 30
When the amount is less than the weight part, the molding shrinkage of the resin concrete composition obtained from this becomes large, cracks are easily generated, and the economical efficiency is lost. If it exceeds 1000 parts by weight, the strength of the resin concrete obtained from this tends to decrease, and the resin concrete tends to become brittle.

Further, in the resin concrete composition of the present invention, an inhibitor, a curing modifier, a thickener, an internal mold release agent, a colorant, and a reinforcing material which are generally blended with the unsaturated polyester resin composition are added. If necessary, an appropriate amount can be blended. As the inhibitor, quinones such as hydroquinone and 1,4-benzoquinone, and catechols such as 4-t-butylcatechol, as the curing regulator, ascorbic acid and α-methylstyrene dimer, and as the thickener, ,
Internal oxides or hydroxides of alkaline earth metals such as magnesium oxide, calcium oxide, magnesium hydroxide and calcium hydroxide are stearic acid,
Zinc stearate, calcium stearate, etc., as a colorant, an organic dye or an inorganic pigment, as a reinforcing material, glass fiber, inorganic fiber such as carbon fiber, aramid fiber,
Organic fibers such as polyester fibers can be mentioned.

The resin concrete composition of the present invention is generally cast at a temperature of 10 to 40 ° C. after casting in a mold such as a mold, a resin mold or a wooden mold.
Molded at room temperature at the molding temperature of. Further, the resin concrete composition of the present invention is applicable in the field of heat molding at a molding temperature of 40 to 150 ° C. using a moderately reactive or highly reactive unsaturated polyester resin, such as a manhole cover. It is also possible to produce the resin concrete molded article of No. 1 by the heat compression molding method. Furthermore, when the resin concrete composition of the present invention is used as a material for forming an intermediate layer of a sewage / agricultural water pipe or a cable protection pipe, a filament winding molding method, a centrifugal molding method, or the like can also be used.

[0034]

The low-shrinking agent, which is a constituent of the resin concrete composition of the present invention, contains a polymer portion having vinyl acetate as a constituent unit, which has excellent compatibility with the unsaturated polyester resin. Therefore, the dispersion stability of the resin concrete composition containing the unsaturated polyester resin as a binder is good. Moreover, since the proportion of the polymer portion having vinyl acetate as a constitutional unit in the low-shrinking agent is the minimum necessary, a low-reactivity unsaturated polyester resin generally used in room-temperature molding of a resin concrete composition. The compatibility with the low-shrinking agent becomes too high, and phase separation does not occur at the time of curing, so that the low-shrinking agent does not act effectively. Therefore, it is possible to obtain a resin concrete composition excellent in low shrinkage at room temperature molding.

[0035]

EXAMPLES The present invention will be described in more detail below with reference to reference examples, examples and comparative examples. In these examples, parts and% represent parts by weight and% by weight, respectively, unless otherwise specified. The measurement items in each example were measured according to the following methods. (1) Block rate A part of the polymer obtained by the production of the AB block copolymer was extracted with a Soxhlet extractor for 24 hours, first using cyclohexane as an eluent and then for 24 hours using methanol as an eluent. . The weight loss due to cyclohexane extraction was used as polystyrene (hereinafter abbreviated as PS), and the weight loss due to methanol extraction was used as content of polyvinyl acetate (hereinafter abbreviated as PVAc), and the extraction residue was used as a net AB block. The content of the polymer was used. The ratio of the net AB block copolymer in the polymer was defined as the block rate. (2) Constitutive ratio of polymer portion A and polymer portion B in AB type block copolymer Nuclear magnetic using a part of the polymer obtained by the production of AB type block copolymer An area of a signal (chemical shift δ = about 5.2 ppm) corresponding to a methine proton of vinyl acetate (hereinafter abbreviated as VAc), that is, an integrated value and a benzene ring of styrene (hereinafter abbreviated as St) was analyzed by resonance spectroscopy. A signal corresponding to a proton (chemical shift δ = about 6.
4 to 7.1 ppm), that is, A from the ratio with the integrated value
The constitutional ratio (hereinafter abbreviated as A / B) between the polymer portion A having VAc as a constitutional unit and the polymer portion B having St as a constitutional unit in the -B type block copolymer was determined. (3) Proportion of polymer portion having VAc as a constituent unit in the low-shrinking agent Proportion of polymer portion having VAc as a constituent unit in the low-shrinking agent according to the following formula (hereinafter abbreviated as proportion of PVAc portion) I asked.

Proportion (%) of PVAc portion = (blending amount of AB type block copolymer × proportion of polymer portion A) / (P
S content + A-B block copolymer content) x 1
00 (4) Linear shrinkage rate 140 mm inside diameter, 1 outside diameter on the glass plate treated with release agent
A stainless steel ring with a height of 70 mm and a height of 30 mm is installed, and various resin concrete or resin mortar compositions are injected into the ring and cured in a thermostatic chamber at 25 ° C. After one day of curing, the molded product is demolded and The linear shrinkage rate was measured by.

Linear shrinkage (%) = [(inner diameter of stainless steel ring)-(outer diameter of molded product)] / (inner diameter of stainless steel ring) × 100 (5) Surface condition of resin concrete or resin mortar Various resin concretes Alternatively, the surface state of the upper surface of the resin mortar molded product was observed, and the presence or absence of tackiness on the surface was examined by a finger touch test according to the following criteria.

◯: Shows a good state in which the low-shrinking agent is not raised on the surface. X: Shows a poor state in which tackiness due to embossing of the low shrinkage agent on the surface is observed. (6) Surface Gloss of Molded Product According to JIS-K-7105 (Plastic optical property test method), a glass surface of various resin concrete or resin mortar molded product is used by using a gloss meter manufactured by Toyo Seiki Seisakusho KK The side surface gloss (60 degree specular gloss) was measured. [Production of AB Block Copolymer of the Present Invention] (Reference Example 1) 300 parts of water in a glass reactor equipped with a thermometer, a nitrogen inlet tube, a stirrer and a condenser, partially saponified polyvinyl alcohol 15 parts of a 1% aqueous solution of Chemical Industry Co., Ltd., trade name: Gohsenol KH-17) and 15 parts of a 10% aqueous dispersion of hydroxyapatite (Nippon Chemical Industry Co., Ltd., trade name: Super Tight 10) are charged. It is. Next, after 0.5 part of the polymeric peroxide represented by the formula (1) (hereinafter abbreviated as P.PO) was dispersed in the aqueous solution for 1 hour at room temperature, 10 parts of VAc was charged, and nitrogen was charged in the reactor. While introducing, polymerization was carried out at 60 ° C. for 2 hours under stirring (first-stage polymerization reaction).

After that, the reactor was cooled to room temperature and St9 was added to the reactor.
After charging 0 part and performing impregnation for 1 hour at room temperature with stirring, nitrogen was introduced into the reactor while stirring at 80 ° C. for 8 hours.
Polymerization at 90 ° C for 30 minutes (second-stage polymerization reaction)
I went. After cooling to room temperature, the resulting polymer is 5%
It was washed with 130 parts of hydrochloric acid, subsequently with water, filtered off, and vacuum dried to obtain 94 parts of a white granular polymer. The block ratio and A / B in the AB block copolymer were determined using a part of the obtained polymer. The results are shown in Table 1. (Reference Examples 2 and 3) An AB block copolymer was produced in the same manner as in Reference Example 1 except that the charged amounts of P.PO, VAc and St were changed as shown in Table 1. A polymer of The block ratio and A / B in the AB block copolymer were determined using a part of the obtained polymer.
The results are shown in Table 1. [Production of AB Block Copolymer Outside of the Present Invention] (Reference Examples 4 and 5) All the same as Reference Example 1 except that the charged amounts of P.PO, VAc and St were changed as shown in Table 1. To produce an AB block copolymer to obtain a white granular polymer. The block ratio and A / B in the AB block copolymer were determined using a part of the obtained polymer.
The results are shown in Table 1.

The AB block copolymers obtained in Reference Examples 1 to 5 were each diluted with St so that the solid content was 30%, and each sample was used as a St dispersion liquid.

[0041]

[Table 1]

[Preparation of St Solution of PS] (Reference Example 6) PS (trade name: Dialex HF77, number average molecular weight: about 80,000) manufactured by Mitsubishi Kasei Co., Ltd., so that the solid content is 30%. Diluted with St and then St of PS
It was a solution. [Comparative low-shrinking agent] (Reference Example 7) MODIPER MS10B manufactured by NOF CORPORATION
-30 (St dispersion of a block copolymer consisting of a polymer part having methyl methacrylate as a constitutional unit and a polymer part having St as a constitutional unit, solid content 30%) as a comparative low shrinkage agent (A) And (Reference Example 8) MODIPER S101-manufactured by NOF CORPORATION
30 (St dispersion of a block copolymer consisting of a polymer part having VAc and crotonic acid as a constitutional unit and a polymer part having St as a constitutional unit, solid content 30%) as a comparative low shrinkage agent (B) And [Production of Unsaturated Polyester Resin] (Reference Example 9) Polycondensation was carried out by a known method using 0.13 mol of fumaric acid, 0.36 mol of orthophthalic acid, 0.36 mol of propylene glycol and 0.15 mol of diethylene glycol. The obtained unsaturated polyester alkyd is St
It was diluted with to prepare a solid content of 61%, and an unsaturated polyester resin of low reactivity (reactivity 26.5 mol%) was produced. [Preparation of Resin Concrete Composition and Preparation of Molded Article] (Example 1) 70 parts of unsaturated polyester resin obtained in Reference Example 9 and 29.8 St solution of PS obtained in Reference Example 6
After mixing 5 parts and 0.15 parts of the St dispersion of the AB block copolymer obtained in Reference Example 1 with a stirrer for 5 minutes,
Permek N (trade name of 55% dimethyl phthalate solution of methyl ethyl ketone peroxide) manufactured by NOF Corporation 1
Parts and 0.4 parts of 6% St solution of cobalt naphthenate were added and further mixed. Then, there calcium carbonate 10
0 part and 300 parts of river sand (maximum particle size 5 mm) were mixed to obtain a resin concrete composition. This composition was placed on a glass plate that had been treated with a release agent, and the inner diameter was 140 mm and the outer diameter was 17 mm.
Pour it into a 0 mm, 30 mm high stainless steel ring for 2
It was cured in a constant temperature bath at 5 ° C., and after 1 day of curing, the molded product was demolded. Then, while observing the surface state of the upper surface of the molded product, the presence or absence of tackiness on the surface was examined by a finger touch test. In addition, the linear shrinkage of the molded product and the surface gloss on the glass surface side were measured. The results are shown in Table 2. (Examples 2 to 7) In Example 1, the unsaturated polyester resin obtained in Reference Example 9, the St solution of PS obtained in Reference Example 6, and the AB type block obtained in Reference Examples 1 to 3 were used. A resin concrete composition was prepared in the same manner as in Example 1 except that the St dispersion liquid of the copolymer was used as shown in Table 2 to prepare a molded product. The results are shown in Tables 2 and 3.

[0043]

[Table 2]

[0044]

[Table 3]

As shown in Tables 2 and 3, Examples 1 to 1
Each of the resin concrete compositions of No. 7 does not have a low shrinkage agent protruding to the surface of the molded product, has a good surface condition, has a low shrinkage rate, and has excellent surface gloss. Comparative Examples 1 to 6 In Example 1, the unsaturated polyester resin obtained in Reference Example 9, the St solution of PS obtained in Reference Example 6 and A obtained in Reference Example 1 or Reference Examples 4 and 5 were used. A resin concrete composition was prepared in the same manner as in Example 1 except that the St dispersion liquid of the B-type block copolymer was used as shown in Table 3 to prepare a molded product. The results are shown in Tables 4 and 5.

In Comparative Examples 1 and 2, the proportion of the PVAc portion in the low-shrinking agent was set, and in Comparative Examples 3 and 4, the blended AB was used.
The proportion of the polymer portion A in the mold block copolymer and the total blending amount of the low-shrinking agent in Comparative Examples 5 and 6 are outside the scope of claims.

[0047]

[Table 4]

[0048]

[Table 5]

In Comparative Example 6 in Table 5, the viscosity is high,
Workability was poor. As shown in Tables 4 and 5, when the ratio of the polymer portion having vinyl acetate as a constituent unit in the low-shrinkage agent is too small (Comparative Example 1), the surface condition of the molded article is particularly poor. On the contrary, when the proportion of the polymer portion having vinyl acetate as a constitutional unit is too large (Comparative Example 2), the shrinkage rate is large and the surface gloss is poor. When the proportion of the polymer portion A in the AB block copolymer is too small or too large (Comparative Examples 3 and 4), the surface condition of the molded product is particularly poor. Furthermore, when the blending ratio of the low-shrinking agent is too small (Comparative Example 5), the shrinkage of the molded product is large and the surface gloss is poor. On the contrary, when the compounding ratio of the low-shrinking agent is excessively large (Comparative Example 6), the viscosity of the composition is high,
Workability is poor. (Comparative Example 7) A resin concrete composition according to Example 1 except that only 30 parts of the St dispersion of the AB block copolymer obtained in Reference Example 1 was used as the low-shrinking agent in Example 1. Was prepared to prepare a molded product. as a result,
The upper surface of the molded product has no tackiness due to the embossing of the low shrinkage agent,
Although it showed a good surface condition, the linear shrinkage was as large as 0.82% and the surface gloss on the glass side was very low at 15%. This comparative example is a follow-up test of JP-A-57-80413. (Comparative Example 8) A resin concrete composition was prepared in the same manner as in Example 1 except that 30 parts of the comparative low shrinkage agent (A) obtained in Reference Example 7 was used as the low shrinkage agent. A molded product was produced. As a result, the linear shrinkage of the molded product was as low as 0.06% and the surface gloss on the glass side was as high as 85%, but the adhesiveness due to the embossing of the low shrinkage agent was observed on the upper surface of the molded product. It was In addition, this comparative example is Japanese Patent Publication Sho 6
This is a supplementary test of JP-A-3-30956. (Comparative Example 9) A resin concrete composition was prepared in the same manner as in Example 1 except that 30 parts of the comparative low shrinkage agent (B) obtained in Reference Example 8 was used as the low shrinkage agent. A molded product was produced. As a result, the upper surface of the molded product did not have tackiness due to the embossing of the low-shrinking agent and showed a good surface condition, but the linear shrinkage ratio was large at 0.79% and the surface gloss on the glass surface side was very high at 18%. It was low. This comparative example is a supplementary test of Japanese Patent Laid-Open No. 4-311761. [Preparation of Resin Mortar Composition and Preparation of Molded Article] (Example 8) 70 parts of unsaturated polyester resin obtained in Reference Example 9 and 29.8 St solution of PS obtained in Reference Example 6
After mixing 5 parts and 0.15 parts of the St dispersion of the AB block copolymer obtained in Reference Example 1 with a stirrer for 5 minutes,
2 parts of Nyper FF-K (trade name of benzoyl peroxide diluted with 50% dicyclohexyl phthalate) manufactured by Nippon Oil & Fats Co., Ltd. and 0.2 part of N, N-dimethylaniline were added and mixed. Then, 100 parts of a filler (a weight ratio of calcium carbonate 1, silica sand No. 3, silica sand No. 4, silica sand No. 4 and silica sand No. 7 was 1) was added and mixed to obtain a resin mortar composition. This composition was poured into a stainless steel ring having an inner diameter of 140 mm, an outer diameter of 170 mm, and a height of 30 mm, which was placed on a glass plate treated with a release agent, and was cured in a constant temperature bath at 25 ° C., and after 1 day of curing. The molded product was demolded. Then, the surface condition of the upper surface of the molded product was observed, and the presence or absence of tackiness on the surface was examined by a finger touch test. In addition, the linear shrinkage of the molded product and the surface gloss on the glass surface side were measured. The results are shown in Table 6. (Examples 9 to 14) In Example 8, the unsaturated polyester resin obtained in Reference Example 9 and the PS obtained in Reference Example 6 were used.
Of St type solution and St type dispersion of the AB block copolymers obtained in Reference Examples 1 to 3 were used as shown in Table 4 to prepare a resin mortar composition according to Example 1.
A molded product was produced. The results are shown in Tables 6 and 7.

[0050]

[Table 6]

[0051]

[Table 7]

As shown in Tables 6 and 7, Examples 8 to
Each of the resin mortar compositions of No. 14 had a molded product in a good surface condition, a low shrinkage ratio, and an excellent surface gloss. (Comparative Examples 10 to 15) In Example 8, the unsaturated polyester resin obtained in Reference Example 9 and P obtained in Reference Example 6 were used.
A resin mortar composition according to Example 1 except that the St solution of S and the St dispersion of the AB block copolymer obtained in Reference Example 1 or Reference Examples 4 and 5 are used as shown in Table 5. An article was prepared and a molded article was produced. The results are shown in Tables 8 and 9.

In Comparative Examples 10 and 11, the proportion of the PVAc portion in the low-shrinking agent was compared, and in Comparative Examples 12 and 13, the proportion of the polymer portion A in the blended AB block copolymer was compared. In Examples 14 and 15, the total compounding amount of the low-shrinking agent deviates from the claimed range.

[0054]

[Table 8]

[0055]

[Table 9]

In Comparative Example 15 in Table 9, the viscosity was high and the workability was poor. As shown in Tables 8 and 9,
When the proportion of the polymer portion containing vinyl acetate as a constituent unit in the low-shrinking agent is too small (Comparative Example 10), the surface condition of the molded product is particularly poor. On the contrary, when the ratio of the polymer portion having vinyl acetate as a constitutional unit is too large (Comparative Example 11),
High shrinkage and poor surface gloss. When the proportion of the polymer portion A in the AB block copolymer is too small or too large (Comparative Examples 12 and 13), the surface condition of the molded product is particularly poor.
In addition, when the compounding ratio of the low-shrinking agent is too small (Comparative Example 1
4) The molded product has a large shrinkage and the surface gloss is poor. On the contrary, when the compounding ratio of the low-shrinking agent is excessive (Comparative Example 15),
The composition has high viscosity and poor workability. (Comparative Example 16) A resin mortar composition according to Example 8 except that only 30 parts of the St dispersion of the AB block copolymer obtained in Reference Example 1 was used as the low-shrinking agent in Example 8. Was prepared to prepare a molded product. As a result, the upper surface of the molded product did not have tackiness due to the embossing of the low-shrinking agent and showed a good surface condition, but the linear shrinkage ratio was as large as 1.42% and the surface gloss on the glass surface side was extremely high at 13%. It was low. This comparative example is a follow-up test of JP-A-57-80413. (Comparative Example 17) A resin mortar composition was prepared in the same manner as in Example 8 except that 30 parts of the comparative low shrinkage agent (A) obtained in Reference Example 7 was used as the low shrinkage agent in Example 8. A molded product was produced. As a result, the linear shrinkage of the molded product was as low as 0.08% and the surface gloss on the glass side was as high as 91%, but the adhesiveness due to the embossing of the low shrinkage agent was observed on the upper surface of the molded product. It was In addition, this comparative example is Japanese Patent Publication Sho 6
This is a supplementary test of JP-A-3-30956. Comparative Example 18 A resin mortar composition was prepared in the same manner as in Example 8 except that 30 parts of the comparative low shrinkage agent (B) obtained in Reference Example 8 was used as the low shrinkage agent. A molded product was produced. As a result, the surface of the molded product did not show tackiness due to the embossing of the low-shrinking agent and showed a good surface condition, but the linear shrinkage ratio was as large as 1.44% and the surface gloss on the glass surface side was 17%. And was very low. This comparative example is a supplementary test of Japanese Patent Laid-Open No. 4-311761.

Comparing the above Examples and Comparative Examples, acetic acid based on an AB block copolymer consisting of a polymer portion A having vinyl acetate as a constitutional unit and a polymer portion B having styrene as a constitutional unit. By blending a low-shrinking agent containing a specific proportion of a polymer portion having vinyl as a structural unit with a resin concrete composition having an unsaturated polyester resin as a binder, excellent dispersion stability and low shrinkage at room temperature molding are excellent. It is obvious that the resin concrete composition can be provided, and a molded product having superior dimensional accuracy and surface property can be obtained.

The technical ideas other than the claims understood from the above embodiment will be described below together with their effects. (1) The unsaturated polyester is produced from a mixture containing α, β-unsaturated dibasic acid or its anhydride as a minor component and a saturated dibasic acid or its anhydride as a main component, and a polyhydric alcohol. The resin concrete composition according to claim 1, which has a low reactivity. According to this structure, room temperature molding with the resin concrete composition can be easily performed. (2) The resin concrete according to claim 1, wherein the AB type block copolymer is produced by a two-stage polymerization reaction, and the polymerization temperature in the second-stage polymerization reaction is set higher than the polymerization temperature in the first-stage polymerization reaction. Composition. With this configuration, the block ratio of the block copolymer can be increased, and the block copolymer can be directly used in the resin concrete composition. (3) The resin concrete composition according to claim 1, wherein the curing agent is used in combination with a curing accelerator. With this configuration, it is possible to increase the curing rate of the resin concrete composition,
Productivity can be improved.

[0059]

As described above in detail, according to the resin concrete composition of the present invention, both the dispersion stability and the low shrinkage at room temperature molding are excellent, and the dimensional accuracy of the concrete molded product is secured. be able to. Moreover, the surface condition of the concrete molded product can be maintained in a good condition. Therefore, the present invention is industrially useful.

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Claims (1)

[Claims] 1. A resin concrete composition comprising an unsaturated polyester, an ethylenically unsaturated monomer copolymerizable with the unsaturated polyester, a low-shrinking agent, a curing agent and a filler as a low-shrinking agent. , An AB type block copolymer consisting of a polymer portion A having vinyl acetate as a constitutional unit and a polymer portion B having styrene as a constitutional unit, and polystyrene in total, the unsaturated polyester and the ethylenically unsaturated monomer. 3 to 18 parts by weight based on the total weight of 100 parts by weight of the monomer, and the proportion of the polymer portion A in the AB block copolymer is 2
˜50% by weight, the proportion of polymer part B is 98-50% by weight
And the proportion of the polymer portion having vinyl acetate as a constituent unit in the low-shrinking agent is 0.01 to 0.19% by weight.